Research And Realization Of AC - DC Converter Based On DSP And

The technology to adjust speed with variable frequency and high voltage is an importanttechnology in the field of power electronic; which involves speed regulation and energy-saving forhigh power AC motor with all kinds of load. High voltage inverter has not a mature and consistenttopological structure as low voltage inverter. At present, cascaded multicell converter, diodeclamped multilevel converter and flying capacitor multilevel converter are3mainly convertingtopologies. Among them, cascaded configuration gains many advantages as follow: input side hasless pollution to the electrical net; output voltage approaches to sine wave so that it doesn’t needoutput filter; structure is simple and easy to be modularized; control method is easy to be realizedand so on. Therefore, cascaded converter has been chosen as the research subject of this paper.The research directions and development state are summarized in this paper, topology,control technology and power electronics three major directions of research are introducedrespectively and H-bridge Cascaded multilevel converter’s circuit structure that is often usedcurrently is introduced and researched carefully. The carrier phase shift PWM (Pulse WidthModulation) modulation at low switching frequencies in the case to achieve a higher switchingfrequency equivalent effect, this technique improves the equivalent switching frequency throughthe counter act of lower order harmonics and it is with a perfect performance on harmonic feature.So it is used in this paper. The emulation waveform by MATLAB is also given, the results provethe feasibility and applicability of academic analysis. The motor rotor field oriented vector controltechnology is researched simulated in this paper and the motor speed and torque is achieved to theclosed-loop control. For multi-modular converters and multilevel converters, the number of PWMgenerators provided by the a single chip control mode is clearly not sufficient. In this paper, thecontrol system is divided into three parts, a host CPU module, pulse control module and powerdevices drive module, the design has a digital signal processing DSP (TMS32F28335)and Field－Programmable Gate Array (FPGA) and Complex Programmable Logic Device (CPLD) are thecore of the inverter control system. DSP is used as the control core of the experiment platform,FPGA and CPLD are used as auxiliary chips which generate multiple PWM trigger pulse, and thehardware and software design of three kinds of chips in three modules are introduced respectively.This paper also makes MATLAB simulation on “rotor field-oriented vector control” to motor bythe implementing of the carrier phase shift SPWM and results verify that the method is feasibleand correct.