Research On PWM Voltage Source Converter And Application In Frequency Inverter

The conventional rectifiers produce harmonic problem in power system.Three-phase PWM voltage source rectifiers (VSR) are applicated to the FrequencyInverter in place of conventional no-control rectifiers based on power diode in thisthesis. It can provide constant dc bus voltage and get low harmonic distortion of inputcurrent. The problem of power pollution by the rectifier cell of Frequency Inverter isessentially resolved. It also has line power feedback capability.This thesis mainly introduces PWM VSR, including its topology, mathematicalmodel, control strategies, the design and choice of the main circuit parameters and itshardware. The mathematical model of VSR is essential means to investigate the VSR.The simulation model is set up in ABC stationary coordinate and the deep research onthree-phase PWM voltage source rectifiers (VSR) based on hysteresis current controlstrategy has been done, including its characteristic, performance and the choice ofcircuit parameter. Comparing indirect current control, the hysteresis current controlstrategy has characteristics of fast dynamic response, good steady and dynamiccapacities, simple circuit and high robustness.Moreover, the hardware scheme of three-phase PWM voltage source rectifiersusing TMS320LF2407A DSP has been introduced. The design of driving circuit andsafeguard circuit, the design of inductance and capacitance in VSR, and the digitalrealization of hysteresis current control are proposed in this paper.