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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.

Multilevel inverters (MLIs) have formed a new wave of interest in research and industry. Switched capacitor-based multilevel inverters are used to avoid the need for multiple separated DC sources compared to cascaded MLIs. However, the inclusion of several capacitors creates problems such as high inrush current, voltage imbalance. To avoid these drawbacks, this paper proposes an isolation-based scheme by using a flyback converter in the switched capacitor multilevel inverter. Further, the overall topology provides step-up AC voltage across the load from a single DC source with fewer power switches. To generate a step-up five-level voltage across the load, switched capacitor-based multilevel inverter needs six power switches and only one capacitor. To get the appropriate switching operation to generate the NL-levels, phase disposition pulse width modulation (PD-PWM) has been developed. The extended nine-level S 2 -MLI is also discussed in this paper under different conditions as change in input source voltage and dynamic load change. Moreover, to prove the superior performance of switched-capacitor single DC source multilevel inverter (S2-MLI), comparative analysis with existing single DC source MLI has been performed. The effectiveness and feasibility of the proposed topology are tested with varieties of loads by simulation using Matlab/Simulink. To validate the simulation results, hardware implementation has been done of five-level S2-MLI considering resistive and motor load by using DSpace 1103 controller.

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.

In this article, a 1-MHz-regulated DCX (RDCX) with single transformer is proposed for high-power-density high-efficiency 48–12 V dc–dc conversion. In the proposed converter, a dc transformer (DCX) works at fixed switching frequency to realize isolation and output power conversion and an auxiliary pulsewidth modulation (PWM) converter is applied to realize voltage regulation. The auxiliary dc–dc is fed from the auxiliary winding of the transformer and its output is in series with the input dc source. The output regulation is achieved by regulating the output voltage of auxiliary dc–dc converter. Furthermore, only a small portion of power is dealt by the auxiliary PWM dc–dc converter. Thus, the total efficiency is a little bit lower than the DCX and higher than that of conventional two-stage solution. The operation principle and the design guidelines of the proposed RDCX are presented in this article. A 360 W 40–60 V/12 V dc–dc prototype is built to verify the theoretical analysis and design guidelines. In the prototype, 9.1% of load power is dealt by the auxiliary dc–dc at nominal 55 V input voltage and, at worst case, which happens rarely and the duration is short, 50% of load power is dealt by the auxiliary dc–dc stage. Finally, 97.3% peak efficiency is achieved.

Rubber Tapping Machine (RTM) consists of a position sensor which senses the first cut provided in the tree and guides the tool which is attached to the tool box which in turn runs over the rail. The tool which we have provided in RTM is an end milling tool, which cuts the bark of the tree leading to the production latex from the tree. The milling tool is operated by a motor of high RPM run by a DC source. The helical cut is achieved by the horizontal as well as vertical movement of the housing. The movement of the housing is due to the vertical movement provided by the power screws and the horizontal movement of the tool post by rack and pinion arrangement over the rail.

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.

The control characteristics of vacuum plasma generators are experimentally studied under glow discharge conditions with transition to the conditions of anomalous glow discharge and arc discharge. The use of a high-frequency current source in parallel to a dc source is shown to increase the ionic current and to decrease the time of starting conditions. A method for heating the bulk hollow cathodes of plasma generators is considered.

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.

Recently, single-stage boost inverter topologies like Z-Source Inverter (ZSI), Switched Boost Inverter (SBI) and quasi-Switched Boost Inverter (qSBI) are gaining more attention in Renewable Energy ...

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.

A comprehensive analysis on a novel topology of Boost converter with passive LC3 configuration has been proposed in this paper. The proposed DC-DC converter achieves a higher efficiency when compared with conventional Boost converter, having maximum efficiency of 98.26%. Its AC-DC topology also achieves similar results, having better performance in efficiency, power factor and THD. Power factor and THD are further improved by integrating a PI controller, achieving a power factor of 0.9904 and THD of 11.67%. Finally a comparison between rippled and unrippled DC source is shown in this paper. All the results are validated by using PSIM.

Single module of ZPUC topology is presented in this paper which can be operated with single DC source. Although ZPUC has one more capacitor compared to its counterpart PUC converter, it requires single DC source instead of three isolated DC sources in three-phase system which is a great advantages to reduce the cost and bulkiness of the system. It also reduces the total components counts of the converters in comparison to the most popular types of multilevel converters. Active voltage balancing through Phase shift pulsed width modulation (PS-PWM) strategy has been used to balance the voltages of three flying capacitors. ZPUC topology based on the 5-L inverter is investigated in Matlab-Simulink to validate the performance of the single module of ZPUC topology.

