3,054 results
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2. Supply Of Oil Filter, Spider Kit, Bearing, Break Piston, Nozzle, Element, Bucket Tooth Nut Bolt, Guard Hose Lh, Guard Hose Rh, Pipe Loader End, Trank Link Assy, Element Super Lib Oil By Pass Filter, Fine Paper Filter, Air Filter Outer, Air Filter Inner, S
- Subjects
Electric filters ,Business, international - Abstract
Tenders are invited for Supply of Oil Filter, Spider Kit, Bearing, Break Piston, Nozzle, Element, Bucket Tooth Nut Bolt, Guard Hose LH, Guard Hose RH, Pipe Loader End, Trank Link [...]
- Published
- 2023
3. Supply Of Snow Light Switch 24 Volt, Blade Lift Cylinder Assy, Blade Lift Cylinder Seal Kit, Cartridge Fuel Filter, Cartridge Oil Filter, Insert Paper Filter, Element Filter, By Pass Filter, Kit Water Pump, Hydrolic Filter, Head Fuel Filter, Rotating Kit
- Subjects
Electric filters ,Business, international - Abstract
Tenders are invited for Supply of snow light switch 24 volt, blade lift cylinder assy, blade lift cylinder seal kit, cartridge fuel filter, cartridge oil filter, insert paper filter, element [...]
- Published
- 2022
4. Operation of the Airmodus A11 nano Condensation Nucleus Counter at various inlet pressures, various operation temperatures and design of a new inlet system.
- Author
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Kangasluoma, J., Franchin, A., Duplissy, J., Ahonen, L., Korhonen, F., Attoui, M., Mikkilä, J., Lehtipalo, K., Vanhanen, J., Kulmala, M., and Petäjä, T.
- Subjects
DIFFUSION measurements ,INLETS ,ATMOSPHERIC nucleation ,CONDENSATION (Meteorology) ,PARTICLE size determination ,ELECTRIC field lines ,ELECTRIC filters ,SUPERSATURATION - Abstract
Measuring sub-3nm particles outside of controlled laboratory conditions is a challenging task, as many of the instruments are operated at their limits and are subjected to changing ambient conditions. In this study, we advance the current understanding on the operation of Airmodus A11 nano Condensation Nucleus Counter (nCNC), which consists of a A10 Particle Size Magnifier (PSM) and A20 condensation particle counter (CPC). We explore the effect of the inlet line pressure on the measured particle concentration. We identify two different regions inside the instrument where supersaturation of working fluid can take place. We show the possibility of varying the cut-off of the instrument from 1 to 6 nm, a wider size range than the one usually covered by the PSM. We also present a new inlet system, which allows automated measurements of the background, minimizes the diffusion losses in the sampling line and is equipped with an electrostatic filter to remove ions. Finally, our view of the guidelines for optimal use of the Airmodus nCNC are provided. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
5. Current-Mode Active Filter Using EX-CCCII.
- Author
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Kumngern, Montree, Khateb, Fabian, Kulej, Tomasz, and Tooprakai, Siraphop
- Subjects
CURRENT conveyors ,COMPLEMENTARY metal oxide semiconductors ,ELECTRIC filters ,INTEGRATED circuits ,CURRENT-mode circuits - Abstract
This paper presents a novel multiple-input and multiple-output current-mode universal analog filter with electronic tuning capability. The proposed circuit uses a single second-generation current-controlled current conveyor with extra-X terminals (EX-CCCII) and two grounded capacitors. The filter can offer five standard filtering functions, namely low-pass, high-pass, band-pass, band-stop, all-pass responses, in the same circuit without changing the internal configuration of the filter by selecting appropriate input and output signals. To obtain the five standard filtering functions, inverted input signal and input matching conditions are absent. The natural frequency of all filter responses can be electronically controlled. The proposed circuit was simulated by SPICE using 0.18 μm CMOS process from Taiwan Semiconductor Manufacturing Company (TSMC). The results of experiments using the integrated circuit operational amplifier AD844 confirm the functionality of the new filter. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. Simple Moment Generating Function Optimisation Technique to Design Optimum Electronic Filter for Underwater Wireless Optical Communication Receiver.
- Author
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Ramley, Intesar F. El, AlZhrani, Saleha M., Bedaiwi, Nada M., Al-Hadeethi, Yas, and Barasheed, Abeer Z.
- Subjects
ELECTRIC filters ,OPTICAL receivers ,OPTICAL communications ,MATHEMATICAL optimization ,WIRELESS communications ,GENERATING functions - Abstract
This paper introduces a new simple moment-generating function (MGF) design modelling method to conclude an optimum filter to maximize the Q-factor and increase the link communication span. This approach mitigates the pulse temporal dispersion, particularly the underwater wireless optical communication (UWOC) systems. Hence, some form of equalizing filter design is highly desirable. The model solution environment includes a Double Gamma Function (DGF) water channel impulse response, intersymbol interference (ISI), stochastic Poisson process, and additive Gaussian thermal noise (AGTN). The optimal filters exhibit temporal profiles comparable to those derived by published works based on complex Chernoff Bound (CB) and Modified Chernoff Bound (MCB) methods. The results show the impact of the optimum filter at a signal level and optical receiver level utilizing Eye-Diagrams and BER vs. Q-Factor, respectively. The computation involves four different UWOC propagation channel models for Coastal and Harbor waters. One of the main conclusions indicates that the optimum filter manages the temporal dispersion due to the ISI impairment correctly. Also, the proposed optimum filter reduces eye-opening and the corresponding Q-Factor by less than 15% for a five-times increase in pulse width for the same transmitted optical power level. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. Present and Future Trends in Filters and Multiplexers.
- Author
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Snyder, Richard V., Mortazawi, Amir, Hunter, Ian, Bastioli, Simone, Macchiarella, Giuseppe, and Wu, Ke
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ELECTRIC filters ,MULTIPLEXING equipment ,BARIUM strontium titanate ,ACOUSTIC resonators ,SUBSTRATE integrated waveguides - Abstract
In the last 10 or 15 years, exciting new developments have occurred in the field of filters and multiplexers. The two words that best explain this phenomenon are “topology” and “technology.” Thus, this paper will cover new connections, new materials, and new processes. This paper summarizes what is new, describes the new devices, and avoids simply surveying the entire field. It is not possible to cover everything, and regrettably, some new and possibly exciting areas are omitted (such as filters fabricated using liquid crystal polymers, active element inclusion, extreme power devices used in accelerators), and others,\ldots, because something has to be left for the next paper! The paper does cover bandstop filters, intrinsically switched film bulk acoustic resonator, and barium–strontium–titanate filters, brand new derivations of lossy filter synthesis and dual-band filter synthesis, multimode networks, new work on optimal multiplexer (multiport network) configurations, and substrate integrated waveguide filters. In each of these areas significant new work has been recently performed and is presented in a summary format suitable for those thinking that the area of filters and multiplexers has become mature (stagnant) with nothing interesting to learn. Nothing could be further from the truth! [ABSTRACT FROM PUBLISHER]
- Published
- 2015
- Full Text
- View/download PDF
8. Investigation of the Effect of Different Electromagnetic Interference Filter Topologies to DC-DC Boost Converter for Continuous Conduction Mode.
