解列时刻对解列后孤网暂态稳定性的影响机理

解列时刻是解列后孤网能否保持同步稳定运行的一个关键参量.文中采用扩展等面积准则方法,将组成孤网的机组通过互补群惯量中心-相对运动变换映射为单机映象.基于单机映象等值电磁功率在解列前后的差值在等值功角变化区间上的积分,提出了解列时刻影响孤网暂态能量变化量的计算方法,从能量角度解释了不同解列时刻对孤网暂态稳定性的影响机理.进而提出了解列后孤网暂态稳定裕度对于解列时刻的灵敏度计算公式,判断延迟解列是否有利于孤网暂态稳定性,并通过仿真证明了分析方法的正确性.

Influence Mechanism of Splitting Timing on Transient Stability of Isolated Power Grid After Splitting

The splitting timing is a key parameter for whether the isolated power grid can keep synchronous and stable operation after splitting. By using the extended equal area criterion (EEAC) method, the units that make up the isolated power grid are mapped into a single-machine image through the complementary-clusters center-of-inertial relative-motion (CCCOI-RM) transform. Based on the integral of the difference between the equivalent electromagnetic power of a single-machine image before and after splitting in the range of equivalent power angle variation, this paper proposes a calculation method of the influence of the splitting timing on the transient energy variation of the isolated power grid. The influence mechanism of different splitting timing on the transient stability of the isolated power grid is explained from the view of energy. Furthermore, the sensitivity calculation formula of transient stability margin of the isolated power grid after splitting to the splitting timing is put forward, which can be used to judge whether the delayed splitting is beneficial to the transient stability of the isolated power grid. The correctness of the analysis method is verified by simulation.