This paper suggests a Hybrid Switched-Capacitor 9-Level Boost Inverter (HSC9LBI) topology that provides quadruple voltage-gain. Capability of feeding zero or low power-factor load types as well as natural voltage balancing of capacitors are other merits of suggested HSC9LBI. Two half-bridges are utilized to create bipolar voltage-waveform. The suggested HSC9LBI requires single DC source, which results in compact size. Different operational modes have been elaborated. The comparison and simulations results have been presented to verify superiority and suitable functionality of suggested configuration.

With the development of DC source and load, the AC/DC hybrid distribution network has become the development direction of the future distribution network. The calculation of its total supply capability can effectively guide its planning and operation. In order to accurately calculate the power supply capacity of the AC/DC hybrid distribution network, the load transfer method under N-1 fault was first analyzed. Second, a total supply capability calculation model considering load balance was proposed. The operating characteristics of different types of loads are considered in the model. Then the proposed model is solved by NSGA-II. Finally, an example is used to verify the effectiveness of the proposed model and algorithm, and the total supply capability and bottlenecks of AC/DC hybrid power distribution networks with different structures are compared and analyzed.

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.

In this paper, a novel single-phase five-level inverter is proposed. It is composed of eight switches and one flying-dc-source. Compared with the conventional active-neutral-point-clamped five-level inverter, the proposed structure has the same number of active devices and it does not require any sensor or balancing circuits to control the split dc-link capacitors. Thereby, the proposed converter reduces the cost and the complexity of the control system. Additionally, the proposed inverter has the capability of boosting the input voltage by a factor of two, which means it allows a reduction of 50 % in the DC-link voltage requirement and it does not require an intermediate DC-boosting stage for applications such as, photovoltaic panels and full-cells systems, characterized by a low and unregulated input voltage. Experimental results have been performed in order to validate the theoretical analysis of the proposed system.

Development of reduced components count switched-capacitor (SC) inverters is in the recent trend for photovoltaic (PV) power processing and high frequency ac systems. The self-voltage balancing without complex control scheme and voltage gain features makes SC based multilevel inverters (MLIs) a perfect choice for PV applications. This paper presents a SC based seven-level MLI (SC7MLI) with three-phase extendibility using a single dc source. The output voltage is boosted to three-times the input magnitude with the aid of natural voltage balancing and using fewer components compared to prior-art MLIs. The proposed topology uses only 9 and 21 switches in single-phase and three-phase extensions, respectively. Simulation results under different steady-state and dynamic conditions validate the feasibility of the proposed design that is further warranted by several experimental results.

The paper describes a digital low-frequency ac voltage source with amplitude stability better than 10⁻⁶ V/V per hour. It was developed to be used as a transfer standard for calibrations with ac Josephson systems and fast synchronous ac-dc transfer measurements. Its low-distortion and superb phase adjustment resolution makes it suitable for impedance measurements as well., Conference on Precision Electromagnetic Measurements (CPEM 2020), August 24-28, 2020, Denver, Colorado [Held Virtually]

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.

A system based on a frequency converter and three-phase electric motors has been developed to permit continuous drive operation when the primary power supply is cut off. Power may be supplied to the frequency converter from a low-voltage dc source such as a rechargeable battery or a supercapacitor.

Recently developed multilevel inverter topologies have drawn major attention in the industry and research, as these are moving into practicable technology for many medium and high-power applications. The main objective of this paper is to provide an overview of transformer based single DC source multilevel inverter (T-SDCMI) topologies which come under the special category of the multilevel inverter. In T-SDCMI, single DC source reduces the cost, size, weight and increase reliability including the advantages of the transformer, which is not possible in symmetrical, asymmetrical and hybrid multilevel inverters which are already available in the literature. From the configuration point of view, T-SDCMI topologies are categorized into three groups: H-bridge based T-SDCMI, three-leg inverter based T-SDCMI and other configurations based T-SDCMI. State of the art with challenges of each topology is discussed categorically. Moreover, in each topology, drawbacks and advantages have been discussed in detail. Finally, the comparative study of existing T-SDCMI topologies has been carried out to select the best topology in terms of different performance parameters.