DC Source Research Articles

A Novel Common‐Ground Switched‐Capacitor Type Dual‐Mode Five‐Level Transformer‐Less Multilevel Inverter

ABSTRACTThis paper presents a novel single‐source common‐ground switched‐capacitor (CGSC) type dual‐mode five‐level (5L) transformer‐less (TL) multilevel inverter (MLI) topology with inherent boosting capability. The proposed topology comprises a single DC source, nine power switches, and two capacitors with self‐voltage balancing ability, reducing the inverter's size, cost, and complexity. The direct connection of the negative terminal of the source to the neutral point of the load eliminates the leakage current. The converter can operate in both buck and boost mode based on the series–parallel switching conversion of the involved switches. The circuit description, control strategy, and design guidelines are discussed in detail. The steady‐state and dynamic performance of the proposed circuit is validated using MATLAB Simulink software. Reliability analysis of the proposed converter is done in detail. Furthermore, the proposed converter is being compared with state‐of‐the‐art topologies.

A 31 L multilevel inverter topology with less switching devices for hybrid electric vehicle applications

In this article, a 12 switch 31 L multi-level inverter (MLI) is proposed with the benefits of least switching devices for electric vehicle applications. In most electric vehicles (EV), conventional inverters are utilized so the lifetime of electric vehicle induction motors is reduced due to the high THD level and high voltage stress. To rectify this, a new inverter topology is proposed with minimum switching devices by increasing the level to 31, and also the THD should be maintained within IEEE standards. This inverter topology is constructed with variable DC sources (PV system) along with required capacitors and a polarity changer. The specific feature of this topology is that it can generate any level of voltage with minimum switching devices, less voltage stress, minimum THD, and less cost are tabulated in the comparison. This type of inverter can also applicable for high voltage (HV) applications and grid-connected systems. Furthermore, the proposed topology is simulated with MATLAB software and the downscale prototype model is developed using the DSPIC30f2010 controller.

A NOVEL FAULT-TOLERANT GENERALIZED SYMMETRICAL TOPOLOGY FOR RENEWABLE ENERGY AND ELECTRIC VEHICLE APPLICATIONS

Multilevel inverters are a versatile and powerful technology for applications such as motor drives, high voltage direct current transmission (HVDC), renewable energy systems, and grid-connected applications. As the demand for high-quality, clean energy and low distortion continues to grow, multilevel inverters are preferred over traditional square wave inverters. This paper proposes a generalized 13-level symmetrical topology to meet the power quality requirements. It consists of six DC sources and twelve semiconductor devices. Further, the topology has cascaded to increase the number of levels, but the cost and circuit complexity increase with the number of units. The gate pulses for switches are produced by the nearest-level modulation technique. The performance comparison of the topology with recent literature provides comprehensive information about the novelty of the configuration. The MLI performance parameters are number of switches, number of gates driving circuits, total harmonic distortion (THD), cost function per level (CCPL), total standing voltage (TSV), and efficiency (η). MATLAB/Simulink investigates the proposed topology, and further, to validate its simulation output, the hardware prototype model has been implemented in the laboratory.

An Enhanced Cascaded Five-Level Inverter Based on Switched Capacitors and Single dc Source

An Enhanced Cascaded Five-Level Inverter Based on Switched Capacitors and Single dc Source

A New Topology of Multi-Input Bidirectional DC-DC Converters for Hybrid Energy Storage Systems

A new topology of multi-input bidirectional DC-DC converters is proposed in this paper. The converter has a boost behavior, i.e., the output voltage is higher than the sum of the input voltages. This family of converters is particularly suited for hybrid energy storage systems, where different DC sources are connected together and where the output voltage is significantly higher than the voltage of a single storage. The proposed converter reduces the number of required switches, leading to higher efficiency and reduced complexity compared to traditional n-input converters. The new topology demonstrates superior performance by enabling higher efficiency with fewer components. A dedicated control, based on PI controllers, is provided to ensure stable operation under dynamic conditions. The effectiveness of the proposed solution is tested using experimental results on a four-input 20 A/100 V converter prototype.

