SINGLE-PHASE VOLTAGE TYPE AC-DC CONVERSION DEVICE

摘要

The purpose of the present invention is to provide a single-phase voltage type AC-DC conversion device which, when a plurality of said devices is connected in parallel and run in parallel with a single-phase alternating current, makes possible autonomous parallel running in which each device autonomously controls output deviation. In the present invention, a single-phase alternating current is generated having a prescribed phase difference with the single-phase AC output voltage of an AC terminal, and the generated single-phase alternating current and the single-phase AC output voltage of the AC terminal are used to perform PWM control of an inverter. Specifically, the single-phase AC output voltage of the AC terminal becomes a first axis corresponding to theα-axis component when a three-phase alternating current undergoes M-conversion. The single-phase alternating current having the prescribed phase difference becomes a second axis corresponding to theβ-axis component when a three-phase alternating current undergoes M-conversion. This single-phase voltage type AC-DC conversion device independently controls the first axis and the second axis and uses the characteristic electrical angle generated in a frequency control circuit to make the single-phase AC output voltage follow the frequency of the power system.