Power Electronic Switches Research Articles

Fractional order PID controlled quasi Z-source inverter with front-line semiconductor material made of power electronics switches fed PMSM motor for EV applications

In the area of control theory, conventional PID controller is most commonly used for various applications to bring out the output of the system at higher efficacy. Now due various technological advancements, PID controller is derived into various advanced controllers. In the advancement of PID controller, there is a controller called Fractional Order PID controller which used widely in industrial applications. The advancement o9f classical integer order PID controller is the FOPID controller. This paper deals with the control of PMSM by FOPID controller. In this work, different control strategies such as Proportional Integral (PI) controller, and Fractional Order Proportional Integral Derivative (FOPID) controller is exploited to sustain the constant yield motor speed of the quasi z-source with 3-phase inverter fed PMSM drive. Also, the source disturbance is introduced to analyze the performance of quasi z-source with 3-phase inverter fed PMSM driven by different controllers. The implementation of FOPID controller will gives out the enhanced response in Quazi Z source inverter fed PMSM. The closed loop system with the FOPID controller has reduced steady state error, improved rise time, settling time and the peak time, when compared with the closed loop system with PI controller. The simulation has been done utilizing MATLAB Simulink software. As discussed, outcomes reveal that the quasi z-source with 3-phase inverter fed PMSM driven by the FOPID-FOPID controller has good-performance such as transient response etc., when compared to the PI-PI controller. Material properties affect the performance and efficiency of power electronic switching devices in three phase inverter circuits. These are generally silicon switches. To increase material technology and performance, switching devices employ wide band-gap semiconductors. This paper also examines the optimal semiconductor material utilized in the three-phase inverter circuit's power electronic switches.

A novel 7-Level symmetric inverter module with less circuit components

Multilevel Power Converters (MPCs) have vast potential in power electronics research and development of DC-AC electrical energy conversion system. MLIs have become an inescapable power electronics device in various power conversion applications due to the incompatibility of traditional two-level inverters. MLIs are extremely popular for medium power and high AC voltage applications, and thus predicted to gather incessant attention in future. This article suggests a novel single-phase symmetric 7-level inverter suitable for a renewable energy application with an effort to lower the count of switching components and conducting devices in the path for the flow of current. The proposed symmetric type inverter circuit could produce 7-level output voltage by using three DC sources and seven power electronic switches. The suggested inverter structure can be used to generate any number of voltage levels, and it can produce all output voltage levels (i.e.,+ve,-ve and zero), which significantly reduces the inverter's total standing voltage. The performance of the suggested 7-level inverter topology was confirmed by simulation results obtained in MATLAB/Simulink.

Common-Mode Voltage Reduction Scheme for MMC With Low Switching Frequency in AC–DC Power Conversion System

In ac–dc power conversion system, modular multilevel converter (MMC) has been a promising technology, especially for high-voltage application. In such kind of application, the common-mode voltage (CMV) generated by power electronic switching can cause damage to electrical components and increase the electromagnetic interference (EMI) to the system. Hence, this article proposes a modulation scheme to reduce the CMV of MMC applied in high-voltage system, such as high-voltage dc. Usually, MMC consisting of numerous submodules (SMs) adopts the nearest level modulation (NLM) with the low switching frequency, so the CMV of the NLM scheme is analyzed, which indicates that the peak value of CMV is one-third of SM voltage. If one more or one less SM is turned <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> compared with NLM, the CMV caused by modulation can be eliminated theoretically. Subsequently, a modulation scheme based on the nearest zero CMV vector (NZCMVV) to reduce CMV is proposed for MMC. The NZCMVV scheme utilizes the two adjacent levels as candidate levels, and the theoretical ZCMVVs are picked out. Finally, the ZCMVV closest to the reference vector is selected to approximately replace the reference. The proposed method is simple and easy to implement. Simulated and experimental results validate that the proposed scheme can reduce CMV and CM current compared with the traditional NLM method.

