基于Saber的IGBT逆变桥无损缓冲电路的仿真分析

IGBT(绝缘栅双极型晶体管)缓冲电路对抑制IGBT开关过程中产生的尖峰电压具有重要作用。本文通过分析无损缓冲电路的原理及特点,结合原有RCD缓冲电路,探索研究了一种新的适用于IGBT逆变桥的无损缓冲电路,并采用Saber软件对两种电路进行了仿真分析,对比比较了两种缓冲吸收电路的优缺点。仿真结果验证了新无损缓冲电路抑制IGBT关断过电压的可靠性。     

大功率BUCK变换器电压电流尖峰的分析及抑制措施

在大功率Buck变换器中电路工作于高频开关状态,由于实际线路的寄生参数和器件的非理想特性的影响,开关器件两端会出现过高的电压和电流尖峰,严重地降低了电路的可靠性。本文详细分析了两种尖峰产生的原因和危害,有针对性地提出了几种RCL缓冲电路,并给出了电路各参数的分析和设计方法。仿真和使用结果证明了该缓冲电路具有良好的软开关效果,对于主开关管的电压尖峰和电流尖峰具有较强的抑制作用。     

大功率BUCK 变换器电压电流尖峰的分析及抑制措施y

摘要: 在大功率Buck 变换器中电路工作于高频开关状态, 由于实际线路的寄生参数和器件的非理想特性的影响, 开关器件两端会出现过高的电压和电流尖峰, 严重地降低了电路的可靠性。本文详细分析了两种尖峰产生的原因 和危害, 有针对性地提出了几种RCL 缓冲电路, 并给出了电路各参数的分析和设计方法。仿真和使用结果证明了 该缓冲电路具有良好的软开关效果, 对于主开关管的电压尖峰和电流尖峰具有较强的抑制作用。     

SiC MOSFET特性分析及应用

碳化硅MOSFET因其材料的特殊性,适合高压、高频和高功率密度场合。该文设计一种碳化硅MOSFET的驱动电路,通过软件PSpice对碳化硅MOSFET以及碳化硅肖特基二极管的开关特性进行仿真研究,并设计RC缓冲电路解决开关的尖峰震荡问题。搭建硬件实验电路,在Buck电路中针对碳化硅MOSFET和Si IGBT在不同负载和占空比下进行电路效率分析。实验结果表明碳化硅MOSFET开关速度快、开关损耗小以及驱动电阻小。碳化硅肖特基二极管无反向恢复特性,适合高频下工作。RC缓冲电路能有效抑制开关产生的尖峰和震荡,在Buck电路中碳化硅MOSFET比Si IGBT在不同负载和占空比下效率要高。     

一种新型ZVT—PWM软开关BOOST变换器

介绍一种带缓冲电路的新型零电压过渡PWM（ZVT－PWM）软件开关BOOST变换器,缓冲电路的加入,使主,辅助开关都能实现软化,减小了开关管的电压和电流应力,提高了整机效率,对电路的工作原理进行了详细分析,推导出了工作过程中各阶段的状态具体表达式,最后进行了仿真分析,并在此基础上进行实验验证,给出实验结果,实验证明,该电路结构简单,效率较高,具有一定的实用价值。     

基于并联型有源电力滤波器的电路设计

本文针对并联型有源电力滤波器(APF)的主电路及其外围电路进行了深入的研究,详细讨论了主电路开关器件的选择、缓冲电路的设计,并且采用理论分析和仿真实验相结合的方法,给出了直流母线电压的取值、直流母线电容量以及交流侧滤波电感值的选择方法。并根据上述分析方法得出了并联型APF的主电路具体器件选型及外围电路的详细设计参数。     

无源缓冲电路参数计算

针对开关电源功率开关管无源缓冲电路参数的确定问题，给出计算无源缓冲电路参数的方法。实践和试验证明，通过这种方法计算出的无源缓冲电路，对减小开关电路的骚扰具有明显的效果。     

