利用暂态能量分析同步发电机调速控制对稳定性的控制效果

Analysis of effect of synchronous generator governor control on stability by using transient energy

故障期间形成的暂态能量造成发电机的摇摆振荡,故障切除后,该暂态能量(TE)是增加还是减少将决定发电机的振荡是增幅还是减幅,TE反映了发电机稳定性受到危害的程度。以单机无穷大系统为例,给出了不同故障类型下TE随时间变化的曲线,分析了汽轮机模型、水轮机模型以及调速系统附加鲁棒控制(GAHC)对TE的影响。通过理论分析和对比仿真实验得到的TE和转速曲线表明:汽轮机调速系统有助于TE衰减,水轮机的水锤效应在故障开始后的一段时间内不利于TE的衰减;从理论上证明了GAHC加快TE衰减提高同步发电机稳定性的作用;利用TE能够定量直观地评价控制方法对发电机稳定性的控制效果。

The transient energy （TE）, is formed during the period of fault in power system. The TE leads to the oscillation of generator. If TE is reduced after the fault, the value of rotor speed oscillation will be reduced also. So TE can be used to reflect the degree of the stability destroyed. The curve of TE was shown in the one machine and infinite system. The effect on TE caused by governor system of turbine generator, hydro-turbine generator and governor additional robust control （GAHC） was analyzed. The results of theoretical analysis and simulating tests show that it is helpful to reduce TE for the turbine governor system and TE will be increased by water hammer effect of hydro-turbine generator during one period after fault. It is proved in theory that TE is reduced more quickly by GAHC and GAHC is helpful to improve the stability of synchronous generator. TE can be used as one quantitative index to compare the effect of different stability control law.