Study On The Anti-disturbance Performance Improvement Of Vector Control System For Three-Level Inverter

High power and high performance AC drive have been part of the hotspots in the field of power electronics and electric drive. Drive system with reliable performance can not only maximize the production efficiency of the production line, but also can be a major guarantee for producing high quality products.This thesis is supported by the funding from2012state science and technology support program, with high power three level induction motor vector control system as the research object, in order to improve the anti disturbance performance of the system. This project focus on control method and interference suppression.Four mainly researches are deeply and systematically researched,including three level chaotic space vector pulse width modulation (SVPWM), vector control with Active Disturbance Rejection Control (ADRC), speed feedback with interference suppression and compensation, full digital-controlled drive system of AC induction motor.Three levels chaotic SVPWM technologies are proposed based on the traditional three level SVPWM algorithm. The tent is applied to the chaotic three level pulse width modulation technologies. Dynamic bias is fixed in switching frequency of power devices. The chaotic characteristics of Tent is mapped to the full range of frequency, so as to improve harmonic distribution of the inverter output voltage and effectively restrain the system disturbance caused by harmonic.Extended state observer of three level inverter vector control state is established, so as to observe the rotor resistance perturbation, observe model coupling and unknown load changes. Active disturbance rejection control of three level inverter vector control is realized. Compared with the traditional PID control algorithm, ADRC improves anti-disturbance performance of control system.A kind of feedback mechanism with pulse width prediction is put forward to solve the speed feedback oscillation problem, including speed sensor fault, body line abnormal or signal disturbed by the electromagnetic interference caused by uncertain factors. Modeling of speed detection is built. Then the sensor signal duty ratio and distortion model are derived and created. According to the real-time acquisition of the encoder pulse width, the pulse width range of the next moment is forecasted, so as to effectively identify sensor faults and signal interference.The concept of fault tolerance and interference tolerance has been formulated. By choosing appropriate parameters of fault tolerance and interference tolerance and combining the identification results and speed observation from extended state observer, the corresponding speed feedback mechanism is established, so as to constrain the speed feedback interference.Based on the high power three level inverter main circuit and high performance DSP and FPGA architecture, a vector control experiment platform and prototypes is designed. Circuit parameter calculation method of the hardware and the software flow chart are given. The anti-disturbance experiment of vector control system is verified in this platform.