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In this paper, we present a new digital resonant current controller that can be applied in single-phase and three-phase alternating current (AC) power converters, based on voltage source inverters (VSI) with pulse width modulation (PWM). Since power converters based on PWM introduce fractional time delays regarding the sampling period (T s), because of the current sampling and PWM command updating techniques that are employed, there is a need to develop analytical tools for precise modelling of these types of delays. To achieve this, the advanced Z-transform is applied in order to model the AC controllers in VSIs with PWM for the general case of a fractional time delay, including power converters with current sampling within a PWM period at any chosen time instance. This new approach to power converter modelling and current sampling allowed us to develop a modified resonant AC current controller for a VSI with RL load, based on the pole-placement parameter tuning method. It includes fractional time delays, which are conventionally employed in the power converter design, in the controller parameter derivations, and introduces the minimal order resonant controller that enables strict placement of all closed-loop control system poles. Simulations and experimental tests are carried out to show the improvements introduced by novel solution in this paper compared with conventional resonant current controllers. In the analysis of dynamic performance and robustness, in this paper conventional indices are applied to compare the proposed controller with a conventional design. • The introduction of the Advanced Z-Transform enables analytical modelling of the plant that includes a fractional time delay. • Novel pole-placement based parameter tuning procedure is presented, which places all closed-loop system poles at required positions. • New controller is compared with existing solution by test runs and conventional dynamic performance and robustness indices. [ABSTRACT FROM AUTHOR]

The high-gain DC converter is a crucial step in the conversion process for raising the voltage from PV panels to the desired voltage level in renewable energy applications. This article proposes a three-phase grid connected PV system with a novel interleaved high gain DC converter fed 3-level Neutral-Point-Clamped (NPC) Inverter. The novel high-gain DC converter consists of an interleaved boost converter (IBC) at its input side, a switched capacitor cell, a passive clamp circuit, and a voltage multiplier unit (VMU). The interleaved arrangement eliminates the input current ripple, and the VMU is utilized to improve the overall voltage gain besides the reverse recovery problem of diodes. The proposed converter is operated at a duty cycle D = 0.6 and a high voltage conversion ratio of 17.5 which is ideal for sustainable energy applications. This paper uses the proposed converter for a grid-connected solar PV system with an NPC inverter controlled using Space Vector Pulse Width Modulation (SVPWM) technique. The SVPWM strategic approach is a prevalent modulation technique for NPC inverter due to its extensibility in choosing the ideal voltage vectors. It uses an active filter, which is more dependable, dynamically better behaved, and capable of operating accurately under distorted grid voltages under varying load conditions. The proposed grid-associated PV system with a novel interleaved converter and 3-level NPC inverter is employed in Matlab/SimPower System and experimentally verified. Power loss and efficiency calculations were performed on the DC converter side, and the efficiency was 96.07%. NPC inverters have a THD of 22.2%. Results from simulations and experiments indicate that the suggested topology can efficiently extricate the maximal amount of power from PV modules and inject energy into the grid system with excellent steady-state and dynamic performance. [Display omitted] • The Incremental & Conductance MPPT method is engaged for tracking MPP. • The grid connected novel DC converter has the high voltage gain of about 17.5 at a nominal duty ratio of D = 0.6. • The novel DC converter is appropriately utilized for 3-level NPC Inverter to generate grid voltage. • The proposed structure is successfully synchronized to the grid by Synchronous Reference Frame Phase Locked Loop (SRFPLL). [ABSTRACT FROM AUTHOR]

Staircase Modulation (SCM) is a popular switching strategy for multilevel inverters (MLI), which is often a preferable alternative to Pulse Width Modulation (PWM) due to its reduced switching losses, especially for MLIs with a relatively high number of voltage levels (N). In some applications, such as motor drives, or when output filters are applicable, SCM may also suit MLIs with moderate N values. While MLIs with Equal DC Sources (EDCS) are more common, MLIs with Unequal DC Sources (UDCS), such as asymmetric Cascaded H-Bridge (CHB) MLIs are known to further reduce the waveforms' Total Harmonic Distortion (THD). The main objective of SCM is to adjust the waveform's fundamental component, while employing some harmonic mitigation strategy, such as THD minimization. Such an optimization approach relies on an accurate THD formulation, which eliminates underestimation errors associated with numerical THD approximations. This paper reveals novel generic analytical formulations of both Phase-voltage THD (PTHD) for single-phase MLIs and Line-voltage THD (LTHD) for three-phase MLIs. The revealed exact formulation approach is derived from Fourier series representation of THD, resulting in simple closed-form PTHD and LTHD expressions, applicable to any MLI topology, with either EDCS or UDCS configurations, and arbitrary value of N (odd and even). Given an arbitrary N value, the proposed formulations can be used to generate symbolic N -level PTHD or LTHD expressions, which are symbolic functions of the Phase Switching Angles (PSA) and (optionally) the DC source Ratios (DCR). The revealed THD formulations are verified and compared against recently introduced time-domain-based THD formulations. It is shown that when both time and frequency-based formulations are employed in THD minimizations to form a novel Hybrid Temporal-Spectral (HTS) Optimal Minimization of THD (OMTHD) approach, even better results can be achieved. The novel OMTHD is deeply explored and verified by both digital simulations and Controller + Hardware in Loop (C-HIL) based real-time experiments using 7- and 8-level three-phase MLI configurations. A downloadable supplemental file containing Maple and MATLAB functions of the proposed THD expressions, as well as pre-calculated sets of optimum variables for different values of N is provided for readers' convenience. [ABSTRACT FROM AUTHOR]

• A power-decoupled current source inverter (PD-CSI) is proposed for the operation in an unbalanced grid to reduce the current rating of the DC-link inductor. • A model predictive control is proposed for the PD-CSI. It achieves high performance in both stability and rapidity. • A space vector pulse width modulation is proposed for the PD-CSI. It helps to reduce the voltage rating of the ripple storage capacitor. The current source inverter (CSI) is a promising interface between the Photovoltaic (PV) panel and the three-phase AC grid. It boosts the PV panel voltage by a DC-link inductor and converts the maximum available PV power. In an unbalanced grid, double-line-frequency pulsating powers will be generated in the CSI, increasing the rating of the DC-link inductor and impeding the maximum power point tracking (MPPT) operation. To address this issue, a power decoupling (PD) circuit for a three-phase CSI is proposed in this paper. By using the DC-link inductor and active switches multiplex, the proposed PD circuit can reduce the current rating of the DC-link inductor with fewer active switches, and no detrimental power components are introduced to the utility grid. Moreover, to concurrently control multiple objectives without multiple loops, a model predictive control (MPC) method is further proposed for the PD-CSI, achieving a rapid response of PD-CSI. Besides, a space vector pulse width modulation (SVPWM) method is proposed for the PD-CSI to enhance the utilization of DC voltage, helping to reduce the voltage stress of the ripple storage capacitor. The priorities of the proposed topology and the corresponding control and modulation methods are finally verified by comparative experimental results. [ABSTRACT FROM AUTHOR]

