基于sBTTC指数的主导稳定形态判别多场景验证——功角失稳场景

Multi-scene Verification of Dominant Stability Mode Discrimination Based on sBTTC for Determining Rotor Angle Instability

功角失稳是威胁交直流混联大电网安全稳定运行的重要形式之一,快速甄别功角失稳形态是实施切机组、送端速升直流外送功率等紧急控制的前提。为更有效判别出功角、电压主导稳定形态,对简化支路暂态输电能力(simplified branch transient transmission capability, sBTTC)指数进行了修正,弱化了原指数的相位因子。依据关键支路sBTTC指数与电压因子的相关性系数、与相位因子的相关性系数以及二者的系数比进行主导稳定形态判别;将支路垂足电压位于支路之上作为判别功角稳定形态的必要条件之一,以提升判别的可靠性。针对功角失稳的四种典型形式,即功角第一摆失稳、第二摆失稳,以及功角低频增幅振荡失稳、超静态稳定极限失稳进行验证,仿真表明判别方法对不同形式功角失稳均可准确有效判别出主导稳定形态。

Rotor angle instability impedes the safe and stable operation of AC and high-voltage direct current(HVDC)hybrid power grids.Rapid identification of rotor angle instability is the premise of emergency control,such as unit switching and HVDC power increase at the sending end.To distinguish between the rotor angle and voltage-dominant stable state more effectively,the sBTTC index is modified to weaken the phase factor of the original index.The dominant stable state is determined based on the correlation coefficient between the sBTTC index and the voltage factor,correlation coefficient of the phase factor,and ratio of the two coefficients.Setting the pedal voltage of the branch to be greater than that of the branch is one of the necessary conditions for judging rotor angle stability.This paper discusses four typical forms of rotor angle instability,namely rotor angle one swing instability,rotor angle two swing instability,rotor angle reverse swing instability,and rotor angle low-frequency amplitude oscillation instability.The simulation results show that the discrimination method can accurately distinguish between the different forms.