交流配电网中柔性直流互联装置阻抗稳定性分析及阻抗协同重塑控制

对于交流配电网中的柔性直流互联装置,当功率方向变化时,负阻抗会随之在装置内定功率控制换流器的直流侧和交流侧进行转移,降低了系统稳定性.针对此问题,提出了一种阻抗协同重塑控制策略.首先,介绍了配电网中柔性直流互联装置的结构;其次,分别建立了装置内两侧换流器多个端口阻抗在功率双向传输下的小信号模型,探究其阻抗特性;然后,对...

Analysis of impedance stability and impedance coordinated reshaping control for flexible DC interconnection device in AC distribution network

For the flexible DC interconnection device in AC distribution network, when the power direction changes, the negative impedance will sequentially exist on DC side and AC side of the constant power-controlled converter in device, reducing system stability. In order to solve this problem, an impedance coordinated reshaping control strategy is proposed. Firstly, the structure of the flexible DC interconnection device in distribution network is introduced. Secondly, the small-signal models of impedance at each port of the converters on both sides under bidirectional power transmission are established to explore their impedance characteristics. Thirdly, the working principle of the proposed control strategy is analyzed, the reshaped impedances are remodeled, and the system stability before and after impedance reshaping is compared and analyzed. Finally, the effectiveness of the proposed control strategy is verified by MATLAB/Simulink simulation model and experimental platform. The results show that the proposed method reshapes the negative impedances of both DC and AC sides into positive impedances through coordinative effect, and can simultaneously improve the stability of both sides of converter.