IGBT Switching Research Articles

Passive Snubber for Reducing Switching-Power Losses of an IGBT in a DC–DC Boost Converter

A passive snubber for an IGBT in a dc-dc boost converter is proposed. The snubber consists of one inductor, two capacitors, and two diodes. It improves the power-conversion efficiency significantly by providing zero-current turn-on and zero-voltage turn-off conditions for an IGBT, without increasing the voltage stress of an IGBT. When the snubber was adapted to the conventional dc-dc boost converter and tested at an output power of 300 W and a switching frequency of 180 kHz, the current noise level of the input current decreased by ~30 dB at a frequency range of 2.5-48 MHz, and the power-conversion efficiency increased by ~7.5% for both the MOSFET and IGBT switches. Also, the temperature of switch was stabilized at ~60 °C, while the IGBT failed in the conventional boost converter. These experimental results show that the proposed snubber is useful for solving the reliability problem of boost converters.

LOW SPEED OPERATION OF DSP BASED PWM CONTROL OF 4 PHASE 8/6 SWITCHED RELUCTANCE MOTOR DRIVE

This paper presents the speed control of 4 phase 8/6 Switched Reluctance Motor drive with PWM controller. The motor is fed from an Asymmetrical bridge converter, because of its fault tolerant capability and all the phases are independently excited. The Hall sensors provided in the motor provide signals corresponding to the position of the rotor. The speed is controlled by varying the duty ratio of the PWM controller. The pulses to the IGBT switches are generated using a Digital Signal Processor. The SRM drive with PWM controller is simulated in MATLAB/SIMULINK and also experimentally implemented at no load & partial load. The waveforms of the PWM signals and phase currents are captured by means of Digital storage oscilloscope and compared with the simulation results.

English

Many existing and developing electrical and electronic technologies require voltages of different levels supplied from a singular available source voltage such as a battery. DC converters are devices designed specially for the purpose of changing DC voltage levels efficiently. The converters are electronic devices, it has an output voltage magnitude that is either greater than or less than the input voltage magnitude. Rising energy intensity leads to a higher cost of delivering power and low power density. Meanwhile, the demand for compact power supplies grows significantly. It requires power supplies with high efficiency, low cost and smaller size. In order to control the output voltage of the converter, the controller is designed to change the duty cycle of the converter. In this converter IGBT switch is digitally controlled by PIC microcontroller. In this work simulation and then hardware implementation is done with results. The converter is mainly used, where load is very sensitive (battery - powered products), it provides variation of _1% only.

10KW/100KHZ High Frequency Induction Heating Power Supply Design

TMS320F2812 was taken as the main controlling chip, MOSFET was taken as the inverter switching device and IGBT was taken as the chopper switching device in the system. This paper introduced the main topology circuit design and circuit components selection.In the process of heating, double-closed loop control strategy fuzzy and DPLL (Digital Phase Locked Loop) was adopted. The simulation model of induction heating power system was built in SIMULINK platform. The simulation results indicate that the load frequency automatic tracking and closed-loop power control are realized. The time to steady output is about 0.1ms. Finally, built the 10kW/100kHZ induction heating power supply experimental platform, As can be seen from the experimental waveforms, the equivalent impedance of the load can always be weakly perceptual state.

A study on IGBT junction temperature (Tj) online estimation using gate-emitter voltage (Vge) at turn-off

A novel method is presented for online estimation of the junction temperature (Tj) of semiconductor chips in IGBT modules, based on evaluating the gate-emitter voltage (Vge) during the IGBT switch off process. It is shown that the Miller plateau width (in the Vge waveform) depend linearly on the junction temperature of the IGBT chips. Hence, a method can be proposed for estimating the junction temperature even during converter operation – without the need of additional thermal sensors or complex Rth network models. A measurement circuit was implemented at gate level to measure the involved time duration and its functionality was demonstrated for different types of IGBT modules. A model has been proposed to extract Tj from Vge measurements. Finally, an IGBT module with semiconductor chips at two different temperatures has been measured using Vge method and this method was found to provide the average junction temperature of all the semiconductor chips.

