一种新颖的ZVZCS双管正激变换器

本文提出了一种新颖的、利用辅助电路实现零电压、零电流开关的双管正激变换器。其中,有源钳位辅助电路用来实现主开关管上的零电压开通,同时使该变换器的占空比拓展到50%以上;变压器副边的辅助电路用来实现主开关管以及副边二极管的零电流关断。因此,该变换器中全部开关管均工作在软开关状态下。与其他软开关双管正激变换器相比,该变换器具有结构简单、所用元器件最少等优点。最后,经过一台250W的样机检验,该变换器效率最高可达95.7%,非常适合IGBT应用的场合。     

Multiple output zero-current switching switched-capacitor bidirectional dc–dc converter

The proposed circuit is a multiple output quasi-resonant (QR) zero-current switching (ZCS) switched-capacitor (SC) converter with a bidirectional power flow control conversion scheme. The principles of the proposed multiple output QR ZCS SC bidirectional dc–dc converter are described using a detailed circuit model for analysis. Simulation and experimental results are carried out to verify the validity and the soft switching performance of the proposed converter. The maximum efficiency achievable is about 94 and 92% for the forward and reverse power flow control schemes, respectively. The output voltage can be regulated by changing the switching frequency for the designed compensated closed-loop controller.     

牵引用3 300 V平面栅IGBT栅极台面结构研究

针对机车牵引用3 300 V/1 500 A IGBT功率模块,采用TCAD仿真工具研究了不同栅极结构对器件静态和动态参数的影响。当平面栅IGBT采用栅极台面结构且台面厚度逐渐降低时,器件的静态阻断电压提高,开关损耗降低,但是器件的开关时间增加;此外,关断时过快的dv/dt会引起栅极电压振荡,开启时过快的di/dt会引起很大的电流过冲,导致器件应用的可靠性降低。在机车牵引的应用环境下,IGBT的栅极结构参数需要从电学参数和可靠性两个方面进行折中设计。     

A study of the internal device dynamics of punch-through andnonpunch-through IGBTs under zero-current switching

The effective use of power insulated gate bipolar transistors (IGBTs) requires a good understanding of their internal device physics. This understanding is essential for the optimal interaction among the IGBTs, their snubber elements and the power circuit in which the IGBTs operate. As switching frequencies are pushed to higher values, switching loss reduction becomes an essential part of the design and optimization process. Soft switching techniques such as zero-voltage switching (ZVS) and zero-current switching (ZCS) are widely used for this purpose. This study provides an insight into the internal dynamic behavior of IGBTs under zero-current switching. The latter is accomplished through mixed-mode simulation, providing the necessary insight for the improvement of circuit and device performance. In particular, the authors have analyzed the behavior of the negative current in nonpunch-through (NPT) devices after the first zero-current crossing and the effect of the turn-off delay on the tail current. They have also experimentally characterized punch-through (PT) and NPT IGBTs to confirm the insights provided by the mixed-mode simulation     

级联式Buck-Boost校正电路在高压电子镇流器中的应用

本文提出了一种带有无源无损缓冲结构的级联式buck-boost校正电路,并成功地应用在高压式电子镇流器中.缓冲电路通过抑制反向恢复电流所引起的di/dt和漏源极电压的dv/dt,有效地减少了开关损耗和EMI噪音.Buck电路中的IGBT实现零电流开通和零电压关断,同时续流二极管也工作在零电压状态.研制的380 V交流输入,400 V直流输出,额定功率600W的实验样机,其功率因数达0.98,THD小于11%.     

MCT与Clustered IGBT在大功率应用中的比较研究

针对两种应用于大功率领域的半导体器件——栅控晶闸管(MCT)和组合式绝缘栅晶体管(CIGBT),采用数值仿真软件进行了比较研究。静态仿真结果表明MCT具有更低的正向压降,只有CIGBT的50%左右,而CIGBT得益于其电流饱和特性,具有更大的短路安全工作区。开关仿真结果表明CIGBT具有比MCT更短的关断时间和更小的关断能量,更适合应用于高频领域。同时研究了MCT和CIGBT在脉冲放电应用中的特性,结果表明MCT具有更大的脉冲峰值电流和更快的电流上升率,并首次论证了脉冲放电过程中器件物理机制的区别。     

Multi-loop control for quasi-resonant converters

A multiloop control scheme for quasi-resonant converters (QRCs) is described. Like current-mode control for pulse width modulation (PWM) converters, this control offers excellent transient response and replaces the voltage-controlled oscillator (VCO) with a simple comparator. In this method, referred to as current-sense frequency modulation (CSFM), a signal proportional to the output-inductor current is compared with an error voltage signal to modulate the switching frequency. The control can be applied to either zero-voltage-switched (ZVS) or zero-current-switched (ZCS) QRCs. Computer simulation is method applied to a ZCS buck QRC. A circuit implementation is presented that allows multiloop control to be used on circuits switching up to 10 MHz. This circuit requires few components and produces clean control waveforms. Experimental results are presented for zero-current flyback and zero-voltage buck QRCs, operating at up to 7 MHz. Good small-signal characteristics have been obtained     

