基于ZVZCS的大功率屏蔽门驱动电源的研究

Research on Drive Power Supply of High-power Shield Gate Based on ZVZCS

屏蔽门是轨道交通系统中的关键设备之一。多台门机同时动作时,要求直流供电系统瞬时提供较大的功率输出,且供电电压不能有太大波动,这对供电电源提出较高要求。基于零电压零电流开关ZVZCS(zero-voltage zero-current switching)全桥变换拓扑,设计了一类大功率直流供电模块,分析开关ZVZCS全桥变换器在周期内的开关模态及关键波形,根据超前臂并联谐振电容在换流时的充放电过程,确定超前臂实现零电压开关ZVS(zero-voltage switching)的条件,综合零电流开关ZCS(zero-current switching)条件下开关管耐压值及原边电流复位时间,推导隔直电容的取值范围。给出最大有效占空比计算公式,详细分析了超前、滞后臂的开关损耗。根据设计参数,制作了1台2.2 kW实验样机。实验结果表明,所设计的直流电源模块在各种负载状态下实现软开关,提高了供电效率,有着良好的动态特性。

Shield gates are key equipment in an urban rail transportation system.When multiple gates are operated under the same order,the DC power supply system is required to provide a large power output instantaneously;meanwhile,the output voltage should keep a small derivation,which imposes higher requirement on the power supply.In this paper,based on the zero-voltage zero-current switching(ZVZCS)full-bridge transform topology,a class of high-power DC power supply module is designed.The switching mode of the ZVZCS full-bridge converter in one cycle is analyzed,and the key waveforms are presented.According to the charging/discharging process of the parallel harmonic capacitor on the leading leg,the condition of zero-voltage switching(ZVS)is determined.With the combination of the switching tube’s withstand voltage and the recovery time of primary winding current under the condition of zero-current switching(ZCS),the range of blocking capacitors is also deduced.In addition,the formula for calculating the maximum effective duty cycle is given,and the switching losses of the leading and lagging legs are analyzed in detail.According to the design parameters,a 2.2 kW experimental prototype was fabricated.Experimental results show that the designed DC power supply module realized soft switching in various load states,which improved the power supply efficiency and presented satisfying dynamic characteristics.