A Preliminary Study on CSAMT Anti-Jamming Transmitter System

On the basis of the relevant identification theory of pseudo-random code signal, the signals of CSAMT are divided into three parts according to the frequency of the signal. The signals which are susceptible to 50Hz interference signal and its harmonic components should be set by pseudo-random code way. Others are set by single square waveform way. The Control and signal generation software of the transmitter system is built on the advanced virtual instrument platform, LabVIEW. The hardware of the transmitter system is mainly composed of host computer, data acquisition card, high-speed optocoupler, IGBT driver module and four IGBT switches. The data acquisition card generate PWM signals, the high-speed optocoupler isolates low-voltage part and high-voltage part. IGBT drive module and four IGBT switches constitute high-voltage part. Entire transmitter system is suitable for different environments and research tasks, the transmit frequency are adjustable, and the pseudo-random code signal has strong capability to suppress the interference signals. The control software on host computer is simple and clear. There is good prospect for the use.

Optimization of a PIII&D System Using a Cathodic Arc with Titanium

A plasma immersion ion implantation and deposition (PIII&D) system was recently built at INFIP. A dc cathodic arc with a Ti cathode of 5 cm in diameter and an annular anode of 8cm in diameter was employed as the plasma source. The substrate chamber was electrically insulated and connected with the main discharge chamber through a straight magnetic duct. The discharge current was run at 100 A. The substrate was biased with a pulsed generator (30 kV, 30 A, 0.05 – 3 kHz) based on a pulse transformer controlled by IGBT switches. In this work the optimization of the process as function of the pulse parameters is presented. The characteristics of Ti coatings on steel substrates obtained varying the pulse amplitude from 2 to 12 kV and the pulse frequency from 200 Hz to 400 Hz were analyzed and compared with films grown without biasing the substrate. The thickness was determined weighting the samples before and after the treatment. The morphology was observed with an atomic force microscope. The film structure was studied by x-ray diffraction.

Repetitive high voltage pulsed power for polytetrafluoroethene film surface processing

In order to explore the effect of the pulse power discharge and surface processing on polytetrafluoroethene(PTFE) film, we used the means of pulse transformer to set up a repetitive rating high voltage pulse power with the semiconductor solid switch IGBT, and finally achieved the target, a variable voltage amplitude of 15-20 kV, a pulse width of 10-15 s, a pulse rise time of about 1-3 s, and a variable repetitive rating 10-15 kHz. Meanwhile, we had a measurement for the water contact angle of the PTFE film before and after processing, and found that the water contact angle decreased from 112 to about 85.

Next Generation High Power Electronic Modules Based on Embedded Power Semiconductors

The spectrum of conventional power electronics packaging reaches from SMD packages for power chips to large power modules. In most of these packages the power semiconductors are connected by bond wires, resulting in large resistances and parasitic inductances. Power chip packages have to carry semiconductors with increasing current densities. Conventional wire bonds are limiting their performance. Today's power modules are based on DCB (Direct Copper bonded) ceramic substrates. IGBT switches are mounted onto the ceramic and their top side contacts are connected by thick Al wires. This allows one wiring layer only and makes an integration of driver chips very difficult. Additionally bond wires result in a high stray inductance which limits the switching frequency. Especially for the use of ultra-fast switching semiconductors, like SiC and GaN, it is very difficult to realize low inductive packages. The embedding of chips offers a solution for many of the problems in power chip packages and power modules. While chip embedding was an academic exercise a decade ago, it is now an industrial solution. A huge advantage of packaging using PCB technology is the cost-effective processing on large panel. Furthermore embedded packages and modules allow either double-side cooling or 3D assembly of components like capacitors, gate drivers or controllers. The advanced results of research projects will be discussed in the paper. An ultra-low inductance power module with SiC switches at 20 A / 600 V has been realized and characterized. The DC link inductance of the module was 0,8 nH only. These results sparked a huge interest in currently starting follow up projects creating package for fast switches. In a further project power modules for automotive power inverters for motor control are under development. As a project demonstrator, a 10 kW module with IGBTs and diodes at 400 V / 500 A, was manufactured. This demonstrator is based on high power PCB technology and was fully characterized; the results will be presented in detail. Recently started research projects will face the challenges of MW solar inverters at 1000 A and 1000 V, using SiC semiconductors as switches. First concepts will be presented as an outlook.

