Research On Fault Diagnosis Method Of Operating Mechanism Of High Voltage Circuit Breaker

High voltage circuit breaker is used as a switching device for controlling the operation of the power grid and protecting the power equipment,and the reliability of its operation is extremely important for the safe operation of the entire power system.The high-voltage circuit breaker opening and closing operation relies on the sequential start,operation,impact,oscillation and stop between the components of the operating mechanism,and the complicated connection between the components causes the operating mechanism to be the main cause of the mechanical failure of the circuit breaker.The circuit breaker operation process is accompanied by a series of signal changes.Through the monitoring,analysis and processing of the accompanying signal characteristics,the internal relationship between the fault symptom and the fault mechanism is found,and the fault diagnosis model is established to find the circuit breaker fault and analyze the fault development trend service in time.Therefore,it is self-evident to study the fault diagnosis technology of the operating mechanism of the high-voltage circuit breaker,to provide the basis and guidance for the maintenance of the circuit breaker and ensure the reliability of the system operation.Based on the analysis of the basic mechanism and working principle of ZN65-12 circuit breaker,and researching the type of fault and its causes,this p aper selects the appropriate sensor to monitor the current signal of the energy storage motor,the current signal of the control coil and the vibration signal during the operation of the circuit breaker,and further research on the fault diagnosis method of the circuit breaker operating mechanism.Firstly,based on the study of fault type and detection signal of circuit breaker operating mechanism,the overall scheme of high voltage circuit breaker fault diagnosis system is designed,and the sensor parameters and hardware components are determined.Secondly,wavelet soft threshold denoising is applied to the acquired signals,and a fault diagnosis method for circuit breaker energy storage mechanism based on electric-vibration signal entropy weight feature is proposed.After Hilbert transform,the time domain characteristics and kurtosis of the motor current envelope are extracted.Combined with the box dimension feature of the product function component after local mean decomposition of the vibration signal,the weighted the feature vector of diagnosis energy storage mechanism is determined by using the entropy weight method,and the fault avoids the error caused by subjective factors.Then,using the mutual information method and Cao method to calculate the delay time and embedding dimension of the reconstructed parameters,a fault diagnosis method for the circuit breaker closing mechanism based on phase space reconstruction and improved k-means algorithm is proposed.The vibration signal is reconstructed into a high-dimensional space,the trajectory matrix is defined,and the singular value of the matrix is decomposed.Finally,the normalized singular value is extracted to characterize the fault of the circuit breaker closing mechanism.Finally,the feasibility of the circuit breaker fault diagnosis method based on the electric-vibration signal entropy weight feature and vibration signal reconstruction is verified by simulating the circuit breaker operating mechanism failure experiment.