Active Support Pre-Synchronization Control and Stability Analysis Based on the Third-Order Model of Synchronous Machine

When traditional grid-forming converters directly participate in the grid-connected operation of the power grid, due to the lack of a pre-synchronization control system, the voltage amplitude and initial phase on both sides of the grid-connected point will deviate, resulting in voltage and current distortion during grid-connected mode. An active support phase-locked loop free pre-synchronization control strategy based on the third-order model of a synchronous generator is proposed to address the grid-connected problem of the grid-forming converter mentioned above. First, a model of active support control with frequency integral feedback at small signal levels was constructed. The root locus method was employed to examine how system parameters affect the stability of the active support control system. Second, by adding phase pre-synchronization controllers and amplitude pre-synchronization controllers to the active frequency loop and excitation voltage loop of the third-order model, it was ensured that the frequency, phase, and voltage amplitude of the unit are consistent with the power grid, achieving a fast and smooth grid-connected mode of the unit. Finally, by using a DC source to simulate all types of new energy power generation equipment, the active support pre-synchronization control system based on the three-order model of synchronous generator is built in the MATLAB/Simulink simulation environment, and the accuracy and effectiveness of the control strategy in this paper is verified.

Design and Application Prototype of soft starting Three-Phase AC Motor by Using Analog Electronics Control for Teaching Aids of Power Electronics Practice

In general, palm oil processing factories, from fresh fruit bunches to Crude Palm Oil, require three-phase electric motors to drive or rotate it. The problems that often arise when using three-phase electric motors simultaneously in large numbers will result in very large surges in the electric current, which can affect the performance of electronic devices. To overcome this problem, a prototype of a three-phase AC voltage regulator circuit was made by adjusting the SCR triggering delay angle using an analog electronics equipment control that can be used for three-phase motor soft start applications in a palm oil factory. This prototype will be used as a learning tool for the practical for Aceh Polytechnic students for power electronics courses. This system is built with a method where the three-phase source is first lowered using a transformer arranged in a star on the primary and secondary sides, then each voltage is compared to the ground using an IC LM324, which aims to produce pulses wave. This pulse then connected to a triangular wave generator circuit, this triangular wave is then compared with the DC source voltage from the potentiometer, which aims to regulate the SCR triggering angle of SCR via MOC3063 driver, where the load used is resistive and connected in a star. The measurement using an oscilloscope and observing the change of triggering angle for several variations of each phase, the different Vrms voltage between measurements compared to mathematical analysis influenced by several factors, including, the transformer is made of three transformers that not identically, the electronic components used are not in ideal condition, and observations on the oscilloscope are carried out visually using the eye and manually adjusting the potentiometer rotation so that the level of measurement accuracy between one person and another will produce different values.

Ultra-high voltage gain achieved with quadratic DC/DC converter design

This work introduces a novel DC/DC converter with an incredibly high voltage gain, specifically designed for renewable energy generating systems. The proposed circuit features a coupled inductor integrated with a quadratic boost circuit and a voltage multiplier cell to achieve a substantial step-up in voltage gain. Ultra-high voltage gain, minimum reverse recovery in diodes, low voltage stress on switching devices, continuous input current, and a shared ground between the input source and output load are some of this topology’s key features. The coupled inductor design reduces power dissipation in magnetic components by distributing the high DC source current with an additional input inductor. Additionally, regenerative clamp circuits alleviate voltage stresses on power switches during simultaneous switching. Theoretical analysis covering the operating principle, steady-state behavior, and efficiency is discussed in detail. An evaluation of the suggested topology’s performance is conducted using a 250-W, 25-V/400-V lab prototype.

Multiple‐Input and Multiple‐Output–Based Cascaded Boost Hybrid Interlink Converter

ABSTRACTThe multiple‐input and multiple‐output (MIMO) DC–DC converters offer various advantages such as improved efficiency and reduced component count. However, the preference of these converters over other types of converters is dependent on the specific application and requirements. Various types of boost‐derived MIMO DC–DC converters are discussed in the literature. However, these converters are either nonisolated or isolated types. In the paper, a MIMO‐based cascaded boost hybrid interlink converter (CBHIC) has been proposed. The proposed converter includes four DC–DC boost converters that are supplied power by two input DC sources. The boosted DC output of these converters can be used independently or in a cascaded manner depending upon the requirement of the load. Further, the cascaded action of these four boost converters leads to the production of two high‐frequency AC outputs. By using bridge rectifiers and high‐frequency transformers, high‐frequency AC voltages are converted into DC. Therefore, two isolated DC output voltages can be achieved using CBHIC. The complementary operation of the cascaded boost converters results in reduction of source current ripples. The design, operating modes, and performance evaluation of the proposed CBHIC have been included in the paper. To validate the efficacy of the proposed CBHIC, a lab prototype of 400 W is prepared. The rms value of high‐frequency AC output voltage at each is isolated port is 141 V. The CBHIC exhibits an efficiency of 94.3 at 400 W. The operation of the converter during voltage control mode is further explored and its dynamic response is studies with the help of experimental results. The obtained simulation and experimental results validate the effectiveness of the proposed converter.