无损缓冲电路与软件开关技术

本文扼要介绍了缓冲电路的产生与发展，今天无损缓冲电路已成为实现软件开关的重要技术之一。本文以单管功率变换电路为例，介绍了几种典型无损缓冲电路拓扑，介绍了缓冲原理与电路的特点，在此基础上总结了几点网络组成的方法。     

反激变换器缓冲回路的设计

变压器是反激式开关电源的核心,但在开关管关断过程中,变压器的漏感较大,能够引起较高的输出电压尖峰。通过分析反激变换器,旨在减少尖峰电压对电路的影响。文章比较RCD缓冲回路与LCD吸收回路:RCD缓冲电路的箝位电压随电阻减小而减小,但损耗增大;LCD缓冲电路的LC谐振频率要求小于开关频率;能量回馈缓冲电路的箝位电压较低,不需要额外的电感。最终给出了LCD吸收回路的设计方法,以达到较好的效果来减小尖峰电压对电路性能的影响。     

连续输出全集成开关电容带隙基准电路

本文提出了一种新型的开关电容带隙基准电路。电路采用双通道开关电容求和电路,能够连续输出基准电压,同时采用输出缓冲电路降低电压过冲,无需片外滤波电容。本设计采用NEC 0.35μm CMOS工艺,使用Hspice仿真软件对电路进行仿真。仿真结果表明:在典型参数情况下,该电路能够连续输出过冲为50μV的基准电压,在-20℃～80℃范围内,其输出电压的温度系数为15.4ppm/℃。     

A generalized Undeland snubber for flying capacitor multilevel inverter and converter

This paper proposes a snubber circuit for a flying capacitor multilevel inverter and converter. It also explains the concept of constructing a snubber circuit for a multilevel inverter and converter. The proposed snubber circuit makes use of an Undeland snubber as a basic snubber unit, and thus can be regarded as a generalized Undeland snubber for a flying capacitor multilevel inverter and converter. It has such an advantage of Undeland snubber used in the two-level inverter. Compared with a conventional RLD/RCD snubber for multilevel inverter and converter, the proposed snubber keeps such good features as fewer number of components, reduction of voltage stress of main switching devices due to low overvoltage, and improved efficiency of system due to low snubber loss. In this paper, the proposed snubber is applied to a three-level flying capacitor inverter, and its features are in detail demonstrated by computer simulation and experimental result.     

A new snubber circuit for high efficiency and overvoltagelimitation in three-level GTO inverters

A new low-loss snubber circuit including an overvoltage clamping circuit for a three-level gate-turn-off (GTO) inverter is presented. The proposed snubber circuit is effective in restriction of the dv/dt and the overvoltage values across each GTO at turnoff and the snubber loss is less than half that of the conventional RCD snubber circuit. In addition, there is no blocking voltage balancing problem between the inner and outer GTOs that occurs in the case where a conventional RCD snubber circuit is used in three-level inverter topology. Experimental results demonstrate that the proposed snubber circuit is very effective for a large capacity three-level GTO inverter     

A passive soft-switching snubber for PWM inverters

This paper presents a regenerative passive snubber circuit for pulse-width modulation (PWM) inverters to achieve soft-switching purposes without significant cost and reliability penalties. This passive soft-switching snubber (PSSS) employs a diode/capacitor snubber circuit for each switching device in an inverter to provide low dv/dt and low switching losses to the device. The PSSS further uses a transformer-based energy regenerative circuit to recover the energy captured in the snubber capacitors. All components in the PSSS circuit are passive, thus leading to reliable and low-cost advantages over those soft-switching schemes relying on additional active switches. The snubber has been incorporated into a 150 kVA PWM inverter. Simulation and experimental results are given to demonstrate the validity and features of the snubber circuit.     

