Number Of Power Switches Research Articles

Soft charging and fewer switches based single‐source double‐boost multilevel DC‐AC converter for low/medium voltage applications

AbstractThis paper presents a novel generalized step‐up switched‐capacitor multilevel inverter (SCMLI) appropriate for low/medium voltage input applications. To reduce the overall number of power switches, the suggested topology makes use of reduction switch count (SC) technology. The complementary working mechanism of each pair of switches simplifies the modulation method. The complete inductive‐load capability is taken into account in the proposed inverter. Furthermore, because capacitor voltages are automatically balanced, complex voltage control circuitry is not necessary. Due to a reduction in current spikes on the devices, the topology also has the ability to soft‐charge the capacitors in a quasi‐resonant manner. Performance is also enhanced by extending the lifetime and dependability of the inverters. The construction, operation, modulation method, values of the capacitors, and circuit losses are explained to demonstrate how the suggested topology should function. One of the inverter's primary differentiators from the others is its double‐boosting capability based on reduced components. Based on loss calculations, a thorough analysis of the suggested topology's efficiency of 98.31% is presented. Next, the benefits of the suggested inverter are compared to those of other inverters that have been recently suggested. The steady‐state and dynamic performance of the suggested topology is then confirmed by modeling the system on the Simulink platform and performing experiments using a DSP‐based prototype experimental setup.

A New Symmetrical Source-Based DC/AC Converter with Experimental Verification

This research paper introduces a new topology for multilevel inverters, emphasizing the reduction of harmonic distortion and the optimization of the component count. The complexity of an inverter is determined by the number of power switches, which is significantly reduced in the presented topology, as fewer switches require fewer driver circuits. In this proposed topology, a new single-phase generalized multilevel inverter is analyzed with an equal magnitude of voltage supply. A 9-level, 11-level, or 13-level symmetrical inverter with RL load is analyzed in MATLAB/Simulink 2019b and then experimentally validated using the dSPACE-1103 controller. The experimental verification of the load voltage and current with different modulation indices is also presented. The analysis of the proposed topology concludes that the total required number of components is lower than that necessary for the classical inverter topologies, as well as for some new proposed multilevel inverters that are also compared with the proposed topology in terms of gate driver circuits, power switches, and DC sources, which thereby enhances the goodness of the proposed topology. Thus, a comparison of this inverter with the other topologies validates its acceptance.

A double T‐type H‐bridge reduced switch multilevel inverter for a wide range of DC voltage variations

AbstractRenewable energy sources are subject to input source uncertainties, which can negatively impact output voltage THD. Having a high number of voltage levels in multilevel inverters (MLIs) with minimum components is cost‐effective. This paper proposes a new structure, Double T‐type H‐bridge (DTH) module, that can produce 9, 13, 17, 19, 21, and 25 levels using reduced components. Switching patterns in MLIs refer to the way in which the power switches are controlled to generate the desired output voltage waveform. As a result, having more switching patterns make the converter flexible to produce voltage levels in the face of input source uncertainties. The DTH structure provides new switching patterns, making it possible to produce levels when the difference of capacitor voltage is negative in a positive cycle or vice versa. This paper presents a new algorithm based on nearest level control to order voltage levels in ascending order, which improves output THD significantly. This topology brings a lower switching state that is linked to switching losses directly compared to the topologies with the same number of power switches. The DTH module's performance is evaluated through graphical analysis, simulations, and experimental results in symmetrical, asymmetrical, and load change conditions.

Investigation of efficient multilevel inverter for photovoltaic energy system and electric vehicle applications

