Parallel high-power inverting power supply for DJ1 locomotive

To solve the problem that the original charger of DJ1 locomotive cannot adapt to voltage fluctuation of Daqin railway catenary, this paper designs a novel locomotive-carrying parallel high-power inverting power supply based on UC3854 BoostPFC circuits and UC3846 DC/DC converting circuits. The parallel and series connection modes are adopted into two sets of PFC circuits and two sets of DC/DC converting circuits respectively. With aid of output voltage feedforward technology and multiplier/divider, PFC circuits adopt average current-mode control to realize normal operation within wide output voltage range. Inverting unit adopts peak current-mode control and voltage-current double closed-loop control to improve line regulation and dynamic response speed. To avoid grid interference, over/under voltage and over current existing in power operation process, this paper also designs a special filtering circuit and a whole machine fault-protecting circuit based on TMP86FH09NG. The three-month operation of 11 kVA prototype verifies that this power supply has high reliability and perfect dynamic/static performance, and satisfies reliable and safe running requirements of locomotive.