- Author
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Şehirli, Erdal
- Subjects
ELECTROMAGNETIC interference ,CONVERTERS (Electronics) ,CAPACITORS ,ELECTRIC inductors ,ELECTRIC filters - Abstract
This paper presents the design and application of a boost converter operated in continuous conduction mode for 15 W, with a 25 kHz switching frequency using an inductor-capacitor-inductor (LCL), pi, inductor capacitor (LC) with damping, and LC electromagnetic interference filters. Also, modeling and analysis of the boost converter in terms of state space and small signal are given. Furthermore, the effect of each filter on differential mode (DM) noise and control characteristics is presented using root locus and bode diagrams, which are not detailed in the literature for the boost converter. All results obtained from applications and simulations are compared. Moreover, frequency spectrums are given to compare DM noises. As a result, from a control point of view, the LCL filter provides better results, and for reducing DM noise, the LC and pi filters are superior to others. Besides, the LCL filter reduces the inductor value by 30% compared to other filters. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
9. Guest Editorial.
- Author
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Boria, Vicente E., Macchiarella, Giuseppe, and Yu, Ming
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TELECOMMUNICATION systems ,HIGH frequency transmission lines ,ELECTRIC filters ,MULTIPLEXING equipment ,DESIGN techniques ,TOPOLOGY - Abstract
The papers in this special section provide deep insights into new solutions, synthesis and design techniques, topologies, and technological realizations of filters and multiplexers that can answer all existing demands from high-frequency communication systems. [ABSTRACT FROM PUBLISHER]
- Published
- 2015
- Full Text
- View/download PDF
10. Compact hybrid eighth‐mode substrate integrated waveguide and microstrip line filters with mixed electric and magnetic coupling.
- Author
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Wang, Xiang, Liu, Qian‐Wen, Yang, Xian‐Long, Li, Huangyan, Zhu, Xiao‐Wei, and Wu, Wen
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ELECTRIC filters ,MICROSTRIP transmission lines ,MICROSTRIP filters ,BANDPASS filters ,INTERRACIAL couples ,TRANSMISSION zeros ,INSERTION loss (Telecommunication) - Abstract
This paper proposes a new type of hybrid eighth‐mode substrate integrated waveguide (EMSIW) and microstrip line (MSL) bandpass filter (BPF) with mixed electric and magnetic coupling. Firstly, two second‐order EMSIW BPFs with mixed coupling and wide stopband performance are investigated. Then, in order to realise high‐order BPF with decent performance, half‐wavelength (λ/2) open‐circuited MSL resonators are employed in the hybrid BPFs design. In the end, two third‐order BPFs and a fourth‐order BPF are developed by combining the EMSIW and MSL resonators together. Extra transmission zeros can be introduced due to the cross couplings in the trisection and quadruplet topologies. For demonstration, the proposed prototypes are designed, fabricated and measured. Reasonable agreements can be achieved between the measurement and simulation. The proposed third‐order BPFs compete against the state of the art, exhibiting the competitive characteristics of the operating bandwidth, physical footprint and upper‐stopband rejection with less order. The proposed fourth‐order BPF features a compact size of 0.34 × 0.34λ0, a low insertion loss of 1 dB, a broad 3‐dB fractional bandwidth of 22.9% and an excellent lower‐stopband suppression. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
11. PMSM Inter-Turn Short Circuit Fault Detection Using the Fuzzy-Extended Kalman Filter in Electric Vehicles.
- Author
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Romdhane, Mabrouka, Naoui, Mohamed, and Mansouri, Ali
- Subjects
ELECTRIC filters ,SHORT circuits ,KALMAN filtering ,PERMANENT magnet motors ,FUZZY logic - Abstract
To avoid damaging the motor and its surrounding equipment, detecting Inter-Turn Short Circuit (ITSC) faults in Permanent Magnet Synchronous Motors (PMSMs) applied in electric vehicles is a crucial task. In this paper, the detection of ITSC faults in stator winding for PMSMs is carried out by means of the Extended KALMAN Filter (EKF) algorithm combined with the Fuzzy Logic Estimator (FLE). To estimate the motor parameters, including the rotor position and speed, the EKF algorithm uses the measured stator currents and voltages beside the stator resistance, which is calculated in advance using fuzzy logic and fed to the EKF. The change behaviors of the estimated parameters were then used to detect short circuit faults in the PMSM. Using Matlab/Simulink, the proposed FL-EKF algorithm was implemented and tested on a faulty PMSM controlled by Field Oriented Control (FOC). The observation of a perfect estimation of the stator resistance through the simulation helps to precisely detect the failure, and that demonstrates the sensitivity and robustness of the proposed approach. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
12. Guest Editorial.
- Author
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Liserre, Marco, Mattavelli, Paolo, and Holmes, Donald Grahame
- Subjects
ELECTRONIC modulation ,ELECTRIC filters - Abstract
An introduction to the journal is presented in which the editor discusses an article on the real-time optimization of a step multilevel modulation, the use of zero state in the minimization of distortion, and the analysis of selective harmonic control based on the utilization of resonant filters.
- Published
- 2009
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- View/download PDF
13. Self-Tuning PLL: A New, Easy, Fast and Highly Efficient Phase-Locked Loop Algorithm.
- Author
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Sanchez-Herrera, Reyes, Andujar, Jose M., Marquez, Marco, Mejias, Andres, and Gomez-Ruiz, Gabriel
- Subjects
PHASE-locked loops ,CLOSED loop systems ,ELECTRIC filters ,ELECTRONIC circuits - Abstract
A phase-locked loop or phase lock loop (PLL) is, essentially, a closed loop control system, where its output signal (regulated) maintains a direct (chosen) relationship to the input signal (unregulated). If the phases of the input and output signals remain the same, their frequencies will also match. In its usual way, a PLL is an electronic circuit with filters and controllers that must be tuned each time, according to the input signal parameters. As a contribution and novelty, this paper introduces a new, easy, fast and highly efficient PLL algorithm, that it does not need to adjust every time the input signal changes. This makes it independent of the input signal it receives and, therefore, and in a certain way, universally applicable. In addition, the proposal is implemented exclusively by software, housed in a microcontroller, which also represents another novelty. As another remarkable feature, the proposed algorithm is very simple, with a very low computational cost, which makes it very stable, practically insensitive to noise, and very fast. These characteristics and the performance shown over a wide range of input signal frequencies, make the proposed algorithm suitable for use in different applications, from the electricity grid synchronization to the demodulation of frequency modulation, DC motor drives, etc. In addition to frequency and phase tracking, the developed algorithm generates the signal corresponding to the fundamental frequency of the input signal. Furthermore, the algorithm behavior is not affected by the input signal distortion and is independent of its initial phase. The performance and excellent behavior of the developed algorithm are evaluated through simulations and experimental tests. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
14. Resonance-Free Shunt Capacitors—Configurations, Design Methods and Comparative Analysis.
- Author
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Xu, Wilsun, Ding, Tianyu, Li, Xin, and Liang, Hao
- Subjects
POWER capacitors ,ELECTRIC filters ,ELECTRICAL harmonics ,RESONANCE ,ELECTRIC impedance - Abstract
Harmonic resonance has become an important concern for the application of shunt capacitors in recent years. A potential solution to address this challenge is to convert a shunt capacitor into a passive filter. This paper presents design methods to configure a shunt capacitor as a C-type filter or a third-order high-pass filter with guaranteed resonance-free performance. The concept of resonance-free condition is first introduced in this paper. It is then used to develop filter design methods that always meet the resonance-free condition. The two filter configurations are also compared. It was found that the third-order high-pass filter has more advantages than the C-type filter. Another useful finding of this work is that the filter parameters, as determined using the proposed design methods, are independent of the system conditions. As a result, a lookup table for the filter parameters has been created to facilitate immediate use by the industry. [ABSTRACT FROM PUBLISHER]
- Published
- 2016
- Full Text
- View/download PDF
15. Enhancement of the Peak Power Handling Capability in Microstrip Filters by Employing Smooth-Profiled Conductor Strips.
