基于开绕组DFIG的交直流混合系统功率协调策略

Power Coordination Strategy for AC/DC Hybrid System Based on Open-winding DFIG

为了提高风电机组与储能单元构建的独立供电系统的供电可靠性,针对开绕组双馈电机和储能单元构建的独立交直流混合供电系统,提出了一种基于下垂控制的功率协调控制方法。该方法采用分层控制,根据储能单元功率变化和荷电状态SOC(state ofcharge),对开绕组双馈电机定子侧变换器的下垂系数进行调整,协调系统中交、直流侧功率,保持各个储能单元输出的功率平衡,实现各个储能单元SOC均衡,提高系统稳定性。仿真结果表明,所提方案可有效协调系统的交、直流侧功率,保证各储能单元的SOC均衡。

To improve the power supply reliability of an islanded power system constructed by wind turbines and energy storage units(ESUs),a power coordination control method based on droop control is proposed for the islanded AC/DC hybrid power supply system constructed by open-winding doubly-fed-induction-generators(DFIGs)and ESUs.By means of hierarchical control,this method adjusts the droop coefficient of the stator-side converter in the open-winding DFIG according to the power changes and state-of-charge(SOC)of each ESU,thus coordinating the AC and DC power of the system and maintaining the power balance between different ESUs.As a result,the system stability is improved.Simula⁃tion results show that the proposed method can effectively coordinate the AC and DC power of the system and ensure the SOC balance between ESUs.