Research And Design Of1.14KV And3.3KV Three-level Converter Main Circuits

Variable frequency speed control is widely applied by stable speed regulation, stepless speed regulation, stable circuit and high efficiency energy conservation and the other merits as one kind of electric motor speed regulation method. Because people adopt mechanical speed regulation and the other low efficiency speed regulation methods in speed regulation system of domestic mesohigh high-power electric motor now, people impatiently need mesohigh converter that can work in industry circumstance to reach speed regulation in industry field. For this situation, this paper takes major research and analysis on diode clamp three-level converter, and designs1.14KV and3.3KV diode clamp three-level converter main circuits schematic.This paper finally chooses IGBT as main circuit switch device, by researching and analyzing on development condition of power-electron device and taking comparison between IGBT and IGCT. By researching and analyzing on recent converter topology, this paper takes diode clamp three-level converter as research and design object because of low bear voltage, simple circuit, power feedback and output high quality of voltage waveform.This paper takes theory analysis on diode clamp three-level converter topology and built mathematic model that will offer theoretical principle for design and control technology. By taking comparison among several kinds of control technology, this paper makes detailed analysis on algorithm of two-level voltage space vector control SVPWM and three-level voltage space vector control SVPWM that will offer theoretical principle for building control system.This paper researches and analyses IGBT circuits over voltage and builds power dissipation computational model of IGBT circuits. This paper presents detailed analysis that6kinds of absorber circuits play overvoltage protection and influence on IGBT circuit power dissipation by building simulation model and simulating in Simulink module of MATLAB7.1software. This paper shows suit situation of every absorber circuit overvoltage protection. By using simulation date, this paper computes and analyses power dissipation of each absorber circuit in IGBT circuit, and presents:Influence of RC absorber circuit and RCD absorber circuit for the IGBT circuit power dissipation are more than other absorber circuits, and it generate power dissipation is1.7times than the IGBT circuit without absorber circuits generate power dissipation; The IGBT circuit with C absorber circuit is lower than the former, and it generate power dissipation is1.2times than the IGBT circuit without absorber circuits generate power dissipation; The IGBT circuit with RCD absorber circuit A and the IGBT circuit with CD2absorber circuit and the IGBT circuit with LCD2absorber circuit is the lowest, it generate power dissipation almost equals the IGBT circuit without absorber circuits generate power dissipation. By research and analysis of absorber circuit, this paper makes theory support for absorber circuit design.Neutral point potential imbalance is a projecting problem in diode clamp three-level converter, this paper takes deeply detailed analysis on reasons and harm of neutral point potential imbalance and methods of restraining neutral point potential imbalance. By researching and analyzing reasons of neutral point potential imbalance, this paper builds mathematic model that will offer theoretical principle for restraining neutral point potential imbalance. This paper adopts grading resistor method and neutral point ground to restrain neutral point potential imbalance by analyzing research findings of predecessors. By building model and simulating for neutral point potential, two kinds of restraining neutral point potential imbalance methods is dependable, this paper will presents a effective way for restraining neutral point potential imbalance.By taking theory analysis on relevant aspect of diode clamp three-level converter, this paper designs two kinds of1.14KV and3.3KV diode clamp three-level converter main circuits (no neutral ground and neutral ground). By theory analysis and parameter compute of main circuit, this paper shows each elements parameter and builds simulation model. By simulating and analyzing main circuit and takes comparison between simulated data and theory analysis, this design of diode clamp three-level converter is feasible and reaches design operating requirement. By design of1.14KV and3.3KV diode clamp three-level converter main circuits, this paper will offer theory evidences for other multi-level converters main design.