- Author
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Ahmad, Jamil, Hussain, Jabir, Arregui, Ivan, Martin-Iglesias, Petronilo, Arnedo, Israel, Laso, Miguel A. G., and Lopetegi, Txema
- Subjects
STRIP transmission lines ,MICROSTRIP filters ,ELECTRIC filters ,ELECTRIC fields ,PHENOMENOLOGICAL theory (Physics) ,MICROSTRIP transmission lines - Abstract
This paper presents a design methodology that significantly increases the peak power handling capability (PPHC) of microstrip filters. The PPHC is limited in microstrip technology by the corona effect: a physical phenomenon caused by the ionization of the air in the presence of strong electric fields around the planar circuit. Microstrip filter with low electric field strength in the air increases the corona threshold level, resulting in high PPHC. Conventional stepped impedance (SI) filters, which consist of cascaded step-shaped elements, exhibit sharp discontinuities. These geometric edges amplify the electric field strength in the air, consequently reducing the corona threshold. Our research group has recently reported a new synthesis technique that introduces a smooth-profile (SP) conductor strip. This SP strip eliminates any sharp discontinuities and significantly reduces the strength of the electric field. This paper focuses on the examination of the high power performance of 7th-order SP and SI low-pass filters. The cut-off frequency (fc) for both types of filters is set at 447.45 MHz, while the frequency for maximum stop-band rejection (fo) is 1 GHz. The findings indicate that the SP filter shows a notable enhancement in peak power handling capability (PPHC), with gains of 2.48 dB and 4.80 dB observed at critical pressure and ambient pressure, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
16. Transformer Switching With Vacuum Circuit Breaker: Case Study of PV Inverter LC Filters Impact on Transient Overvoltages.
- Author
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Kuczek, T., Florkowski, M., and Piasecki, W.
- Subjects
OVERVOLTAGE ,VACUUM circuit breakers ,PHOTOVOLTAIC power systems ,ELECTRIC transformers ,ELECTRIC filters ,ELECTRIC transients ,SIMULATION methods & models - Abstract
This paper presents the analysis of possible transient overvoltages that can be generated during vacuum circuit-breaker (VCB) operation at the connection point of a photovoltaic powerplant. A typical switching event that is related to the VCB concerns energization and de-energization of the unloaded transformer. However, at the typical photovoltaic powerplant, the transformer is fed by an inverter equipped with LC (or LCL) filters that are necessary for limitation of harmonics and ripple in voltage and current. From the point of view of switching operations, the inductance and capacitance of the low-voltage (LV)-side connected filter affect the natural frequency of the transformer, which is reflected by different transient system response during VCB operation. In this paper, laboratory measurement of overvoltages generated during distribution transformer switching by means of VCBs is analyzed. The impact of the LC filter connected at the LV side on the overvoltages suppression was studied. Electromagnetic Transients Program–Alternative Transients Program simulations were conducted in order to verify the possibility of transients elimination by means of the additional series-connected RL choke at the transformer medium-voltage side. [ABSTRACT FROM PUBLISHER]
- Published
- 2016
- Full Text
- View/download PDF
17. MOSFET-C Shadow Filters Based on FDCCII for Cognitive Communications.
- Author
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Serdar, Hasan
- Subjects
CURRENT conveyors ,ELECTRIC filters ,TRANSFER functions ,SIGNAL processing ,MACHINE-to-machine communications - Abstract
In cognitive communications, it is very important to be able to use data in different standards with a single receiver for reducing the cost. In order to achieve this, the application of shadow filters in cognitive communications provides an advantage in terms of having both a wide frequency range and an easy reconfiguration. In this paper, new MOSFET-C shadow filters based on the Fully Differential Second-Generation Current Conveyor (FDCCII) are proposed for cognitive communications. To facilitate electronic tuning of the filter parameters, MOSFET-C-based implementation is used. Fully differential applications increase the dynamic range of analog blocks. Also, fully differential implementations with MOSFET-C filters are useful in analog signal processing. The presented filters have the least number of components and no additional summing circuit. This study presents new FDCCII-based MOSFET-C shadow filters for cognitive communications design that provide HP, LP and BP transfer functions at the same time. In this study, two MOSFET-C shadow filters based on FDCCII are designed for single gain and double gain. The presented filters offer circuit simplicity compared to past shadow filter designs. The features of these new shadow filters are explained. Simulation results are presented to confirm the theoretical analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
18. Frequency Design of Lossless Passive Electronic Filters: A State-Space Formulation of the Direct Synthesis Approach.
- Author
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Perodou, Arthur, Korniienko, Anton, Scorletti, Gerard, Zarudniev, Mykhailo, David, Jean-Baptiste, and O'Connor, Ian
- Subjects
ELECTRIC filters ,ALGEBRAIC equations ,MOBILE apps ,SYSTEMS design ,FREQUENCY synthesizers - Abstract
This paper deals with the frequency design of lossless passive electronic filters under magnitude constraints. With the huge increase in design complexity for mobile applications, new systematic and efficient methods are required. This paper focuses on the direct synthesis approach, an historical design approach that has not been recently updated. It consists in directly synthesizing the $LC$ values of a pre-specified circuit until the spectral mask is satisfied. While beneficial in practice, this approach typically leads to an important computational time and requires an initial guess to reduce it. Based on recent developments of the System and Control community, that led to efficient methods for system design, the direct synthesis approach is revisited. To achieve this, the port-Hamiltonian Differential Algebraic Equation (pHDAE) representation, that particularly fits the design problem, is introduced. A synthesis method is then developed, leading to solve an optimization problem of moderate complexity. For particular cases, this complexity happens to be remarkably low. Based on this observation, a second method reveals how to obtain such complexity for the more general case, using an original combination between the pHDAE and the LFT representations. Finally, a numerical example shows the validity and illustrates the benefits of this work. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
19. Influences of Frequency-Dependent Shunt Admittances on Underground Cable Systems.
- Author
-
Ting-Chung Yu
- Subjects
ELECTRIC power distribution ,POWER transmission ,ELECTRIC power systems ,ELECTRIC power transmission ,PERTURBATION theory ,ELECTRIC filters ,SHUNT electric reactors ,ELECTRIC lines ,FINITE element method - Abstract
Due to the structure of underground cables, the frequency dependence of shunt admittances is more important to underground cables than to overhead lines. The main purpose of this paper is to establish a frequency-dependent underground cable model for advanced research and analysis regarding the influences of frequency-dependent shunt admittances on underground cable systems. The model will be more practical by adding the frequency dependence of shunt admittances into mathematical models and transferring them to the corresponding programming codes. In the cable Electromagnetic Transient Program (EMTP) models, the frequency dependence of shunt admittances could be represented by a set of equivalent circuits with constant parameters that can be determined by observing the characteristics of shunt admittances, then synthesizing them with a rational function approximation for discrete-time EMTP solutions. A number of simulation cases are presented in this paper to show that the frequency dependence of shunt admittances for underground cable systems leads to magnitude attenuation and strong traveling time reduction in a transient period of voltages. Also, the influences of frequency-dependent capacitances on cable systems are comparatively more impressive than those of frequency-dependent conductances. The conclusions are supported by numerical simulation results. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
20. A Simplified Control Technique for a Dual Unified Power Quality Conditioner.
- Author
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Millnitz dos Santos, Raphael J., da Cunha, Jean Carlo, and Mezaroba, Marcello
- Subjects
CONTROL theory (Engineering) ,ELECTRIC filters ,POWER supply quality ,TOPOLOGY ,FREQUENCY spectra ,SPECTRUM analysis - Abstract
This paper presents a simplified control technique for a dual three-phase topology of a unified power quality conditioner—iUPQC. The iUPQC is composed of two active filters, a series active filter and a shunt active filter (parallel active filter), used to eliminate harmonics and unbalances. Different from a conventional UPQC, the iUPQC has the series filter controlled as a sinusoidal current source and the shunt filter controlled as a sinusoidal voltage source. Therefore, the pulse width modulation (PWM) controls of the iUPQC deal with a well-known frequency spectrum, since it is controlled using voltage and current sinusoidal references, different from the conventional UPQC that is controlled using nonsinusoidal references. In this paper, the proposed design control, power flow analysis, and experimental results of the developed prototype are presented. [ABSTRACT FROM PUBLISHER]
