130 kHz 7.5 kW current source inverters using static inductiontransistors for induction heating applications

A control scheme of a high-frequency high-power current source inverters using static induction transistors is described which aims at the suppression of the surge voltage and reduction of the switching loss during the commutation of current. The inverter is operated at a leading power factor, which requires the phase angle of the output current to be adjusted to each specific load point by the controller. The stable operation is verified by the experiments under the commutation inductance 1.8 μH, i.e., 18% reactance (130 kHz, 250 V, 30 A, base). As a result, the inverter efficiency is estimated to be 97%, excluding the loss of the drive circuit and the control circuit     

Optimized design of a merged bipolar MOSFET device

Numerical techniques have been applied to predict the steady-state characteristics of lateral bipolar-MOSFET (BIMOS) power switching devices. The BIMOS has the same structure as a lateral double-diffused MOSFET (LDMOS), with the p-type channel region acting as the base of an n-p-n transistor. By merging MOSFET and bipolar transistors in a lateral configuration, a monolithic power-integrated circuit is realized which retains some of the desirable features of both types of transistors for switching applications. Specifically, the structure of a switching device with low on-resistance high voltage capability, fast switching speed, and high input impedance is derived which does not require significantly increased device fabrication complexity. A special junction isolation design was used to limit the parasitic effects involving the substrate. These parasitic effects can degrade the performance of the BIMOS by reducing the gain of the n-p-n transistor and introducing a large substrate current. An off-state model has been developed in order to study the field shaping effects which occur with the inclusion of the junction isolation. The design is optimized to obtain a high-breakdown-voltage low-on-resistance parasitic-free monolithic-power integrated circuit.     

Protection and Switching-Aid Networks for Transistor Bridge Inverters

The present trend in the industry is towards the use of power transistors in the development of efficient Pulsewidth Modulated (PWM) inverters, because of their operation at high frequency, simplicity of turn-off, and low commutation losses compared to the technology using thyristors. But the protection of power transistors, minimization of switching power loss, and design of base drive circuit are very important for a reliable operation of the system. The requirements, analysis, and a simplified procedure for calculation of the switching-aid network components are presented. The transistor is protected against short circuit using a modified autoregulated and autoprotection drive circuit. The experimental results show that the switching power loss and voltage stress in the device can be reduced by suitable choice of the switching-aid network component values.     

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     

PWM Inverter Using High-Gain Pulse-Triggered Power Transistors and a New PWM Control Method

Rugged PWM transistor inverters are expected to be put into practical use for providing high reliability under adverse operating conditions. The bipolar power transistors are more common compared with MOSFET's power transistors in balance between power-handling capability and switching speed. High over current capability, low switching loss, high-speed switching, and high-current gain are requisite functions in the PWM inverter employing bipolar power transistors. These functions are of great concern in the power electronics field. A new PWM transistor inverter which can meet these requirements is presented in this paper. For this purpose, a concept of high-gain pulse-triggered power transistor (PTPT) with amorphous saturable current transformer (CT) is introduced.     

Leakage Biased pMOS Sleep Switch Dynamic Circuits

In this brief, a low-overhead circuit technique is proposed to simultaneously reduce subthreshold and gate-oxide leakage currents in domino logic circuits. pMOS sleep transistors and a dual threshold voltage CMOS technology are utilized to place an idle domino logic circuit into a low leakage state. A sleep transistor added to the dynamic node strongly turns off all of the high threshold voltage transistors. Similarly, a sleep switch added to the output inverter exploits the initially high subthreshold and gate-oxide leakage currents for placing a circuit into an ultimately low leakage state. The proposed circuit technique lowers the total leakage power by 56.1% to 97.6% as compared to standard dual threshold voltage domino logic circuits. Similarly, a 4.6% to 50.6% reduction in total leakage power is observed as compared to a previously published sleep switch scheme in a 45-nm CMOS technology     

中小功率三相高频节能型谐振极逆变器

作为中小功率发电系统重要环节的三相逆变器的开关频率增大时,开关损耗也显著增大,不利于节能。为实现中小功率三相逆变器的高频化和节能化,提出了一种三相零电压开关谐振极逆变器拓扑结构.当桥臂上的辅助谐振电路处于工作状态时,开关器件并联的电容的电压能周期性变化到零,使开关器件完成零电压软切换,这有利于高频金属氧化物半导体场效应晶体管（Metal Oxide Semiconductor Field Effect Transistor,MOSFET）作为逆变器的开关器件.分析了电路的工作流程,实验结果表明开关器件处于零电压软切换.因此,该拓扑结构对于研发高性能的中小功率三相逆变器具有参考价值.     

