火力发电厂再热汽温控制系统现状频域分析

Frequency-domain Analysis on Reheated Steam Temperature Control System for Thermal Power Plant

文章通过对某电厂的再热汽温系统进行频域特性分析,发现大多数扰动下的系统对象呈带通滤波特性。针对一实际的600 MW级火力发电机组,通过对影响再热汽温的9种扰动信号进行频谱密度分析,发现除了再热减温水温度和机组负荷以外的扰动信号都有通带以外频率,因此采用单纯串级控制结构系统不能对现场扰动信号进行有效抑制,需要设计新的控制方案。

The spectral densities of nine disturbance signals for reheat steam temperature in a 600 MW thermal power plant were analyzed.Through the frequency domain characteristics analysis of the reheat steam temperature system,it was found that the target system under the majority disturbance was the same as the band-pass filter characteristics.Through spectrum analysis showed that in addition to desuperheating water temperature and unit load other disturbance signals have a frequency outside the passband,so it was difficult for single cascade control system to effectively damp the combustion disturbance.