交直流混合微电网中电力电子变压器功率控制与模式切换方法

Power control and mode switching method of power electronic transformer in AC/DC hybrid microgrid

提出电力电子变压器在交直流混合微电网中的功率控制与模式切换方法。在交直流混合微电网的离网模式下,提出剩余功率下垂控制方法实现交直流系统的相互支撑。为实现电力电子变压器不同运行模式下的无缝切换,将不同运行模式融合到1个功能外环中,有效地降低了模式切换时的暂态波动。仿真结果表明,所提功率控制策略既能避免交直流母线的过度耦合,又能为交直流混合微电网提供一定的相互支撑作用;所提模式切换方法在保持稳态性能不变的情况下,显著提高了电力电子变压器的暂态性能。

The power control and mode switching method of power electronic transformer in AC/DC hybrid microgrid are proposed.For the islanded mode of AC/DC hybrid microgird,a droop control method of surplus power is presented to guarantee the mutual support of AC/DC system.In order to realize seamless switching of power electronic transformer under different operation modes,the different operation modes are integrated into one function loop,so as to reduce the transient impact efficiently during the mode switching process.The simulative results show that the proposed power control strategy can not only avoid the over coupling of AC and DC buses,but also provide some mutual support for AC/DC hybrid microgrid.Moreover,the proposed mode switching method can improve the transient characteristics while maintaining the stability performance unchanged.