Abstract This paper proposes an active bus voltage limiter with a modified modulation strategy for bi-directional power flow applications. When the motor is braking, the regenerative energy raises the DC bus voltage. Additional shunt resistors are usually used to dissipate the regenerative energy, which is a waste. The active rectifiers, which are also mentioned as PWM (Pulse Width Modulation) rectifiers, can transfer the regenerative power to the power grid but the cost is high and not economic, especially when the regenerative power is comparatively low. This paper investigates the zero-sequence current produced by the active bus voltage limiter and then presents a modified space vector modulation strategy to effectively suppress the zero-sequence current and keep the unity power factor. The analysis about the control strategy of the topology is carried out. And the algorithms for regenerative applications are discussed. An industrial prototype is built to verify the configuration. Highlights • The proposed limiter can transfer the regenerative energy to the power grids. • The model of the zero-sequence current generated in the applications is established. • A modified SVPWM is proposed and the zero-sequence currents are suppressed. • The strategy proposed can be further used when many inverters run in parallel. • An industrial prototype is built and has been used in elevators. [ABSTRACT FROM AUTHOR]

Control of multi-phase machine in both healthy and post-fault operations has recently gained considerable interest. Finite control set model predictive control (FCS-MPC), in particular, has been proposed to drive multi-phase machines to avoid sophisticated pulse width modulation (PWM) methods. Nevertheless, FCS-MPC generally experiences some technical limitations. One of the widely reported challenges related to FCS-MPC is the weighting factor (WF) design, which is empirically designed and found to be an operating point dependent factor. Thus, assuming a constant WF can result in poor performance. In this paper, the prediction stage of FCS-MPC for asymmetrical six-phase (A6P) induction motor (IM) has been reformulated based on double dq (2dq) modeling approach. Unlike the reported vector space decomposing (VSD)-based FCS-MPC algorithms, the proposed approach results in four control variables (the stator sequence currents i s α 1 , i s β 1 , i s α 2 , and i s β 2 ) which have the same priority. Thus, equal weighting factors could be used in the cost function, which will inherently minimize the effect of the circulating x-y current components. Performance comparison of the proposed method against VSD-based FCS-MPC is investigated. The theoretical findings are experimentally validated using a 1 kW prototype six-phase IM. [ABSTRACT FROM AUTHOR]

As a main driving force of electric vehicles (EVs), the losses of in-wheel permanent-magnet synchronous motor (PMSM) direct drive system can seriously affect the energy consumption of EVs. This paper proposes a loss optimization control strategy for in-wheel PMSM direct drive system of EVs which optimizes the losses of both the PMSM and the inverter. The proposed method adjusts the copper losses and iron losses by identifying the optimal flux-weakening current, which results in the PMSM achieving the lower losses in the whole operational range. Moreover there are strongly nonlinear characteristics for the power devices, this paper creates a nonlinear loss model for three-phase half-bridge inverters to obtain accurate inverter losses under space vector pulse width modulation (SVPWM). Based on the inverter loss model and double Fourier integral analysis theory, the PWM frequency is optimized by the control strategy in order to maximize the inverter efficiency without affecting the operational stability of the drive. The proposed loss optimization control strategy can quickly find the optimum flux-weakening current and PWM frequency, and as a result, significantly broaden the high efficiency area of the PMSM direct drive system. The effects of the aforementioned strategy are verified by both theoretical analysis and experimental results. [ABSTRACT FROM AUTHOR]

To increase the reliability of motor drive system, many fault diagnosis approaches have been reported with regard to three-phase Pulse Width Modulation Voltage Source Inverter (PWM-VSI). Based on feature engineering and deep neural network, this paper proposes a fault diagnosis approach for the VSI in three-phase Permanent-magnet Synchronous Motor (PMSM) drive. The three-phase current signals are used for the fault diagnosis of VSI. 10 typical signal features are extracted from the three-phase current signals and used as the input of deep neural network. To improve the diagnostic performance, the network structure of the presented deep neural network is designed like a pyramid. Experimental results show that the presented method can detect not only the single open-circuit faults but also the double open-circuit faults in power switches, with high diagnostic accuracy (more than 95%). Besides, comparison results show that the presented method has strong generalization performance. This paper provides theoretical guidance for the fault diagnosis of VSI in PMSM. [ABSTRACT FROM AUTHOR]

The paper describes various modified algorithms of classical sinusoidal pulse width modulation (PWM) serving for a three-phase two-level inverter control. The paper presents the results of a research of 3 PWM versions with varying duty cycle parameters and frequency of the pulse signal modulation. The method is to divide the modulated sinusoidal signal cycle (half-cycle) into intervals in order to change the modulation frequency within the separate sectors of forming the quasi-sinusoidal output voltage waves. In addition, algorithmic ways to compensate the additional losses in the inverter and the induction motor at high modulation frequencies of a discrete control signal are investigated and described in the paper. Calculations and simulations are performed by NI Multisim simulation program and NI LabVIEW visual programming environment. Theoretical studies are performed using the electric drive theories, discrete control systems and spectral analysis. The practical implementation performed by Texas Instruments Stellaris Launchpad using the Energia prototyping platform, field-programmable gate arrays (FPGA) of National Instruments CompactRIO-9074 and NI Single-Board RIO GPIC (sbRIO-9606, NI 9683 (GPIC), LX45 FPGA) using NI LabVIEW software and add-on modules (LabVIEW Real Time, LabVIEW FPGA). The suggested inverter control methods make it possible to reduce the distortion of the output quasi-sinusoidal signal and reduce the power consumption of the DC link while significantly reducing the number of inverter transistor switching in comparison with the classical method without premodulation or technical devices (filter-compensating devices). [ABSTRACT FROM AUTHOR]

