Online Security Assessment of Power System Frequency Deviation

Large frequency deviation during transient progress has effects on system stability, primary components security and products quality. Online monitoring and security analysis on frequency based on the wide-area measurement system have great significance. A wide area data collecting system from 220V user side is introduced. A method to quantitatively assess the transient frequency deviation security is presented, which takes into account the frequency deviation cumulative effect. The implementation of online security assessment of transient frequency deviation is described in detail, including data filtering, online computation of security margin, automatic alarming of security broken, etc. According to collected data from the actual operation of power system, the state of frequency has been statistically analyzed. The system is playing an important role in large scale power dynamics analysis, and is a helpful complement to numerical simulation.