A high efficient and reliable DC-DC converter for Electronically Controlled Pneumatic brake system applications

The Electronically Controlled Pneumatic (ECP) brake system is being applied to the heavy-haul trains for its control accracy and real time performance. A high power supply with high efficiency and reliability is essential to the safe operation of the ECP brake system. In this paper, a push-pull forward converter with a secondary full bridge rectifier is proposed for the ECP power supply. The voltage stress of the rectifier diodes can be reduced by a modified nodissipative snubber. Furthermore, hybrid control methods and criteria are utilized to improve the converter performance, including forced flux balancing circuit design, power supply output impedance and noise requirements. Finally, A 2.5kW prototype of the converter with efficiency up to 93% verifies the proposed circuit and theoretical analysis.