A Pencil Shaped 9-Level Multilevel Inverter With Voltage Boosting Ability: Configuration and Experimental Investigation

A comprehensive study of a minimized component pencil shaped (PS) 9-level inverter constructed with just two DC supplies is presented in this research. Many of the suggested low component multilevel inverters (MLIs) use DC supplies that are not being used appropriately along with additional conducting switches. Since this proposed MLI has a reduced quantity of power electronic switches, it is more efficient. The architecture may be expanded to a modular higher voltage level inverter, which uses less DC supplies and uses them correctly without the need of an extra H-bridge circuit. To determine their optimum capabilities, the proposed inverter parameters&#x2019; simplified formulas are constructed. Furthermore, the extended model of the proposed architecture is used to generate an optimum PSMLI design for lowering the total standing voltage (TSV) of the inverter. To demonstrate its advantages over recent MLIs of similar types, comparison studies are given to justify the proposed inverter. Through proper simulation and laboratory experiment, the MLI obtained a higher efficiency of 95.54%. On the other hand, the optimized 17-level version of PSMLI obtained total harmonic distortions (THD) of only 5.15% which successfully attained IEEE 519 standard performance.

DC microgrid-A short review on control strategies

In order to develop a secure and sustainable electric grid, the maximum possible energy must be harvested from distributed renewable energy sources (DER). Also, the ever-continuing aid coming from semiconductor materials technology in development and advancements in power electronic switching devices has enabled cost-effective power conversions, power conditioning, regulation and control of electrical parameters like voltage, current, impedance and phase angle. As a result, power utilities are swiftly moving towards more flexible forms of power generation to support sensitive loads such as electronic systems and commercial equipment. Microgrids powered by direct current (DC) have recently drawn a lot of consideration because of the proliferation of DC power sources, ESS (energy storage systems) besides load devices in power systems. Additionally, DC microgrids don't have issues related to harmonics, synchronization, frequency control or reactive power control like conventional AC systems. Nevertheless, the incorporation of multiple distributed generators into the same DC bus, like wind, PV, fuel cells, ESS and loads complicates the voltage and power sharing control of the DC bus. An outline of the benefits of DC microgrid (MG) over AC microgrid is provided in this paper. There is also a thorough discussion on control aspects applicable to a DC MG.

Modelling and analysis of vienna rectifier for more electric aircraft applications using wide band-gap materials

This paper presents a comprehensive study on the switching effects of wide bandgap devices and the importance of power electronics in an aircraft application. Silicon (Si), silicon carbide (SiC), and gallium nitride (GaN) are wide bandgap devices that act as a power electronic switch in the AC-DC converter for More Electric Aircraft (MEA) applications. Therefore, it is important to observe their converting efficiency to identify the most suitable wide bandgap device among three devices for AC-DC converters in aircraft applications to provide high efficiency and high-power density. In this study, the characteristics of Si, SIC, and GaN devices are simulated using PSIM software. Also, this paper presents the performance of the Vienna rectifier for aircraft application. The Vienna rectifier using Si, SiC, and GaN devices are simulated using PSIM software for aircraft application. GaN with Vienna rectifier provides better performance than Si and SiC devices for aircraft applications among the three devices. It gives high efficiency, high power density, low input current THD to meet IEEE-519 standard, and high-power factor at mains.

Modeling, Simulation and Control of Electrical Drives [Book News

Until recently, more than 50% of all electric power has been used by electric drives. This figure should further increase in the future. Recently observed rapid developments in power electronic semiconductor switches, sensors, and supporting embedded control products have inspired many new control techniques and machine designs that are important for modern electric drives. As a result, electric drive systems are being used in new applications that were once bastions of other technologies. The automotive traction drive system for electric vehicles is just one example.

