汽轮机侧引发的电网低频振荡分析

Analysis of the Low-frequency Oscillation of Power Grid Caused by Turbine Sides

汽轮发电机组功率振荡可能诱发电网的低频振荡。分析了汽轮机调节系统波动的原因,涉及其控制器部分、伺服系统、执行机构、阀位反馈系统和功率反馈系统。以控制器部分为例,可能的原因有:调门流量特性曲线与实际偏差大、调节系统速度变动率过小、调节系统迟缓率过大、重叠度设置过大和PID调节器的控制参数设置不当。针对各种可能的情况提出了相应的预防措施。

Turbo-generator’s power swing may lead to low-frequency oscillation of power grids.Causes of the swing are analyzed in this paper over the controller,servo-system,actuator,valve position feedback system,and power feedback system.Taking the controller as an example,the paper points out that the swing may be due to the following factors： the valve flow property curve being different from the real one,the steady-state speed regulation not enough,too large dead band of speed-governing system,too large superpose band and unreasonable parameter setting of PID controller.Related countermeasures are given against the hidden trouble.