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     

An active circuit for cancellation of common-mode voltage generatedby a PWM inverter

This paper proposes an active common-noise canceler (ACC) that is capable of eliminating the common-mode voltage produced by a pulsewidth modulation (PWM) inverter. An emitter follower using complementary transistors and a common-mode transformer are incorporated into the ACC, the design method of which is also presented in detail. Experiments using a prototype ACC, whose design and construction are discussed in this paper, verify its viability and effectiveness in eliminating common-mode voltage in a 3.7 kW induction motor drive using an insulated gate bipolar transistor (IGBT) inverter. Some experimental results show that the ACC makes significant contributions to reducing a ground current and a conducted electromagnetic interference (EMI). In addition, the ACC can prevent an electric shock on a nongrounded motor frame and can suppress motor shaft voltage     

High-efficiency dual transistor base drive circuit based on the Cukconverter topology

A dual transistor base drive circuit that unifies all important functions (on-state base current power supply for two power transistors, off-state negative U_be =-5 V base-emitter voltage, overcurrent and short-circuit protection scheme based on saturation voltage, and on- and off-state monitoring circuits) is described. The unit provides two base drive outputs using a single switching converter. It can be used to control two individual power transistors in different inverter configurations, e.g. common emitter or bridge configuration. The concept of a dual transistor base drive circuit using the Cuk switching regulator topology enables the low volume construction of a high-efficiency base drive unit for a high-power transistor inverter bridge leg. The circuit is powered from a common DC rail. The base current waveforms are characterized by steep slopes and an overcurrent peak at turn on     

A rugged soft commutated PWM inverter for AC drives

A novel DC-DC power converter for variable-speed AC power drives using the zero-voltage switching technique is described. This converter combines the advantages of soft commutated inverters and those of conventional pulsewidth modulated (PWM) inverters. In the proposed scheme, the soft commutation reduces the constraints on the switches, and the PWM enables simple and efficient regulation of the power flow. Furthermore, the zero-voltage switching technique makes operation safe, and the switching of bipolar transistors at 20 kHz is easily achieved without compromising the efficiency of the system     

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.     

Electrothermal simulation of an IGBT PWM inverter

An electrothermal network simulation methodology is used to analyze the behavior of a full-bridge, pulse-width-modulated (PWM), voltage-source inverter, which uses insulated gate bipolar transistors (IGBTs) as the switching devices. The electrothermal simulations are performed using the Saber circuit simulator and include control logic circuitry, IGBT gate drivers, the physics-based IGBT electrothermal model, and thermal network component models for the power-device silicon chips, packages, and heat sinks. It is shown that the thermal response of the silicon chip determines the IGBT temperature rise during the device switching cycle. The thermal response of the device TO247 package and silicon chip determines the device temperature rise during a single phase of the 60-Hz sinusoidal output. Also, the thermal response of the heat sink determines the device temperature rise during the system startup and after load-impedance changes. It is also shown that the full electrothermal analysis is required to accurately describe the power losses and circuit efficiency     

Reverse bipolar transistor conduction in high-current PWM inverters

Most PWM (pulse width-modulated) inverters using bipolar transistors experience the problem of reverse transistor conduction. This effect is analyzed for various types of base drives. It is shown to be the most serious for low-impedance direct drives. A model is developed for this case and verified experimentally. Problems associated with turn-on and turn-off in the reverse conduction mode are investigated. Various base drives, including both direct drives and Darlington configurations, are analyzed. Reverse transistor conduction is found to have the most serious implications for transistors driven directly by a low impedance source. Although discrete devices are discussed, the results also apply to integrated Darlington modules     

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     

Soft switching space vector PWM inverter using a new quasi-parallelresonant DC link

A soft switching quasi-parallel resonant DC-link (QPRDCL) inverter with improved PWM capability has been recently presented. The circuit has the minimum voltage stress of the devices and provides the flexibility of selecting the on/off instants of the resonant link, resulting in improved PWM capability. In this paper, the operational principles and the detailed analysis of the QPRDCL inverter are presented for the resonant components design and the inverter control. An SVPWM with optimal vector sequence suitable for the QPRDCL inverter is also presented through the comparisons among five different modified space vector PWM (SVPWM) techniques classified by the voltage vector sequences. The performance of the selected optimal SVPWM is verified by the experimental results     

A new single-phase five-level PWM inverter employing a deadbeat control scheme

A single-phase five-level PWM inverter is presented to alleviate harmonic components of the output voltage and the load current. Operational principles with switching functions are analyzed. To keep the output voltage sinusoidal and to have the high dynamic performances even in the cases of load variations and the partial magnetization in filter inductor, the deadbeat controller is designed and implemented on a prototype. The validity of the proposed inverter is verified through simulation and experiments. To assess the proposed inverter, it is compared with the conventional single-phase three-level PWM inverter under the conditions of identical supply DC voltage and switching frequency. In addition, it is compared with the five-level cascaded PWM inverter.     

New Lossless Turn-On and Turn-Off (Snubber) Networks for Inverters, Including Circuits for Blocking Voltage Limitation

Transistorized pulsewidth modulated (PWM) inverters require careful dimensioning of turn-on and turn-off circuits in order to minimize switching loss in the power transistors. New lossless circuits are described. In particular the turn-off circuits show a highly reduced part count compared to circuits known from the literature. The turn-on circuits apply energy recovery. Furthermore, due to a special circuit the voltage across the power transistor is strictly limited. This is important especially due to the usually low voltage blocking capability of high-current power transistors.     

