解列后孤岛频率电压相互作用仿真及机理探讨

Simulation and Discussion on Mechanism of Dynamic Interaction Between Frequency and Voltage in Islanded Power Grid

目前的低频、低压减载装置相互独立,当用于保持解列后孤岛的频率、电压安全控制时,由于孤岛内频率和电压的动态过程相互耦合,仅通过初始有功功率缺额不能准确判断孤岛频率变化趋势,通过典型算例的仿真,分析了初始有功缺额、初始无功缺额、负荷特性等对孤岛频率动态过程的影响,指出负荷特性和初始无功缺额对于孤岛电压状况和孤岛频率动态的变化有强烈的影响,在研究解列后存在大量有功功率缺额的孤岛频率动态时需要充分考虑电压变化对其的作用,相关工作为解列后孤岛频率电压联合紧急控制的研究提供了参考。

At present the under-frequency load shedding device and the under-voltage load shedding device are configured in power grid independently. When these devices are applied in the secure control of frequency and voltage in an islanded power grid, due to the intereoupling of dynamic processes of voltage and frequency it is impossible to accurately judge the frequency variation of the islanded grid only by initial active power vacancy. Through the simulation of typical example, the impacts of initial active power vacancy, initial reactive power vacancy, load characteristics, etc： on dynamic process of island frequency are analyzed, and it is pointed out that the load characteristics and initial reactive power vacancy intensively impact on both island voltage condition and dynamic variation of island frequency. During the research on post-splitting dynamic frequency in the island with a lot of active power vacancy it is necessary to fully consider the impact of voltage variation on dynamic frequency. Conclusion of this research is available for reference to joint emergency control of island frequency and voltage after the splitting of power grid.