Introduction. This research presents a simple single-phase pulse-width modulated 7-level inverter topology for renewable system which allows home-grid applications with electric vehicle charging. Although multilevel inverters have appealing qualities, their vast range of application is limited by the use of more switches in the traditional arrangement. As a result, a novel symmetrical 7-level inverter is proposed, which has the fewest number of unidirectional switches with gate circuits, providing the lowest switching losses, conduction losses, total harmonic distortion and higher efficiency than conventional topology. The novelty of the proposed work consists of a novel modular inverter structure for photovoltaic energy system and electric vehicle applications with fewer numbers of switches and compact in size. Purpose. The proposed system aims to reduce switch count, overall harmonic distortions, and power loss. There are no passive filters required, and the constituted optimizes power quality by producing distortion-free sinusoidal output voltage as the level count increases while reducing power losses. Methods. The proposed topology is implemented with MATLAB/Simulink, using gating pulses and various pulse-width modulation methodologies. Moreover, the proposed model also has been validated and compared to the hardware system. Results. Total harmonic distortion, number of power switches, output voltage, current, power losses and number of DC sources are investigated with conventional topology. Practical value. The proposed topology has proven to be extremely beneficial for implementing photovoltaic-based stand-alone multilevel inverter and electric vehicle charging applications.

Mitigation of harmonics for five level multilevel inverter with fuzzy logic controller

Introduction. The advantages of a high-power quality waveform and a high voltage capability of multilevel inverters have made them increasingly popular in recent years. These inverters reduce harmonic distortion and improve the voltage output. Realistically speaking, as the number of voltage levels increases, so does the quality of the multilevel output-voltage waveform. When it comes to industrial power converters, these inverters are by far the most critical. Novelty. Multilevel cascade inverters can be used to convert multiple direct current sources into one direct current. These inverters have been getting a lot of attention recently for high-power applications. A cascade H-bridge multilevel inverter controller is proposed in this paper. A change in the pulse width of selective pulse width modulation modulates the output of the multilevel cascade inverter. Purpose. The total harmonic distortion can be reduced by using filters on controllers like PI and fuzzy logic controllers. Methods. The proposed topology is implemented with MATLAB/Simulink, using gating pulses and pulse width modulation methodology and fuzzy logic controllers. Moreover, the proposed model also has been validated and compared to the hardware system. Results. Total harmonic distortion, number of power switches, output voltage and number of DC sources are analyzed with conventional topologies. Practical value. The proposed topology has been very supportive for implementing photovoltaic based multilevel inverter, which is connected to large demand in grid and industry.

A Novel Active Neutral Point-Clamped Five-Level Inverter With Single-Stage-Integrated Dynamic Voltage Boosting Feature

Application of mid-point-clamped multilevel inverters, e.g., active neutral point-clamped (ANPC) or stacked multicell (SMC) converters, have been significantly broadened in recent years due to better performance, reduced common-mode voltage and leakage current, bidirectional power flow capability and simplicity in circuit design. Nonetheless, the dc-link voltage utilization factor is only 50% (i.e., the peak of the ac output voltage is half of the dc-link voltage), which requires additional front-end boost integrated circuit to accommodate low and wide varying input voltage. In this article, a single-stage ANPC-based five-level (5 L) boost integrated inverter is proposed, which is able to meet the peak amplitude of the grid voltage even when the dc-link voltage is low and wide varying. The proposed topology is comprised of two boost inductors, four capacitors, and 10 power switches, which can be assembled with two standard T-Type modules and two additional discrete power switches. Compared with the conventional two-stage ANPC and/or SMC-5 L inverters with a front-end bidirectional boost converter, the proposed topology requires the same number of power switches, whilst providing more flexible/dynamic voltage conversion gain with a reduced total standing voltage across the switches. Operating principles, circuit analysis and modulation strategy of the proposed topology are discussed. Finally, a comparative study supported by closed-loop grid-tied experimental results are presented to confirm the potentiality and feasibility of this proposal.

A Novel Multiport Hybrid Wave Energy System for Grid-Connected and Off-Grid Applications

Direct drive wave energy converters (DDWECs) have gradually become the mainstream of wave energy converters (WECs). In order to make better use of wave energy, energy storage devices and other renewable energy sources are often used to suppress power fluctuation in DDWECs. However, the addition of other energy sources will increase the complexity of the converter system and the number of power switches. Considering the flexibility of nine-switch converters (NSCs), this paper proposes a novel nine-switch grid-connected/off-grid multiport hybrid wave energy system (HWES). First, the system structure and modulation principle are described. Then, a model for a generator, a grid and energy storage are built, including a control strategy of each part. Finally, a simulation for the grid-connected/off-grid application and an experiment on the off-grid HWES are carried out. The results show that the multiport wave energy system can achieve the objective of stable and reliable power transmission by reducing power devices.

