Fast current protection algorithm for intelligent high voltage circuit breaker

To improve the accuracy and speed of fault current computation, a variable step size window length adaptive algorithm based on the adaptive filtering theory is proposed in the paper. Digital signal processing algorithm is one of the most important factor for the current protection algorithm. The paper analyzes the principle of the proposed algorithm and the way how to vary the step size and window length. The proposed adaptive algorithm can change the step size of the length changeable window in the filtering algorithm. It is sensitive to fault signals and has a fast response speed, and also have a more efficiently performance. The results of simulations show that the algorithm possesses good performance and is suitable for realizing the fast current protection function to the intelligent high voltage circuit breaker. According to the definite criterions to choosing the fault line, both theoretical analysis and simulation results show that the method has satisfactory reliability and sensitivity.