Research On Multi-module Inverters With Space Vector Pulse Width Modulation Technology

In this paper multi-module inverters for low voltage input and high power output is researched. The output-voltage of traditional multi-module inverters can't be adjusted. Several schemes for the output-voltage regulation are analyzed, and a new scheme adopting SVPWM technology to control multi-module inverters is presented. While an asymmetry SVPWM strategy is used, the multi-module inverters can achieve a high quality output waveform with low switching frequency.The principle of output-voltage regulation with SVPWM technology is introduced in the paper. With the asymmetry SVPWM strategy the optimum switching frequency, the optimum sample deviation angle and the optimum modulation ratio are given by analyzing the performance of 4-module inverters. The digital control system based on DSP and FPGA has the merits such as simple circuit and accurate control. The feasibility of the new SVPWM scheme has been verified by a 4kVA prototype.Different multi-module inverters are analyzed and the optimum design rules are given in the paper. According to the rules, multi-module inverters can be used for variant applications with high performance.