Performance investigation of modular multilevel inverter topologies for photovoltaic applications with minimal switches

Introduction. In recent years, a growing variety of technical applications have necessitated the employment of more powerful equipment. Power electronics and megawatt power levels are required in far too many medium voltage motor drives and utility applications. It is challenging to incorporate a medium voltage grid with only one power semiconductor that has been extensively modified. As a result, in high power and medium voltage settings, multiple power converter structure has been offered as a solution. A multilevel converter has high power ratings while also allowing for the utilization of renewable energy sources. Renewable energy sources such as photovoltaic, wind, and fuel cells may be readily connected to a multilevel inverter topology for enhanced outcomes. The novelty of the proposed work consists of a novel modular inverter structure for solar applications that uses fewer switches. Purpose. The proposed architecture is to decrease the number of switches and Total Harmonic Distortions. There is no need for passive filters, and the proposed design enhances power quality by creating distortion-free sinusoidal output voltage as the level count grows while also lowering power losses. Methods. The proposed topology is implemented with MATLAB / Simulink, using gating pulses and various pulse width modulation methodologies. Moreover, the proposed model also has been validated and compared to the hardware system. Results. Total harmonic distortion, number of power switches, output voltage and number of DC sources are compared with conventional topologies. Practical value. The proposed topology has been very supportive for implementing photovoltaic based multilevel inverter, which is connected to large demand in grid.

A Novel Single-Phase Multilevel High-Gain Inverter With Low Voltage Stress

This article proposes a high performance with 13-step, switched-capacitor multilevel inverter (SCMLI). The gain factor of 6 is achieved, along with self-voltage balancing of capacitors. The suggested structure can be cascaded to generate any number of voltage steps with the inherent property of generating both positive and negative voltage steps. All the power switches withstand voltages lower than 50% of maximum output voltage. The number of power switches, the number of dc input sources, the voltage stress on the switches, and the power losses are reduced. Also, the presented inverter has a minimum cost function compared to the other similar structures. The performance of the proposed 13-step converter has been validated by the simulation, extracted by PSCAD/EMTDC, and also the experimental results, obtained from an implemented laboratory prototype.

A simplified methodology for mitigating the harmonics and common-mode voltage using multi-level inverters for renewable energy applications

ABSTRACT Multi-level inverters have outstanding construction, making it feasible to achieve high voltage levels with less THD value. These harmonics can be mitigated by decreasing the number of voltage switches and DC links in the modified cascaded H-bridge multi-level inverter. This research deals with the novel 15-level inverter and reducing the number of power switches. The proposed work consists of three simulation circuits, one with 10 switches and the second with 12 switches. The mitigation of harmonics, voltage stress, and common-mode voltage is achieved with the help of modifying the pulses of the switches in the proposed 10 switches topology. Additionally, a filter is applied at the terminal to reduce the overall THD value for variable AC load applications. The multi-level inverter can generate the high-level output with less harmonics, losses, and common-mode voltage with the help of low switching frequencies. These types of a multi-level inverters are used in renewable energy applications. Finally, the simulation of a 15-level novel inverter is carried out with the help of MATLAB/Simulink software and compared with the conventional cascaded H-bridge multi-level inverter. The total harmonics distortion for modified CHBMI with 12 switches with or without filter and modified CHBMI with 10 switches with or without are mitigated as 13.53, 6.91, 12.86, and 4.56, respectively, compared to the conventional method with 28 switches. The proposed method is implemented in the hardware to validate the simulated results of the proposed topology.

Space vector modulation control of a Z-source 9-switch power inverter based on two virtual three-phase inverters for electric vehicles application

ABSTRACT This paper deals with space vector modulation of a Z-source 9-switch inverter for electric vehicle application. Indeed, the Z-source 9-switch inverter can supply two induction motors of two-driving wheels electric vehicle. The proposed electric vehicle powertrain composed mainly of a Z-source structure contains inductances and capacitors, and 9-switch power inverter forms two virtual three-phase inverters. So, the Z-source 9-switch inverter structure minimises the number of power switches, the volume and therefore the cost of the electric vehicle powertrain. In this context, an adapted space vector modulation of a Z-source 9-switches inverter is developed in order to ensure simultaneously an independent control of two induction motors and boost the output voltage of batteries. Experimental and simulation results have been carried out to demonstrate the effectiveness of the developed system.