Review on Reactive Power and Voltage Optimization of Active Distribution Network with Renewable Distributed Generation and Time-Varying Loads

With a high proportion of renewable distributed generation and time-varying load connected to the distribution network, great challenges have appeared in the reactive power optimization control of the active distribution networks. This paper first introduces the characteristics of active distribution networks, the mechanism and research status of wind power, photovoltaic, and other renewable distributed generators, and time-varying loads participating in reactive power and voltage optimization. Then, the paper summarizes the methods of reactive power optimization and voltage regulation of active distribution network, including multi-timescale voltage optimization, coordinated optimization of network reconfiguration and reactive power optimization, coordinated optimization of active and reactive power optimization based on model predictive control, hierarchical and zoning control of reactive power, and voltage and power electronic switch voltage regulation. The pros and cons of the reactive power optimization algorithms mentioned above are summarized. Finally, combined with the development trend of the energy Internet, the future directions of reactive power and voltage control technology in the active distribution network are discussed.

Research on real time simulation modeling method of large scale MMC electromagnetic transient

Modular multilevel converter (MMC) contains a large number of power electronic switching devices. The modeling method based on switching circuit model needs a lot of resources and the simulation speed is slow, so it is difficult to realize large-scale real-time simulation of electromagnetic transient. A MMC electromagnetic transient numerical modeling method based on ideal transformer model (ITM) is presented. Firstly, the MMC system is divided into the main circuit network and the sub module group network by ITM method, and the error caused by decoupling delay in serial and parallel real time simulation is compensated respectively by interpolation prediction and advanced interpolation prediction. Secondly, the capacitor in sub module is discreted respectively by trapezoidal integration method, backward Euler method and Gear-2 method. Based on the above numerical integration, the difference equations of capacitance voltage, capacitance current and output voltage of half bridge and full bridge sub modules are derived. Then, in order to improve the calculation speed, a simplified numerical model of half bridge and full bridge sub module based on switching function is proposed. Finally, the MMC based on switching circuit model runs off-line simulation in the simulation software, and the above MMC numerical modeling method runs real-time simulation in Speedgoat real-time simulator. The off-line and real-time simulation results of the MMC numerical modeling method and the switching circuit model are compared. And the simulation results verify the feasibility and effectiveness of the above MMC numerical modeling method in real time simulation.

New Three-Pole Combined Radial–Axial Magnetic Bearing for Industrial Bearingless Motor Systems

This article investigates combined radial–axial magneticbearing (CRAMB) technology as an enabling component for shafted bearingless motor systems. The unique requirements of high-speed bearingless motors designed for significant power levels are used to guide a literature review on CRAMB designs. Fundamental bearing topology aspects are identified and compared. Based on the outcome of this review, a new CRAMB topology is proposed and developed to meet the needs of a bearingless motor. Key features of the proposed design include a three-pole radial force stage (driven by a three-phase motor drive) and utilization of an optimal bias flux that improves radial force density by approximately 15% (improved rotor dynamics). A full design procedure for the new bearing topology is developed and it is shown that compared to a conventional four-pole side-by-side CRAMB, this topology decreases the bearing shaft length and requires two fewer power electronic switches (6 instead of 8). The new bearing is validated via finite-element analysis and experimental test results.

Design of Self-Powered Solid-State Fault Current Limiters for VSC DC Grids

Abstract-Fault current limiters (FCLs) can suppress the rise of short-circuit fault currents in voltage source converter (VSC) based DC grids. However, the power electronic switches of FCLs need extra source equipment to supply the required power, which increases complexity and cost. This paper presents three kinds of self-powered solid-state FCLs (SSFCLs). The proposed self-powered SSFCLs detect short-circuit faults by sensing fault current increases and draw energy from the fault DC line to automatically drive the power electronic switches. The self-powered SSFCLs are equipped with a self-powered supply system (SPSS). The SPSS obtains energy from the magnetic field induced by short-circuit fault current using magnetic-coupling mutual inductance coils. In PSCAD/EMTDC, the proposed self-powered SSFCLs are placed directly on the DC line without external power supply equipment. When a short-circuit fault occurs, the simulation results verify that the proposed self-powered SSFCLs can rapidly acquire power to drive the power electronic switches and then suppress the rise of the fault current. The proposed self-powered SSFCL prototypes provide a solution for decreasing the cost and complexity associated with installing extra source equipment.

