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A new configuration of three-phase Wye Packed U-cells (Y-PUC) with a single DC source is proposed in this paper. In fact, this configuration represents a single DC source modular three-phase PUC converter. The DC source on PUC topology is replaced by a flying capacitor to obtain a suitable submodule. Moreover, the modularity of the Y-PUC configuration makes it an appropriate alternative for MMC applications. Furthermore, the proposed structure is an advantageous configuration for high voltage applications such as high voltage direct current (HVDC) transmission lines with the capability of DC fault handling. All PUC topologies such as PUC5, PUC7, PUC9, PUC15 can be replaced in the modules of this proposed single-phase and three-phase configuration to multiply the load voltage levels for improving the output waveform. Active voltage balancing technique through carrier-based modulation is applied. System modeling and operating sequences are developed. Simulation and experimental results are presented and discussed to validate the performance of the proposed structure.

Cascaded H‐bridge inverter (CHBI) is widely used in the industry application for its outstanding features. However, CHBI needs a large number of isolated DC sources. If some of the DC sources are out of work, the DC voltage cannot maintain the desired value and even decreases to zero, thus degrading the quality of the output voltage of the CHBI. Thus, a soft‐switching modulation strategy based on the carrier phase shift SPWM is proposed in this paper to cope with the DC source failure. The strategy is proposed to achieve two goals: 1) one is to adjust the DC voltage of faulty cells back to the normal; 2) the other one is to make the pulse width modulation (PWM) pulses of each cell change without cell voltage level‐skip. The correction and efficiency are verified by a prototype of three‐cell CHBI built in the laboratory.

This paper proposes a diamond‐shaped high step‐up switched‐capacitor based basic multilevel inverter topology. The basic switched‐capacitor (SC) stage consists of 2 active switches, 2 diodes, and 2 capacitors. Using a single DC source with the unfolding circuit (10 switches, 5 capacitors, and 5 diodes) results in the production of 17 voltage‐steps at the output with the gain of up to 8 times of the input voltage. By extending the diamond‐shaped switched‐capacitor stages, higher voltage levels and voltage gains can be possible. The suggested topology employs two half‐bridges (instead of a full‐bridge) to produce positive, zero, and negative steps, which reduces the Voltage Stress (VS) on two output switches and consequently reduces Total Voltage Stress (TVS). In addition, the natural voltage balancing of capacitors eliminates the need to an additional control circuitry and consequently reduces the total converter size, complexity, and cost. In addition, modularity, scalability, low voltage ripple on capacitors, low total voltage stress, high power quality, and capability of supplying low/medium power factor (R‐L) loads are some of the merits of the proposed topology. The low Cost Function (CF) obtained in the comparison section as well as experimental results verifies the advantages of the proposed topology.

This paper is dealing about Switched Capacitor Multi-Level Inverter (SCMLI) circuit which is controlled by triangular multicarrier Sinewave Pulse Width Modulation (SPWM) technique. The proposed SCMLI is powered from asymmetric DC source configuration to obtain multi-level output voltage by applying switching pulse to the main circuit from control circuit for switching operation. Fourteen switches and four capacitors are employing to do the proposed inversion operation in an effective way. Switching capacitors can perform boost operation to enhance voltage from the source level to the required level. Input DC from the asymmetric sources is converted to AC voltage for the application of consumers. This proposed conversion system is applicable for mainly in industrial and renewable energy-based energy conversion system because it can carry high output voltages. This proposed method gives about more efficiency. Also reduces switching losses in lower value, low conduction losses and capacitor ripple losses. The simulation model is analyzed in MATLAB/SIMULINK platform and the same validated in hardware results. The developed SCMLI structure is witness over other topologies for the power inversion process in the multi-level.

In this study, a seventeen-level diode-assisted hybrid multilevel inverter (DAH-MLI) is proposed. The DAH-MLI eliminates any external voltage balancing and/or sensing circuit by inherently balancing the capacitors using a series–parallel combination of capacitors and DC voltage source. The DAH-MLI uses only one DC source and a reduced number of active and passive elements to generate a multilevel staircase output voltage. The proposed circuit can also be extended to obtain the higher number of voltage levels than seventeen by the addition of a single module comprising of two diodes, one switch, and one capacitor. The proposed DAH-MLI can boost the input voltage and possesses reverse current carrying capability. The proposed DAH-MLI is compared with several existing topologies on the basis of the number of active and passive components, total standing voltage, and peak inverse voltage to verify its advantages. A cost function is used in this study to compare the proposed DAH-MLI and other existing typologies. Finally, the performance of the proposed DAH-MLI is validated through a 570 W experimental prototype.