Three-level modified sine wave inverter equipped with online temperature monitoring system

Research and development on power converters are getting more interesting in recent years. It is also buttressed by rapid development in related fields, such as power semiconductor, digital advanced control, magnetic material and use of power converters in many sectors. In addition to the power quality matter, simplicity of inverter circuits is another notable aspect that should be considered toward economical feature. Adding the quantity of power switches will increase complexity of overall inverter circuits. This paper discusses a circuit configuration of three-level modified sine wave neutral point shorted power inverter which work converting dc power into ac power with less number of power switches. To improve the performance and feature of inverter circuits, the inverter was equipped with online temperature monitoring, and overheat protection based on internet of things. Adding online temperature monitoring system makes easier in monitoring of circuits to prevent the excessive faults of inverter. Some computer based test data are shown and discussed. Furthermore, experiment results of the inverter prototype, and its online monitoring system are presented. Test outputs demonstrated that the proposed system worked properly generating a three-level modified sine wave voltage, with online temperature monitoring system.

Reduced device count version of single‐stage switched‐capacitor module for cascaded multilevel inverters

Switched capacitors are being increasingly employed in multilevel inverters for various applications. Of the new topologies that have been recently introduced, single-stage switched-capacitor module (S 3 CM) has gained a lot of attention. In this work, a modified version of S 3 CM is presented that leads to a significant reduction in a number of power switches, with a simultaneous reduction in total peak inverse voltage. The proposed topology can generate 9 voltage levels in symmetric configuration and 11 voltage levels in asymmetric configuration with two dc sources, two capacitors, and eight power switches. Moreover, for the higher voltage-rated power switches in the structure, the switching losses are minimised by fundamental frequency operation of these switches. The operation and the performance of the proposed topology have been validated through simulation and experimental results of a single-phase prototype with symmetric and asymmetric source configurations.

New 8-Level Basic Structure for Cascaded Multilevel Inverters with Reduced Number of Switches and DC Voltage Sources

Multilevel inverters are generally used in medium-voltage and high-power applications. In this paper, a new 8-level basic structure for cascaded multilevel inverters is proposed. Based on proposed basic structure, two different cascaded multilevel topologies are proposed. The proposed cascaded multilevel inverters use less number of power switches, IGBTs and dc voltage sources compared with the conventional multilevel inverters. In order to generate all steps at the output voltage, three different algorithms to determine the amplitudes of dc voltage sources are presented. To reconfirm the performance and correct operation of the proposed topologies, the experimental results for a 15-level inverter are presented.

Flexible transformer‐based multilevel inverter topologies

Cascaded multilevel inverters (MLIs) have been proposed that utilise transformers in the basic unit. The proposed inverters primarily serve to step up the input voltages in addition to using lower number of components in comparison to traditional MLIs. In order to generate all voltage levels (even and odd) at the output, three different algorithms are proposed to determine the magnitude of DC voltage sources and transformer turn ratios. Also, the basic inverter unit was further developed and two new flexible MLI structures have been obtained. The developed structures increase the input voltage with no need for an additional boost converter. A reduction in the number of power switches, the peak inverse voltage, and the number of DC voltage sources are other advantages of the proposed topologies. Also, a simple cost model was developed and the dimensionless cost coefficient was determined. The overall cost of the proposed MLIs was compared to the similar MLIs from the literature. It was shown that the proposed MLI decrease the overall cost of the system if the cost coefficient is selected appropriately. To verify the performance of the proposed topologies simulated by the mathematical model; several lab-scale inverters were built and tested and good agreement was achieved.

