Main Circuit Topology Research Articles

Retracted: Main Circuit Topology and Electromagnetic Interference of Electric Vehicle Bidirectional Charger

Retracted: Main Circuit Topology and Electromagnetic Interference of Electric Vehicle Bidirectional Charger

Multi-physics coupling analysis of high-power IGBT module bonding wires fault considering stray inductance of main circuit

The insulated gate bipolar transistor (IGBT) module is subjected to unbalanced electric-thermal stress for a long time due to its own turn-on and turn-off, the fluctuation of processing power and the change of external operating environment, resulting in fatigue failure. And there is a strong coupling effect between its electrical, temperature and mechanical properties. At the same time, the fatigue failure of IGBT module is also the result of multi-physical field coupling. This paper reveals the influence mechanism of main circuit stray inductance on the electric-thermal-stress coupling characteristics of high power IGBT module bonding wires fault in the context of mine-used inverter application. First, the inverter main circuit topology model considering stray inductance is constructed, and the loss value of the power chip is obtained based on extracting the busbar stray inductance and establishing the IGBT module behavior model, and the validity of the results is verified. Secondly, the package structure model of IGBT module is established and the failure analysis boundary conditions are determined, and then the joint circuit-finite element method is used to reveal the operation behavior characteristics of IGBT module under the combined action of multi-physical fields. Finally, the influence of main circuit stray inductance on the multi-physical field coupling characteristics of IGBT module and its change law are compared and analyzed under the bonding wires fault condition to study the causes of fatigue failure of IGBT module.

Main Circuit Topology and Electromagnetic Interference of Electric Vehicle Bidirectional Charger

In order to improve the electromagnetic compatibility performance of electric vehicle bidirectional chargers, the authors propose a main circuit topology and electromagnetic interference of the electric vehicle bidirectional charger. The design adopts the parallel connection of silicon carbide (SiC) MOSFETs and completes the bidirectional charging system based on the cascade connection of dual active bridge (DAB) and three-phase four-wire inverter. This paper mainly analyzes the influence of parasitic inductance on the drive and power loop of the T0-247 packaged switch in actual use, and according to the operating characteristics of the system, different gate resistors are used to reduce switching losses and improve system efficiency. And, we explore on how to reduce the overshoot voltage through the RC absorption circuit, thereby reducing the conducted interference. The result shows the following: the primary side absorption circuit resistance is 470 Ω and the capacitor is 47 nf, the secondary side absorption circuit resistance is 40 Ω and the capacitance is 4.7 nf, and the circuit power is 5000 W. Under the same conditions, without adding the RC absorption circuit, the conducted interference on the AC side does not meet the standard, and the amount of disturbance is large. After adding a suitable RC absorption circuit, the conducted interference on the AC side reaches the required value. Conclusion. This research provides a systematic design scheme and optimization method for designing power electronic devices using SiC.

Research on the STATCOM Mathematical Model of Battery Storage in HVDC Transmission System

When traditional STATCOM (Static Synchronous Compensator) performs large-capacity reactive power compensation, the control accuracy of the DC side voltage will be affected and the DC side voltage will fluctuate greatly. Therefore, this study proposes to use battery energy storage STATCOM (STATCOM/BESS) and gives the main circuit topology of STATCOM/BESS. By analyzing the working principle of STATCOM/BESS, the mathematical model and control method are derived and modeled, in which the Shepherd model is used as the energy storage battery in STATCOM/BESS. Aiming at the possible imbalance of the battery state of charge (SOC) in STATCOM/BESS, the phase-to-phase SOC balance control and phase control are proposed. At last, in PSCAD/EMTDC simulation software, STATCOM/BESS is tested for dynamic response and steady-state response performance of active power control, reactive power control, and transformation failure suppression test, which verifies the effectiveness and superiority of STATCOM/BESS commutation failure.

A Novel LED Driving Power Supply with High Power Factor and Low Total Harmonic Distortion

proposing a new type of LED driving power supply which is based on buck-boost cascade quad and analysing it in this paper. The main circuit topology structure is based on a quadratic buck and a buck-boost converter. They share the same switch through cascading which not only simplify the topology but also control strategy, reducing the cost of the control circuit. Eliminate the input current dead-time problem of the original quadratic buck topology by adopting two-stage cascade structure. The main circuit topology improves the power factor and ameliorates the input current THD as well. Meanwhile, making the duty cycle of the switch operates in a more plausible area. Finally, relevant experiments demonstrate that the theoretical analysis is correct.

