水电机组原动机及其调节系统精细化建模

Refined Modeling of Hydraulic Prime Mover and Its Governing System for Hydropower Generation Unit

针对目前电力系统仿真计算中水电机组模型过于简化的问题,建立一种水电机组原动机及其调节系统精细化模型。该模型不仅包含调压室效应,还考虑分叉管影响,从而可以模拟机组功率的低频振荡和机组间的水力耦合现象。此外,通过分析双曲正切函数的频率特性,提出一种新的降阶弹性水击方程,在较低的阶数下实现了更好的逼近精度。某水电站仿真结果表明,文中提出的精细化模型能够更准确地再现水轮机调节系统在各个工况下的动态响应过程。

In allusion to the oversimplification of hydropower generation units in present power system simulation, a refined model of hydraulic prime mover and its governing system for hydropower generation unit, which not only includes the effect of surge tank but also takes the effect of branch pipe into account, is established, thus using the established refined model the low-frequency oscillation of the power of generation unit as well as the hydraulic coupling among hydraulic turbines can be simulated. Besides, through analyzing the frequency characteristic of hyperbolic tangent function, a new order-reduced elastic water hammer equation, by which a better approximation accuracy under the lower orders can be realized, is proposed. Simulation results of a certain actual hydropower station show that using the established refined model the dynamic response processes of hydro-turbine governing system under various operating conditions can be reproduced more accurately.