- Published
- 2014
- Full Text
- View/download PDF
21. Wideband Single-Ended and Differential Bandpass Filters Based on Terminated Coupled Line Structures.
- Author
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Zhang, Bo, Wu, Yongle, and Liu, Yuanan
- Subjects
BANDPASS filters ,BANDWIDTHS ,BROADBAND communication systems ,ELECTRIC filters ,TOPOLOGY - Abstract
In this paper, a novel terminated coupled line structure (TCLS) is introduced, which is constructed by a coupled line section and four terminations loaded on it. Introducing different kinds of terminations, three types of bandpass filters (BPFs) based on TCLSs are proposed, theoretically analyzed, and fabricated, including two single-ended wideband BPFs with fractional bandwidths (FBWs) of 67% and 40% respectively, and a wideband differential BPF with 74% differential-mode FBW. These BPFs can achieve wide passband bandwidth, low in-band insertion loss, high passband selectivity, as well as deep stopband rejection performance simultaneously, benefited from the multiple transmission zeros and transmission poles obtained by the TCLSs. The practical design procedures of these BPFs are presented and explained. The agreement among theoretical predictions, EM-simulated, and measured results validates our proposed filter structures. Finally, the generalized multistage filter topology based on TCLSs is proposed to design high-order filters with better filtering performances. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
22. Fuzzy quasi-PRD control for the photovoltaic inverter with LCL filter.
- Author
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Cao, Like, Yu, Yongjin, and Han, Qingchun
- Subjects
ELECTRIC current converters ,PHOTOVOLTAIC power generation ,ELECTRIC filters ,MICROGRIDS ,DISTRIBUTED power generation - Abstract
With the development of photovoltaic power generation technology, a large number of micro-power grid with distributed generation system have appeared in remote areas. It has the longer transmission line between the traditional power grid and the inverter of the distributed generation system. This caused the equivalent network impedance would be increased and would weak the power-grid characteristics. When the photovoltaic inverter is connected to a weaker power grid, the bandwidth of the control system of the inverter will be reduced. Using the traditional PR control to solve the problem is not ideal. This paper proposes fuzzy quasi-PRD control to improve the current quality. The inverter with the LCL filter has the peak of the resonance oscillation, it will affect the stability of the system. The paper adopts the adjustable virtual damping to suppress resonance. At last, the idea is verified by MATLAB/Simulink. The results show that the fuzzy quasi-PRD control method has better control performance, and dynamic tracking characteristics. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
23. Analysis of high-frequency interference characteristics of UHVDC converters.
- Author
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Ying, Chaonan, Xu, Zheng, and Luo, Chenxi
- Subjects
ELECTRIC current converters ,ELECTRIC filters ,VOLTAGE ,FOURIER transforms ,SIMULATION methods & models - Abstract
The converter is the main component of the converter station and the main noise source of the PLC interference. The accurate modelling of the high-frequency characteristics of the converter is the foundation for the design of the ± 1100 kV UHVDC PLC filter. Based on deep analysis of the high-frequency characteristics of the converter valve, this paper first proposes three high-frequency models of the converter valve. Compared with a real converter valve used in similar HVDC project, model two is chosen to analyse the high-frequency characteristics. Second, the model of Zhundong–Wannan UHVDC transmission project is established in the PSCAD simulation platform to determine the actual high-frequency characteristics of the converter valve. The voltage before the smoothing reactor is calculated, and the high-frequency noise level is obtained by Fourier transform. Considering the practical application of the high-frequency model of the converter valve, this paper finally proposes a formula to express the measured noise level. The noise source expressed by the formula is more practical for research on high-frequency characteristics of the converter station. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
24. An Improved Fundamental Harmonic Approximation to Describe Filter Inductor Influence on Steady-State Performance of Parallel-Type Resonant Converter.
- Author
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Chen, Yiming, Xu, Jianping, Sha, Jin, Lin, Leiming, and Cao, Jing
- Subjects
HARMONIC analysis (Mathematics) ,ELECTRIC filters ,ELECTRIC inductors ,CONVERTERS (Electronics) ,STEADY-state responses - Abstract
The influence of a filter inductor on the steady-state performance of a parallel-type resonant converter is elaborated and analyzed in this paper. By steady-state operation analysis, it is shown that the ripple current of the filter inductor results in an inaccurate prediction of fundamental harmonic approximation (FHA), and such problem would become serious when the filter inductance is small. In order to portray such feature, an improved fundamental harmonic approximation (IFHA) is proposed. Unlike an FHA equivalent circuit, an equivalent inductor is added to the ac resistance parallelly in an IFHA equivalent circuit. Due to that, the equivalent inductor branch takes account of the ripple current of the filter inductor, and the IFHA is expected to own higher accuracy and can be used in a parameter design procedure. In this paper, the equivalent inductor expressions of full-bridge rectifier and current-doubler rectifier are derived as examples. In order to verify the theoretical analysis, a 500 W LCC resonant converter is built as a prototype. The close-loop experiment results show that small filter inductance would lead to the failure of output voltage regulation and hard-switching operation of power switches. And open-loop experiment results show the IFHA gives more accurate predictions than those of FHA. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
25. Design of LCL Filter for Grid-Interfaced PV System Based on Cost Minimization.
- Author
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Poongothai, C. and Vasudevan, Krishna
- Subjects
ELECTRIC filters ,ELECTRIC power distribution grids ,ELECTRIC inverters ,ELECTRIC currents ,ELECTRIC potential ,HARMONIC distortion (Physics) - Abstract
Many research works report the use of LCL filters for grid-interfaced PV systems. Indiscreet selection of passive LCL filter parameters may result in poor filtering and increased power losses. LCL filter parameter selection is critical to get a good performance and at the same time ensure that losses and costs stay low. This paper proposes a novel approach to design the LCL filter for a grid-interfaced PV system. A cost-based minimization approach on a cost per joule basis for each of the filter elements is explored to obtain the optimal filter design. Simulation results for a 10-kVA grid-connected inverter with an LCL filter are presented in order to verify the efficacy of the proposed design. The impact of designed filter parameters on the ripple current is also discussed in this paper. The total inductance of the LCL filter is varied and filter parameter values which give lowest cost is identified while meeting harmonic standard requirements and the fundamental voltage drop across the filter. Finally, the proposed design is also experimentally validated via a hardware prototype. Results validate the design method in terms of the harmonic attenuation and total harmonic distortion. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
26. Time Domain Processing Techniques Using Ring Oscillator-Based Filter Structures.
- Author
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Leene, Lieuwe B. and Constandinou, Timothy G.