An improved zero-voltage and zero-current-switching full-bridge PWMconverter using a simple resonant circuit

An improved zero-voltage and zero-current-witching full-bridge pulsewidth modulation (ZVZCS-FB-PWM) DC-to-DC converter is presented and analyzed. An auxiliary resonant circuit, which consists of a switch and a capacitor, are added to provide zero-current switching (ZCS) conditions to the primary lagging-leg switches. Due to the auxiliary circuit, when the primary current is being extinguished, the voltage applied on the leakage inductance of the transformer is larger than DC-link voltage. This large voltage increases the maximal output current that can be handled in ZCS. Furthermore, the auxiliary switch softly turns on and turns off     

A ZCS Current-Fed Full-Bridge PWM Converter With Self-Adaptable Soft-Switching Snubber Energy

A new soft-switched, current-driven full-bridge converter is presented. The structure utilizes a simple snubber formed by two unidirectional switches and a capacitor to realize soft-switching operation over a wide line and load range. All primary-side switches are operated with zero-current switching (ZCS) and the snubber switches are operated with zero-voltage switching. The energy used for soft-switching is self-adaptable. For a given input current, the snubber capacitor is charged to the minimum required energy for ZCS of the switches. Thus, less resonant energy is used and the conduction loss can be kept minimal. The cyclical switching operation and control of the converter will be discussed. By compromising the voltage stress on the switches and loss of duty cycle (i.e., the regulation range), an optimized design procedure of the circuit elements is derived. The input voltage range and load variation that ensure both output voltage regulation and soft switching are determined. By studying the small-signal characteristics of the entire system, a current-controlled feedback control circuit has been implemented with a DSP. The experimental results measured on a 5-kW, 530-V/15-kV prototype confirms the advantages of the proposed converter.      

一类零电流谐振开关电容变换器的特性分析

具有零电流开关特性的谐振开关电容变换器是开关电容变换器的一种新拓扑形式.本文着重分析电路寄生参数和变换器运行条件对该类谐振开关电容变换器稳态特性的影响,推出变换器输出电压和效率的数学表达式,为研究负载或输入电压变化时变换器的输出性能提供了分析和设计依据.基于输出电压表达式,还提出谐振开关电容变换器的频率控制方案.全文以一个降压式谐振开关电容变换器为例详细说明公式的推导过程,并将此稳态特性分析推广到其它类型的谐振开关电容变换器.最后,文中设计了一台12V/5V/2.5A降压式谐振开关电容变换器样机,实验结果验证了本文的理论分析结果.     

节能型三相桥式零电流开关整流器

为使三相桥式整流器实现节能运行,提出了一种节能型三相桥式零电流开关整流器拓扑结构,在各相桥臂上的辅助谐振电路处于工作状态时,整流器的开关器件能完成零电流软关断.三相桥式整流器通常以绝缘栅双极型晶体管（Insulated Gate Bipolar Transistor,IGBT）作为开关器件,实现零电流软关断能消除IGBT拖尾电流产生的关断损耗.分析了电路工作过程,在三相3kW样机上的实验结果表明开关器件实现了零电流软切换.因此,该拓扑结构可实现以IGBT作为开关器件的三相桥式整流器的节能运行.     

高压大功率IGBT元器件开关特性的分析研究

自从IGBT器件出现之后,大量的研究人员对IGBT器件的开关特性进行了大量的研究,以便准确地预测和改善器件的开关瞬态特性.在实际应用中,IGBT器件的开关特性不仅和其物理结构、制作工艺以及工作的原理有着密切的关系,同时和其工作的环境也具有密切的关系.在IGBT器件工作的时候,常常受到驱动电压和电阻以及工作电压、集电极电流等的影响.因此研究工作环境对IGBT器件开关特性的影响,不断地改善其设计来优化其性能,成为研究的重点.论文详尽研究分析了功率器件IGBT的开关特性,对IGBT及其系统的理解、应用具有一定的指导意义.     

The complementary insulated-gate bipolar transistor (CIGBT)-a newpower switching device

A new power switching device, the complementary insulated-gate bipolar transistor (CIGBT), is described. The device achieves very high switching speeds typical of DMOS transistors, while it maintains the low on-state resistance of the insulated-gate bipolar transistor (IGBT) on which it is based. The device incorporates a p-channel MOS transistor which acts to draw excess charge out of the base region of the IGBT as the device is turned off. Fabricated devices whose specific on-resistance is only 20% greater than that of equal-area IGBTs display turn-off times under 700 ns, while the IGBTs require 35 μs to reach the off state. The device is compared to equal-area IGBTs, DMOS transistors, and IGBTs whose minority-carrier lifetime has been reduced to achieve 700-ns turn-off times     

