A new approximate entropy-based method to detect sub-synchronous resonance

A new approximate entropy-based method, which can perform real-time detection of sub-synchronous resonance (SSR), is proposed. Firstly, the current signal is sampled and its approximate entropy is calculated; then whether SSR occurs or not is judged by observing variation law of approximate entropy in continuous time intervals, in addition, the real-time performance of approximate entropy, its good anti-interference ability and its ability of processing random signals and deterministic signals are analyzed; finally, the proposed method is simulated by IEEE first benchmark system model. Simulation results show that the approximate entropy-based SSR detection method is effective.