Abstract:In order to address the limitations of the traditional feature current identification method in terms of reception identification accuracy, a characteristic current signal detection method based on Duffing oscillator is proposed in the paper. The method utilizes the sensitivity of the Duffing oscillator system to the initial value and the good anti-noise characteristics, and qualitatively analyzes the critical state of the Duffing oscillator system by observing or monitoring the change of the system phase trajectory. The fusion terminal initiates a topology identification command, the outgoing monitoring unit generates and transmits a characteristic current signal, and the extracted signal to be measured is used as an input to the Duffing oscillator detection system. When the signal to be measured contains components with the same frequency as the Duffing oscillator system, the detection of the known frequency characteristic current signal is realized by quantitatively calculating the critical threshold of the system. In the simulation test, the change of the critical threshold of the Duffing oscillator system is accurately determined by the change of the sample entropy of the system state variable before and after the addition of the signal to be measured. The simulation results prove that the proposed method can realize the efficient detection of the specified frequency characteristic current signal, which significantly improves the reliability of the identification of transformer-customer relationship in distribution networks.