Power Distribution Control Framework for Renewable Energy Architecture with Battery-Supercapacitor Based Hybrid Energy Storage Systems

Due to the intermittence and randomness of the renewable energy, hybrid energy storage system is widely adopted to suppress the power fluctuation. Power distribution is crucial for the robust and efficient operation of hybrid energy system. This paper proposes an innovative framework for hybrid energy storage system power distribution combining main circuit topology, modulation method and power distribution strategy. Firstly, hybrid modulation strategy to realize power distribution in a single-phase inverter is introduced. Then, power load prediction and low frequency filter are utilized to generate references for power distribution. Finally, the simulation model is established to test the framework and the result demonstrates the superiority of the proposed framework. The mean absolute percent error of the proposed SSA-LSTM mdoel is 0.0955 and the prediciton error by 40% compared with conventional LSTM model. Additionally, the energy management framework can adjust the port power distribution ratio flexibily to significantly suppress the power fluctuation of the grid and the operation cost of the hybrid energy storage system by reducing the charge and discharge cycle of the battery.

Research on Design and Simulation of Compound Voltage Quality Regulator

A voltage regulator based on cascaded multi-level structure is proposed. Based on the analysis of its working principle, the voltage quality problems (voltage sag, swell, voltage harmonics, Fluctuation, flicker) in the power quality appearing in the distribution network, the main circuit topology, control methods and compensation strategies are proposed. The regulator can compensate for various voltage quality problems. To ensure that the voltage quality is within the rated range, a simulation model of a cascaded multi-level composite voltage regulator is established in the simulation software, and it is verified that the design scheme proposed in this paper can solve various voltage quality problems in the distribution network.

A Review of Solid-State Circuit Breakers

Although conventional electromechanical circuit breakers have a proven record as effective and reliable devices for circuit protection, emerging power distribution technologies and architectures, such as dc microgrids, require improved interruption performance characteristics (e.g., faster switching speed). The need for faster switching operation, in combination with the latest developments of advanced power semiconductor technologies, has spurred an increase in the research and development in the area of solid-state circuit breakers. This article provides a comprehensive review of various solid-state circuit breaker technologies that have been reported in the literature during recent years. First, we categorize solid-state circuit breakers based on key features and subsystems, including power semiconductor devices, main circuit topologies, voltage clamping methods, gate drivers, fault detection methods, and commutation methods for power semiconductor devices. Second, we discuss the various challenges associated with the design of solid-state circuit breakers from the perspective of generic applications and provide a comparison of several solid-state breaker technologies based on key metrics. Finally, we provide a useful framework and point of reference for future development of solid-state circuit breakers for many emerging power distribution applications.

Research on three-phase four-wire active power filter based on LCLCL coupling structure

In this paper, the main circuit topology of the three-phase four-wire active power filter (APF) and its harmonic current detection and control algorithm are studied. An active power filter system combining LCLCL filter and a three-phase H-bridge structure is proposed. This paper has applied harmonic detection algorithm based on an improved synchronous phase-locked loop (SRF-PLL) and recursive discrete Fourier transform (RDFT) while using triangular carrier modulation control based on PI adjustment to realize the harmonic compensation of the power filter to the grid current. The system has a notch effect on the harmonic at the switching frequency. It can detect the fundamental component and each harmonic component of the load current separately with a small amount of calculation, good real-time performance. Finally, a 5KVA single-phase APF prototype was built to test the superiority of the main circuit topology and the algorithm of current detection and control.

A Phase-Shifted Full-Bridge Converter Used for DC Charging Pile

The zero-voltage switching (ZVS) phase-shifted full-bridge (PSFB) converter has the advantages of simple circuit topology, low voltage and current stress, and controllable working frequency. If applied to the dc charging pile, it can effectively reduce the switching loss and improve the overall operating efficiency of the power supply system. The working principle of ZVS PSFB converter is analyzed, and the main circuit topology of the converter is determined by combining with the technical specifications required by the dc charging pile. Based on PI control, wide range dc voltage output of converter is realized. Finally, PSIM is used to carry out simulation test on the PSFB converter, and the simulation results verify the correctness of ZVS operation and the effectiveness of closed-loop control.

A Turn-off Delay Controlled Bleeder Circuit for Single-Stage TRIAC Dimmable LED Driver With Small-Scale Implementation and Low Output Current Ripple

A single-stage TRIAC (TRIode for alternating current switch) dimmable LED (light emitting diode) driver using a buck converter fed through a capacitor input rectifier provides many advantages such as small-scale implementation, low output current ripple, and stable dimming operation. This circuit topology, however, has a serious issue: A large inrush current to the smoothing capacitor. To solve this issue, this paper focuses on a bleeder circuit in the TRIAC dimmable LED driver. This paper presents the mechanism of the large inrush current issue and its relationship to a conventional bleeder circuit. Moreover, this paper proposes a turn-off delay controlled bleeder circuit. The proposed bleeder circuit is analyzed by using its discrete-time state-space model in order to set proper circuit parameters for inrush current reduction. Experimental results demonstrate the inrush current reduction by the proposed method, which leads to a 37% reduction of maximum input current, as well as proper dimming operation and low output current ripple. The proposed method achieves further small-scale implementation, which enhances the advantages of the intended main circuit topology.

