柔性直流和常规直流互联输电系统协调控制策略

对一种新型的柔性直流与常规直流互联输电系统进行了研究,针对常规直流送端可能出现的功率不平衡问题,提出了常规直流和柔性直流功率附加器的协调控制策略。该策略通过2种直流有功附加控制器来提高区域内有功功率平衡能力,针对常规直流进行有功功率调节时换流站无功不平衡引起的电压波动问题,设计了柔性直流无功附加控制器。最后,通过仿真验证了协调策略的有效性,结果表明所设计的有功-无功附加控制器能够相互配合,有效提升整个系统的功率平衡能力。

Coordinated control strategy for interconnected transmission system of VSC-HVDC and LCC-HVDC

An interconnected power transmission system of VSC-HVDC(Voltage Source Converter based High Voltage Direct Current) and LCC-HVDC(Line Commutated Converter based High Voltage Direct Current) is studied and a coordinated control strategy is proposed for the power supplementary controllers of LCC-HVDC and VSC-HVDC to deal with the possible power imbalance at the sending end of LCC-HVDC. Two kinds of DC active power supplementary controller are designed to enhance the balance capacity of areal active power and a reactive power supplementary controller is designed for VSC-HVDC to deal with the voltage fluctuation due to the reactive power imbalance of LCC-HVDC converter station during active power regulation. The simulative results show that the designed power supplementary controllers coordinate with each other to effectively enhance the power balance ability of whole system, verifying the validity of the proposed control strategy.