Multilevel Inverter: A Survey on Classical and Advanced Topologies, Control Schemes, Applications to Power System and Future Prospects

In recent years, multilevel inverters (MLIs) have emerged to be the most empowered power transformation technology for numerous operations such as renewable energy resources (RERs), flexible AC transmission systems (FACTS), electric motor drives, etc. MLI has gained popularity in medium- to high-power operations because of numerous merits such as minimum harmonic contents, less dissipation of power from power electronic switches, and less electromagnetic interference (EMI) at the receiving end. The MLI possesses many essential advantages in comparison to a conventional two-level inverter, such as voltage profile enhancement, increased efficiency of the overall system, the capability of high-quality output generation with the reduced switching frequency, decreased total harmonic distortions (THD) without reducing the power of the inverter and use of very low ratings of the device. Although classical MLIs find their use in various vital key areas, newer MLI configurations have an expanding concern to the limited count of power electronic devices, gate drivers, and isolated DC sources. In this review article, an attempt has been made to focus on various aspects of MLIs such as different configurations, modulation techniques, the concept of new reduced switch count MLI topologies, applications regarding interface with renewable energy, motor drives, and FACTS controller. Further, deep insights for future prospective towards hassle-free addition of MLI technology towards more enhanced application for various fields of the power system have also been discussed. This article is believed to be extremely helpful for academics, researchers, and industrialists working in the direction of MLI technology.

A Novel Dual Slope Delta Modulation Technique for a Current Source Inverter Based Dynamic Voltage Restorer for Mitigation of Voltage Sags

This article investigates the use of a dual-slope delta modulation (DSDM) technique to control a dynamic voltage restorer (DVR) that can mitigate the voltage sag problems in power systems. Traditionally, the DVR uses a pulsewidth modulation technique to control the power electronic switches in a voltage source inverter (VSI). However, the VSI suffers from several disadvantages, such as ripples in the output voltage, high dv/dt, and high total harmonic distortion. To overcome these problems, this article proposes a novel DSDM technique for a current source inverter (CSI) based DVR. The proposed DSDM technique generates the switching pulses for the power electronic switches in the CSI to produce the required missing voltage waveforms with the necessary phase angle jump to restore the load voltage to its nominal value following power systems faults. The DVR usually requires an energy storage device to support the system voltage during voltage sag, which is referred to as a storage-energy-supplied (SES) DVR. However, the energy storage device makes the DVR bulkier and costlier. A line-energy-supplied (LES) DVR scheme has been proposed in the literature that can eliminate the need for the energy storage device and hence has the potential to reduce the cost of the DVR. To validate the proposed DSDM technique, different types of fault-induced voltage sags are simulated in a radial distribution system. The proposed DSDM technique is tested to control the CSI-based SES-DVR and LES-DVR to mitigate the voltage sag. The simulation results show that the proposed DSDM technique is effective to mitigate the voltage sags by accurately injecting the required missing voltage both in magnitude and phase angle.

The Effects of High-Frequency Residual Currents on the Operation of Residual Current Devices

This research investigates the effects of high frequency currents between 50 Hz and 150 kHz on the operation of Residual Current Devices (RCDs). Nowadays, the increasing amount of large power-electronic switching devices can be a source of both harmonics (&lt;2 kHz) and supraharmonics (2-150 kHz) currents injected to the grid. This can have several effects and possibly lead to unwanted tripping of RCDs, due to high earth-currents that can be emitted by the devices. The question is if supraharmonics can also lead to misoperation or fail-to-operate conditions for the RCDs, potentially leading to serious safety risks. A set-up is developed to introduce both 50 Hz and highfrequency leakage currents. First, the 50 Hz tripping-current of the RCDs is tested under nominal conditions. Secondly, the tripping current for non-nominal frequencies (between 50 Hz and 150 kHz) is determined to verify the possibility for false tripping. Lastly, the 50 Hz tripping current for the RCD is tested in the presence of a high-frequency current. The most important conclusion is that RCDs of type A and AC have an increased fundamental (50 Hz) tripping current when there are HFcomponents present. This potentially results in a safety risk.