Dual Interleaved LLC Converter for High Power Applications and Wide Load Range

Dual interleaved LLC resonant converter with half bridge topology of main circuit characterized by high switching frequency (500 kHz), high power density (60 W/inch3) and high efficiency (above 96 %) over entire operational range (20 %–100 %) is described. Focus was given on the practical design of power converter, which will be able to fulfil requirements on wide load range operation characterized by upcoming normative. Since proposed topology is based on dual interleaved LLC converter, the resonant component´s critical tolerance was also investigated to secure reliable and optimal operational point. Consequently, proposals for elimination of intolerance negative impact are also described. The results of theoretical analysis were verified directly through experimental measurements. Experimental results are finally compared with upcoming industrial standard 80 Plus Titanium.

A Four-Winding Inductive Filtering Transformer to Enhance Power Quality in a High-Voltage Distribution Network Supplying Nonlinear Loads

This paper solves the problem of reactive power and harmonics compensation in a high-voltage (HV) distribution network supplying nonlinear loads. An inductive filtering (IF) approach where passive filters connect to the filtering winding of a four-winding inductive filtering transformer (FW-IFT) is presented to enhance the power quality of the public grid. This method can not only greatly suppress harmonic currents of the medium and/or low-voltage (LV) side, but also prevent them from flowing into the public grid. The new main circuit topology, where the FW-IFT has specific filtering winding by adopting the ampere-turn balance of the transformer, is presented. On the basis of the structure of the FW-IFT, the magnetic potential balanced equation and inductive filtering technology, its equivalent circuit and mathematical model are established, and the filtering performances are analyzed in detail. Simulation and experimental results rated at SN-10/0.38 of the FW-IFT are presented to prove the efficacy of the comprehensive enhancement of power quality on the grid side.

The design of the superconducting wiggler power supply system for HEPS-TF

PurposeThis paper describes the design of power supply system for superconducting wiggler in the project of high energy photon source-test facility. It includes three sets of high precision DC stabilized current power supplies for superconducting magnet excitation and three sets of quench protection assembly (QPA). A special magnetic load which has a very large time constant is studied in this paper. In this paper, a stable superconducting excitation power supply is developed, which can adjust the response quickly under the condition of very large load time constant. Meanwhile, the energy dissipation circuit of the QPA is integrated into the power supply in an active quenching protection mode to accelerate the energy release of the superconducting magnet and protect the superconducting magnet.MethodThe main circuit topology, control algorithm, quenching protection circuit and interlocking logic function are designed for the superconducting magnet with large inductance. The upper computer controls the switch of the three main power circuits through the serial port, sets the output current and adjusts the parameters according to the load.ConclusionThrough a series of scientific and rigorous experiments, the rationality of superconducting wiggler magnet power supply scheme is demonstrated. The output current stability test and output voltage ripple test of the power supply meet or exceed the requirements of the magnet system.

Suppression Methods for Low Frequency Oscillation of Wind Farm Considering SVG Minimum Output Dead Zone

At present, the research of Static Var Generator (SVG) mainly focuses on the main circuit topology, the optimization of control strategy, the method of selection, and lack of research on the low frequency oscillation of the wind farm caused by SVG minimum reactive output dead zone in practical engineering applications. For this reason, this paper first studies the mechanism of the low frequency oscillation of the wind electric field induced by the SVG minimum output dead zone of the wind farm, and discusses the conditions of this type of oscillation. On this basis, the automatic voltage control system (AVC) optimization model of wind farm is established with the minimum reactive variation of SVG output near the zero point as the optimization goal, and an optimization control strategy of wind farm with SVG minimum output reactive dead zone is proposed. Finally, the correctness of the result is verified by simulation. The results show that, due to the existence of the minimum output dead zone in the wind farm, the large reactive step may occur near the zero point of the SVG output, which causes the voltage low frequency oscillation of the wind farm. The optimization strategy proposed in this paper can significantly suppress the low frequency oscillation by coordinating and optimizing reactive power output near the zero point of multiple SVGs in wind farm.

