Research on mechanical fault diagnoses methodology of a circuit breaker based on the voltage and current during its operation
The performance of a circuit breaker during its operation has great impact to the power system security and is of great concern to the operation and management department of power grid. This paper presents a new method to acquire the performance information of the circuit breaker during its connecting/disconnecting operation through the voltage and current waveforms‥ Due to capacitance effects between dynamic and static contact, the voltage and current parameters in the process of connecting/disconnecting can be decomposed into two parts by orthogonal transformation method. The two parts are active and reactive power. The reactive component is generated by the capacitance effects. When the circuit breaker mechanical failure, particularly in velocity of contact anomalies, the capacitance effects will naturally be affected, that is, the reactive component will contain abnormal part inevitably. This method can effectively suppress interference, highlight the major characteristic quantities of the circuit breaker, and evaluate its mechanical performance.
Research on a novel on-line monitoring system for Mechanical Characteristic of Circuit Breaker
Detection Device of Circuit Breaker (CB) Mechanical Characteristic is established in the paper, which takes TMS320F2812 as a core, and makes a logic extension. The necessary signal is collected, stored, and transmitted to position machine Upper memory block through CAN bus. The signal is analyzed and disposed, and the experimental data is transported to remote monitoring machine, thus the date is accumulated and information is shared. The paper improves maintenance level of CB, realizes the condition maintenance of CB, and enhances the efficiency of detection, so that this design has very important theoretical meaning and practical value.
Design of On-line Monitoring System for Circuit Breaker
The designed system is capable of on-line monitoring the temperature rise, insulation and mechanical characteristic of circuit breakers. It has a local monitoring unit and a computer, the former collecting local data and showing users the condition report on LCD, indicating the condition of exceeding the threshold value that can be preset by user through keyboard, and sending the data to computer through RS-485 communication interface. The application of PSD device and a software method called task schedule makes the local monitoring unit more stable and more flexible.