This paper presents the modeling and controlling the power of Quasi Z-Source cascaded H-bridge multilevel inverter for grid connected photovoltaic systems. The Quasi Z-Source inverter is an inverter that provides buck / boost output along with DC-AC conversion in a single stage. This topology has numerous advantages which makes it reliable and suitable for PV applications. Due to the impedance network and the cascaded H-bridge structure, it provides high gain, reduced total harmonic distortion (THD) and high reliability in PV systems. In this paper, a five level cascaded H-Bridge Quasi Z-source inverter has been considered for which the impedance network has been designed. Phase Shifted Inverted Sine carrier pulse width modulation has been implemented along with shoot- through control for controlling the switches of the inverter. The closed loop power control scheme has been implemented in two stages. In the PV input side, each string voltage is controlled by adjusting the shoot-through states of the inverter using Independent Maximum Power Point Tracking Control. DC link voltage of each bridge has been balanced by using DC link voltage control. Both of these controlling actions result in the control of grid injected power. A 2kVA PV inverter has been designed and built using MATLAB/SIMULINK and the hardware has been completed for the open loop control. The simulation and open loop hardware results are discussed. [ABSTRACT FROM AUTHOR]

This paper introduces a new HT-type module for both symmetrical and asymmetrical multilevel inverters (MLIs) with reduced power electric components. The proposed module comprises of two back to back T-type inverters connected with four cross-connected switches. This MLI addresses two major drawbacks associated with the conventional and other recently proposed MLIs which are the high voltage stress of switches and higher power component counts. The structure of the proposed device is designed combining the beneficial features of both T-type inverter and cross-switched inverter. The 1st feature allows the module to produce negative voltage levels deprived of any extra H-bridge circuit and thus decreasing the overall voltage stress significantly. The latter feature allows the device to utilize reduced number of switches to produce higher voltage levels. A comprehensive comparative analysis is additionally established between other MLI topologies to confirm the superiority of the HT-type MLI. From this analysis, it is found that the proposed MLI has successfully overcome the issues associated with other MLIs, it was able to produce the results following industrial standards and it outperformed other MLIs in different aspects such as power components count, cost, efficiency and dynamic performance. Selective harmonic elimination pulse width modulation (SHE-PWM) and nearest level control (NLC) algorithm is considered in this manuscript to generate the output results from the proposed HT-type module. All the details about the operating principle and modulation techniques utilized for the proposed MLI module are stated and validated by both simulation and experimental results. [ABSTRACT FROM AUTHOR]

• Developed a nonlinear model of droop-controlled sources, established a system-level model of direct current microgrids. • Proposed a low-conservation constrained region of attraction-based stability analysis method. • Those new achievements are verified by case studies and have been proved to be effective in expanding the existing knowledge base. Large-signal stability of direct current (DC) microgrids (MGs) are required to be seriously considered when more power converters are penetrated. For DC MGs suffering from large disturbances, the power electronics at both source and load sides are operated within the voltage and current limits to ensure the stability and safety. However, no existing methods have been developed to address the non-conservative stability analysis of a DC MGs with physical variable constraints. To this end, a comprehensive is developed in this paper to analyze the large-signal stability of typical DC MGs with voltage/current and pulse-width modulation duty cycle constraints, with a low level of conservatism. First, the system-level model of a DC MG is established as the basis of stability analysis. Then, a workflow based on the Lyapunov theory and numerical integration is developed to evaluate the large signal stability with physical variable constraints. The developed stability analysis method has less conservatism than the existing methods with only one moderate computational cost. The effectiveness of the proposed strategy is validated by case studies based on a single-bus direct current microgrid. [ABSTRACT FROM AUTHOR]

• The proposed space vector modulation (SVM) method for active power decoupling quasi-Z-source inverter (APD-qZSI) is easy to implement. • Compared with the SPWM, the proposed SVM method has smaller storage capacitance and a wider normal operation range. • The APD method under the proposed SVM method is effective for suppressing the 2ω ripple power and reducing the qZS inductance and capacitance. The double-line frequency ripple power of the single-phase quasi-Z source inverter (qZSI) will result in a large designed qZS impedance on the dc side, which can be greatly reduced by the coupled-type active power decoupling (APD) method. However, the traditional sinusoidal pulse width modulation (SPWM) for the APD-qZSI needs extravagant APD storage capacitance and may cause abnormal operation under low load conditions. Classical space vector modulation (SVM) has higher flexibility and dc-link voltage utilization, but it cannot be directly applied to the APD-qZSI. In this paper, a simplified SVM method for the coupled-type APD-qZSI is proposed, where the switching time sequence is transformed to carrier-based pulse width modulation, so the shoot-through control of the qZSI is easy to implement. Next, the passive component parameters and normal operation range of the traditional SPWM and the proposed SVM are analyzed and compared. The proposed SVM has a smaller APD storage capacitance but a slightly larger ac side filter inductance. In addition, the decreased current of the APD branch under SVM can help suppress the abnormal operation of the inverter, so the APD-qZSI can operate at a lower load condition. Finally, experimental results validate the effectiveness and superiority of the proposed SVM method. [ABSTRACT FROM AUTHOR]

This paper proposes a double source double diode double switch (DSDDDS) multilevel inverter to generate positive voltage and a connecting polarity changing circuit of an H-bridge inverter to generate negative voltage. By connecting the jth number of basic units in series, the desired level is obtained. Various algorithms, such as Natural, Binary, Trinary, and Quasi-Linear sequences, and two proposed algorithms are discussed to determine the magnitude of DC voltage sources in order to generate more stepped levels with fewer switches. The proposed multilevel inverter eliminates the need to turn on additional power switches for different levels, which is the main advantages of this topology. The proposed multilevel inverter is compared to conventional switched diode multilevel inverters in terms of switch count, number of ON state switches per level, driver circuits, and total standing voltage. Real-time results from the OPAL-RT test bench and simulation have validated the proposed inverter. [ABSTRACT FROM AUTHOR]

Using variable blank holding force, which is conventionally achieved by hydraulic or mechanical drive, can effectively reduce defects in the forming process. To overcome the obstacles of low response and high complexity of conventional drives, this paper proposes a holding system for variable blank holding force driven by the electro-permanent magnet. Focusing on the variable electromagnetic force, a control method based on grading voltage pulse width modulation and mode matching is addressed. The model of the transient electromagnetic force is first established, the relationship between electromagnetic force and current is obtained, and the migration law of the working point of the magnet with the change of current is analyzed. Then, the grading voltage pulse width modulation control, which regulates current by the pulse width and its amplitude, is developed for continuously increasing or decreasing force control. When force variations occur, mode matching is introduced to identify the working point and allocate matching parameters for better control. To validate the feasibility of the control method, the co-simulation based on Simulink-Simplorer-Maxwell and the experiment bench are built. Results of electromagnetic force show that the step response time is 0.13 s and the mean relative error is less than 1% for a given variable blanking force. The control method can reduce the thickness variations of sheet metal by 14–20% compared to the existing electro-permanent magnet blank holder. This work assists in realizing the loading of variable blank holding force driven by electromagnetics to improve the forming quality of parts. [Display omitted] • Transient model was built for the electromagnetic blank holding system. • Grading voltage PWM control was developed for quickly tracking of the system. • Mode matching was introduced for accurate control of the system. • Response and accuracy of the system was validated by experiments. • Better forming quality was revealed compared with the existing control. [ABSTRACT FROM AUTHOR]

