薄弱电网中某特大型贯流式机组调速器控制策略探讨

针对西南某水电站首批机组投运期间遇到的水轮机调速系统的实际问题,结合电站在电网中的特殊地位,提出了电站处于薄弱电网中大机小网模式下系统频率稳定的控制策略及大网小网的判断方法,并提出新型调频公式解决了单机在空载开度附近带区域负荷问题。在不改变外界条件情况下,通过优化导叶最小开度限制,桨叶关闭速度及控制策略,极大降低了贯流式机组甩负荷导致低频灭磁的风险,满足了电站处于电网终端需不间断保障地方负荷及厂用电的需求,且通过现地试验验证了策略的有效性。

Discussion on Control Strategy of Super Large-scale Tubular Turbine Unit Governor in Weak Power Grid

Aiming at the actual problems of turbine governor system in the first batch of units of a hydropower station in southwest China,combined with the special status of power stations in the power grid,the control strategy of the system frequency stability in the mode of large turbine-small grid and the judgment method of large grid and small grid are put forward.A new frequency modulation formula is proposed to solve the problem of load in the zone near no-load opening.Without changing of external conditions,the risk of low frequency excitation suppression caused by the turbine unit load rejection is greatly reduced through the optimization of the opening of the guide vane minimum limit,blade closing speed and the control strategy.As the grid terminals,power station meets the need of uninterrupted protection of local load and auxiliary power demand.Finally,field test verifies the effectiveness of the strategy.