A 6.6-kV Transformerless Motor Drive Using a Five-Level Diode-Clamped PWM Inverter for Energy Savings of Pumps and Blowers

This paper describes a 6.6-kV adjustable-speed motor drive for pumps and blowers without transformer. The power conversion system consists of a front-end diode rectifier, a five-level diode-clamped pulsewidth modulation (PWM) inverter with a voltage balancing circuit, and a hybrid active filter for harmonic-current mitigation of the diode rectifier. The control of the inverter is characterized by superimposing a third-harmonic zero-sequence voltage on each of the three-phase reference voltages to achieve the so-called overmodulation and reduce the switching stress of insulated gate bipolar transistors (IGBTs). A 200-V 5.5-kW downscale model is designed, constructed, and tested with focus on the five-level PWM inverter and the voltage balancing circuit. Experimental results obtained from the 200-V downscale model verify the viability and effectiveness of the 6.6-kV adjustable-speed motor drive, showing that the four split dc capacitor voltages are well balanced in all the operating conditions and that the switching stress of the IGBTs is reduced at low modulation indexes.     

Analysis of the large-signal characteristics of powerheterojunction bipolar transistors exhibiting self-heating effects

The large-signal microwave characteristics of AlGaAs/GaAs heterojunction bipolar transistors (HBTs) are modeled using the conventional Gummel-Poon-based bipolar junction transistor (BJT) model and extending it to include self-heating effects. The model is incorporated as a user-defined model in a commercial circuit simulator. The experimental microwave characteristics of HBTs are analyzed using the new model and harmonic balance techniques and the impact of self-heating effects on the device large-signal characteristics is investigated. Use of constant base voltage rather than constant current is more suitable for achieving maximum output power. Self-heating induced by RF drive is reduced under constant base current conditions. Increased thermal capacitance values result in gain enhancement at high power levels     

中小功率三相高频节能型谐振直流环节逆变器

为使中小功率三相逆变器实现在高开关频率下的节能运行,首次提出了一种新型三相谐振直流环节逆变器拓扑结构.设置在逆变器直流环节的辅助电路参与换流过程时,桥臂输入端的直流环节电压能周期性形成零电压状态,主开关和辅助开关都能完成零电压软切换.在高频金属氧化物半导体场效应晶体管（Metal Oxide Semiconductor Field Effect Transistor,MOSFET）作为该逆变器的开关器件时,实现零电压软切换能消除MOSFET的容性开通损耗,有利于优化逆变器效率.文中分析了电路的工作流程.2.5kW样机上的实验结果表明开关器件都处于零电压软切换.因此,该拓扑结构对于研发高性能的中小功率三相逆变器具有参考价值.     

Design of LIGBT protection circuit for smart power integration

Development of a monolithic power integrated circuit by making the lateral insulated gate bipolar transistor (IGBT) the main switching device is a current topic. The overcurrent protection scheme is usually necessary to be built as part of the function in such a power integrated circuit. The protection circuit requires distinguishing various fault conditions and reacting differently based on the device safe operating area (SOA) limitation. At the same time, the protection circuit should also be relatively concise and suitable for integration. In this paper, a concise circuit suitable for integration and with gate drive capability is proposed to provide the complete function of overcurrent SOA protection for the LIGBT. The operational principle was described in detail and the circuit performance was verified with experimental results from both the discrete circuit and the fabricated LIGBT integrated circuit     

中小功率单相全桥节能型谐振极逆变器

中小功率单相全桥逆变器常以金属氧化物半导体场效应晶体管（Metal Oxide Semiconductor Field Effect Transistor,MOSFET）作为开关器件,为实现逆变器在高开关频率下的节能运行,本文提出了一种单相全桥节能型谐振极逆变器拓扑结构,其桥臂上分别并联相同的辅助谐振电路.桥臂上的主开关开通前,其并联的谐振电容的电压能周期性变为零,使主开关完成零电压软开通,可消除MOSFET的容性开通损耗,有利于逆变器的节能运行.本文分析了电路的工作模态,实验结果表明主开关器件处于零电压软切换.因此,该拓扑结构对于研发高性能的中小功率单相全桥逆变器具有参考价值.     