Review of recent trends of advancements in multilevel inverter topologies with reduced power switches and control techniques

AbstractCurrently, multilevel inverters (MLI) are comprehensively used to integrate renewable energy sources with the grid or high‐power applications. MLI has outstanding properties such as high‐level output voltage with tremendous power quality and negligible harmonics distortion. General MLI topologies have a more complex circuit, high overall cost and installation area. Due to a large number of power switches and isolation of control circuit, fewer power electronic switches and DC source along with its suitable control logic is the need of the hour. Therefore, a lot of research scope exists in this area. Here, some of the topologies with a fewer number of power switches are reviewed and scrutinized. An extensive analysis of the topologies, control strategy and applications are presented here, suggesting suitable multilevel inverter solutions to the known industrial application or new research.

Analysis of Cascaded H Bridge Multilevel Inverter for Three-Phase Induction Motor Drive

The last ten years have seen a rise in the usage of multilayer inverters. Because they can produce waveforms with a greater harmonic spectrum and reliable output. Several high voltages and high-power applications are suitable for these new inverters. A multilayer converter not only produce high power ratings, but it also saves time and money and enhances the system performance in terms of harmonics, dv/dt strains, and pressures on the motor bearings. Owing to its flexibility and modularity, the possible topology for a power application is the cascaded H-bridge multilevel inverter (CMI) with separated DC sources. This study investigates a cascade H bridge multilevel inverter, such as a Three, Five, Seven, Nine and Eleven level inverter in order to drive a three phase AC induction motor. A Level shifted Pulse Width Modulation (LSPWM) technique was applied for the CHBMLI. Specific emphasis is given to aspects like modulation and total harmonic distortion that are preferable or necessary for multi-level converters. For both intellectual and scientific considerations, investigating sine triangle carrier pulse width modulation is deemed to be the most auspicious approach. Analysis of the many performance parameters, including load torque, motor speed, and efficiency, an extensive survey is conducted. MATLAB / Simulink is built into the entire system, and simulation results are developed. The purpose of this research is to demonstrate the performance of 9-level and 11-level fed induction motor driving results for Electric Vehicle applications. CHBMLI fed motor drive is better suitable for Induction Motor Drives.

A novel artificial neural network based selection harmonic reduction technique for single source fed high gain switched capacitor coupled multilevel inverter for renewable energy applications

Multilevel inverters (MLIs) are commonly used in renewable energy systems for their high-quality output, low total harmonic distortion (THD), and reduced component count. This study presents a high-gain, single-source MLI designed for renewable applications like solar or wind power. It features a novel topology with twice the voltage-boosting factor, utilizing a single DC source. The inverter achieves thirteen voltage levels using just 10 power switches and three switched capacitors. The voltage gain is achieved without the need for bulky DC-DC converters or transformers. This is accomplished by configuring the switched capacitors in series and parallel arrangements to attain the desired voltage boost. Additionally, the self-balancing capacitors eliminate the need for extra sensors. Both symmetric and asymmetric variants of the extensible configuration are investigated. The suggested design lowers the total standing voltage (TSV) while achieving high gain. A selective harmonic removal technique using artificial neural networks (ANN) reduces THD by up to 6.07 %. An extensive review of recent literature reveals significant advancements and applications of ANNs in this field. The proposed system's benefits, such as gain factor, total standing voltage (TSV), and minimized device count, are assessed. Comparative analysis reveals that the proposed topology employs fewer components and features a more simplified design. Additionally, the inverter achieves an efficiency of 96.9 %. The design is validated through an experimental prototype after being confirmed with MATLAB/SIMULINK.© YEAR The Authors. Published by Elsevier Ltd.Peer-review under responsibility of the scientific committee of the Name of the Conference, Conference Organizer Name, Year or Edition of Conference.