Split-source inverter (SSI) is a topology developed for flexibly stepping up and down its ac output voltage using only a standard inverter bridge. However, when configured as a single-phase inverter, it is still burdened by common second-order ripples. This study, therefore, proposes a modified SSI (MSSI) that can perform dual power decoupling. Unlike existing schemes, dual power decoupling makes use of both dc- and ac-side capacitors for diverting second-order ripples away from the dc source, which may be solar or other types of sources that do not work well with sizable ripples. Dual power decoupling, however, requires careful topological changes, before its effective realisation can be achieved with only a standard inverter bridge and a very small overall capacitance. Design of this capacitance and its comparison with passive decoupling have then been analysed, before testing the MSSI in experiments. Results obtained have verified the MSSI as an enhanced single-phase inverter with both buck and boost abilities while using no extra switches.

Used cellphone charger components are used as an alternative to create emergency lights which can later be used by the community when the power source from the grid goes out. The purpose of this study is to utilize the components of a used cellphone charger which is the Joule Thief transformer to create 1.5 Vdc to 220V ac mini inverter. The method used in this study is the experimental method, which starts from the selection of tools and materials to measuring the outputs. The results showed that the design of a 1.5 Vdc to 220 Vac mini inverter with Joule Thief can turn on 220 Vac LED lights without drivers. Tests were carried out on 1 watt driverless 220 Vac LED lights. Experiments were carried out to test the dc source durability in the form of 1.5 Vac battery. From testing for LED lights 1, 2 and 3 it turns out that the current and voltage gradually decreased due to the use of LED lights. The resources quickly ran out when the inverter was used for 3 LED lights. The design of tools can be used as an emergency light when the source of electricity from the grid.

The ongoing global pandemic due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is in the crucial stage. The vaccine is still at the developing stage. Currently, the only way to check the spreading of this virus is self-isolation. It is reported that a good number of health workers are infected while treating patients suffering from COVID 19. Therefore, an effort is made to develop a system that can enhance safety and check unwanted viruses. Although the complete specification of the SARS-CoV-2 is yet to be evaluated, the present work considers the characteristic of SARS-CoV-1, which closely relates to that of SARS-CoV-2. The proteins are one of the most important structural and functional molecules of the virus; therefore, few properties of a protein are considered. In this work, we propose a sanitization procedure of the personal protective equipment (PPE), such as gloves and masks, before and after the use, by employing high voltage charge generator (30 kV) from a very low DC source of 5 V to eliminate the virus from the surface of PPE. The positive output is connected to a metallic surface coated with carbon nanotubes (CNT) or a metallic surface ablated using lithography to achieve desired nano-grooves of 200 nm. At the tip of these nano-grooves, a very high electric field is generated which readily ionises the air in the vicinity of the tip. The high electric field alters the induced dipole of the protein of the virus, causing permanent damage in terms of electroporation. Further positive salt ions diffuse into the protein of the viruses, causing it inactive and disintegrate.

In this letter, a novel damped AC (DAC) generator is proposed and implemented, whose working principle is based on the seamless combination of the high voltage (HV) DC source and the HV solid switch by replacing the diodes in the DC voltage multiplier (VM) with controllable insulated gate bipolar translators (IGBTs). Both laboratory tests on a lumped capacitor and field tests on a 10 kV MV cable were performed to prove the feasibility of the proposed techniques.

A major disadvantage of two-stage topologies of switched capacitors based multilevel inverters is the use of H-bridge switches which endure high peak-inverse-voltage (PIV). In such topologies, the H-bridge stage is preceded by a level-generation stage which synthesises unipolar voltage levels. In this work, a bi-polar module is proposed which can synthesise nine levels at the AC terminals with a single DC input. The proposed module uses power switches with PIV equal to that of the input DC source. Use of switched capacitors in each of the proposed module enables a voltage gain of two. Such bi-polar voltage-doubler modules can be easily connected in a cascaded fashion to increase the number of levels, without involving H-bridge switches. Working modes of the module ensure that the capacitors are self-balanced. A complete analysis of the proposed module is presented. Also, experimental results are presented for validation. In addition, a comparison with other topologies has been presented.

