考虑负荷频率特性的可中断负荷切除策略研究

特高压直流规模激增使得大受端电网面临严重的频率问题。为了充分利用可中断负荷,减小低周减载首轮动作可能,降低触发严重事故等级的风险,文中提出了一种可中断负荷就地按频率切除策略及其定值选择方法。在考虑负荷频率特性的基础上,采用单机等值模型进行可中断负荷切除策略研究,选择合理的可中断负荷起切频率定值和切负荷量,方案制定完成后,通过全网模型进行校验。仿真结果表明,所提策略能够在系统发生易引发低周减载的大功率缺额时切除可中断负荷,减小低周减载首轮动作可能,提高电网的频率稳定性。

Interruptible Load Shedding Scheme Considering Load Frequency Characteristics

The blooming HVDC links has caused a serious frequency problem for the multi-infeed grid.To make full use of the interruptible load,reduce the risk of under-frequency load shedding and the risk of triggering a serious accident,an interruptible load shedding scheme according to the frequency and the value setting method is proposed.An equivalent model is adopted for the interruptible load shedding study considering the load frequency characteristics.The reasonable frequency setting values and load shedding percentage are analyzed.The completed scheme is checked by the detailed grid model.The simulation results show that the proposed scheme is effective.In case of large power loss which may cause the under-frequency load shedding,the scheme can remove the interruptible load.As a result,the risk of under-frequency load shedding is reduced and the frequency stability of the grid is improved.