Zero Voltage Switching Converters

In this paper zero voltage switching converters are investigated. The investigation starts by discussing the RCD charge-discharge snubber. The concept of resonant and quasi-resonant DC link converters is discussed. One of the most promising quasi-resonant DC links reported in the literature is implemented and tested in a battery charger application. Simulated resonant link voltage and current waveforms are analyzed. IGBT switching waveforms under zero voltage conditions are investigated. Measured waveforms are shown and the converter and the overall battery charger efficiency are measured.

Digital Simulation and Analysis of Six Modes of Operation of BLDC Motor Drives Using Hysteresis Band PWM Switching Scheme

Permanent magnet Brushless DC (BLDC) motors are gaining popularity mainly because of their better characteristics and performance in comparison to other electrical motors. BLDC motors are generally controlled using a three phase power semiconductor bridge. For starting and providing proper commutation sequence to turn on the power devices in the inverter bridge, the rotor position sensors are required. Based on the rotor position, the power devices are commutated sequentially every 60 degrees. This paper presents MATLAB/SIMULINK based simulation of BLDC motor drives. BLDC motor drive operates in six modes for one complete revolution of the rotor. The complete analysis of six modes of operation with position of rotor has been presented in this paper. The switching of the IGBT switches and corresponding phase currents and line voltages are shown here for each sequence. The presented BLDC motor drive is based on hysteresis band PWM current controller for generating modulated switching signals.

3상 3.3kV/220V 6kVA 모듈형 반도체 변압기의 프로토타입 개발

This paper describes a prototype of 3-phase 3.3kV/220V 6kVA modular semiconductor transformer developed in the lab for feasibility study. The developed prototype is composed of three single-phase units coupled in Y-connection. Each single-phase unit with a rating of 1.9kV/127V 2kVA consists of a high-voltage high-frequency resonant AC-DC converter, a low-voltage hybrid-switching DC-DC converter, and a low-voltage hybrid-switching DC-AC converter. Also each single-phase unit has two DSP controllers to control converter operation and to acquire monitoring data. Monitoring system was developed based on LabView by using CAN communication link between the DSP controller and PC. Through various experimental analyses it was verified that the prototype operates with proper performance under normal and sag condition. The system efficiency can be improved by adopting optimal design and replacing the IGBT switch with the SiC MOSFET switch. The developed prototype confirms a possibility to build a commercial high-voltage high-power semiconductor transformer by increasing the number of series-connected converter modules in high-voltage side and improving the performance of switching element.

Real-time performance analysis and comparison of various control schemes for particle swarm optimization-based shunt active power filters

Selection of proper reference compensation current extraction scheme plays the most crucial role in the performance of an active power filter (APF). This paper mainly describes three different control schemes used in APFs namely, Conventional instantaneous active and reactive power (p–q), Modified p–q, and Instantaneous active and reactive current component (id–iq) schemes. Our objective here is to bring down the total harmonic distortion (THD) of source current sufficiently below 5% at the point of common-coupling (PCC), in order to satisfy the IEEE 519-1992 Standard recommendations on harmonic limits. Comparative evaluation of the three control schemes shows that, id–iq method is the best control scheme to be implemented on shunt APFs, irrespective of the supply voltage conditions, even under sudden load fluctuations. Results have been validated using MATLAB/Simulink simulations followed by real-time performance verification in Opal-RT Lab simulator. Here, the APF is comprised of a voltage source inverter (VSI) based on pulse-width modulation (PWM) technique. Hence, undesirable power loss takes place inside VSI due to the presence of inductors and frequent switching of IGBTs. This is effectively minimized with inverter DC-link voltage regulation using a PI controller, whose gains are optimized using particle swarm optimization (PSO).