This paper presents a new six-level flying capacitor based (FC-based) multilevel converter with one dc source and the capability of operating in all power factors and modulation indexes. Multilevel converters with one dc voltage source are attractive in many applications as they do not need rather expensive and bulky multiwinding input transformer connection at the dc side. On the other hand, not all classic multilevel converters with one dc source can produce any desirable number of output voltage levels at all power factors and/or modulation indexes. In this paper, a hybrid structure is proposed in which six voltage levels can be realized at the ac terminals. The modulation technique and the control strategy for the FC voltage balancing are presented. To show the advantages of the proposed converter, different performance criteria, such as switch count and rating, the size of capacitors, switching frequency, and power losses, are compared with other existing six-level topologies. The results indicate that the proposed structure is superior to other six-level converters from different standpoints. Simulation results are used to further evaluate the performance of the proposed converter. A laboratory-type experimental setup is used to validate the theoretical results.

In this paper a novel multilevel boost DC to DC converter with H-Bridge inverter circuit for single DC source is proposed. The proposed scheme has two stages: the first one is a multilevel boost converter which gives a multilevel dc output for a single dc source and the second level is a H-Bridge converter which converts multilevel DC to multilevel AC at required frequency. This DC-DC converter not only reduces the DC source but also reduces the switches, diodes and capacitors. This leads to decrease of the amount and the inverter space installation in order to increase the required output voltage by increasing the number of capacitors and diodes in the DC to DC converter. Comparison between the number of power switches for the suggested topology and other topologies in the recent literature is presented. Simulation results are conveyed through MatLAB/Simulink domain and the working of the suggested converter is realized.

Multilevel inverters (MLIs) are an imperative solution for high power and high voltage applications. The MLIs can be classified into two categories such as symmetric and asymmetric. The asymmetric type MLIs has large number of output voltage steps with less number of input DC voltage sources and switching devices. In this paper, a single phase asymmetric (trinary sequence DC source) Cascaded H-Bridge MLI has been developed using unipolar PWM control schemes. The topology can produce 27-level output voltage with the help of 12 switches and 3 DC sources. It has been examined with a diverse combination of multicarrier unipolar PWM control. The PWM control includes Phase Disposition (PDPWM), Alternative Opposition Disposition (APODPWM), Carrier overlapping (COPWM), and Variable Frequency (VFPWM). The harmonic content of output voltage for each technique has been observed with different modulation indices. The demonstration of proposed topology for generating 27-level output voltage has been tested through simulation in MATLAB-SIMULINK and verified with laboratory-based experimental setup. From the results, it is evident that the APODPWM offers quality output voltage with relatively low harmonic distortion. Also, it has been observed that COPWM performance is superior since it delivers relatively higher fundamental RMS output voltage.

U ovom se radu opisuje trofazni asinhroni motor pogonjen široko usmjerenim sustavom. Tako je za postavljanje sustava potrebno primijeniti matematički model pretvarača (konvertera), modulaciju širine sinusnog impulsa za trofazni izmjenjivač i matematički model trofaznog asinhronog motora. Nakon postavljanja takvog sustava, fokusiraju se PID i regulatori neizrazite logike kako bi se dobili zadovoljavajući rezultati, a to su kratko vrijeme smirivanja brzine rotora, malo harmonijsko i kratko vrijeme smirivanja višefazne struje. Kreirani matematički modeli primijenjeni su na MATLAB Simulinku. Napon istosmjerne struje primijenjen je na ulazu pretvarača. Taj napon je predstavljen obnovljivim izvorom energije koji može biti solarna energija. Napon istosmjerne struje je niži od vršne izmjenične struje. Napon izmjenične struje postiže se iz izlaza izmjenjivača za pogon indukcijskog motora. Najprije se pogone rezistivni (R) i induktivni (L) potrošači. Zatim se pogoni trofazni asinhroni motor (ASM) s istosmjernom strujom niskog napona. Nakon toga, daju se simulacijski rezultati kako bi se pokazao rad i učinkovitost predloženog sustava., In this study, a three-phase asynchronous motor driven by a broad-based system is described. So, mathematical model of converter, sinus pulse width modulation for the three phase inverter, and mathematical model of three-phase asynchronous motor have to be utilized in order to establish the system. After creating such a system, Fuzzy Logic and PID controllers are focused in order to get satisfactory results which are short settling time of rotor speed, low harmonic and short settling time of high phase current. Created mathematical models are run at the MATLAB Simulink. Direct voltage is applied to converter input. This voltage is represented by a renewable energy source that could be obtained from solar energy source. The direct voltage is lower than the peak of the alternating voltage. The alternating voltage is obtained from output of the inverter to drive the induction motor. Firstly, resistive (R) and inductive (L) loads are driven. Secondly, three-phase asynchronous motor (ASM) is driven with the low direct voltage. After that, simulation results are given in order to demonstrate performance and effectiveness of the proposed system.

