一管多机布置抽水蓄能电站非线性动力学建模与瞬态分析

Nonlinear dynamic modeling and transient analysis of pumped storage power station with one tube and multi-unit

一管多机布置抽水蓄能电站存在共用管段引水系统,其中共用管段的水力耦合相互作用是抽水蓄能电站系统动力学建模的关键。考虑共用管段水力系统耦合作用,将其分解成多个仅依赖于各子管段流量的单变量函数,通过结合水泵水轮机组动态特性,建立一管多机布置抽水蓄能电站非线性动力学模型。利用数值模拟探究了两机在额定工况并列运行时,一机突甩全负荷在不同导叶关闭规律且另一机组在调速器PID控制下,对各支管内机组流量、水头、出力动态特性的影响规律。仿真结果表明正常运行机组出力和流量动态响应具有正相关关系,机组水头动态响应与其流量和出力具有负相关关系,且波动周期相近。突甩负荷机组水头与流量的动态响应与导叶关闭规律密切相关,突甩负荷机组水头波动程度始终高于正常运行机组水头,且两机组水头波动周期相近;研究结果为探究一管多机抽水蓄能电站系统瞬态动力学建模与稳定性调控提供理论参考。

There is a shared pipe segment diversion system in a pumped storage power station with one pipe and multi-unit,hydraulic coupling interaction of the shared pipe segment is the key to the system dynamic modeling of pumped storage power station.Here,the coupling action of hydraulic system of the shared pipe segment was considered,and it was decomposed into several single variable functions only depending on the flow rate of each sub-pipe segment.Combining with dynamic characteristics of a pump-water turbine set,the non-linear dynamic model of a pumped storage power station with one pipe and multi-unit was established.When two units running in parallel under the rated condition,numerical simulation was used to explore effects of sudden full load rejection of one unit on dynamic characteristics of unit flow rate,water head and output inside each branch pipe under different guide blade closing rules and the other unit with speeder PID control.The simulation results showed that there is a positive correlation between dynamic responses of normal operation unit output and flow rate,dynamic response of unit water head has a negative correlation to its flow rate and output,and their fluctuation periods are close to each other;dynamic responses of water head and flow rate of the unit with sudden load rejection are closely related to closing rules of guide blade;fluctuation degree of water head of the unit with sudden load rejection is always higher than that of normal operation unit,and their fluctuation periods are similar;the study results provide a theoretical reference for exploring transient dynamic modeling and stability control of pumped storage power station systems with one tube and multi-unit.