Extra/Ultra High Voltage AC Filter Circuit Breaker Pre-Insertion Resistors State Evaluation Based on Wavelet Decomposition and TLS-ESPRIT

Frequent switching of Extra/Ultra High Voltage (EHV/UHV) AC filters places harsh operational demands on circuit breakers, leading to a high failure rate of the pre-insertion resistors. Moreover, there is a lack of effective assessment methods for the operational state of pre-insertion resistors. Based on this, this paper proposes a method for assessing the state of pre-insertion resistors by combining wavelet decomposition and TLS-ESPRIT The method in this paper uses the modulus maxima of wavelet decomposition to automatically extract transient current data during the switching process of high-voltage filter bank circuit breakers. Subsequently, the TLS-ESPRIT is employed to decompose the transient currents to identify various frequency modal components. Finally, the pre-insertion resistor operating state is evaluated in real time using the characteristic parameters of different frequency modal current components.