柔性直流输电系统的联网和孤岛运行通用控制策略

针对当前柔性直流输电系统缺乏在联网和孤岛运行条件下的通用控制策略的现状,根据高压电网的特点引入了交流侧的频率—有功功率的下垂控制和直流侧的有功功率—直流电压的下垂控制,并由此提出了柔性直流输电系统联网和孤岛运行的通用控制策略。该控制策略可有效适用于换流站的联网和孤岛运行工况,且能够与电网的一次调频、二次调频配合工作,适用于孤远电网及海上风电场等弱电网互联情况。电磁暂态仿真结果表明,该柔性直流输电系统通用控制策略可实现对柔性直流输电系统联网和孤岛运行工况的有效控制。

Generalized Control Strategy for Grid-connected and Island Operation of VSC-HVDC System

In view of the current lack of a generalized control strategy for grid-connected and island operation of voltage source converter based high voltage direct current (VSC-HVDC) transmission system, the AC-side frequency-power droop control and the DC-side power-voltage droop control are introduced, based on which the generalized control strategy for VSC station is proposed. The proposed control strategy can be effectively applied to both grid-connected and island operation of VSC-HVDC transmission system while coordinating with both primary and secondary frequency modulation of the grid, which makes it applicable to weak and isolated grids away from the main grid. The effectiveness of the proposed control strategy is validated by the time domain simulation results. This work is supported by the Key Science and Technology Project of State Grid Zhejiang Electric Power Company (No. 5211011306Z4).