Extended hybrid cross-switched multilevel inverter circuit topology

PurposeMultilevel inverters (MLIs) have been studied widely over the past two decades because of their inherent advantages and interesting features. However, most of the newly introduced structures suffer from the increased standing voltage of the switches, which is defined as the maximum off-state voltage on the switches, losing modularity and increased number of direct current (DC) voltage sources. The purpose of this study is to propose a new hybrid MLI topology to alleviate the mentioned problems.Design/methodology/approachThe proposed approach in this study includes using the advantage of two different topologies and combine them in a way that the advantages of both of the topologies are achieved. Therefore, the approach is to design a hybrid topology from two existing topologies so that a new topology has resulted.FindingsThis paper proposes a new hybrid MLI with lower power electronic switches and lowers DC voltage sources in comparison with the classic structures. The proposed MLIs maintain a balance between the number of switches, the standing voltage on the switches and the number of DC sources. The topology description, modulation method and comparative study have been presented. Also, another more reduced structure is presented for higher power factor operation. The MATLAB simulation and experimental results of a nine-level inverter have been presented to verify its operation.Originality/valueThe hybrid topology has a new structure that has not been presented before. It is important to emphasize that the topology combination and achieving the hybrid topology is wisely accomplished to improve some features of the MLI.

Independent predictive control with current limiting capability of three-phase four-leg inverter-interfaced isolated microgrids

Over-current restriction in converter-interfaced distributed energy resources within a microgrid is a crucial challenging issue, arising from the limited thermal capacity of power electronic switching devices. Available current limiting studies are only concerned with linear balanced loads, exerting poor voltage quality under unbalanced and/or non-linear loads. Moreover, they exhibit sluggish dynamic response, especially under heavy load conditions as well as at load dropouts. This paper proposes a novel control structure in conjunction with a peak detection-based current limiting function for droop-controlled converters with independently controlled neutral leg topology. Furthermore, a finite control set-model predictive control is designed and employed, allowing direct generation of the voltage switching signals, enabling aggregated voltage and current control. An auxiliary sliding mode control-based voltage controller is also utilized to provide reference current for the proposed current limiting strategy. Simulation results are examined on the isolated CIGRE benchmark low voltage microgrid. Comparison results demonstrate the excellent performance of the proposed control structure under various load conditions. Faster and robuster dynamic response and higher voltage quality delivery at output terminals are clearly observed. Lastly, the results are verified by real-time simulations.

Multi-Input Multi-Output Converter for Universal Power Conversion Operation

This novel converter proposes a Multiple Input and Multiple Output (MIMO) power conversion approach for step-up and step-down processes in AC-DC, DC-DC, AC-AC and DC-AC conversions. This versatile converter is designed by using power electronic switches, for AC-DC and AC-AC conversions thyristors are preferred, whereas DC-DC and DC-AC operations require both turn-on and turn-off control so that transistor (IGBT) is the most suitable switch. The proposed converter is highly recommended for multiple source and multiple output operations, but it can perform one conversion at a time. Power rating of the converter can be up to kilowatts during DC-DC and DC-AC conversions process and AC-AC and AC-DC conversions rating may extend up to megawatts. Simulation model of the MIMO converter is examined in the MATLAB simulink model and the same verified in the real-time test bench model. Conversion in all the stages can be controlled by a digital controller according to the requirement. All four conversions can perform step-up as well as step-down process, so design of inductor and capacitor values are very much important. All four modes of operations for thyristor-based transistors and two diode-based transistors are used to ensure switching operations. Novelty of the research work is conversion of power in all the modes can be bidirectional and also in single-stage process, but in the existing systems of power conversions is a unidirectional process. Proposed single-stage power conversion has more efficiency because of low switching losses. This proposed converter was designed by using mathematical analysis, tested at simulation level and verified in the real-time experiment.

