ABSTRACT
This chapter analyzes the current fault current detection methods including its advantages and disadvantages, and proposes a new detection method for short-circuit current by using the comprehensive criterion of absolute value of current, rate of change, and curvature. It also proposes to use different combinations in different angles of the short-circuit current by analyzing the rate of change and the size of the impact for detection the rate of change of current. The method of setting current threshold has been often used for the detection of short-circuit in traditional current limiter, considering the on-off difficulty of current caused by the rising of short-circuit current, and the problem of the increase of electric power. Short-circuit current, the raising rate of short-circuit current and the second derivative of the current have different forms at different short-circuit time. The chapter introduces the current curvature, which is the derivative of current change rate to detect the short-circuit current.
