Control Strategy for Three Phase Inverter Supply Based on Back-to-Back

The paper is talked about a 3-phase 4-leg style of supply system. The part of converter is a power-factor variable and can be decreased the pollution of power net. While the converter can be adapted to the input line voltage´s fluctuation. The bus DC voltage is very stable. The inverter is adopted to four-legged in order to suit unbalanced load. The inverter brings to a simple and effective control algorithm of proportion and resonant controller. The system can maintain a good capability under unbalanced loads. A 30KW supply system is manufactured, which based on theoretical analysis. The system makes use of double DSP and carries out the algorithm. Two DSP chips exchange the information through dual-RAM. The experiment results further verity the validity of the proposed control method.