Comprehensive Loss Analysis of Isolated Bidirectional Matrix based AC-DC Converter

In this paper a comparison of traditional two stage back-to-back AC-DC converter with matrix based AC-DC converter using comprehensive loss analysis is presented. The two-stage AC-DC converter uses a boost rectifier with power factor correction at the grid side while a full bridge converter at the load end. A current control based closed loop control is developed for the grid end converter while synchronous rectification is used for the corresponding half when full bridge converter is operated in the bidirectional mode. Matrix based AC-AC converter eliminates the use of DC-link and hence the bulky DC link capacitor. Space Vector Modulation based switching scheme is used for matrix based single stage converter. As, the matrix based converter uses back-to-back switches, it contributes to maximum proportion of the total loss followed by input LC filter and controlled rectifier part of the AC-DC converter. Maximum efficiency calculated is about 95.5 % for the matrix based converter, while for two stage converter is about 80 %. Matrix based converter provides higher efficiency, power density, reliability, etc.