This study introduces a new single phase nine-level inverter using two capacitors and a single DC source. Voltage imbalances in the capacitors are eliminated using two control algorithms namely charging algorithm and discharging algorithm. The charging algorithm is used to change the inverter switching states when the measured voltage across the capacitors is less than the prescribed value. Alternatively, if the voltage across the capacitors is greater than the set value, the discharging algorithm determines the switching pattern of the inverter switches. The proposed voltage balancing algorithm is very simple to implement and makes the proposed inverter attractive for industrial applications. An extensive comparison of the proposed inverter is made against other topologies proposed in the literature in terms of the components used. The proposed inverter is tested in both standalone and grid connected modes. The proposed inverter is simulated and implemented as a prototype in the laboratory. Experimental results obtained from the prototype confirm the high-quality transient performance of the proposed inverter in terms of its dc capacitor voltage balancing capability.

This paper presents a nine-level transformer-based inverter requiring only eight switches. The envisaged structure consists of two standard H-bridges fed from a single dc source. Besides, a single-phase transformer is employed to aid the process of intermediate voltage level generation. An ad-hoc pulsewidth modulation scheme based on boolean logic form equations is developed to derive the gating pulses. An effortless extension of the proposed inverter to a higher number of voltage levels is also achieved by generalizing the switching functions. Furthermore, the superior performance of the proposed topology is demonstrated through a comprehensive cost-based analysis. Finally, the validation of the proposed topology is accomplished through experiments on a down-scale prototype, and the measurement results are included.

In this work, dry carbon/salt adhesive (CSA) electrodes are found to be suitable for collecting electrodermal activity (EDA) signals. Silver/silver chloride (Ag/AgCl) electrodes have been considered as a reliable media to obtain EDA signals. However, mainly the cost and the need for a hydrogel layer make it difficult to disseminate the practice of using EDA signals in practical applications. A mixture of carbon salt and adhesive has shown to be suitable for collecting bioelectric signals (FLEXcon’s Patent #8,673,184). With the objective of testing how these electrodes compare for collecting EDA signals, AC and DC source devices were employed. Sixteen subjects underwent electric shocks and tonic emotional and cognitive stress. No significant differences were found in amplitude, onset-to-peak time and onset time between CSA and Ag/AgCl electrodes. Frequency-domain index, EDASympn, was not found to be different between the two electrode types. The time-varying spectral index was different between Ag/AgCl and EDA electrodes for DC devices, not for the AC devices. Ag/AgCl electrodes often polarized impeding the collection of EDA signals, suggesting that CSA electrodes provide better fidelity EDA measures. We conclude that CSA electrodes are a suitable surrogate of Ag/AgCl electrodes for collecting EDA signals.

Distributed Generation Sources are becoming an inseparable part of modern electrical grids. Finding the control strategies which can help them to be as much as possibly beneficial for the grid has been a big concern among the researchers. In this work, a PQ controller for connecting A DC source simulates the effect of a Distributed Generation to the grid based on the decoupling of Active and Reactive powers has been proposed. The Simulation results which have been in the MATLAB/Simulink environment show the effectiveness of this control technique for injecting the defined value of active and reactive power to the grid.

An approach is presented to predict fatigue life and energy dissipation based on the measurement of the electrical power consumption of an external heat source. In this method, the steady-state temperature profile of a specimen experiencing cyclic fatigue test is reproduced simply by externally heating the specimen with an electric coil with a DC source. The results show a direct relationship between the electric power consumption of heating coils and the fatigue plastic energy dissipation. This relationship is used as a tool to predict fatigue life.