The radio frequency spectrum, which has been steadily getting smaller, is under pressure from growing cellular data traffic. A more dependable communication channel is required. To setup the communication medium, VLC uses LED illumination. In order to increase network throughput, the goal of this study is to analyze and model signal conditioning techniques in the visible spectrum. VLC technology offers synchronized illumination of LED lamps as well as wireless broadband connectivity. Using the real-valued O-OFDM baseband signal, optical orthogonal frequency division multiplexing (O-OFDM) offers a viable modulation option for very-low-bit-rate (VLC) systems to modulate the optical carrier's instantaneous power to attain gigabit data rates. However, one important design difficulty preventing VLC from being commercialized is how to combine industry-favored pulse width modulation (PWM) dimming technology while retaining a dependable, broadband connection. In this paper, Reverse Polarity optical orthogonal frequency division multiplexing (RPO-OFDM) is proposed as a new signal format for combining the fast O-OFDM contact signal with the comparatively slow PWM dimming signal, as both signals contribute to the illuminative brightness of the LED. The average SNR, additional testing demonstrates that the suggested method outperforms the Asymmetrically clipped optical OFDM (ACO), Optimized Flipped Optical (OFO) and DC biased optical OFDM (DCO), and algorithms in similar operating conditions. [ABSTRACT FROM AUTHOR]

The paper considers recent trends in the development of electrically operated hydraulic drive. The main requirements to the dynamic characteristics of variable axial piston pumps with electric control and the need for search of ways of their improvement are specified. The investigation results show the dynamic characteristics of the process to control electro-hydraulic axial piston pump capacity at different parameters of pulse width modulation (PWM) signal. The regularity between PWM-signal frequency and the time of establishing the proper pump displacement was found. The paper stresses the need for more detailed study of this fact and its usage for the optimization of variable pump regulation speed in order to be applied in electro-hydraulic flow control systems. [ABSTRACT FROM AUTHOR]

In this paper the Selective Harmonic Elimination Pulse Width Modulation (SHE-PWM) technique with considering controllable DC link voltages is implemented in the cascaded multilevel inverter. The novelty of this work is the method of mathematical modelling of SHE-PWM with respect to variable voltage of DC links. With respect to variable voltage of DC links, the number of degrees of freedom are increased compared to ordinary SHE techniques with constant voltage of DC links. One of the issues in SHE-PWM technique is solution of nonlinear equations under various operating conditions of the converter. In the proposed formulation, the resulted nonlinear equations are solved only one time for entire reachable range of output voltage amplitude, which leads to considerable reduction of computational burden. Also, the THD of output voltage waveform remains constant at minimum value for different operating points. The theoretical results of proposed technique are verified by the simulation and scale-down experimental setup of a cascaded 7-level inverter. [ABSTRACT FROM AUTHOR]

A novel technique to control the speed of BLDC motor and to maintain the power quality fed directly from the grid using a single stage Direct Matrix Converter (DMC) instead of using back to back converters is presented in this paper. The main advantage of using the DMC is the reduction of switches at the converter stage to nine as compared to twelve in case of back to back converters and hence results in a reduction of losses. Also, the system becomes robust with the removal of the bulky dc-link storage capacitor and provides all silicon solution to the controller part of the motor. The use of SVM at the grid side of the converter gives an improved input power factor with low distortion. The indirect modulation method of matrix converter gives the flexibility to apply closed-loop hysteresis current control at the load side of the converter for efficient speed control of the motor. The simulation results verify the efficiency and effectiveness of the proposed technique carried out in MATLAB/Simulink platform. [ABSTRACT FROM AUTHOR]

Selective Harmonics Elimination Pulse width modulation (SHE PWM) presents an alternative modulation technique to operate medium voltage medium and high power converters as it reduces the switching losses. SHE PWM generates high-quality output waveform at the low switching frequency. Its application to multilevel converters furthers leads to improvement in output waveforms with lower switching losses, lesser dv/dt and lowers switching devices ratings. In this Paper SHE PWM for an asymmetrical cascaded H-bridge multilevel inverter under unequal DC voltage condition for fundamental and multiple switching cases are investigated. More harmonics can be eliminated by considering multiple switching's. The Solution of the Nonlinear transcendental SHE equation is obtained using an advanced derivative free numerical technique which. The method is simple in implementation with fast calculations per iteration as it avoids the evaluation of Jacobian and its matrix. Also the need for precise initial guess in the proximity of actual solution is not needed as an identity matrix of the size of designed variable serves the purpose. Different inequality in the dc voltages is taken to eliminate the lower order harmonics from the output. Only exact solutions for the switching angles which ensure the complete elimination of targeted harmonics are reported. Simulation and Hardware results are presented to confirm the validity of the proposed technique. • SHE PWM for an asymmetrical CHB MLI under unequal DC Sources for different switching cases are given. • The Solution of transcendental SHE equation is obtained using derivative free numerical technique. • Simple in implementation with fast calculations as it avoids the evaluation of Jacobian matrix. • The need for initial guess in the proximity of actual solution is not needed in the proposed technique. • Inequality in the dc voltages is considered to eliminate the lower order harmonics in output. [ABSTRACT FROM AUTHOR]

This paper presents the unique design and processing conditions of a micro-CAES device that generates, stores and delivers electrical energy with highly efficient total energy conversion. The micro-CAES installation is divided into six parts, where air, the energy carrier, is compressed, stored, heated and expanded in appropriate sections. We focus mainly on the post-preparation section, where the air mass flow is pulse heated and controlled by Pulse Width Modulation (PWM), and the expansion section, where multiple piston drives are used to achieve maximum energy conversion efficiency or the required amount of electricity to be fed into the grid. We discover that the controllability of expansion process performance is improved by exploiting the inertia of the following elements in multiple reciprocating engines: piston, piston rod, connecting rod, crank, and crankshaft, connected with air injection dynamics and pulse heating by Thermal Energy Storage (TES). Furthermore, we investigate the efficiency using our own zero-dimensional mathematical model illustrating the complex dynamics of air processing. The mathematical model was compared with experimental data for the single-drive air expander, showing qualitatively and quantitatively satisfying model reliability. Moreover, we performed a sensitivity analysis to determine the best number of reciprocating drives involved in the expansion section and the best operating conditions. The use of the PWM function of mass flow of air supplied the expander with an index of 0.5 together with pulsating air heating in the expander installation, including three- reciprocating drives, allows a maximum total energy conversion efficiency of 81%. The presented piston drive expander seems to be a promising solution for micro-CAES in residential and industrial applications, especially where additional low-temperature waste heat is available, and an intermittent control strategy is implemented. [Display omitted] • Original construction of the air expander includes multi-piston-drives. • The micro-CAES with air preheat and PWM control strategy ware implemented. • Obtained maximum efficiency of piston-drive micro-CAES is 81%. • Generated electrical power could be control with overall efficiency change up to 10%. [ABSTRACT FROM AUTHOR]