A simple 60‐pulse voltage source inverter using voltage reinjection strategy to improve voltage harmonics for high‐power local loads

AbstractThe voltage reinjection strategy is an effective solution to improve the voltage quality of the voltage source inverters for high‐power applications. In this article, the fundamentals of voltage reinjection strategy are analyzed to reduce voltage harmonics of the output voltage. Then, a novel voltage reinjection circuit is proposed which can generate a 5‐level voltage to be injected on the voltages of the DC sources. The reinjected voltage can create a 60‐pulse voltage waveform for a three‐phase load. Turn ratio optimization of the reinjection transformer has a significant effect on the improvement of the harmonic situation of the output voltage. Furthermore, the proposed reinjection circuit provides ZVS conditions for the main switches to reduce switching losses considerably. The simulation results indicate that the proposed reinjection circuit can reduce the output voltage THD to 3.16% without any type of filter or modulation, and the load variation does not have a considerable effect on the voltage quality. The experimental results approve the analytical trend and simulation process and also confirm the reinjection circuit performance. According to the results, the proposed method has generated a semi‐sinusoidal voltage waveform with in the laboratory.

Minimizing conduction losses in multiple active bridge converters across wide voltage ranges using advanced dual‐duty modulation

AbstractMultiple port DC/DC converters have applications in many fields: hybrid energy storage systems where batteries are combined with supercapacitors, multi‐level and multi‐modular inverters that need multiple DC sources, and DC microgrids. Among these converters, the Multiple Active Bridge (MAB) is particularly attractive due to its high power ratings and galvanic isolation capabilities. This paper introduces an advanced dual‐duty modulation technique for MAB converters designed to significantly reduce conduction losses over a wide range of input voltages by minimizing the harmonics’ reactive power on the AC stage. Consequently, it can improve the converter's efficiency when dealing with non‐constant voltage sources such as batteries and supercapacitors. The overall control technique is based on the dq‐frame control method under the first harmonic approach (FHA). This method is verified through simulations and implemented in a 1000 W triple‐port prototype. In the simulation, conductive and switching losses are modelled, and the trade‐off between these loss types is discussed. The experimental results affirm an overall improvement in efficiency for certain scenarios involving non‐unit voltage conversion ratios.

A New Cascaded Multilevel Inverter for Modular Structure and Reduced Passive Components

In high-power applications, achieving adequate power quality in power converter design is accomplished by utilizing multilevel inverters instead of using two-level and three-level inverters. The device generates a sinusoidal output voltage, which results in reduced total harmonic distortion and lower voltage stress on the switches and leads to lower electromagnetic interference, making it suitable for use in renewable energy applications. However, to illustrate the advantages mentioned above, a significant number of switching devices and DC sources are necessary while raising the voltage levels. This article proposes an asymmetrical voltage generation method, which operates in a ratio of 1:5 and generates 25 levels using 11 power switches. The topology is modular in structure, and each module has a lower component count, which significantly reduces the overall cost. The proposed topology is capable of generating negative output voltage levels without the use of an H-bridge configuration, where only three switches are used to generate any voltage levels. The functionality of the developed module is amended by fixing different voltage values in DC sources. This article also presents a comprehensive examination of the circuit and the functioning of various voltage levels. The advantages of the proposed inverter have been demonstrated by comparative research with the currently existing MLI topologies. Ultimately, both the simulation and experimental findings validated the practical capabilities.

Cost-effective soft-switching ultra-high step-up DC–DC converter with high power density for DC microgrid application

DC microgrids are integral to smart grids, enhancing grid reliability, power quality, and energy efficiency while enabling individual grid independence. They combine distributed and renewable energy sources, reducing overall energy consumption. High-gain DC–DC converters are crucial for elevating voltages from low-voltage DC sources like solar panels and wind turbines in DC microgrids. This paper introduces a non-isolated DC–DC converter designed to achieve ultra-high step-up (UHSU) voltage conversion utilizing a two-winding coupled inductor (CI). The propounded UHSU configuration achieves a substantial voltage increase by employing low duty cycles and a decreased turn ratio for the CI, resulting in a smaller core size. Moreover, this UHSU circuit incorporates soft-switching capabilities for both power switches and diodes, enhancing its efficiency. By keeping the voltage stress on the switches low, the design minimizes losses and improves overall efficiency. The operational modes are thoroughly analyzed, and comparisons with other topologies are presented to demonstrate the effectiveness of the proffered UHSU circuit. Finally, the performance of the UHSU circuit is validated through the construction and testing of a 150-W laboratory prototype operating at a switching frequency of 50 kHz, with Vin = 20 V and Vout = 300 V.