- Subjects
ELECTRIC filters ,TIME-domain analysis ,COMPLEMENTARY metal oxide semiconductors - Abstract
The ability to process time-encoded signals with high fidelity is becoming increasingly important for the time domain (TD) circuit techniques that are used at the advanced nanometer technology nodes. This paper proposes a compact oscillator-based subsystem that performs precise filtering of asynchronous pulse-width modulation encoded signals and makes extensive use of digital logic, enabling low-voltage operation. First- and second-order primitives are introduced that can be used as TD memory or to enable analogue filtering of TD signals. These structures can be modeled precisely to realize more advanced linear or nonlinear functionality using an ensemble of units. This paper presents the measured results of a prototype fabricated using a 65-nm CMOS technology to realize a fourth-order low-pass Butterworth filter. The system utilizes a 0.5-V supply voltage with asynchronous digital control for closed-loop operation to achieve a 73-nW power budget. The implemented filter achieves a maximum signal to noise and distortion ratio of 53 dB with a narrow 5-kHz bandwidth resulting in an figure-of-merit of 8.2 fJ/pole. With this circuit occupying a compact 0.004-mm2 silicon footprint, this technique promises a substantial reduction in size over conventional Gm-C filters, whilst additionally offering direct integration with digital systems. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
27. Modeling and Stability Analysis of Active Differential-Mode EMI Filters for AC/DC Power Converters.
- Author
-
Goswami, Rajib and Wang, Shuo
- Subjects
ALTERNATING currents ,CONVERTERS (Electronics) ,DIRECT currents ,ELECTRIC filters ,ELECTRIC impedance - Abstract
In this paper, the active differential-mode (DM) electromagnetic interference (EMI) filter topology for ac/dc converters is first briefly investigated. The active DM EMI filter model was developed based on the models of filter components including a current transformer, a high-pass filter, an operational amplifier, and a class AB amplifier. The system model including the active filter, ac/dc converter, and line impedance stabilization networks (LISNs) are explored. With the developed system model, the loop gain and insertion gain of the active filter are derived. Based on the loop gain, the stability of the active filter is investigated and the compensation is applied to achieve stability and good EMI reduction. Both simulations and experiments are conducted to validate the developed technique. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
28. A Conversion Methodology for 200 mm Bulk Acoustic Wave Filter Production Line at Qorvo.
- Author
-
Huang, Xiaokang, Dark, Charles, Mcclure, Michael, Diep, Buu, Hall, Craig, Isom, Harold, and Mortensen, Donna
- Subjects
SEMICONDUCTOR manufacturing ,ELECTRIC filters ,SOUND waves ,FAILURE mode & effects analysis ,INTEGRATED circuits - Abstract
There are many different methodologies for a line startup, process transfer, line conversion, and process upgrade in semiconductor IC manufacturing. In our startup of a 200 mm bulk acoustic wave filter line converted from an existing 150 mm production line, a methodology of copy, scale, develop, and match (CSDM) was introduced. This methodology includes four phases of matching (unit qualification, short flow verification, pathfinder validation, and qualification lot process) between 150 mm and 200 mm process, different failure mode effects analysis (DFMEA) for the risk assessment of the differences between two processes, process flow breakdown with process blocks and sub-blocks, a decide, define, determine, and design method of process evaluation with short loop flow process monitors based on DFMEA assessment. Following this CSDM methodology throughout the conversion process ensures that both electrical and reliability performances of 200 mm product wafers match to those of the 150 mm line. The first 200 mm full flow pathfinder lot with electrical yield on parity to 150 mm line yield. In this paper, the application of this CSDM methodology is discussed in detail. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
29. Compact Chebyshev Differential-Mode Bandpass Filter on $\lambda$ /4 CPS Resonator With Intrinsic Common-Mode Rejection.
- Author
-
Feng, Lin-Ping, Zhu, Lei, Zhang, Songbai, and Zhang, Xiao
- Subjects
BANDPASS filters ,ELECTRIC filters ,RESONATORS ,ELECTROMECHANICAL devices ,ELECTROMAGNETISM - Abstract
In this paper, a new class of compact Chebyshev differential-mode (DM) bandpass filters with intrinsic common-mode (CM) rejection is proposed and demonstrated on $\lambda$ /4 coplanar stripline (CPS) resonators with an improved unloaded quality factor ($Q_{u}$). The distinct advantage of the proposed $\lambda$ /4 CPS resonator with higher $Q_{u}$ than slotline resonator, together with intrinsic CM rejection of CPS line, can demonstrate that $\lambda$ /4 CPS resonator is more suitable for the design of narrowband DM filter than others on slotline resonator. Then, the underlying physics why CPS resonator possesses higher $Q_{u}$ than slotline resonator is numerically studied and further interpreted by the radiation loss. To facilitate the design process, an analytical design approach is introduced by using alternative J/K inverters and a tailored method is used to extract J/K inverter values with their associated effective electrical lengths based on their equivalent circuit models. Finally, two design examples, a second-order and a fourth-order DM Chebyshev bandpass filter, are designed and implemented, operating at the center frequency of 1.8 GHz with the fractional bandwidths of 6% and 19%, respectively. The simulated and measured DM/CM frequency responses match well with each other. The proposed DM filters based on $\lambda$ /4 CPS resonators have demonstrated the claimed superior performances in terms of intrinsic CM rejection, improved unloaded quality factor, easy implementation of J/K inverter, inherent suppression of first DM harmonic, and compact size. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
30. Harmonic Compensation Analysis in Offshore Wind Power Plants Using Hybrid Filters.
- Author
-
Hasan, Khairul Nisak Binti Md., Rauma, Kalle, Luna, Alvaro, Candela, J. Ignacio, and Rodriguez, Pedro
- Subjects
OFFSHORE wind power plants ,ELECTRIC filters ,WIND turbines ,CASCADE converters ,HARMONIC analysis (Mathematics) - Abstract
The harmful effects of harmonics are an important issue in wind power plants (WPPs), especially in offshore applications. In offshore WPPs, the wind turbines are linked to the network through high-power converters that produce harmonics at relative low frequencies. Moreover, in the network of a WPP, the propagation of noncharacteristic harmonics and the effect of resonance contribute as well in boosting the harmonic distortion. In this paper, a solution for compensating the harmonics in a WPP by means of using hybrid filters is proposed. In this paper, not only the filtering solution is tested, but also a method for finding the best place where to connect the filter, based on a modal analysis or a harmonic modal resonance analysis, is implemented. The proposed solution has been tested by considering the model of a real 400-MW offshore WPP as the study case. As it will be shown, the hybrid filter is capable of damping the resonances in the plant, while the analysis conducted permits us to optimize its location in the plant. [ABSTRACT FROM PUBLISHER]
- Published
- 2014
- Full Text
- View/download PDF
31. Grid-Connected VSI With $LCL$ Filter—Models and Comparison.
- Author
-
Hoff, Bjarte and Sulkowski, Waldemar
- Subjects
ELECTRIC power distribution grids ,IDEAL sources (Electric circuits) ,ELECTRIC inverters ,ELECTRIC filters ,CAPACITORS - Abstract
There are several ways to model three-phase gridconnected voltage-source inverters (VSIs) with an $LCL$ filter. Such models often use simplifications like constant dc-link voltage or averaging over a switching period. These simplifications remove transistor switching and dc-link capacitor dynamics from the model. In this paper, a comprehensive modeling of a three-phase VSI, including an $LCL$ filter, is described and compared to models using one or more of the aforementioned simplifications. Advantages and disadvantages of different models are discussed. All simulations are verified by comparing with experimental results. [ABSTRACT FROM PUBLISHER]
- Published
- 2014
- Full Text
- View/download PDF
32. Open access notice for the paper 'Determining Spectral Response of a Photovoltaic Device using Polychromatic Filters'.