TEMPERATURE CALCULATION OF IGBT MODULE FREQUENCY CONVERTOR AT START OF INDUCTION MOTOR

The most effective and economical way to a smooth start and control the rotor speed of the induction motor is to change the frequency of the voltage supply. During acceleration of the motor it is necessary to ensure not only the actuator static torque, and the dynamic inertia overcoming. Thus, the value of the dynamic moment of inertia depends on the time of increasing the motor rotational speed. To overcome this dynamic torque on the engine during acceleration, stator windings create additional magnetic field due to increase current consumption. Typically, it is desirable that the duration of the engine acceleration was minimal, i.e. , the acceleration is maximized. This may cause excessive increase in the output current of the frequency converter and damage of bipolar transistors with insulated gate (IGBT), which power switches are used. To ensure reliable operation of AC Drivers the method to perform calculations to determine the type of IGBT module, temperatures structures of transistor and inverse diode of the inverter, when starting the engine, depending on the load torque and the moment of inertia of the actuator is proposed. Method for determination of the values of the polynomials coefficients that approximate energy IGBT switching losses and reverse diode recovery losses depending on the value of the collector current IGBT is proposed. A method for determination of the required values of heat sink thermal resistance, which cool IGBT module is proposed. Charts of the transistor temperature dependence and inverse diode values of the acceleration duration and of induction motor inertia – the actuator are shown.

Design and Optimum Arrangement Of 3-phase Cascade Multilevel Inverter for Control of DTC Induction Motor

In present days the Multi level inverter increasing popularly especial in high power and high voltage applications. The Multi level inverter having new set of features. When the level is increasing and output become nearly sinusoidal. When the sinusoidal means the output voltage having less losses the more levels of output voltage produces different methods is there the cascade H bridge is the most efficient method .In my project cascade H bridge used to producing more levels of output voltages in cascade H bridge. In this cascade H bridge two types of arrangement they are symmetrical and asymmetrical .In this cascade H bridge I find out experimentally that the asymmetrical Multi level inverter is most efficient method than the symmetrical method by using DTC technique. The DTC technique provides ripple losses and friction losses reduce. So the induction motor having the most efficient .Here we are using IGBT switching and for the controlling purpose uses the state vector modulation. The cascade out experiment show that an asymmetrical configuration provides nearly sinusoidal voltages with low distortion using less switching devices moreover torque ripples are reduced.

GENERATION OF RECTANGULAR BIPHASIC WAVEFORM TO DECREASE DEFIBRILLATION THRESHOLD FOR EXTERNAL DEFIBRILLATOR

Studies have shown that defibrillation threshold for current amplitude of biphasic truncated exponential (BTE) waveform has a hyperbolic strength–duration relationship. Theoretical and experimental results have shown that decreasing the tilt of BTE waveforms decreases the defibrillation threshold. On the other hand, low peak current waveform reduces probability of myocardium damage and burn. Therefore, achieving a waveform with low tilt and low peak current is desired. All DC defibrillators use a capacitor to store and deliver required energy. Because of capacitor discharging nature, the tilt of waveforms is high. In rectilinear biphasic waveform (RBW), which was generated by ZOLL M-series defibrillator, the tilt of the first phase was decreased using an adjustable resistor connected in series with current path. But the defibrillator cannot keep the current constant in the second phase and in the both phases for high transthoracic impedances (TTI) either. In this paper, for solving these problems, a circuit that generates rectangular biphasic waveform is designed. In this circuit, five resistors are used and connected in series. Then an IGBT switch is connected to each resistor in parallel. Also, control of minimum current ripple is applied in order to decide which resistors should be worked in each time. The circuit is simulated in MATLAB/Simulink and a prototype model is constructed. Results demonstrate that the tilt of the waveform is notably reduced to a value less than 10%.

