双端口多功能交-直流双PWM变流器控制策略

Control strategy of dual-ported multifunctional AC-DC double PWM converters

针对传统中大功率密度的交-直流PWM变流器存在输出直流电压降压困难、电路设计复杂的问题,提出一种以三相交-直流变换和三重化直-直流变换为核心的交-直流双PWM变流器电路拓扑。在分析其工作原理,建立数学模型的基础上,综合运用软件锁相技术,瞬时无功理论,正序、负序、零序分解理论,自动限流及均流控制。同时采用交流电网和(或)直流电网双端口供电方式,实现交直流能量的双向流动。在理论分析和仿真研究的基础上,完成了380 kW原理样机的研制。样机实验结果表明:采用该控制策略的双PWM变流器具备了充电器、不间断电源、无功补偿器等多种功能,同时输出直流电压调节范围宽、电路设计简洁且具有扩展性。

Focus on conventional medium and high power density AC/DC PWM converter output DC voltage stepping down hard and circuit design being complex,a AC-DC double PWM converter with three phase AC/DC converter and triple-channel interleaved DC/DC converter was presented.Based on analyzing the operation principle of the converters and establishing the model,control technique including software phase locked loop,instantaneous reactive theory,separation theory of positive sequence,negative sequence and zero sequence,auto current-limit and current sharing control were adopted.The converters realized bidirectional power flow by employing dual-ported power supply（AC supply or DC supply）.Finally,the measurements were taken on a 380kW prototype converter.The experiment results show that a AC-DC double PWM converter has the multifunction of charger,UPS and reactive power compensation.Meanwhile the output DC voltage has wide adjusting range,circuit design brevity and extension.