Undeland缓冲电路在IGBT逆变桥中的应用

将Undeland缓冲电路用于IGBT逆变桥中,通过合理的归并元器件,提出了一种简单、实用的多桥臂逆变电路缓冲拓扑结构。并通过一个400 Hz逆变电路的仿真和实验波形得到验证。     

Passive snubber energy recovery for a GTO thyristor inverter bridgeleg

This paper presents a turn-on and turn-off passive energy recovery snubber circuit suitable for high-voltage high-power gate-turn-off thyristor inverter bridge configurations. The circuit recovers not only inductive turn-on and capacitive turn-off snubber energies, but also energies associated with freewheel diode reverse recovery. Energy is transferred back to the DC supply via a high-frequency transformer, that is fully reset. A method for reducing the transformer secondary diode voltage stress is presented. The performance of the circuit is supported by PSpice simulation, mathematical analysis, and practical results     

Symmetric GTO and snubber component characterization in PWMcurrent-source inverters

The pulsewidth-modulated (PWM) current-source inverter (CSI) used in AC motor drive applications can be implemented with symmetric gate turn-off thyristors (GTOs). One of the major difficulties in the optimization of the GTO switch and the snubber components of the inverter is the variation in different switching conditions encountered during normal operation. Past work has concentrated on the GTO and snubber components in voltage-source applications, where commutation of the GTO device is an independent process and does not affect the operation of the other inverter devices. This paper proposes the characterization of the GTO and the snubber components by formulation of the CSI equivalent circuit during the device commutation period. From the equivalent circuit, the state equations are derived, thereby obtaining accurate voltage and current waveforms of the GTO and associated snubbers. From the analysis, the component power loss can be calculated and optimization performed. Simulation results are verified by using both a laboratory prototype and medium-voltage drive system     

Simple passive lossless snubber for high-power multilevel inverters

A passive lossless snubber circuit for multilevel inverters is proposed in this paper. The topology is simple and requires no extra control circuit. In order to reduce the high-voltage stress on power switches with this snubber circuit, an improved snubber circuit is presented by adding separate low-power direct current voltage sources into the original one. The operating principles and design considerations are described in detail in this paper. A prototype of a three-phase three-level diode-clamped inverter with the improved passive lossless snubber is built and tested. The simulation and experimental results indicate that not only can it realize the soft switching operation of the three-level inverter with low-voltage stress but also the topology and the control are simple.     

A Nonisolated Single-Phase UPS Topology With 110-V/220-V Input–Output Voltage Ratings

A circuit configuration of a single-phase nonisolated online uninterruptible power supply (UPS) with 110-V/220-V input–output voltage ratings is proposed, allowing the bypass operation without a transformer even if the input voltage is different from the output voltage. The converter consists of an ac–dc/dc–dc three-level boost converter combined with a double half-bridge inverter. In this type of configuration size, cost and efficiency are improved due to the reduced number of switches and batteries, and also, no low-frequency isolation transformer is required to realize bypass operation because of the common neutral connection. Both stages of the proposed circuit operate at high frequency by using a passive nondissipative snubber circuit in the boost converter and insulated-gate bipolar-transistor switches in the double half-bridge inverter, with low conduction losses, low tail current, and low switching losses. Principle of operation and experimental results for a 2.6-kVA prototype are presented to demonstrate the UPS performance.      

Enhanced regenerative switching circuit for power transistors

The letter describes a novel combination of the conventional regenerative base drive circuit and the snubber circuit, which utilises the snubber current to accelerate the switching performance of a power transistor. The technique is particularly useful in high-frequency switch mode power supply applications.     

A high switching frequency IGBT PWM rectifier/inverter system forAC motor drives operating from single phase supply

A pulse width modulated (PWM) rectifier/inverter system using insulated gate bipolar transistors (IGBTs), capable of switching at 20 kHz is reported. The base drive circuit for the IGBT, incorporating short-circuit protection, is presented. The inverter uses an Undeland snubber together with a simple energy recovery circuit, which ensures reliable and efficient operation even for 20 kHz switching. The front end for the system is a regenerative single phase full bridge IGBT inverter along with an AC reactor. Steady-state design considerations are explained, and control techniques for unity power factor operation and fast current control of the front end power converter, in a rotating as well as a stationary reference frame, are discussed and compared. Results from computer simulations and experimental results for a 1.5 kW prototype system are presented