基于模拟退火算法的水轮机导叶分段关闭规律优化

Optimizing closure law of wicket gates in hydraulic turbine based on simulated annealing

为了解决水电站过渡过程中输水系统水锤压力和机组转速上升难以协调控制的问题,保证电站安全运行,建立了一种水轮机导叶关闭规律非线性优化模型,该优化模型可以调整各控制参数的重要程度并应用于多工况优化.基于水力瞬变计算的特征线法,应用模拟退火算法对该优化模型进行计算,寻找满足调节保证计算要求的较优关闭规律.结合工程实例,针对蜗壳末端最大压力和机组转速最大上升率2种控制工况,比较导叶一段直线关闭和二段折线关闭的数值计算结果,并应用模拟退火算法对折线关闭规律进行优化.使用优化后的关闭规律进行过渡过程计算,蜗壳末端最大压力、机组最大转速上升率和尾水管进口最小压力均满足调保计算要求,且安全裕量较大.结果表明,模拟退火算法可以快速优化导叶关闭规律,且算法稳定性较好,安全裕量分配合理,为类似工程的导叶关闭规律优化提供了新方法.

A new optimization model was set up to solve the contradictions between water hammer pressure and turbine speed during the transient process in hydropower stations.The model can be applied to the multi-condition optimization and the parameters can be adjusted easily.Based on the cha-racteristic method,simulated annealing algorithm was applied to the optimization of the wicket gate closure law.In a practical case,two controlling conditions were selected in maximum volute pressure and maximum turbine speed numerical calculation,and results of different closure laws were compared and analyzed.Then the two-segment closure law was optimized using simulated annealing algorithm.The maximum volute pressure,maximum turbine speed and minimum draft tube pressure met the design requirements and the safety margins were allocated reasonably.The results show that simulated annealing algorithm can quickly and stably optimize the wicket gate closure law,which provides a new method for closure law selection in similar hydropower stations.