基于单机负荷模型系统的紧急状态研究

Study on system emergency state based on single generator load model

研究了电力系统的运行状态分类及其之间的转换关系,建立简单的单机负荷模型系统的状态方程,重点研究系统的稳态及紧急运行状态。电力系统中出现大的扰动,系统中将出现有功、无功功率的不平衡。借助Matlab仿真分析系统频率和电压的运行轨迹变化,结果表明,频率是系统有功功率平衡的指示器,而无功功率不平衡决定母线电压的变化,在紧急状态下,系统频率和电压稳定是不能完全解耦的。该研究对传统的低频减载策略设计和改进具有重要的指导意义。

The classification of system running state is determined and the transformational relation among them is studied. State equations are constructed about simple single generator-load model system. Steady state and the state of emergency running are focused. The occurrence of a large disturbance in a power system can arouse active and reactive power imbalances. System frequency and voltage trajectory are simulated and analyzed with Matlab. The results show that the frequency is an indicator of real power balance and reactive power imbalance determines the change of bus voltage. Frequency and voltage stability cannot be decoupled completely under emergency situations. This conclusion has an important guiding significance for the design and improvement of traditional under frequency load shedding （UFLS） strategy.