Adaptive frequency domain control of PWM switched power lineconditioner

An adaptive frequency domain control algorithm for a pulse width modulation (PWM) switched active power line conditioner (PLC) is discussed. An active power line conditioner that minimizes harmonic current in the AC line and improves power factor to unity is recommended. A six switch pulse width modulated current source inverter implements the active PLC. Simulation results of the PLC adaptive frequency domain control using the PWM switching algorithm are presented     

A novel vector control scheme for transistor PWM inverter-fedinduction motor drive

A novel vector control scheme for a transistor pulse-width-modulation (PWM)-inverter-fed induction motor drive is presented. The system is based on a current control loop that consists of two independent nonlinear controllers that regulate the DC (field-oriented) components of the stator current vector. Three-level hysteresis comparators are used as current controllers. The outputs of the comparators select the appropriate inverter output voltage vectors via a switching erasable programmable ROM (EPROM) table. The theoretical principle of this method is discussed. Simulation and experimental results that illustrate the operation of the proposed system and performance in comparison with the other known schemes based on two-level hysteresis comparators are presented     

Control of Single-Phase-to-Three-Phase AC/DC/AC PWM Converters for Induction Motor Drives

This paper proposes a novel control scheme of single-phase-to-three-phase pulsewidth-modulation (PWM) converters for low-power three-phase induction motor drives, where a single-phase half-bridge PWM rectifier and a two-leg inverter are used. With this converter topology, the number of switching devices is reduced to six from ten in the case of full-bridge rectifier and three-leg inverter systems. In addition, the source voltage sensor is eliminated with a state observer, which controls the deviation between the model current and the system current to be zero. A simple scalar voltage modulation method is used for a two-leg inverter, and a new technique to eliminate the effect of the dc-link voltage ripple on the inverter output current is proposed. Although the converter topology itself is of lower cost than the conventional one, it retains the same functions such as sinusoidal input current, unity power factor, dc-link voltage control, bidirectional power flow, and variable-voltage and variable-frequency output voltage. The experimental results for the V/f control of 3-hp induction motor drives controlled by a digital signal processor TMS320C31 chip have verified the effectiveness of the proposed scheme     

Improved PWM Control Strategy for Inverters and Induction Motor Drives

This paper develops a novel pulse-width modulation (PWM) strategy for application in uninterruptible power supply (UPS) and ac motor drive systems. The voltage/current harmonic spectra and other properties of this PWM scheme are thoroughly investigated. This modulation strategy is compared with other modulation techniques, especially with the commonly used sinusoidal modulation scheme, from the standpoints of simplicity, inverter switching losses, motor losses, and other output performance features. This novel modulation scheme produces an acceptable motor curent waveform while keeping the number of inverter commutations low. Implementation of this scheme is quite simple in hardware-based as well as microprocessor-based systems.     

A new trench base-shielded bipolar transistor

In this paper, a new power bipolar transistor structure called the trench base-shielded bipolar transistor (TBSBT) Is proposed and experimentally demonstrated. This structure incorporates deep p⁺ poly-Si trenches into the base of a conventional bipolar transistor. With the base shielded effectively by the p⁺ trenches, the base of the TBSBT can be made very narrow to achieve high current gain h_FE and high cut-off frequency f_T without compromising on the breakdown voltage. Experimental results show that the on-state anti switching characteristics of the TBSBT are significantly better than those of the existing power bipolar transistors     

Novel zero-current-switching (ZCS) PWM switch cell minimizingadditional conduction loss

This paper proposes a new zero-current-switching (ZCS) pulsewidth modulation (PWM) switch cell that has no additional conduction loss of the main switch. In this cell, the main switch and the auxiliary switch turn on and turn off under zero-current condition. The diodes commutate softly and the reverse-recovery problems are alleviated. The conduction loss and the current stress of the main switch are minimized, since the resonating current for the soft switching does not flow through the main switch. Based on the proposed ZCS PWM switch cell, a new family of DC-to-DC PWM converters is derived. The new family of ZCS PWM converters is suitable for the high-power applications employing insulated gate bipolar transistors. Among the new family of DC-to-DC PWM converters, a boost converter was taken as an example and has been analyzed. Design guidelines with a design example are described and verified by experimental results from the 2.5 kW prototype boost converter operating at 40 kHz     

双极场引晶体管:I.电化电流理论(双MOS栅纯基)

本文描述双极场引晶体管(BiFET)及其理论.把两维晶体管分解成两个一维晶体管,得到解析方程.以表面势为参变量,采用电化(准费米)势梯度驱动力计算电流.提供实用电极直流电压及器件参数范围,随直流电压变化,输出和转移电流和电导.电子和空穴表面沟道同时存在,这新特点可以用来在单管实现CMOS电路倒相和SRAM存储电路.     

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.     

双极场引晶体管:I.电化电流理论(双MOS栅纯基）

本文描述双极场引晶体管(BiFET)及其理论.把两维晶体管分解成两个一维晶体管,得到解析方程.以表面势为参变量,采用电化(准费米)势梯度驱动力计算电流.提供实用电极直流电压及器件参数范围,随直流电压变化,输出和转移电流和电导.电子和空穴表面沟道同时存在,这新特点可以用来在单管实现CMOS电路倒相和SRAM存储电路.