Sampling frequency self-adapting software algorithm in protection relay measure and control system

Frequency spectrum leakage caused by synchronous error in nonsynchronous sampling system reduces the accuracy of frequency spectrum analysis and harmonic measurement. A sampling frequency self-adapting software algorithm in protection relay measure and control system is presented in this paper. The sampling frequency self-adapting software algorithm obtained the actual signal frequency fairly accurately by calculating the sampling data from protection relay measure and control system, and adjusted the sampling time interval according to the frequency which was calculated by the self- adapting software algorithm. The process of the software algorithm design is introduced, simulation and analysis are discussed. The results of simulation and analysis show that this software algorithm can improve the accuracy of frequency spectrum analysis and harmonic measurement for power system signal, and the algorithm can be realized easily.