Optimum buck converter with a single switch

A new DC-DC power converter with only one active switch operating at a constant switching frequency and with low-current and voltage stress is proposed. The conduction losses are minimized because of the ability to use a minimum number of elements in the path of direct energy transfer from the input to the load. Furthermore, because only one switch is used, the design of the control circuit is greatly simplified. The new power converter achieves soft switching for the diodes and zero-current switching (ZCS) at turn on for the active switch     

节能型单相全桥零电流开关谐振极逆变器

为改善以绝缘栅双极型晶体管（Insulated Gate Bipolar Transistor,IGBT）作为开关器件的单相全桥逆变器的效率,提出了一种节能型单相全桥零电流开关谐振极逆变器,在每个桥臂上分别并联1组辅助电路.在工作过程中,主开关和辅助开关都能完成零电流软切换,可消除IGBT拖尾电流造成的关断损耗.分析了电路工作过程,在2kW样机上的实验结果表明开关器件实现了零电流软切换.因此,该拓扑结构可实现以IGBT作为开关器件的单相全桥逆变器的节能运行.     

A new two-quadrant zero-current transition converter for DC motor drives

A new two-quadrant (2Q) zero-current-transition (ZCT) converter with the capabilities of 2Q power flow and ZCT switching profile for DC motor drives is presented. It possesses the advantages that both the main and auxiliary switches can operate with zero-current switching (ZCS), reduced switching losses and stresses, minimum voltage and current stresses as well as minimum circulating energy during both the motoring and regenerating modes. It also offers simple circuit topology, minimum component count and low cost. This converter is particularly useful for DC traction systems in which both motoring and regenerative braking are desired to have high efficiency. The corresponding theoretical analysis and its high-efficiency performance are supported by both simulation and experimental results.     

A new single-phase ZCS-PWM boost rectifier with high power factor and low conduction losses

This paper proposes a new single-phase high-power-factor rectifier, which features regulation by conventional pulsewidth modulation (PWM), soft commutation, and instantaneous average line current control. A new zero-current switching PWM (ZCS-PWM) auxiliary circuit is configured in the presented ZCS-PWM rectifier to perform ZCS in the active switches and zero-voltage switching (ZVS) in the passive switches. Furthermore, soft commutation of the main switch is achieved without additional current stress by the presented ZCS-PWM auxiliary circuit. A significant reduction in the conduction losses is achieved because of the following reasons: 1) the circulating current for the soft switching flows only through the auxiliary circuit; 2) a minimum number of switching devices are involved in the circulating current path; and 3) the proposed rectifier uses a single converter instead of the conventional configuration composed of a four-diode front-end rectifier followed by a boost converter. Seven transition states for describing the behavior of the ZCS-PWM rectifier in one switching period are described. The PWM-switch model is used to predict the system performance. A prototype rated at 1 kW, operating at 60 kHz, with an input alternating current voltage of 220 V/sub rms/ and an output voltage of 400 V/sub dc/, has been implemented in laboratory. An efficiency of 98.3% and a power factor over 0.99 have been measured. Analysis, design, and the control circuitry are also presented in this paper.     

Design considerations of IGBT's in resonant converter applications

The switching dynamics of insulated gate bipolar transistors (IGBT's) in zero voltage switching (ZVS) resonant converter applications is studied and optimized using an advanced mixed device and circuit simulator. It is shown that bipolar and MOS device parameters must be carefully optimized to obtain the lowest total power loss. A simple circuit simulation model was used in an advanced behavioral circuit simulator where the model parameters were extracted from mixed device and circuit simulations. Performance analysis of a typical series resonant converter (SRC) shows that ZVS condition is more favorable than the zero current switching (ZCS) condition from the standpoint of obtaining efficient power conversion. It is shown that IGBT's with narrower source result in lower total switching power loss     

Turn-Off Behavior of 1.2 kV/25 A NPT-CIGBT Under Clamped Inductive Load Switching

For the first time, this paper analyzes the turn-off behavior of the planar 1.2 kV/25, A nonpunch-through clustered insulated gate bipolar transistor (NPT-CIGBT) under clamped inductive load switching, in detail and through experiment simulation. Turn-off behavior of the CIGBT involves strong interaction between device and circuit parameters. The circuit parameter such as gate resistance was varied in order to observe the dlldt, dV/dt, and turn-off energy loss of the device. Experimental results are shown at 25degC and 125degC. In addition, numerical simulation results are used to enhance understanding of the internal physics of the NPT-CIGBT turn-off process.     

IGBT dynamics for clamped inductive switching

Clamped inductive switching performance of insulated gate bipolar transistors (IGBTs) have been studied in detail with the aid of extensive measurements and numerical simulations. Internal dynamics of a latch-up free punch-through IGBT during clamped inductive switching is studied using two-dimensional (2-D) mixed device and circuit simulations incorporating the self-heating mechanism. Failure of IGBT during inductive load turn-off is shown to occur due to thermally assisted carrier multiplication at the reverse biased p-base n-drift region junction under the emitter contact