This paper presents the design of the coil power supply system which provides a pulsed current of ±16 kA for several coils within the DIII-D Tokamak. The coil power supply system consists of 6 power supply modules and a master module controller. Each power supply module would be designed to produce ±450 VDC and ±2.66 kA (nominal) in all 4 quadrants, and 12 times carrier phase shifting PWM (Pulse Width Modulation) technology was adopted to satisfy the fast response and low ripple content of the power supply system. Meanwhile, the mathematical model of the power supply system was established to analyze the dynamic relationship between the system input and output variables, the transfer function was optimized by compensation circuit to increase the stability of the system. At last, the simulation and theoretical analysis had been completed to verify the stability and fast response of the coil power supply system. [ABSTRACT FROM AUTHOR]

The dynamic false contour phenomenon of digital driving microdisplays affects the display quality seriously when displaying moving images. By analyzing the generation mechanism of dynamic false contour and considering the visual characteristics of the human eyes, this paper proposes a just noticeable distortion integral method to quantify the dynamic false contour level of different scan strategies. A series of experiments are designed to verify the reliability of the proposed evaluation method. Combining the linear pulse width modulation scan method and the subframe scan method, a centralized subframe scan method is proposed to alleviate the dynamic false contour phenomenon. The system verification platform is performed on a silicon-based OLED microdisplay with a resolution of 1280×1024. When the parameter K of centralized subframe scan method is not less than 4, the average Peak-Signal-to-Noise Ratio of image data set is above 35db, and the display effect is close to the original image. • The research field is digital driving silicon-based microdisplays. Aiming at the problem of the dynamic false contours, this paper proposes a novel evaluation method named Just Noticeable Distortion Integral Method (JNDIM). • Compared with existing evaluation methods, JNDIM evaluation results are more consistent with the subjective feelings of human eyes. • By analyzing the evaluation results, this paper proposes a centralized subframe scan method to alleviate DFC phenomenon. The image simulation results and actual displays effects have proved the effectiveness of the scan method. [ABSTRACT FROM AUTHOR]

Abstract: In order to improve the control performance of boost converter with large signal disturbance, a composite PWM control strategy for boost converter operating in continuous condition mode (CCM) was proposed in this paper. The parasitical loss of Boost converter was analyzed and a loss compensation strategy was adopted to design feed-forward tracker for converter. The composite PWM controller consisted of the tracker and PID controller. Simulation and experiment results validated the validity of the control strategy presented in this paper. [Copyright &y& Elsevier]

• Interaction between superconducting magnetic energy storage (SMES) components is discussed. • Integrated design method for SMES is proposed. • Conceptual design of SMES system applied in micro grid is carried out. • Dynamic operation characteristic of the designed SMES system is analyzed. Superconducting magnetic energy storage (SMES) is composed of three main components, which are superconducting magnet, power conditioning system (PCS), and system controller to fulfil the task of power exchange between the power system and SMES. In addition to the basic design of single component, the interaction between different components of SMES should be considered during the design process. Firstly, the dynamic power compensation has effect on the losses of SMES magnet, which should be considered in the magnet design. Secondly, the dynamic response characteristic of PCS influences the power response capability of SMES. Thirdly, the high frequency pulse width modulation (PWM) pulse voltage generated by the PCS and applied directly to the SMES magnet could induce insulation issues of the magnet, which is the key factor of ensuring the security of the magnet. Considering the mutual effect of SMES components comprehensively, an integrated design method for SMES system is proposed in this paper. To evaluate the effectiveness of the proposed integrated design method, a 3.8 MJ/1.2 MW SMES system applied in a micro grid is designed comprehensively. [ABSTRACT FROM AUTHOR]

Abstract Pulse width modulation (PWM) AC–AC converter is a power electronic device which has many applications, because it can control the load voltage and active power. This converter cuts the voltage wave form, so the output voltage will have harmonics. Since the fundamental component of output voltage influences the active power, assigning weighting factor to the optimization problem of harmonic reduction in the converter has been proposed in this paper. To solve the optimization problem a hybrid algorithm including biogeography-based optimization BBO and simulated annealing (SA) has been presented. This algorithm has the advantages of the two method simultaneously. Since many evolutionary optimization algorithms may not reach the global optimum solution, in order to develop the search process, a local search algorithm in an inner loop i.e. SA is applied to the obtained solution by main search algorithm i.e. BBO. In the other word, the second level optimization by SA is applied to the best answer of BBO in each iteration, to find the global extreme point. The proposed algorithm has been applied to some standard benchmark functions. After validation using these problems, the main problem which is a practical problem to minimize the harmonics for PWM AC–AC converter has been solved. Simulation results show the efficiency of proposed method by considering weighting factor to optimize a practical problem in power engineering area in order to harmonic reduction as well as improving fundamental voltage as an important issue. Highlights • Developing a new optimization algorithm including both global and local search. • Proposing weighting factors for harmonics reduction optimization problem for AC–AC converter. • Obtaining optimal switching pattern for AC–AC converter by minimizing harmonics as well as maximizing the fundamental component of voltage. • Implementation the main purpose of using an AC–AC converter means controlling active power. [ABSTRACT FROM AUTHOR]

Abstract: Thermally activated building systems (TABS) integrate the building structure as energy storage, and have proofed to be energy efficient and economic viable for the heating and cooling of buildings. Although TABS are increasingly used, in many cases control has remained an issue to be improved. In this paper, a method is outlined allowing for automated control of TABS in intermittent operation with pulse width modulation (PWM). This method represents one part of a TABS control solution with automatic switching between cooling and heating modes for variable comfort criteria which was published before. A first pulse width modulation control solution is derived based on a simple 1st order model of TABS. Then a second, even simpler solution is given that significantly reduces the tuning effort. Finally, the paper outlines a pulse width modulation control procedure and gives two application examples of the PWM control carried out in a laboratory test room. [Copyright &y& Elsevier]

