调节阀特性非线性对再热机组动态性能影响的仿真研究

本文通过仿真试验的方法,全面研究了阀门特性非线性对再热机组动态特性的影响.结果表明:采用快关阀门特性的机组比采用其它阀门特性的机组具有更好的空载稳定性和更小的动态超速;不同阀门特性时,系统延时、容积时间常数改变对过渡过程的影响是相同的;油动机、转子时间常数和系统不等率的改变对快开阀门特性机组的影响比对其它阀门特性时产生的影响来得大.最后,从系统的稳定性、甩负荷后的安全性和参与电网的一次调频等方面出发,提出了合理的调节系统静态特性形状.

SIMULATION RESEARCH ON THE EFFECTS OF NONLINEAR VALVE CHARACTERISTICS ON THE DYNAMIC BEHAVIOURS OF REHEAT STEAM TURBINES

In this paper, the effects of nonlinear valve characteristics on the dynamic behaviours of reheat steam turbine are analysed with digital simulation method. The results show that the sets using fast closing valves have better stability and smaller over-speed on load rejection than those using other valves. The flow-limit, system time delay and volume time constants have the same effects on the dynamic behaviours in different valve characteristics; system droop, actuator and rotor time constants have greater effects on the dynamic behaviours of the sets which use fast opening valve than those using other valve. Proceeding from requirement of stability, operational safety at load rejection and also the flexibility of primary frequency control of the set, the authors propose suitable valve characteristics.