交直流混合微电网接口变换器双向下垂控制

交直流混合微电网中的接口变换器对于系统的稳定运行和功率的协调分配有着重要的作用。提出了一种接口变换器的双向下垂控制方法，分别采用变换器两侧的交流母线频率和直流母线电压对交流、直流微电网的电能需求程度进行衡量，确定变换器传输功率的大小与方向。控制架构中包括直流电压-有功功率和交流频率-有功功率两个下垂环节，并将二者输出之差作为接口变换器的功率参考值。同时，为了减缓下垂控制导致的电压或频率的跌落，在下垂控制基础上设计了恢复控制策略，以提高交直流混合微电网的电能质量和可靠性。这种双向下垂控制可以更精确地协调交流与直流微电网之间的能量传输，实现分布式能源的充分利用。利用DigSILENT软件搭建系统仿真模型，验证了控制方法的正确性。

Bidirectional Droop Control of AC/DC Hybrid Microgrid Interlinking Converter

The interlinking converter in an AC/DC hybrid microgrid plays a crucial role in the stable operation and power allocation of power system.A bidirectional droop control method for the converter is proposed,which measures the power demand degree of AC subgrid and DC subgrid according to AC bus frequency and DC bus voltage respectively, and determines the direction and magnitude of the converter transmission power.Two droop control modules, DC voltage-active power and AC frequency active power,are included in the control structure.The power reference value of the converter is achieved from the output subtraction of two modules.Meanwhile,to reduce the deviation of voltage and frequency caused by droop control,a recovery control is designed to improve the power quality and the reliability of the hybrid microgrid.The bidirectional droop control can accurately coordinate the power transmission between AC subgrid and DC subgrid and make full use of the distributed energy.The feasibility of the control method is verified by a simulation system built with DigSILENT.