Study On Failure Diagnosis For Mechanical Characteristics Of High-voltage Vacuum Circuit Breaker

In electrical power system, High-voltage circuit breaker is one of the most important equipment, is the most important one kind of electric appliance in the switch electric appliance, is the the essential part in the power plant and distribution equipment. High-voltage vacuum circuit breaker plays a dual role of control and protection in electric grid. Its failure will cause or expand the electric grid's accident, and bring considerable economic and social influence. The reliability of high-voltage circuit relates the entire electrical power system's safe operation, so the study on on-line monitoring and fault diagnosis for mechanical characteristics of high-voltage vacuum circuit breaker is of great significance. This paper is supported by the foundation of scientific and technological research project-the development and industrialization of a new intelligent module in high-voltage vacuum circuit breaker with permanent magnetic actuator in Jiangsu Province (Item Number:BE2006086).Firstly, the paper elaborates the concept, classification and characteristic of high-voltage vacuum circuit breaker and working principle of high-voltage vacuum circuit breaker with permanent magnetic actuator. From the aspects of principle, objective and contents of general on-line monitoring system of high-voltage vacuum circuit breaker, the on-line monitoring system for mechanical characteristics of high-voltage vacuum circuit breaker which is designed in this paper is planned and the mechanical parameters of this system are identified. The definition and monitoring methods of mechanical parameters are introduced, and the selection of sensors and their working principles are also explained.Secondly, the function modules of on-line monitoring system are planned. A new kind of site monitoring module based on TMS320F2812DSP is designed. The system hardware is made up of tow floors: the bottom floor and the upper floor. The bottom floor is the site monitoring module, which is primarily responsible for sampling data, disposing data and communicating with the computer. The upper floor is the PC, which is primarily responsible for man-machine interface's display, fault diagnosis, creating high-voltage breaker running states database and so on. The system uses CAN bus as communication method between site monitoring module and the PC. The paper emphasizes on the designment of hardware and software, such as signal conditioning circuit, display module, the design of the communication module and the monitoring software design for the PC. The management software takes LabVIEW as developing platform and realizes the function of displaying and analyzing for metrical data by means of its powerful functions.Finally, the fault diagnosis method of hall electric current signal of high-voltage vacuum circuit breaker is mainly researched. On the basis of monitoring hall electric current signal of circuit breaker, the new method of wavelet analysis and RBF neural network is comprehensively adopted to analyze and extract the characteristic of the vibration signals of circuit breaker. The methods adopted in this paper are provide basis for fault analysis of circuit breaker. Also, the elementary work of fault diagnosis is completed.The results of field experiments show that the on-line monitoring system and fault diagnosis method researched in this paper can validly monitor the main mechanical characteristic parameters of high-voltage vacuum circuit breaker and make right judgement for fault conditions.