A 30 A 30 V DMOS motor controller and driver

A power DMOS half bridge (R_on=40 mΩ, 30-V operating voltage, 30 A peak current) for windshield-wiper motors is presented. Double speed (DC and 20 kHz PWM output), motor braking, full protection and fault detection functions, and timing sequence (up to 200 ms) are performed by an integrated circuit that integrates the pull-up power transistor as well as the signal circuits on a technology process that allows the integration of bipolar, CMOS, and power DMOS transistors. The power pull-down transistor is a discrete device mounted in the same power package (Multi-watt 11) on an isolated tab     

LD在开关电源驱动下的结温与输出特性研究

半导体激光器（LD）的驱动电路要求能够提供充足的载流子,且工作状态要稳定.从半导体物理学理论出发,分析了半导体激光器在恒流和稳压2种状态下,结电压、结电流和结温三者的关系.并以此为理论基础,进行了半导体激光器在双路跟踪电源恒流模式和开关电源LT1912驱动下的实验.实验结果表明,开关稳压电源驱动半导体激光器正常工作的核心条件是能够提供充足的载流子,即开关电源要具备低电压高功率的输出特性.开关稳压电源驱动半导体激光器的优点在于电路设计简单,不用考虑过流保护和过压保护电路,且半导体激光器的工作状态也很稳定.     

Class-E amplifier with an inductive impedance inverter

A design procedure and experimental results are presented for a class-E amplifier with an inductive impedance inverter. Experimental waveforms and characteristics measured at 1 MHz with an IRF620 MOSFET are given for the amplifier, which can operate under zero-voltage switching conditions for load resistances ranging from a short circuit to an open circuit. As the load resistance is increased at a fixed frequency, (1) the output power decreases, (2) a maximum efficiency of 96% occurs for optimum operation, (3) the peak values of the transistor voltage and the transistor current decrease, (4) the normalized peak values of the transistor voltage decrease, and (5) the normalized peak values of the transistor current increase     

Two-dimensional nonisothermal carrier flow in a transistor structure under reactive circuit conditions

The current density and temperature distribution in a bi-polar power transistor operating in the switching mode under transient conditions has been computed as a function of circuit environment. A modeling was done of the turnoff of the transistor in a circuit containing resistive and inductive elements. Of particular interest was the study of the local current and temperature distribution achieved in the transistor during turnoff in a circuit with a large inductance; in the process of shutoff this inductance maintains the transistor collector current at a high value as the collector junction undergoes avalanche multiplication due to the high voltage induced across this junction by the inductive load. The length of time that the transistor remains in the high-current high-voltage mode during the turnoff transient determines the extent of current crowding and local heating in the device. The method of computation was to solve numerically the electrical carrier flow as well as Poisson's and the heat-flow equations in a two-dimensional model of an n⁺-p-n-n⁺transistor structure, as a function of time. The electrical boundary conditions on the emitter, base, and collector contacts were determined by considering the transistors interaction with its electric circuit environment. This interaction was calculated at each step in time, in an iterative fashion, as the transistor was turned off by extracting current from its base lead. The study permits the evaluation of a given bipolar transistor design with respect to current crowding, heating, and impact ionization in switching circuits containing inductive loads.     

基于SET/MOS混合结构的译码器电路的设计

基于SET的I-V特性以及SET与MOS管互补的特性,以MOS管的逻辑电路为设计思想,首先提出了一个SET/MOS混合结构的反相器,进而推出或非门电路,并最终实现了一个唯一地址译码器.通过SET和MOS管两者的混合构建的电路与纯SET实现的电路相比,电路的带负载能力增强;与纯MOS晶体管实现的电路相比,电路同样仅需要单电源供电,且元器件数目得到了减少,电路的静态功耗大大降低.仿真结果验证了电路设计的正确性.     

New VVVF control-based high-frequency resonant inverters using static induction transistors

Voltage-fed high-frequency resonant inverters are proposed having a variable-voltage variable-frequency (VVVF) control function based on new circuit topologies called resonant voltage phasor controlled type and current phasor controlled type. The steady-state characteristics of the circuit topologies proposed are illustrated and the circuit design algorithm is described. A resonant voltage phasor controlled type high-frequency resonant inverter newly developed by using a static induction transistor (SIT) is applied as a 100-500 kHz induction-heating power supply. This paper thus refers to the results of an experiment including the optimum drive circuit of SITs.     

一种应用于PD的高精度限流保护调节电路

在POE(PowerOverEthernet)系统的终端受电设备中,限流保护调节电路保证了其稳定可靠工作。根据IEEE802.3af标准规定,受电设备开关电源启动到正常工作的过程中,电流要限制在100mA以内,在正常工作情况下电流要限制在390mA以下。本设计通过栅源比例电阻使采样功率管栅源电压与输出功率管的栅源电压保持一致,采样功率管精确采样输出功率管的电流值,采样电流经栅源比例电阻转换为电压后,调节输出功率管栅源电压,来完成PD(PowerDevice)限流保护。     

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.