非对称过水系统抽蓄机组调速系统稳定性分析

Stability Analysis of Pump Turbine Governing System with Asymmetric Water Diversion System

为研究非对称过水系统抽蓄电站的稳定性,基于Hopf分岔理论,先建立了带上游调压室的一管双机非对称过水系统抽蓄机组调速系统数学模型,在此基础上进行了Hopf分岔分析获得了调速系统的理论稳定域,并分析了不同控制参数下机组的动态响应特性,验证其理论稳定域;再揭示了一管双机式抽蓄机组动态响应的多尺度振荡特性及其产生机理;最后,探究了水流惯性时间常数、水轮机惯性时间常数和调压室时间常数对系统稳定性的影响规律。结果表明,带上游调压室的一管双机非对称过水系统抽蓄机组调速系统的Hopf分岔是超临界的,其稳定域由两条分岔线共同决定;调压室及机组间的水力干扰使得机组的响应特性呈现明显的多尺度振荡特性;较大的水流惯性时间常数和较小的水轮机惯性时间常数对系统稳定性有利,调压室时间常数对系统的稳定性影响呈现饱和特性。研究结果对抽蓄机组的智能控制和电站过水系统设计优化具有重要的指导意义。

Based on Hopf bifurcation theory,the stability of pumped storage power station considering asymmetric water passing system is studied.Firstly,the mathematical model of the speed regulation system of the pumping and storage unit of the one-pipe two-machine asymmetric water passing system with the upstream surge chamber is established.On this basis,the Hopf bifurcation analysis is carried out to obtain the theoretical stability region of the speed regulation system,and the dynamic response characteristics of the unit under different control parameters are analyzed to verify its theoretical stability region.Furthermore,the multi-scale oscillation characteristics and its generation mechanism of the dynamic response of a pipe double pump storage unit are revealed.Finally,the influence laws of flow inertia time constant,turbine inertia time constant and surge chamber time constant on system stability are explored.The results show that the Hopf bifurcation of the speed control system of the pumping and storage unit of the one-pipe two-machine asymmetric overflow system with the upstream surge chamber is supercritical,and its stability region is determined by two bifurcation lines;The hydraulic interference between the surge chamber and the units makes the response characteristics of the units show obvious multi-scale oscillation characteristics;Larger flow inertia time constant and smaller turbine inertia time constant are beneficial to system stability,and the influence of surge chamber time constant on system stability presents saturation characteristics.The research results have important guiding significance for the intelligent control of pumping and storage units and the design optimization of water passing system in power stations.