Space Vector Control Of Three-phase Four-leg Inverter

With the rapid development of science and technology in our daily walks of life, all kinds ofelectrical equipment to be used, the same time energy requirements are increasing. In that context,power electronics conversion technology came into being.Usually require three-phase inverter output is three-phase symmetrical voltage, the three-phasefull-bridge inverter must be three-phase symmetrical load to output three-phase symmetrical voltage.However, in practical application, the three-phase loads are usually asymmetrical and nonlinearloads, then the three-phase inverter can’t meet the requirement. In order to the three-phase inverterhas the ability to bring unbalanced loads, this article study based on the traditional three-leg inverteron adding an arm to form a four-leg structure inverter. And four-leg inverter with simple structure,small size, light weight and high voltage utilization rate and so on.This paper studies the three-phase four-leg inverter which under space vector control. Spacevector control has a high DC voltage utilization rate, the control thought more intuitive, easy toimplement digital control and so on. First, for a total power of3kw specific system, detailedanalysis of the space vector modulation principle, gives the formula of the resultant vector voltage,designed its DC side filter capacitor, the power switch, filter inductors, filter capacitors and midlineinductors; then, through simulation software MATLAB/SIMULINK for simulation, establishmenta system simulation model and design simulation parameters, the simulation results verify thefeasibility of the program; Finally, use of the TI’s DSP TMS320x2812for the digital controlplatform, make a prototype, to verify correctness of the theory.