Conceptual Design of the Power Supply System for the CFETR CS Model Coil

The central solenoid (CS) model coil (CSMC), which has a high stored energy, is developed to validate the CS manufacturing methods for the China Fusion Engineering Test Reactor (CFETR). The designed operation current of the model coil is 47.65 kA. The maximum rate of the magnetic field is 1.5 T/s. The stored energy of the model coil is 407.6 MJ. A set of verification test of the model coil will be conducted after manufacture, so a CSMC power supply, which generates the current for coil operation, and a quench protection, which could quickly release the stored energy, are required. The main circuit topology of power supply was designed according to the requirements of the testing current waveform. The current control was adopted, which controlled the actual output current provided by the power supply system to track any specified current reference of the model coil within acceptable precision. The design of the quench protection system for model coil was also described in this paper.

Research on Battery Energy Storage System Based on User Side

This paper introduces the effect of user side energy storage on the user side and the network side, a battery energy storage system for the user side is designed. The main circuit topology of the battery energy storage system based on the user side is given, the structure is mainly composed of two parts: DC-DC two-way half bridge converter and DC-AC two-way converter, a control strategy combining battery charging and discharging characteristics is proposed to decouple the grid side and the energy storage side, and the block diagram of the charging and discharging control of the energy storage system is given. The simulation results show that the battery energy storage system of the user side can not only realize reactive power compensation of low-voltage distribution network, but also improve the power quality of the users.

A Controllably Inductive Filtering Method With Transformer-Integrated Linear Reactor for Power Quality Improvement of Shipboard Power System

This paper proposes a controllably inductive power filtering (CIPF) method to improve the power quality of a shipboard power system (SPS). The main circuit topology for implementing the CIPF method in the SPS is presented, which contains a rectifier transformer integrated with linear filtering reactors, fully tuned branches, and a voltage-source inverter. The characteristic parameters of the rectifier transformer integrated with linear filtering reactors are investigated in detail by theoretical analysis. Furthermore, a mathematical model and an equivalent model are established to reveal the mechanism of harmonic suppression and the advantage of damping harmonic resonance of SPS. Moreover, a coordinated control strategy is designed based on the theoretical analysis. Finally, a detailed case study validates the proposed CIPF method and indicates that this method is suitable for SPS, because it can decrease the installed space and effectively prevent harmonic components from flowing into the generator side (power source), thus resulting in suppressing the vibration and noise pollution of the rectifier transformer. Besides, this method can effectively dampen harmonic resonance caused by the varied short-circuit capacity or the harmonic voltage in SPS.

A Virtual Impedance Comprehensive Control Strategy for the Controllably Inductive Power Filtering System

In this letter, a virtual impedance comprehensive control (VICC) strategy is proposed for the controllably inductive power filtering (CIPF) system with a new filtering mechanism. This control strategy aims to satisfy the zero-impedance design precondition of the inductive power filtering system, and can dampen the harmonic resonance at the grid side. By the proposed zero-impedance control, the quality factor of the passive power device can be adjustable, and the single-tuned filter can be multituned. First, the main circuit topology for implementing the VICC-based CIPF is presented. Then, on the basis of the multipurpose control, the VICC strategy is designed. Furthermore, by means of the established equivalent circuit model and the corresponding mathematical model, the principles of the harmonic damping and the zero-impedance realization are revealed. Finally, the experimental results verify that the proposed control strategy can weaken the harmonic amplification effectively, and improve the filtering performance significantly.

Adaptive Sliding-Mode With Hysteresis Control Strategy for Simple Multimode Hybrid Energy Storage System in Electric Vehicles

In this paper, a simple multimode hybrid energy storage system (HESS) is proposed for electric vehicles (EVs). Compared to the improved semiactive HESS, only two switches are added in the main circuit topology of the multimode HESS, thereby achieving the operating modes can be actively switched. The mode switch strategy is designed according to the driving modes of the EV and the status of the power sources. To improve the overall system efficiency of the multimode HESS, the boost converter will operate at the peak efficiency to convey the energy from the battery to the supercapacitor (SC). An adaptive sliding-mode control (ASMC) with hysteresis control (HC) strategy is also developed by combining practical application of the multimode HESS. Simulations and experiments are presented to verify the effectiveness of the proposed multimode HESS and its ASMC strategy. Simulated results show that the multimode HESS can select suitable operating modes in corresponding conditions. Compared to the total sliding-mode control strategy, experimental results demonstrate that the ASMC with HC strategy can improve the operating stability of the multimode HESS under different operating modes. The multimode HESS can not only switch to suitable operating modes, but also avoid the excessive output power of the battery to meet different power demands of the load. In addition, the SC absorbs all the braking energy such that the battery safety can be effectively ensured.