Power Factor Corrected by Buck-Boost Converter type Battery Charger Employing PWM Technique with Capacitor Bank

In this paper, a buck-boost type battery charger is developed for charging battery set with a lower voltage. This battery charger is configured by a rectifier circuit, an integrated boost/buck power converter and a switched capacitors circuit. A boost power converter and a buck power converter sharing a common power electronic switch are integrated to form the integrated boost/buck power converter. By controlling the common power electronic switch, the battery charger performs a hybrid constant-current/constant-voltage charging method and gets a high input power factor. Accordingly, both the power circuit and the control circuit of the developed battery charger are simplified. The switched capacitors circuit is applied to be the output of the boost converter and the input of the buck converter. The switched capacitors circuit can change its voltage according to the utility voltage so as to reduce the step-up voltage gain of the boost converter when the utility voltage is small. Hence, the power efficiency of a buck-boost type battery charger can be improved. Moreover, the step-down voltage gain of the buck power converter is reduced to increase the controllable range of the duty ratio for the common power electronic switch. A prototype is developed and tested to verify the performance of the proposed battery charger

Carbon & boron substituted-Dibenzo[1,4]azaborinine as a quantum dot-based organic molecular single-electron device for high switching speed applications

The present work investigates the carbon & boron substituted-Dibenzo[1,4]azaborinine molecule as an island or quantum dot(QD) of an organic molecular single electron device(SED). The ‘carbon & boron substituted-Dibenzo[1,4]azaborinine(C13H9BN) as a QD’ is a modified variant of the acene group organic molecule ‘anthracene(C14H10)’, where boron atom are substitution of dangling hydrogens of middle honeycomb and nitrogen substitution of its parent molecule anthracene. Similar to anthracene, the carbon & boron substituted-Dibenzo[1,4]azaborinine is also made up of three linearly fused benzene rings, and has a planar structure with aromatic character. The carbon & boron substituted-Dibenzo[1,4]azaborinine molecule is considered as a QD owing to its impressive stability and conductance that originate from the aromaticity, making it ideal for low power electronic and high switching speed device applications. The calculations have been carried out using the tools AtomisticToolkit-Virtual Nanolab(ATK-VNL) and Gaussian09 packages, which is based on density functional theory (DFT), non-equilibrium green’s function (NEGF) formalisms and ab-initio approach. The charging energies in both isolated and SED conditions, total energy, and the charge stability diagram (CSD) as a function of bias potentials have been used to evaluate the device's efficiency. In comparison to anthracene based SED and its other acene organic molecular derivative SEDs, the proposed ‘carbon & boron substituted-Dibenzo[1,4]azaborinine as a quantum dot based organic molecular SED’ has high switching speed and power efficiency.

Improvement of DC Fault Current Limiting and Interrupting Operation of Hybrid DC Circuit Breaker Using Double Quench

In this paper, direct current (DC) fault current limiting and interrupting operation of hybrid DC circuit breaker (DCCB) using double quench, which consists of DCCB, a series resonance circuit, power electronic switch, surge arrestor, two separated current limiting reactor/resistor, and two superconducting elements, were suggested. The suggested hybrid DCCB can perform the interrupting operation after twice or once DC fault current limiting operation according to DC fault current amplitude. To verify the effective operation of the suggested hybrid DCCB, the modeling for the components of DCCB, the surge arrestor, and the SCE was carried out and its DC operational characteristics were analyzed. Through the analysis of the modeling results for the suggested hybrid DCCB, the advantages of hybrid DCCB were discussed.