分层接入下绝对最小滤波器不满足回降功率策略研究

DC power runback control strategy for unfulfilled absolute minimum filter of UHVDC with hierarchical connection mode

分层接入方式的特高压直流输电工程与常规直流特高压直流输电工程的明显差异之一是前者存在2个交流滤波器场,在绝对最小滤波器不满足功率回降、闭锁换流器等无功功率控制策略方面与常规特高压工程的无功功率控制策略差异较大。为了解决分层接入带来的绝对最小滤波器不满足回降直流功率协调控制问题,对分层侧的各种运行方式下出现绝对最小滤波器不满足回降直流功率的控制策略进行了研究,提出了通过控制模式转换、减少非故障电网被动功率损失量等措施,使得某一交流电网回降功率对另一交流电网影响最小,并在此基础上进行了RTDS仿真验证。仿真结果表明,所提的分层侧绝对最小滤波器不满足回降直流功率的策略可以较好地解决因分层接入带来的绝对滤波器不满足回降直流功率协调控制问题。

One of the obvious differences between the UHVDC with single-layer connection transmission project and the UHVDC with hierarchical connection mode transmission project is latter has two AC filter yard,which will make some differences between both connection mode′s reactive power control strategy,such as DC power runback for unfulfilled ABSMIN filter and block converter for unfulfilled ABSMIN filter.In order to solve the DC power runback control problem for unfulfilled ABSMIN filter caused by UHVDC with hierarchical connection mode,the control strategy that DC power runback for unfulfilled ABSMIN filter in different operation modes of layered side is studied and some methods are proposed to reduce the impact of another normal AC grid,such as changing control mode and reducing power loss of normal layer.The control strategy test by RTDS simulation.The simulation results show that the control strategy can solve the DC power runback for unfulfilled ABSMIN filter control problems caused by UHVDC with hierarchical connection mode.