- Subjects
OPEN access publishing ,SPECTRAL sensitivity ,PHOTOVOLTAIC power systems ,POLYCHROMY ,ELECTRIC filters - Published
- 2014
- Full Text
- View/download PDF
33. Gain-Controllable Transadmittance-Mode First-Order Allpass Filters with Electronic Tune Using Single Active Element.
- Author
-
Tanaphatsiri, Chaiya, Khateb, Fabian, Sotner, Roman, and Jaikla, Winai
- Subjects
- *
ELECTRIC filters , *INTEGRATED circuits , *ANALOG circuits , *PHASE shifters , *CAPACITORS - Abstract
First-order allpass filters are analog filters with a unit magnitude response, but they change the phase shift between input and output signals at various frequencies. This paper presents the transadmittance-mode first-order allpass filters based on the modified current-controlled current differencing transconductance amplifier (M-CCCDTA). The proposed filters utilize a single M-CCCDTA and a grounded capacitor with no external resistors, making them well suited for implementation in an integrated circuit. The gain and phase response of the proposed filters can be adjusted electronically and separately. Also, the high output impedance of the proposed filters at both the input voltage node and the output current node makes cascading easy without the need for buffer devices. A quadrature sinusoidal oscillator based on the proposed first-order allpass filter has been designed as an example of an application. The PSpice simulation and actual experiments are utilized to validate the functionality of the proposed filters. The simulation and experimental results are consistent with the idea of anticipation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Universal resistorless current-mode filters employing CCCIIs
- Author
-
Erkan Yuce, Ali Kircay, and Sezai Tokat
- Subjects
Energy storage ,Testing ,Current-controlled conveyors ,Capacitance ,All pass (AP) filters ,Experimental testing ,Capacitors ,Frequency-domain (FD) ,Low-pass ,Output currents ,Current-mode circuits ,Paper capacitors ,Electric currents ,Wave filters ,Second orders ,High pass ,Electrical and Electronic Engineering ,Active filters ,SPICE ,Band pass ,Grounded capacitors ,Current mode filter (CMF) ,Passive elements ,Generation current ,Output impedance ,Applied Mathematics ,Analog filters ,Single output ,Electric filters ,Passive filters ,Computer simulation ,Ketones ,SPICE simulations ,Electric equipment ,current-controlled conveyors ,current-mode circuits ,analog filters ,Computer Science Applications ,Electronic, Optical and Magnetic Materials ,signal limitations ,stability problems ,Matching conditions ,Power supply voltages ,Dielectric devices ,Low pass filters ,Notch filters ,Stability problems ,Signal limitations ,Sensitivity analysis ,Active devices ,High pass filters - Abstract
In this paper, four different-type second-order current-mode filters, employing second-generation current-controlled conveyors (CCCIIs) and two capacitors, are proposed. The first two of the presented filters can simultaneously realize high-output impedance low-pass, band-pass and high-pass responses. Also, the two filters can provide notch and all-pass filter responses with interconnection of the relevant output currents. The first developed one needs no critical active and passive element matching conditions and/or cancellation constraints. The second and third introduced ones employ only grounded capacitors. The fourth proposed filter derived from the third one uses only plus-type single output CCCIIs (CCCII+s). The fifth filter can be constructed using commercially available active devices such as AD844s along with additional resistors instead of CCCII+s of the fourth proposed filter to perform experimental test easily. All of the proposed filters have low active and passive element sensitivities. Time and frequency domain analyses are performed for the first, second and third realized filters using SPICE simulation program. Also, experimental test is achieved for the fifth filter. In this study, stability problems attributed to non-ideal gains of the CCCIIs and signal limitations of the first, second and third introduced filters due to restricted power supply voltages are investigated. Copyright © 2007 John Wiley & Sons, Ltd.
- Published
- 2008
35. Analytical Support for the T 000 Tellurium Preparation Process.
- Author
-
Lundovskaya, O. V., Tsygankova, A. R., Orlov, N. A., and Yatsunov, F. V.
- Subjects
INDUCTIVELY coupled plasma atomic emission spectrometry ,TELLURIUM ,ELECTRIC filters - Abstract
In this paper, we report the development of a unified inductively coupled plasma atomic emission spectrometry technique that allows one to assess the purity of T 000 metallic tellurium. The process comprises two sequential steps: hydrometallurgical processing of electric filter dust concentrate, based on a classic hydrometallurgical scheme of processing anode slime from copper production, and electrolytic tellurium extraction followed by reducing–refining melting for the preparation of metallic tellurium. For high-speed analytical monitoring of the preparation of T 000 tellurium, we have developed an atomic emission spectrometry technique; chosen analytical lines, the inductively coupled plasma power, and an optimal-compromise matrix component concentration; and evaluated the adequacy of the proposed technique. No high-speed versatile techniques for chemical analysis of metallic tellurium, intermediate products differing in purity, or raw materials have been previously reported in the literature. The proposed technique allows one to determine up to 61 analytes with limits of detection (LODs) in the range from n × 10
–7 to n × 10–4 wt % and intralaboratory precision better than 25%. Information about analyte concentrations obtained using the proposed technique allows one to optimize technologically important process parameters, draw conclusions regarding the quality of raw materials, and infer whether the final product—metallic tellurium—corresponds to grade T 000. The data we present on the chemical composition of the final product, intermediate products, and raw materials clearly demonstrate effectiveness of each step in the proposed scheme for the preparation of pure tellurium. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
36. A New Control Philosophy for a Unified Power Quality Conditioner (UPQC) to Coordinate Load-Reactive Power Demand Between Shunt and Series Inverters.
- Author
-
Khadkikar, Vinod and Chandra, Ambrish
- Subjects
ALGORITHMS ,MATRICES (Mathematics) ,ELECTRIC power distribution ,POWER transmission ,ELECTRIC power systems ,ELECTRIC power transmission ,PERTURBATION theory ,ELECTRIC filters ,SHUNT electric reactors - Abstract
This paper presents a novel philosophy to compensate the load-reactive power demand through a three-phase unified power quality conditioner (UPQC). Most of the UPQC-based applications show the dependency on shunt inverter for load-reactive power compensation, whereas the series inverter is always looked as controlled voltage source to handle all voltage-related problems. This paper proposes a new functionality of UPQC in which both the shunt and series APFs supply the load-reactive power demand. This feature not only helps to share the load-reactive power demand, but also helps to reduce the shunt APF rating, and hence, the overall cost of UPQC. This results in better utilization of the existing series inverter. The theory and complete mathematical analysis termed as "power angle control (PAC)" is presented. The simulation results based on MATLAB/Simulink are discussed in detail to support the concept developed in the paper. The proposed approach is also validated through experimental study. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
37. Efficiency Comparison of Voltage-Source and Current-Source Drive Systems for Medium-Voltage Applications.
- Author
-
Yongsug Suh, Steinke, Juergen K., and Steimer, Peter K.
- Subjects
ELECTRIC current rectifiers ,ENERGY consumption ,ELECTRIC power consumption ,ELECTRIC power supplies to apparatus ,ELECTRIC transformers ,ELECTRIC current converters ,SIMULATION methods & models ,ELECTRIC machinery ,ELECTRIC filters - Abstract
This paper calculates and compares the efficiency and loss distribution in the three most popular state-of-the-art types of large motor drive systems: 1) current-source drive with active front-end rectifier; 2) current-source drive with 18-pulse thyristor rectifier; and 3) three-level voltage-source drive with 12-pulse/24-pulse diode rectifier. For converter systems with efficiencies better than 90%, it is suggested to calculate or measure the losses of all the components separately and add them up to calculate the total efficiency. A simple and accurate method of calculating switching losses for a current-source and voltage-source converter is proposed. Through the calculation and simulation of each loss factor such as switching losses, conduction losses, and snubber and filter losses, the three-level voltage-source drive system has been found to have the highest efficiency of 98.77% under the rated load of 1.6 MW. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
38. Two-Dimensional Space Time Pilot-Symbol Assisted Demodulation for Frequency-Nonselective Rayleigh Fading Channels.
- Author
-
Chen, Tai-Ann, Fitz, Michael P., Shengchao Li, and Zoltowski, Michael D.
