汽轮机中不同扰动源对共振机理低频振荡的影响

Influence of Different Mechanical Disturbances on Low Frequency Oscillation of Resonance Mechanism

汽轮机输出的功率扰动可能引发共振机理的低频振荡,威胁电力系统的安全稳定运行。文中比较了扰动位于汽轮机本身机械部分和位于调速器部分对共振机理低频振荡的影响。首先介绍了共振机理的基本原理,在此基础上推导证明了汽轮机对其调速器内扰动信号具有较强地抑制作用。然后在单机无穷大系统中分别对扰动位于汽轮机本身机械部分和位于调速器部分时对低频振荡的影响进行仿真,仿真结果表明相同幅值和频率的扰动信号分别位于上述2种位置时,后者比前者产生更大的低频振荡幅值,验证了理论分析的有效性,为实际应用中共振机理低频振荡的抑制措施提供了参考。

Output power disturbance of steam turbine could lead to low frequency oscillation of resonance mechanism, threatening the safe and steady operation of the power system. This paper compares the influences of the disturbance of mechanical part of steam turbine with disturbance of governor. The fundamental principles of resonance mechanism are presented in this paper firstly. Then, it will be proved that steam turbine has strong restrain effect on disturbance of governor through mathematical derivation. Influences of disturbance of mechanical part of steam turbine and disturbance of governor on low frequency oscillation are simulated in a single-machine and infinite bus system separately. The simulation results illustrate that disturbance of mechanical part of steam turbine leads to larger amplitude than disturbance of governor when the disturbances are of same amplitude and frequency. The simulation results are in accordance with theoretical analysis, which can provide reference for suppressing low frequency oscillation of resonance mechanism.