The global use of renewable energy resources has led to the design and development of high performance, efficient, controllable, and cheap multilevel inverters, which act as a solution to the numerous power deficiencies. However, in terms of control, these multilevel inverters are often associated with DC sources and complexity. Therefore, this research designed a single-phase five-level inverter using a DC source, with a novel sinusoidal pulse-width-modulated (SPWM) control scheme. The system consists of a Flying Capacitor DC-DC Converter and H-Bridge Inverter (FCDCDC-HBI). A single absolute reference signal and the phase-shifted triangular carrier were used to generate SPWM to enhance the capacitor voltage balance. The designed inverter is capable of producing five levels of output voltage levels, namely Vi, Vi/2, 0, −Vi/2, and −Vi from a DC supply, thereby reducing the overall cost and complexity of the SPWM system. This research also produced a detailed operation principle of the proposed system, which was verified through simulation and implemented using a prototype. Finally, hardware implementation results are presented to check the performance of the inverter.

This paper presents a proposal of a new control method of the switched reluctance motor (SRM) in the low-speed range. The proposed method limits the maximum value of SRM drive supply current. The application of this method results also in improvement of the drive efficiency compared to the classical current control method, so it can be applied to control switched reluctance motors designed to the electric vehicles drive. The method may be effective especially in congested traffic. Nowadays, the urban traffic is characterized by frequent occurrence of traffic jams in which cars move at low speeds. The sources of supply for electric vehicles are mainly electrochemical batteries. Reduction of the maximum value of supply current allows to extend the service life of batteries and improvement of the drive efficiency extends the vehicle range.

In this research, a pv panel built from previous work will be used as a DC source for voltage cancellation inverter with help of PSPICE program. PV panel model defined as a hierarchical block in PSPICE library so, it called directly from PSPICE library as a special source and used it for most PV systems applications. A designed voltage cancellation inverter will be connected with this hierarchical block to simulate it in PSPICE. All results obtained from this simulation will be compared with experimental results. The voltage cancellation inverter will convert the dc input voltage to an approximate 130V 50Hz modified square signal.

The present study analyzed the characteristics of switching overvoltage, and discussed in detail the main influencing factors and worst-case conditions of switching overvoltage in the ${\pm} $ 1100-kV ultra-high-voltage direct-current (UHVDC) converter station. The results showed that ac bus overvoltage was produced by oscillation, and would not be a threat to the equipment in the converter station. The results also showed there were two cases for overvoltage on related valves. In the first case, the valve overvoltage was on converter valves in the upper three-pulse group of the 12-pulse converter, and was caused by the voltage difference between the dc line and ac bus at the valve side under a specific fault. In the second case, the overvoltage was on other valves, and was caused by a phase-to-phase switching surge that penetrated into the valve hall. Other results were that overvoltage on the dc bus was mainly caused by the full reflection of the wave, and overvoltage on the neutral bus was caused by high-voltage sources, such as the dc source creating stress on the neutral bus under specific faults, or the freewheeling current of the metal return line and the smoothing reactors.

In this paper, a novel cascaded transformer multilevel inverter is proposed. The number of the switching devices is reduced in the proposed topology. This topology comprises of a DC source, several single phase low-frequency transformers, two main power switches and some bidirectional switching devices. In this topology, only one bidirectional switch is employed for each transformer. However, in conventional cascaded transformer multilevel inverter, four switching devices are required for each transformer. Therefore, more output voltage levels can be obtained using fewer switching components. Reduction in the number of switching devices which also means reduction in the number of gate drivers results in smaller size and low implementation cost. Switching power losses are also reduced in this topology. Selective harmonic elimination (SHE) technique is applied to the proposed inverter to obtain a high quality output voltage. Simulation and experimental results are also provided to verify the feasibility of the proposed converter.