- Subjects
DEMODULATION ,RADIO frequency modulation ,DIGITAL modulation ,ELECTRIC filters ,STATISTICAL correlation ,RADIO transmitter fading - Abstract
A two-dimensional space-time pilot-symbol assisted demodulation system is proposed in this paper. Since complex scattering environments can produce nontrivial space-time correlation characteristics, this paper proposes coherent demodulation by estimating the fading channel distortion using pilot observations across both space and time. The optimum interpolation filter takes in multiple signals from receiving antennas and exploiting the space-time channel correlation to produce multiple channel-estimate outputs corresponding to every antenna. The optimal channel-estimation filter, its mean-square error performance, and the pairwise symbol-error probability are derived for realistic scattering models to characterize the system performance. A design criterion is proposed for the pilot-symbol spacing and the filter length. Since the filter is a function of the statistical description of the channel, we investigate if this statistical description and the resulting optimal filters can be estimated simply from the pilot observations. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
39. Instantaneous Phase Voltage Sensing in PWM Voltage-Source Inverters.
- Author
-
Schubert, Michael and De Doncker, Rik W.
- Subjects
PULSE width modulation transformers ,ELECTROMECHANICAL devices ,ROTORS ,ELECTRIC potential ,POWER electronics ,ELECTRIC filters - Abstract
The output voltage of power electronic converters is a very important quantity for dynamic control of power electronic systems. In electrical drives without electromechanical position or speed sensor, the terminal reference voltage is used to obtain the rotor position. Dead-time effects and semiconductor voltage drop lead to distortion in the actual output voltage and degrade the control performance when the back electromotive force magnitude is low. Thus, for stable low-speed operation, output voltage sensing becomes necessary. Due to the switching nature of power electronic systems, this is not a trivial task, especially when instantaneous measurement of the terminal voltage is required. In this paper, an instantaneous switching-period average voltage sensing technique is proposed that utilizes a combined approach of oversampling and filtering. Based on the theoretical analysis of the sampling- and filter-induced measurement distortion, a general solution for an optimal filter design is derived. The additional sensing circuit is integrated into the low-side gate driver of the converter outputs. This paper includes details about the hardware implementation and extensive verification measurements. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
40. Analysis and Design of Filters for the Energy Storage System: Optimal Tradeoff Between Frequency Guarantee and Energy Capacity/Power Rating.
- Author
-
Koiwa, Kenta, Liu, Kang-Zhi, and Tamura, Junji
- Subjects
ENERGY storage ,ELECTRIC power systems ,ELECTRIC filters ,ELECTRIC power production ,WIND power - Abstract
This paper proposes a new filter design method that can smooth the wind power generation output while keeping the energy capacity and power rating of the energy storage system (ESS) small. Wind power generation causes frequency fluctuations in power systems. Therefore, in many cases, the ESS is needed for smoothing the fluctuations of wind generator output. In order to improve the performance of the ESS controlled with the conventional low-pass filter (LPF), this paper investigates other types of filters. First, the relations between filter and energy capacity/power rating of the ESS are disclosed through the worst-case study. Then, the frequency fluctuation analysis of the power system with respect to the wind power generation is carried out in order to realize a pin-point smoothing. Finally, a metaheuristic optimization method is proposed for the multiobjective design of the filter based on these relations so as to achieve an optimal tradeoff between the output smoothing and energy capacity/power rating of the ESS. It is shown via simulation analysis with real wind data that the proposed method can suppress the frequency fluctuation of the power system effectively with the ESS having smaller energy capacity and power rating. [ABSTRACT FROM PUBLISHER]
- Published
- 2018
- Full Text
- View/download PDF
41. An Accurate Method for Synthesis of Reflecting Elements to Design Wideband Reflectarray Antenna.
- Author
-
Delafkar, Hamideh and Pirhadi, Abbas
- Subjects
REFLECTARRAY antennas ,FREQUENCY selective surfaces ,ELECTRIC filters ,TIME delay systems ,FREQUENCY response - Abstract
This paper presents an accurate method for synthesis of true time delay (TTD) reflecting elements to design wideband reflectarray (RA) antennas. In doing so, primarily the conventional phase distribution formulation of RA is modified to accommodate the design of resonant reflecting elements based on TTD technique. An accurate circuit model is then presented to realize the linear reflection coefficient phase of the reflecting elements of the RA antenna using the continued fraction theory. Finally, the equivalent circuit models of reflecting elements are implemented via multilayer frequency selective-surface structures. The RA antenna is designed and fabricated to operate in the X-band frequency. Stable aperture phase efficiency of about 80% and stable radiation patterns throughout the operating frequency band, confirm the accuracy of the proposed method. [ABSTRACT FROM PUBLISHER]
- Published
- 2018
- Full Text
- View/download PDF
42. The realisation of selected signal processing functions by means of stack filters.
- Author
-
KUŚ, Z. and NAWRAT, A.
- Subjects
SIGNAL processing ,SIGNAL theory ,ALGORITHMS ,STACK filters ,ELECTRIC filters - Abstract
The goal of the paper was to shorten the calculation time by realising all used signal processing algorithms in the form of stack filters. The architecture of these filters allows us to process signals using the advantages of hardware processing and simultaneous signal processing. This paper elaborated on the synthesis of stack filters which realise median, averaging, opening and closing operations. The novel achievement was to develop the binary box method which allows us to obtain stack filters for more complex algorithms. This method consists of two stages and requires that we construct a spatial structure of the data. This structure allows us to examine the stacking property in two steps. Obtained in this way architecture of the function is predisposed to VLSI implementation. The authors devised this method transforming the averaging filter into stack filter; however, the invented binary box method allows us to synthesise stack filter which realises more complex signal processing algorithms. The only assumption which limits the class of acceptable algorithms is the fact that the algorithm has to satisfy the stacking property at each stage of the signal processing. The proposed approach allows us to convert well-known signal processing algorithms into realisation which guarantees significantly greater speeds of signal processing. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
43. An Optimal Digital Pulse-Width-Modulated Dither Technique to Enhance the Resolution of High-Frequency Power Converters.
- Author
-
Fang, Jingyang, Yang, Xu, Zhang, Lei, and Tang, Yi
- Subjects
PULSE width modulation ,MICROPROCESSORS ,WIDE gap semiconductors ,SEMICONDUCTOR switches ,CONVERTERS (Electronics) ,ELECTRIC filters - Abstract
Wide bandgap semiconductor switches have been increasingly utilized to improve the power density and efficiency of power converters, as such devices are able to operate at very high frequencies, e.g., up to 100 MHz, with reduced power losses. However, such a high-frequency operation may impose a challenge to the digital control system, and the system clock frequency should be up to 100 GHz in high-precision applications, which is difficult to realize in low-cost microprocessors. Instead of using extremely high-frequency clocks, preprocessing-based solutions that utilize digital pulse-width-modulated (DPWM) dither techniques can also enhance the DPWM resolution with moderate frequency clocks. Unfortunately, this is usually achieved at the expense of introducing low-frequency harmonics, which may complicate system controller and output filter design. In this paper, an optimal dither technique is proposed to enhance the resolution of DPWM power converters. The concepts of positive dither and negative dither are first proposed in this paper. Furthermore, vector-diagram-based analysis indicates that with proper utilization of positive dithers and negative dithers and carefully selected dither sequences, the lowest order harmonic introduced by the conventional dither technique can be completely eliminated when the dither period is multiples of six switching periods. In other cases, the proposed optimal dither technique can produce minimized lowest order harmonic. Finally, experimental results obtained from a Gallium Nitride (GaN) devices-based synchronous buck converter validate the feasibility of the proposed dither technique. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
44. Analytical Formulas for the Coverage of Tunable Matching Networks for Reconfigurable Applications.
- Author
-
Arabi, Eyad, Morris, Kevin A., and Beach, Mark A.