Three-phase rectifier is typically realized by six power switches. However, this rectifier is fault sensitive in power switches. To enable continued controllable operation, the grid phase with fault rectifier leg can be connected to center tap of the dc-link capacitors, known as the four-switch three-phase rectifier (FSTPR), using hardware reconfiguration. However, the symmetry of three-phase currents and reliable operation of the FSTPR cannot be retained due to the offset of the two-capacitor voltages. This paper proposes a finite control set model predictive control (FCS-MPC) to obtain the balanced three-phase current with the offset of two-capacitor voltages suppressed. The PI-Controller-free FCS-MPC with a second-order Luenberger observer is adopted to improve the dynamic performance of FSTPR. The performance of the proposed control scheme is illustrated by extensive simulation and experimental results. The comparison with the conventional voltage-oriented-control, which is based on PI controller and pulse width modulation (PWM), is also presented to show the superiority of the proposed FCS-MPC. [ABSTRACT FROM AUTHOR]

Wind power generation is one of the most mature and most large-scale power-generating approaches in the new energy generation technology. With the development of large-capacity and long-distance offshore wind power, regarded as the main developing direction in the windy power systems in future, the application of voltage source converter based high-voltage direct current (VSC-HVDC) has gradually attracted the attention of circles. It also puts forward higher requirements for offshore wind farm HVDC Converter. The project for offshore wind farm HVDC is introduced and then the characteristics of three-level converter are discussed in this paper. After analyzing the strategy of three-level converter, an improved SVPWM modulation method is introduced, finally verified in the MATLAB/Simulink software platform. [ABSTRACT FROM AUTHOR]

To accommodate ocean-wave energy extraction in a wide operating range of sea-states, a nonlinear model predictive control (NMPC) methodology was applied to a lab-scale dual coaxial-cylinder wave-energy converter (WEC), coupled with a permanent-magnet linear generator (PMLG) as the power take-off (PTO). The paper focuses on the experimental implementation of the optimal damping control of the PMLG as guided by the NMPC process, which yielded intermediate values of damping subjected to prescribed damping capacity. This damping behavior was implemented electronically in the coupled PTO-WEC system by employing a solid-state relay (SSR) with pulse-width modulation (PWM) technique so as to mimic analog current flow. The effectiveness of the combination of SSR and PWM was demonstrated. Successful real-time lab-scale testing in regular and irregular waves was experimentally confirmed. Peak values of energy capture and a broadened bandwidth were favorably improved compared to those obtained using just constant, non-time-varying damping control. [ABSTRACT FROM AUTHOR]

Recent attention has focused on trapezoidal reference-based pulse width modulation (PWM) schemes in multilevel converters (MLCs) with easier implementation and better harmonic performance. Nevertheless, these studies utilize trapezoidal reference only for multi carrier PWM methods and details of FPGA implementation are not provided. This paper proposes a trapezoidal reference-based single carrier PWM (TSC-PWM) with its novel FPGA implementation. Design parameters of TSC-PWM is determined such that harmonic performance is maximized and architectural details of FPGA implementation of TSC-PWM are provided. Results reveal that TSC-PWM significantly reduces the resource utilization compared to other methods. Single-phase three-module cascaded H-bridge MLC (CHB-MLC) is established in both simulation and experimental platforms. Results indicate that the TSC-PWM provides better harmonic performance along with higher DC utilization ratio compared to other methods. Moreover, both half-wave and quarter-wave symmetries are ensured with TSC-PWM. • TSC-PWM is proposed for CHB-MLCs to improve output waveform quality. • Both half-wave and quarter-wave symmetries are ensured with proposed gate-decoding. • FPGA implementation of TSC-PWM is given with corresponding behavioral models. • Superior behavior of TSC-PWM is given in terms of resource utilization within FPGA. [ABSTRACT FROM AUTHOR]

It is well known that unmodeled dynamics and uncertainties can deteriorate the performance of classical controllers. To resolve this problem, there is growing popularity in using the capabilities of Artificial Intelligence (AI) algorithms, especially Reinforcement Learning (RL) in power systems, because it is a promising adaptive model-free control strategy that can take optimal decisions in unknown environments (dynamics). For this reason, in this paper, two state-of-the-art RL agents, namely Deep Q-Network (DQN) and Deep Deterministic Policy Gradient (DDPG), are used for voltage control of a DC–DC buck converter, and their performance is reported compared with other classical controllers such as Model Predictive Control (MPC) and Sliding Mode Control (SMC). The DQN agent directly controls the power switches of converters. In other words, based on the current condition of the converter, the agent decides whether or not to close the power switches. On the other hand, the DDPG agent and the other mentioned traditional controllers manipulate the duty cycle of a Pulse Width Modulation (PWM) signal to adjust the output voltage of the converter at desired setpoints. According to experimental results, both RL agents outperform the classical controllers in terms of transient response error and robustness against uncertainties. Also, with regard to computational costs and learning rate among RL-based controllers, the DQN agent can learn more from a single interaction with fewer computations because of its simpler structure and direct control of the switches of the converter. Additionally, one of the most important advantages of the RL-based controllers is that they can be applied to various configurations of DC–DC​ converters like buck, boost, and buck-boost converters, provided that it is retrained for the new environments. Finally, the number of transitions in the semiconductor switches of the converter reduces appreciably by using the DQN agent, which certainly prolongs their longevity. [ABSTRACT FROM AUTHOR]

The control of inverters has degrees of freedom that open the way to improve the output harmonic spectrum. Numerous works dealing with this objective have been proposed in the literature, particularly within the definition of switching angles. Among them, the well-known PWM techniques such as Quarter Wave Symmetry (QWS), Half Wave Symmetry (HWS), and Full Wave Symmetry (FWS) are based on Optimal Pulse Patterns (OPP) computation using symmetries angles constraints. In this paper to improve the harmonic quality, the symmetry angles constraints are not considered leading to a new OPP method: Phases Symmetry Relaxation (PSR). To highlight the interest in the proposed PSR method, an evaluation in terms of Weighted Total Harmonic Distortion (WTHD) is performed. Simulation and experimental tests are conducted in comparison with the well known FWS, highlighting the interest in the proposed PSR strategy. • Optimal pulse pattern pulse width modulation. • Phase symmetry relaxation. • Voltage source two levels inverter. • Optimization based on Sequential quadratic programming. • Weighted Total Harmonic distortion. [ABSTRACT FROM AUTHOR]