Svaka periodična funkcija 𝑦(𝑡) može se prikazati pomoću Fourierovog reda kao suma sinusnih i kosinusnih članova čije su frekvencije cjelobrojni višekratnici osnovne frekvencije. Prije svakog mjerenja u laboratoriju bilo je potrebno matematički dobiti vrijednosti za svaki sinusni, pravokutni i trokutasti valni oblik. Sva mjerenja u laboratoriju obavljena su digitalnim osciloskopom, koji se svojim mogućnostima uvelike razlikuje od analognog osciloskopa. Za punjenje i pražnjenje RC člana, osim osciloskopa, korišteni su i istosmjerni izvor, mjerni instrument, kapacitivna i otpornička dekada. Dobiveni rezultati spremljeni su na računalo te su obrađeni pomoću Microsoft Excela. Every periodic function 𝑦(𝑡) can be represented through a Fourier series as the sum of the sine and cosine waves, whose frequencies are the integer multiples of the basic frequency. Prior to conducting laboratory measuring, it was necessary to calculate mathematical values for each sinusoidal, rectangular and triangular wave form. All measurements in the laboratory were performed by a digital oscilloscope, which significantly differs from the analogue oscilloscope. For RC charging circuit and RC discharging circuit are, along with an oscilloscope, used a DC source, a measurement instrument, a capacitance and a resistance decade box. All the results were saved to the computer and processed using Microsoft Excel

This paper presents the study of common-mode (CM) voltage measurements for IEC62684 regulatory. Due to the digitization error caused by the limited vertical bit number of the analog-to-digital converter (ADC) in oscilloscopes, the CM voltage spectrum measurement of the flyback converter with AC source occurs significant inaccuracy. In order to avoid the digitization error, the CM voltage measurement of the flyback converter with DC source is proposed in this paper. The simplified equivalent circuits of the flyback converter with AC and DC input sources are derived to calculate the ratio of their CM voltages. With 64-bit circuit simulation software SIMPLIS®, the digitization error can be significantly reduced to have high-resolution measurements for the verification of the calculated CM voltage ratio. The ratio of the calculated CM voltages can be used to modify the measurement result with DC source to obtain the equivalent result with AC source.

In this paper, a new asymmetric switched diode (ASD) multilevel inverter is presented for medium-voltage and high-power applications. The proposed converter consists of series connection basic unit with full-bridge inverter. In addition to this, a cascaded switched diode (CSD) structure is recommended to generate the higher number of voltage levels. Seven different algorithms are presented to determine the magnitudes of DC sources in CSD topology. To prove the advantages of proposed multilevel converter over recent multilevel converters in terms of blocking voltage, numbers of IGBTs and on-state switches are presented. To show the authority of the proposed multilevel inverter, it is simulated using MATLAB/Simulink and is experimentally tested using prototype model for 13-level inverter. Finally, various output voltage and current waveforms are shown to prove the dynamic behavior of proposed inverter.

We report the magnetic anisotropy and domain configuration of cosputtered TbFeGa alloys. The layers were deposited from two targets with compositions TbFe2 and Fe3Ga, respectively. The structural and magnetic properties do not only depend on the composition but also on the growth conditions. Alloys with the same composition but deposited using a DC or a pulsed power source in the TbFe2 target exhibit a different magnetic anisotropy. The perpendicular magnetic anisotropy, the size and topology of domain patterns can be tailored by changing the evaporation parameters of TbFe2. The width of the stripe domain increases from 235 to 835 nm when using the DC source in the TbFe2. We correlate this effect with Tb enrichment of the TbxFe1−x phases present in the samples.

In this study, two types of multilevel convertors, cascaded multilevel inverter with separate DC sources and diode clamped multilevel inverter with common DC source are modeled and compared in the case of feeding of an induction motor. Here, SHEPWM technique is used as the switching strategy. Also a new variable torque feedback control on modulation index is presented, to preserve the induction motor in stable condition. Furthermore, the merits and demerits of each convertor from power quality point of view are compared. Outputs of simulations shows that despite of that feeding of loads using diode clamped multilevel convertors with common dc source is easier than cascaded converters from feeding inverters with DC sources point of view, even thought cascaded multilevel inverters has more robust performance in case of feeding variable torque induction motor loads. And our feedback controller works to improve outputs of multilevel inverter and parameters of induction motor in both cases.

The popular 555 IC timer incorporated as time delay circuit and operated with a 5V DC source was adapted to design and construct an automatic day and night household Electrical lights monitoring and control circuitry for residences. KEYWORD: 555 IC Timers, Comparator, Potentiometer, Photocell, Signal