- Subjects
RADIO frequency ,DYNAMIC loads ,SMITH charts ,LONG-Term Evolution (Telecommunications) ,ELECTRIC filters - Abstract
Tunable matching networks (MNs) are essential components for agile radio frequency systems. To optimally design such networks, the total area they cover on the Smith chart needs to be determined. In this paper, the coverage areas of typical MNs have been determined analytically for the first time. It has been found that the coverage area is encompassed by up to five arcs. Analytical expressions for the centers and radii for these arcs have been derived. The theoretical analysis is provided for four typical MNs and verified by circuit simulation and measured data. Moreover, a dynamically load-modulated power amplifier has been designed using the presented theoretical techniques, which demonstrates a measured improvement in the power added efficiency of up to 5% in the frequency range of (0.8–0.9) GHz. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
45. Modeling and Resonance Control of Modular Three-Level Shunt Active Power Filter.
- Author
-
Feng, Ling and Wang, Yong
- Subjects
ELECTRIC filters ,ELECTRIC circuits ,ELECTRIC networks ,ELECTRICAL harmonics ,ELECTRIC waves - Abstract
Compared with the conventional central shunt active power filter (SAPF), modular designed SAPF can track the harmonics more precisely and quickly with a compact and expandable structure, which makes it a better solution for harmonic mitigation. But there are very few paper discussed about the modeling and parallel resonance issues of modular SAPF parallel system. This paper provides a modeling of three-level SAPF, aiming to guide the modular design and research the parallel resonance control method. First, a simplified modular three-level SAPF modeling is proposed based on averaging impedance modeling and small signal linearization techniques. Then, the coupling issues between modules are researched, and a self-adaptive active damping method is proposed to suppress the system resonance. Based on the modeling results, an improved three-level SAPF module topology is proposed to construct the modular system. The theoretical analysis and experimental results verify that the module topology improvement together with the damping strategy can promise the compensating bandwidth, reliability, and fast, precise harmonics tracking ability. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
46. A Compact, Voltage-Mode Type-I PLL With Gain-Boosted Saturated PFD and Synchronous Peak Tracking Loop Filter.
- Author
-
Sharkia, Ahmad, Aniruddhan, Sankaran, Mirabbasi, Shahriar, and Shekhar, Sudip
- Subjects
PHASE-locked loops ,ELECTRIC filters ,VOLTAGE-controlled oscillators - Abstract
Despite their inherent stability, area-efficient loop filters, and insensitivity to phase-frequency detector nonlinearity and dead-zone, type-I phase-locked loops (PLLs) are used infrequently because of two major limitations—limited lock-range and large reference spurs. This paper introduces a type-I PLL that takes advantage of the inherent benefits of the architecture, while tackling its limitations by means of gain boosting in the forward path for lock-range improvement and synchronous peak tracking of the voltage-controlled oscillator control voltage for reference spur reduction. Sampling in the loop filter changes the loop dynamics, and methods to accurately predict the closed-loop response, starting from state-space equations, are provided. A digital-friendly, voltage-mode topology is proposed that does not need charge pumps or opamps. A prototype 2.2–2.8-GHz PLL occupies a core area of 0.12 mm2 in 0.13- $\mu \text{m}$ CMOS and achieves −103.4 dBc/Hz in-band phase noise, −65-dBc reference spur, and 2.5- $\mu \text{s}$ worst-case lock-time while consuming 6.8 mW from a 1.2-V supply. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
47. Resilient Filtering for Linear Time-Varying Repetitive Processes Under Uniform Quantizations and Round-Robin Protocols.
- Author
-
Wang, Fan, Wang, Zidong, Liang, Jinling, and Liu, Xiaohui
- Subjects
TIME-varying systems ,SIGNAL quantization ,ELECTRIC filters - Abstract
In this paper, the resilient filtering problem is investigated for a class of linear time-varying repetitive processes with communication constraints. The communication between the sensors and the remote filter, which is subject to uniform quantizations, is carried out through a shared communication medium where only one sensor has access to the network at each transmission time. To prevent data from collisions, the Round-Robin (R-R) protocol scheduling is applied to orchestrate the transmission order of sensor nodes in a periodic manner. Moreover, stochastic perturbations on the gain parameters are taken into account in the course of the actual filter implementation. The main purpose of the addressed problem is to design a resilient filter such that, in the presence of the uniform quantization, the R-R protocol, and the filter gain perturbation, a certain upper bound is guaranteed on the filtering error variance and subsequently minimized at each time instant. By means of intensive stochastic analysis and mathematical induction, sufficient condition is provided to ensure the local minimization of certain upper bound on the filtering error variance. Furthermore, the boundedness issue is also discussed with respect to the filtering error variance. Finally, a numerical example is employed to demonstrate the effectiveness of the proposed filter strategy. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
48. INFLUENCE OF RADIATION ON THE STABILITY OF ELECTRICAL FILTERS CHARACTERISTICS AS COMPONENTS FOR OVERVOLTAGE PROTECTION.
- Author
-
NEDIC, Teodora M., JANICIJEVIC, Aco J., JUSIC, Alija R., and STANKOVIC, Koviljka Dj.
- Subjects
ELECTRIC filters ,RADIATION ,OVERVOLTAGE ,GAMMA rays ,NEUTRONS - Abstract
Copyright of Nuclear Technology & Radiation Protection is the property of Vinca Institute of Nuclear Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
- View/download PDF
49. Hybrid Active Filter With Variable Conductance for Harmonic Resonance Suppression in Industrial Power Systems.
- Author
-
Lee, Tzung-Lin, Wang, Yen-Ching, Li, Jian-Cheng, and Guerrero, Josep M.
- Subjects
PASSIVE electric filters ,PARALLEL resonant circuits ,HARMONIC distortion (Physics) ,ELECTRIC filters ,ELECTRIC resonators - Abstract
Unintentional series and/or parallel resonances, due to the tuned passive filter and the line inductance, may result in severe harmonic distortion in the industrial power system. This paper presents a hybrid active filter to suppress harmonic resonance and to reduce harmonic distortion. The proposed hybrid filter is operated as variable harmonic conductance according to the voltage total harmonic distortion; therefore, harmonic distortion can be reduced to an acceptable level in response to load change or parameter variation of the power system. Since the hybrid filter is composed of a seventh-tuned passive filter and an active filter in series connection, both dc voltage and kVA rating of the active filter are dramatically decreased compared with the pure shunt active filter. In real application, this feature is very attractive since the active power filter with fully power electronics is very expensive. A reasonable tradeoff between filtering performances and cost is to use the hybrid active filter. Design consideration are presented, and experimental results are provided to validate effectiveness of the proposed method. Furthermore, this paper discusses filtering performances on line impedance, line resistance, voltage unbalance, and capacitive filters. [ABSTRACT FROM PUBLISHER]
- Published
- 2015
- Full Text
- View/download PDF
50. Reconfigurable Parallel Coupled Band Notch Resonator With Wide Tuning Range.
- Author
-
Wang, Zhengpeng, Kelly, James R., Hall, Peter S., Borja, Alejandro L., and Gardner, Peter
- Subjects
ELECTRIC resonators ,ELECTRIC capacity ,VARACTORS ,ELECTRIC filters ,RESONATOR filters - Abstract
This paper presents a new form of reconfigurable band notch resonator with a wide tuning range. The whole structure consists of a through line and two parallel coupled resonators. This paper presents an accurate lumped element equivalent circuit for the parallel coupled resonator. The mechanism giving rise to the wide tuning range is also investigated. The first harmonic of the fundamental stop-band is analyzed and compared with that of the varactor-coupled resonator. Measurement results show that the stop-band of the filter can be tuned from 0.6 to 4.0 GHz. This is achieved by varying the capacitance of two pairs of varactor diodes. The stop-band tuning range is restricted by the capacitance variation which can be achieved using the varactor diode. The potential tuning range of a filter based on this resonator is greater than one decade. [ABSTRACT FROM PUBLISHER]
- Published
- 2014
- Full Text
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