Reduction of total harmonic distortion (THD) in fundamental output voltage and current in wind energy conversion systems (WECS) is the primary objective of this research paper. Reduction of distortion effects help in regulating the output voltage to a great extent. The paper suggests a novel perturb-and-observe (P&O)-based maximum power point tracking (MPPT) for the front-end single-ended primary-inductor converter (SEPIC), in an effort to exploit the maximum power from the available wind source. It further involves a hybrid space vector pulse width modulation (HSVPWM) scheme for generating the pulses to switches in the voltage source inverter (VSI), to improve the quality of the output AC power. It examines the performance through simulation in the MATLAB platform over a range of operating loads to illustrate the benefits of the scheme, in terms of a lower THD. The experimental results obtained from a prototype serve to validate the simulated response and claim its suitability for use in real world applications. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of controlled periodic illumination by visible LEDs on the performances of a flat-plate photocatalytic reactor for wastewater treatment. Different LED dimming techniques are investigated and compared, including the classical Pulse Width Modulation (PWM) technique and a novel proposed Variable-Peak PWM technique. A modulation of dimming duty-cycle is adopted as well, which allows to control the light irradiation in a new way with respect to previously used methods. Experimental results highlight the improvement in the photocatalytic degradation process obtained by using the proposed modulation techniques. [ABSTRACT FROM AUTHOR]

Nowadays, an approach for coordinating large numbers of autonomous robots, which is called as swarm robots, has becoming an important issue in robotics research. In swarm robot systems, each robot must cooperate with other robots in order to perform a given task. The main obstacle in swarm robot research is the cost of making robots. Building one robot with limited capabilities commonly has to spend substantial amount of money and certainly making robots for intelligent systems research need much more investment. In this paper, we would like to present the development of affordable mobile robot, but also having powerful capabilities and intelligence. The mobile robot is specifically designed and made to be used as a stand-alone or in swarm robot systems. It is essential that the mobile robot has learning ability to adapt the dynamic environments. Furthermore, for swarm robot systems, each mobile robot must be able to communicate with other robots in order to coordinate each other. In our research, we used differential drive model for mobile robot locomotion and then apply the model through Android smartphone based controller. The mobile robot was constructed by using two actuators on the right and left side, and one castor wheel which has no steering system and can move freely. The differences velocity between left and right actuators determines the direction and final position of the mobile robot. The angular velocity of two main actuators is set by Pulse Width Modulation (PWM) parameter in IOIO board microcontroller. In our experiment, we showed that the capability of our robot in performing several movement tasks. We are sure that Android based robotic platforms are ideal candidates for affordable robotics for swarm robot system research. [ABSTRACT FROM AUTHOR]

The employments of Multilevel DC Link Inverters offer dependable points of interest attributable to the expansion in the highest levels at the yield output voltage and are broadly acknowledged for industrial applications. The execution of these bores on high when contrasted with the routine conventional two-level inverters because of their drawbacks. Be that as it may, the expanded number of devices, complex PWM control, and voltage-adjusting issue are a portion of the hindrances. This paper goes for presenting another topology, which can perilously decrease the switch number by introducing a module called polarity generation module. This topology gives a DC voltage fit as a fiddle of a staircase which approximates the corrected state of a directed sinusoidal wave to the extension inverter, which thusly interchanges the extremity to deliver an AC voltage with low THD and switching loss. The topology is tested by adopting a choice of control techniques and enhanced execution of the proposed inverter contrasted with the overarching topologies. The FPGA has been selected to verify the proposed inverter with modulating technique due its advanced futures and computing facility. For validation, simulation and experimental results are offered. [ABSTRACT FROM AUTHOR]

The grid connected inverters are increasingly used nowadays in distributed generation and smart grid. But the main challenge in grid connected systems is their compatibility with grid utility and also to maintain the harmonic contents of output current. To overcome these challenges, different current control techniques are used so far. This paper presents a multilevel inverter for single phase grid connected system. The switching of the inverter is based on Selective Harmonic Elimination PWM method where switching angles are calculated by Newton Raphson (NR) method. The main objective is to inject power in to the grid, to reduce the harmonics of grid current and to synchronise the grid frequency with inverter frequency. The results are verified through MATLAB/Simulink and experimentally using low cost microcontroller. [ABSTRACT FROM AUTHOR]

This research paper describes the Particle Swarm Optimization algorithm real with Selective Harmonic Elimination-Pulse Width Modulation (SHEPWM) method for harmonic minimization of Cascaded H-Bridge Multi-Level Inverter. In SHEPWM method- PSO algorithm is capable of determining the required switching angles to eliminate desired value of harmonics. The value of harmonics may reach up to the 11th order from the inverter output voltage waveform while keeping the magnitude of the funda- mental harmonics at a certain value. Hence, the proposed method does capable of eliminating a great number of specific harmonics and the output voltage results in a minimum Total Harmonic Distortion value. The simulation results shows that the PSO algorithm successfully attains the global solution faster than other algorithms. [ABSTRACT FROM AUTHOR]

This paper introduces a new single phase hybrid multilevel inverter with a minimum number of switches for a Photovoltaic application. A Perturb and observe maximum power point tracking is used for tracking maximum power from solar panel. A boost converter is used for boosting the generated voltage because proposed inverter operates at the asymmetric condition. The proposed inverter is the combination of reduced switch topology and cascaded H-Bridge topology. Two types of Phase Disposition carrier arrangement with sinusoidal reference is utilized for generating the gating pulses for proposed inverter. It generates a 15-level output voltage with 8.12% of total harmonic distortion. [ABSTRACT FROM AUTHOR]

A quasi-linear Cascaded H-Bridge multilevel inverter is introduced for solar application. In this paper, a separate solar panel with boost converter is placed instead of DC sources in the proposed configuration. The Incremental and Conductance maximum power point algorithm method is implemented for tracking maximum power with a fast response. Sinusoidal reference with triangular carriers is utilized in pulse width modulation for generating the switching pulses for proposed inverter. The proposed inverter can generate a 19-level output voltage with total harmonic distortion of 6.10% which is simulated using MATLAB/Simulink. Cost analysis of power switches is discussed. [ABSTRACT FROM AUTHOR]

This paper analyzes the stability and switching controllability properties of a single-phase PWM rectifier and its relationship with parameter uncertainty. Based on this analysis, a switching control strategy is proposed that has as objectives (i) to achieve input current tracking and low current THD (total harmonic distortion) as well as (ii) to regulate the output voltage in spite of perturbations. The proposed control does not require a PWM generation step design. Numerical simulations and experimental tests in a 1 kW prototype demonstrate the effectiveness of the proposed controller and illustrate the limits of system's controllability. [ABSTRACT FROM AUTHOR]

