Daning Zhou

A Novel Commutation Method of Matrix Converter Fed Induction Motor Drive Using RB-IGBT

A 3-phase to 3-phase matrix converter is developed based on 600 V/100 A RB-IGBT (Reverse Blocking IGBT). This RB-IGBT is newly developed based on ultra-thin wafer technology and one important feature of it is reverse leakage current is mostly affected by Vge. Under the same temperature condition, when Vce is negative, a positively biased Vge leads to the great reduction of the reverse leakage current therefore, a novel commutation method is proposed for reducing the losses caused by this reverse leakage current. The realization of this method is based on output current direction and certain voltage polarities of bi-directional switches and it is featured as a 2-step commutation. A simple circuit in the designed RB-IGBT drive circuit is used to obtain the required signals by sensing Vce of RB-IGBT. Then the constant Volts/Hz method is employed for controlling the matrix converter induction motor drive. Finally, detail experimental results and analysis are presented.

Compensation control of matrix converter fed induction motor drive under abnormal input voltage conditions

Matrix converter (MC) is a direct energy conversion device with high input power factor and regeneration capability. As a device without dc link elements, the ac line side disturbances can degrade its output characteristic and reliability, even deteriorate the drive performance of motor load. In this paper, the behaviors of the MC drive under abnormal input voltage conditions, in terms of unbalance, nonsinusoidal and short-time voltage sag, have been investigated. A feedback compensation method based on close loop control of output current is proposed to improve the output performance of MC. In addition, a feedforward compensation method by measuring instantaneous values of input voltage is developed to compensate the output voltages of MC and ensure the drive performance of induction motor under abnormal input voltage conditions. The effectiveness and feasibility of the two proposed compensation methods have been proven through numerical simulations and experimental tests.

A novel driving and protection circuit for reverse blocking IGBT used in matrix converter

Reverse blocking IGBT (RB-IGBT), with the capability of blocking both forward and reverse voltage, is now receiving widely attention in power converter applications. In this paper, by introducing two dynamical current sources, a three-stage driving circuit is designed for RB-IGBT to reduce the switching transition while limiting the turn-on di/dt and the turn-off dv/dt within the safe area. Furthermore, a novel v/sub ce/ sensing method is proposed. Using the detected v/sub ce/, over-current and short-circuit protection schemes are implemented respectively. The v/sub ce/ is also used as a sign of current direction, which is helpful for commutation between bidirectional switches.

A nonlinear robust controller for matrix converter fed induction motor drives

Matrix converter (MC) fed induction motor drive has more attractive advantages than conventional pulse width modulation (PWM) inverter drives for the absence of large DC-link capacitors, higher input power factor and energy regeneration capability. However, due to the direct conversion characteristic of matrix converter, the drive performance of induction motor is easy to be influenced by input voltage disturbances of the MC. A nonlinear robust auto disturbance rejection controller (ADRC) is applied to the MC fed induction motor drive system, taking the place of proportional-integral (PI) regulator. In the drive system, the effects of external disturbance and model uncertainty are estimated and compensated by ADRC. Using this controller, the anti-disturbance capability of the drive system under abnormal input voltage conditions can be enhanced. In addition, the dynamic drive performances of induction motor are also improved, such as fast responses of speed change and load torque change. Experiments have been carried out to analyze the drive system, and simulation results verify the effectiveness of the proposed controller

Performance Improvements for Matrix Converter Based on Reverse Blocking IGBT

Researches on performance improvements of matrix converter based on reverse blocking IGBT are carried out in terms of PWM strategy, commutation technique and short-circuit protection. An optimization method of space vector PWM for matrix converter is proposed to minimize the distortion of output voltage and current. Commutation technique improvements by using a two-step commutation method are discussed deeply through power loss comparison and output waveform quality comparison. A short-circuit fault protection circuit is proposed to limit the peak values of power device voltage and current during short-circuit intervals. Simulation and experiments demonstrate the feasibility and effectiveness of these proposed methods.