中间再热机组一次调频特性研究

Study of the Primary Frequency-modulation Characteristics of an Intermediate Reheat Unit

针对电网频率变化大,并网机组一次调频性能差的现象,对中间再热汽轮机组的调节系统进行设计,将频差信号以前馈信号的方式叠加到高压调门和中压调门指令上,让中压调门和高压调门同时参与一次调频,充分利用中间再热容积中的蓄热。仿真结果显示,设置了高、中压调门前馈信号后,中间再热机组的一次调频性能得到了很大程度的改善,负荷响应能力显著提高,调节系统的稳定性能良好,但要实现中压调门前馈信号的控制方式则还需要完成相关的研究工作。

In the light of the great change in power grid frequency and the poor performance of primary frequency-modulation of the on-line units,the regulating system of an intermediate reheat steam turbine unit was redesigned to superimpose the frequency difference signal to the instructions for HP and IP regulating valve in the form of a feedforward signal to let the HP (High Pressure) and IP (Intermediate Pressure) regulating valve take part in the primary frequency modulation simultaneously. This makes it possible to fully use the heat stored in the intermediate reheat volume. The simulation results show that after the feedforward signals have been provided for the HP and IP regulating valve,the primary frequency modulation performance of the reheat steam turbine unit has been greatly improved with the load response ability being enhanced remarkably,retaining at the same time the stable performance of the regulation system. However,to realize feedforward signal control mode of the IP regulating valve still necessitates the completion of relevant research.