水轮发电机组甩负荷工况多目标优化研究

Multi-Objective Optimization Research on Load Rejection Condition of Hydropower Units

为解决具有水力干扰的大流量、中水头传统水电站在双机甩负荷工况下对于导叶关闭规律的多样性研究不足的问题,以某双机共尾水调压井巨型水电站为例,构建水电站精细化模型,提出了多目标人工羊群算法(MOASA)优化双机同时甩负荷工况下两段式、三段式导叶关闭规律。为避免极值弱化,考虑了两个水力系统的非对称性,选择两台机组中蜗壳末端压力最大值和转速上升最大值为两个极值优化目标,再从两种控制策略的优化前沿上、中、下区域中选取6种控制规律,并分成3组对比两段式、三段式导叶关闭规律控制效果。结果表明,水电站双机同时甩负荷时,采用三段式关闭规律优于两段式关闭规律。同时采用MOASA优化的两段式、三段式导叶关闭规律的控制效果对比调保要求均留有较大的裕度,可见提出的MOASA可有效指导水电站甩负荷导叶关闭规律设计。

The research on the diversity of guide vane closing law is insufficient for the medium head and large flow hydropower station with hydraulic disturbance when it is load rejection simultaneously.This paper built a refined model of a certain giant hydropower station whose tail race surge chamber shared by two units.A multi-objection artificial sheep algorithm(MOASA)was proposed to optimize two-stage closing law and three-stage closing law when two units are load rejection simultaneously.The asymmetry of two hydraulic systems was considered and the maximum volute pressure and rotation rate rising rate in the two units were chosen as two optimization objectives to avoid the extreme value be weakened.Six control laws were selected from the upper,middle and lower regions of the two control strategies.They were divided into three groups to compare the control effect of two-stage guide vane closing law and three-stage guide vane closing law.The results show that the optimization three-stage closing law is better than two-stage closing law after two units load rejection simultaneously.In addition,compared the control effect of the two-stage guide vane closing law and the three-stage guide vane closing law optimized by MO ASA with regulation and maintenance requirements,they all have a large margin.Therefore,the proposed MO ASA can effectively guide design of guide vane closing law after load rejection.