Design and control of lightweight static inverter for EMU

A static inverter for EMU (Electric Multiple Unit) is massive because of passive components such as high power transformers, reactors and capacitors etc. In this paper how to design and control the lightweight static inverter is proposed. The system consists of hard switched boost chopper, soft switched high frequency inverter, high frequency transformer and rectifier. This system features a boost chopper to control the input current and to set up a controlled DC link. And a soft switched half bridge inverter powers a high frequency transformer from this DC link. Therefore the 750DC link voltages are inverted into 10kHz high frequency ac voltage, which is isolated by high frequency transformer, and then the output voltage of the transformer is rectified by single phase rectifiers. Owing to using zero voltage and zero current, the onboard static inverter on rolling stock has advantages of high efficiency, high energy density, small volume and lightweight. Experimental results show the proposed system is highly efficient and lightweight.