Development of Battery Charger for Industrial Mobile Robots

The conducted electromagnetic interference (EMI) and efficiency are the two important issues in the hard-switched power converters. This paper proposes an improved full-bridge pulse-width-modulated converter for a robotic battery charging application. Because of the zero-voltage-switching (ZVS) characteristics of isolated phase-shift full-bridge (PSFB) converter, the typical switching losses and conduction losses can be mitigated obviously. The efficiency of PSFB converter is significantly improved compared with the traditional hard-switch full-bridge dc-dc converter. In order to reduce the size of magnetic components, the switching frequency of PSFB converter have to be raised. The operation principle of the proposed system is analyzed and discussed. The design specifications of the ZVS PWM converter is also listed. The experimental results of the isolated phase-shift full-bridge converter, rated 1-kW and operating at 100kHz, is provided and verified in the paper.