Pulse Width Modulation (PWM) is nowadays the most used method for controlling a servo-motor. When combining PWM with motors and long cables, such as the ones that will be found at ITER, the standing waves originated are potentially very harmful for both actuator’s life span and control performance. Several methods have been investigated to cope with this issue, such as the use of chokes, filters, snubbers or active modification of the PWM signal. Of all possible locations where an electrical servo-motor could be used at ITER, the most critical scenario arises when mounting a low power motor, with a low gear ratio, in a dexterous manipulator for bilateral teleoperation. In those circumstances cable lengths of more than 150 m are expected between manipulator and control cubicle. In this paper, the effects of long cables in the system safety are analysed on a custom made test bench. The most common solutions to cope with this issue are analysed and a commercial LC filter is selected for further experimentation. An extensive set of experiments are carried out in order to validate the proposed solution for being used on remote handling equipment at ITER. [ABSTRACT FROM AUTHOR]

The basic idea of proposed system is to utilize the renewable resources by digital PWM control of Bi-directional DC – DC converter. Usually PWM pulse is being generated through a digital system such as microcontroller or Digital signal controller. In stand – alone application these controllers increases the cost but XILINX FPGA based PWM generation reduces the cost. XILINX FPGA is programmable device developed by XILINX which is being considered as an efficient device for rapid prototyping and also to perform concurrent operations. In this paper two PWM signals was generated to control the switch duty cycles in Bi-directional DC-DC Converter. In addition to that different modes of operation of the proposed circuit are verified by MATLAB / SIMULINK. [ABSTRACT FROM AUTHOR]

• The power supply circuit is simplified as a second-order LCR model. • The method of optimizing the bus output voltage is possible. • A resistive branch (BSRB) is designed with particular PWM control. • The testing figures are given and the results fulfill the experimental request. This paper proposes a novel bus regulating strategy that improves the dynamic response of active coil current in order to providing dynamic resonant magnetic perturbation (DRMP). The DRMP power supply, adopting the topology of a thyristor rectifier linked with a resonant inverter, part of the circuit comprising a bus filter, resonant inverter and load, can be simplified as a second-order model when the bus parameters are analyzed. On this basis, a controlled resistive branch with particular open-loop pulse width modulation (PWM) control is designed, installed and experimentally shown to greatly reduce the rising time and overshoot percentage of coil current. Moreover, this strategy has advantages in terms of compactness and economics but the power consumption of the new branch should be considered. [ABSTRACT FROM AUTHOR]

In this paper, a Zero-Voltage-Transition (ZVT)–Zero-Current Transition (ZCT) Pulse-width Modulated (PWM) synchronous buck converter (SBC), with a simple passive auxiliary circuit is proposed, which reduces the stresses and improves the efficiency by pacifying the conduction losses compared to a traditional PWM converter, typically suitable for photovoltaic applications. The important design feature of ZVT–ZCT PWM SBC converters is placement of resonant components that mollifies the conduction losses. Due to the ZVT–ZCT, the resonant components with low values are used, thereby resulting in the increase of switching frequency. The ZVT–ZCT operation of the proposed converter is presented through theoretical analysis. The characteristics of the proposed converter are verified with the simulation in the PSIM co-simulated with MATLAB/SIMULINK environment and implemented experimentally. [ABSTRACT FROM AUTHOR]

The fundamental issue in the area of remote handling and robotics is the reliability of power electronics system. Detailed analysis and simulation studies are very much relevant as the prebuilt drive solutions are costly and performance of drive system depends upon the reliability of control algorithms incorporated in the drive. The modulation techniques also play an important role in the dc voltage utilization. This paper presents a comparative simulation study for the analysis of complete BLAC drive using PI controller using two types of modulation techniques namely Sinusoidal Pulse Width (SPWM) and Space Vector Modulation (SVPWM). [ABSTRACT FROM AUTHOR]

This paper proposes a multi-objective cost function-based finite control set sliding mode control (SMC) strategy for single-phase split-source inverters (SSI). The single-phase SSI is a fourth order system in which the control of four (inductor current and capacitor voltage in DC-side and inductor current and capacitor voltage in AC-side) variables is essential. Moreover, a complex modulation scheme is needed to generate the pulse width modulation signals for the switching devices of SSI. The proposed control strategy is based on a multi-objective cost function finite control set SMC approach. As a consequence of using multi-objective cost function, the control of DC- and AC-side variables can be accomplished simultaneously. Moreover, the use of finite control set eliminates the modulation scheme requirement. Also, the use of multi-objective cost function together with the finite control set simplifies the controller design as the hysteresis band and its tuning requirement are not needed. The robustness of proposed control strategy against parameter variations is investigated and compared with that of the hysteresis band-based SMC and conventional MPC methods. Experimental results are presented to verify the effectiveness of the proposed control strategy. • Sliding surface functions in sliding mode control are combined in a multi-objective cost function. • The proposed multi-objective formulation offers an easy design process for controlling multiple variables. • The proposed multi-objective cost function finite control set SMC method can be implemented without hysteresis band. • Finite control set concept is integrated with sliding mode control theory for eliminating the complicated modulation requirements. [ABSTRACT FROM AUTHOR]

This paper proposes a new fusion of digital controls for Photovoltaic (PV) fed DC-DC-AC inverter. The proposed PV-DC-DC-AC design includes the control for voltage regulation of the closed-loop buck converter by combining two duty cycles of Digital Proportional Integral-Digital Pulse Width Modulation (DPI-DPWM) and Maximum Power Point Tracking (MPPT) for one of the DC supply (9V) of the 81-level Trinary Cascaded Hybrid Multi-Level Inverter (TCHMLI). The control for the DC-DC converter is provided by the DPWM techniques, and the TCHMLI requires 16 switching patterns that are to be controlled by the Half Height-Switching Angle Method (HH-SAM). The real-time implementation for the proposed fusion control is verified with a resolution of 28 and 210 bits and validated using Field Programmable Gate Array (FPGA). The hardware result of the proposed photovoltaic inverter is compared with the existing methods and proves to be feasible. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, modeling and PWM based control of an electro-pneumatic system, including the four 2–2 valves and a double acting cylinder are studied. Dynamic nonlinear behavior of the system, containing fast switching solenoid valves and a pneumatic cylinder, as well as electrical, magnetic, mechanical, and fluid subsystems are modeled. A DC–DC power converter is employed to improve solenoid valve performance and suppress system delay. Among different position control methods, a proportional integrator derivative (PID) controller and fuzzy logic controller (FLC) are evaluated. An experimental setup, using an AVR microcontroller is implemented. Simulation and experimental results verify the effectiveness of the proposed control strategies. [Copyright &y& Elsevier]