Novel synchronization technique for two parallel connected sparkgap switches

In this article a novel way of synchronizing two parallel connected sparkgap switches with accuracies of 1-5 ns for high frequency pulsed power applications is described. The circuit design of a synchronized sparkgap switch circuit is discussed. The circuit uses a combination of one master sparkgap and a set of inductor and capacitors to synchronize two sparkgaps and can be controlled via an IGBT switch. Critical issues for circuit design are presented together with analytical calculations and simulations. Experimental verification of the novel topology is carried out in a prototype experimental setup. Results showing nanosecond level of accuracy in synchronization are reported in this paper along with simulations and analysis.

Six-switch converter fed sensorless three-phase IM drive for home appliances

Abstract In this paper, a single-phase to three-phase converter is proposed to provide variable output voltage and frequency. The proposed topology employs only six IGBT switches, which form the front-end rectifier and the output inverter for the one step conversion from single-phase supply to output three-phase supply. The front-end rectifier permits bidirectional power flow and provides excellent regulation against fluctuations in source voltage. Moreover, it incorporates active input current shaping feature. An easy method to implement control strategy is proposed. This control strategy ensures nearly unity input power factor with sinusoidal input current over the operating range. Based on sensorless vector control technique, the proposed converter is used for the speed control of the three-phase induction motor. A low cost motor drive can be achieved using the proposed converter and control technique. Simulation and experimental results are carried out to analyse and explore the characteristics of the low cost drive system.

Single-to-three phase induction motor sensorless drive system

This paper presented a single to three-phase induction motor drive system to provide variable output voltage and frequency. The proposed drive system employs only six IGBT switches, which form the front-end rectifier and the output inverter for the one step conversion from single-phase supply to output three-phase supply. The front-end rectifier permits bidirectional power flow and provides excellent regulation against fluctuations in source voltage. Moreover, it incorporates active input current shaping feature. The control strategy of the proposed drive system of three-phase induction motor is based on speed sensorless vector control technique. A low cost of motor drive and much more advantages can be achieved using the proposed drive system. Simulation and experimental results are carried out to analysis and explore the characteristics of the proposed drive system.

Novel Scheme for Improving the Performance of a Wind Driven Doubly Fed Induction Generator during Grid Fault

Enhancement of fault ride-through (FRT) capability and subsequent improvement of rotor speed stability of wind farms equipped with doubly fed induction generator (DFIG) is the objective of this paper. The objective is achieved by employing a novel FRT scheme with suitable control strategy. The proposed FRT scheme, which is connected between the rotor circuit and dc link capacitor in parallel with Rotor Side Converter, consists of an uncontrolled rectifier, two sets of IGBT switches, a diode and an inductor. In this scheme, the input mechanical energy of the wind turbine during grid fault is stored and utilized at the moment of fault clearance, instead of being dissipated in the resistors of the crowbar circuit as in the existing FRT schemes. Consequently, torque balance between the electrical and mechanical quantities is achieved and hence the rotor speed deviation and electromagnetic torque fluctuations are reduced. This results in reduced reactive power requirement and rapid reestablishment of terminal voltage on fault clearance. Furthermore, the stored electromagnetic energy in the inductor is transferred into the dc link capacitor on fault clearance and hence the grid side converter is relieved from charging the dc link capacitor, which is very crucial at this moment, and this converter can be utilized to its full capacity for rapid restoration of terminal voltage and normal operation of DFIG. Extensive simulation study carried out employing MATLAB/SIMULINK software vividly demonstrates the potential capabilities of the proposed scheme in enhancing the performance of DFIG based wind farms to fault ride-through.