Modeling and Simulation of 127 Level Optimal Multilevel Inverter with Lower Number of Switches and Minimum THD

<p><span lang="EN-US">This paper proposes a new optimal high level multilevel inverter with minimum number of components. This multi level inverter (MLI) is designed with series combination of basic units which can generate positive levels at output. DC source values applied for each basic unit is different with another. An H bridge is connected across proposed MLI for generating negative levels along with positive levels at output and that inverter considered as proposed high level optimal multilevel inverter. Single unit is responsible producing 21 levels. Therefore six units are connected in cascaded form to increase number of levels as 127 at output. Decrease in the number of power switches, driver circuits, and dc voltage sources are the improvement of the proposed MLI. Sinusoidal multiple pulse width modulation (SPWM) technique is implemented to produce pulses for turning ON switches according requirement. Low total harmonic distortion at output voltage or current production is major advantage of proposed module. The validations of proposed MLI results are verified through MATLAB/SIMULINK.</span></p>

A New Structure of the Nine Level Inverter Used as Active Power Filter with a Reduced Number of Swiches

In the scope of this work, a new structure of the nine level inverter is proposed using a reduced number of power switches. This inverter is used as a shunt active power filter to compensate harmonic currents and the reactive power. The modeling and simulation of the proposed model were carried out in Matlab/Simulink environment. The simulation results show that the filtering performances were achieved despite the reduction of the switches number. It was found that the current waveform becomes purely sinusoidal with a reduction in the harmonic distortion rate (THD) to 2.68%. This implies good compensation of both harmonics and reactive power with a power factor closer to unity. Reducing the switches number allows reducing the switching losses and lowering the duration of the applied voltage supported by the semiconductors. The proposed topology also allows to get simple structure of the inverter with a reduced cost.

Design and Simulation of Single-Phase Five-Level Symmetrical Cascaded H-Bridge Multilevel Inverter with Reduces Number of Switches

Multilevel inverter is an effective and practical solution for increasing power demand and reducing harmonics of ac waveforms. Such inverters synthesize a desired output voltage from several levels of dc voltages as inputs. This paper analyzes the performance of five level cascaded H-bridge multilevel inverter with reduce number of power switches. Further by reducing switches and increasing level will reduce filter cost & harmonic content. 5- Level cascaded H-bridge asymmetrical multilevel inverter topology requires 8 switches but in this new multilevel inverter it requires 6 switches in which same multilevel is obtained. Invariably switching losses and cost also reduced. In this paper only multilevel inverter circuitry will be studied. The performance has been analyzed by the MATLAB/Simulink.

A Modified Switched-Diode Topology for Cascaded Multilevel Inverters

In this paper, a single phase modified switched-diode topology for both symmetrical and asymmetrical cascaded multilevel inverters is presented. It consists of a Modified Switched-Diode Unit (MSDU) and a Twin Source Two Switch Unit (TSTSU) to produce distinct positive voltage levels according to the operating modes. An additional H-bridge synthesizes a voltage waveform, where the voltage levels of either polarity have less Total Harmonic Distortion (THD). Higher-level inverters can be built by cascading MSDUs. A comparative analysis is done with other topologies. The proposed topology results in reductions in the number of power switches, losses, installation area, voltage stress and converter cost. The Nearest Level Control (NLC) technique is employed to generate the gating signals for the power switches. To verify the performance of the proposed structure, simulation results are carried out by a PSIM under both steady state and dynamic conditions. Experimental results are presented to validate the simulation results.

Активний фільтр-стабілізатор для випрямної установки тягової підстанції

The article discusses ways to improve the electromagnetic compatibility of the traction power supply systems of direct current to the adjacent electrical installations and improve the quality of electric energy supply of railway rolling stock. To ensure effective filtration and stabilization of the voltage at the output of traction substations proposed to be used in the rectifier Active Filter Settings stabilizers serial type based on capacitive energy storage with the increased frequency of the pulse-width modulation.As an advantage of active filter-regulator can be noted that for its single-phase bridge switch needed only two uncontrolled and two fully managed keys, and only one of them must be quick on IGBT basis. For buck converters – rectifiers three-phase PWM voltage needed six-speed fully managed keys on the IGBT, which are connected in series with diodes and transistors are protected against reverse voltage. Thus, the number of power switches, the losses of energy in them and the cost of stabilizing the active filter will be lower than in buck converters, and the output voltage will be higher quality.