A new single-source, single-phase, 9-L 4-B switched capacitor-based multilevel inverter

ABSTRACT All types of non-conventional energy sources (NCES) produce low voltage, but offer it to be converted into usable and essential form. Switched capacitor multilevel inverter (SC-MLIs) has played a vital role in extracting power from NCES to fulfill the requirements of today’s need. Researchers have shown a great interest in extracting this power which comes from solar PV, wind, fuel cells and other miniature sources which is often not significant at all. This research offers a topology that is very simple and easy to implement. The authors also demonstrate a novel SC-MLI with a single ground and four voltage boosting capabilities. This paper analyzes and reviews the suggested inverter can create nine levels along with four times the voltage from a single dc source. Three self-balanced switched capacitors in association with a pair of five switches and single diode are used to offer quadruple boosting. A level-shifted pulse width modulation technique helps to generate the output voltage. The execution of the SC-MLI and the capacitor architecture for the suggested topology are fully investigated. The availability of common neutral is advantageous in reducing leakage current, especially in green energy utilization. In the context of voltage gain, the number of components employed, and the presence of common neutral, the designed inverter is contrasted to several other previously revealed inverters.

Determination of the electron temperature and electron density in reduced pressure hydrogen peroxide (H2O2) discharge.

A reduced pressure glow discharge is produced by passing a high-power pulsed DC source of 0-500W with a frequency of 50Hz across two parallel disk electrodes. A hydrogen peroxide aqueous solution is used as a flowing gas for discharge generation. Optical emission spectroscopy is employed to diagnose the discharge generated at a reduced pressure of 0.2mbar with an electrode gap of 4cm. The spectra are recorded at a power density of 9.4 mW/cm3 and typically lie in the visible wavelength range of 380-880nm. The spectra are analyzed using the line intensity ratio method to estimate electron temperature and density. The results indicated that the electron temperature and density are, respectively, 0.87eV and 6.4 × 1014cm-3.

Design and performance evaluation of a novel modular asymmetrical multilevel inverter with minimal switches

In the present scenario, emerging topologies in the area of Asymmetrical Multilevel Inverter (AMLI) with fewer power switches and voltage sources have been received greater attention to achieve higher levels with low THD and voltage stress. The present work proposes a novel modular AMLI topology to generate 7-level and 15-level in the output voltage. This topology needs minimal components in comparison of topologies reported in literature. Simulation of the 7-level and 15-level AMLI is performed using MATLAB to generate all the desired levels in the output voltage for different operating frequencies and different modulation indexes. Further, a comparison of the suggested topology with other similar multilevel inverter (MLI) topologies has also been performed on the basis of number of drivers, number of DC sources, levels in the output voltage and power switches. Furthermore, efficiency, losses and total harmonic analysis of 7-level and 15-level AMLI have been calculated and compared with other studies. Finally, simulation results are validated on a hardware set up of the proposed inverter using Opal-RT 4510 controller.

An AC and DC Electric Field Effect Based Charged Particle Focusing Scheme for Particle Beam Mass Spectrometer

Particle Beam Mass Spectrometer (PBMS) is a mass analyzer based particle sizer, features a few to hundreds of nanometer (nm) sizing capabilities in environmental pressures above hundreds of mTorr. The above feature makes the PBMS be used as in-situ process monitoring schemes for several kinds of semiconductor process equipment (e.g. Chemical Vapor Deposition). However, it still cannot be used in other process equipment (e.g. Plasma etching, Ion implantation) which requires lower process pressure conditions than the PBMS operation limits. The bottleneck of pressure limits comes from an aerodynamic lens component, which focuses incoming particles in background gas using repetitive fluidic contraction and expansion effects. These effects hard to be happened when the target particles are surrounded in molecular or transition background gas regions. In order to lower the operating pressure limits, other focusing schemes are required.In this study, an alternative particle focusing scheme which uses AC and DC electric field effects is proposed. The proposed scheme uses a stacked-ring ion funnel structure with variable AC and DC electric sources, for driving AC and DC potential variations along the funnel’s axial direction. While radial electric potential wells produced by AC frequency components induce particles’ radial position concentration to the funnel axis center, potential well depth and axial well depth steepness is controlled by AC amplitudes and DC source values.Simulation results show that with the proposed scheme, more than 50% of particle transmission efficiencies are obtained for 5 nm – 100 nm sized charged particles moving with Maxwellian velocities in molecular background region. The results come from AC electric sources with 200 Hz - 20 kHz frequency ranges and within 50 V amplitude ranges, and DC electric sources within 50 V ranges which are feasible values for hardware implementation.