Research And Application Of State Monitoring And Fault Diagnosis For Power Capacitor

Reactive power compensation for the stability of the power system,economic operation has an important role,the power capacitor is as the most important reactive power compensation equipment is widely used in power systems.Due to the complexity of the operation of the power capacitor,coupled with the lack of sufficient attention,resulting in the daily operation of the failure rate is high,and most of the current maintenance work is the traditional preventive test,can not real-time monitoring of the power capacitor running,Of the defect or failure to make advance judgment.Therefore,it is very important to carry out the research on the monitoring and fault diagnosis of power capacitor.It is very important to ensure the safe and stable operation of capacitor equipment.Based on the above background,this paper studies two aspects of power capacitor condition monitoring method and fault diagnosis and positioning technology.The main works are as follows:(1)Briefly summarize the basic structural characteristics of power capacitor,summarize the common fault types and characterization of capacitor Phenomenon,the cause of the failure and the impact of the impact of an in-depth analysis.(2)According to the characteristics of the power capacitor fault,the fault diagnosis technology such as capacitance,dielectric loss factor,operating voltage,circulating current,unbalanced signal and temperature is taken as the condition monitoring quantity.The capacitor is analyzed by off-line test and the online monitoring and synthesis Method,real-time comprehensive grasp of the operation of the capacitor state.(3)A fault diagnosis scheme based on the condition quantity as the fault condition is proposed in combination with the relevant rules.For the characteristics of fault fuzziness,the fuzzy theory is applied to the insulation fault diagnosis,and the insulation level of the equipment depends on the insulation dampness and aging degree Diagnosis,while a variety of state information on the state of the power capacitor to assess the state.(4)The MATLAB / Simulink platform was used to simulate the breakdown of the internal components of the capacitor and the fuse failure.The changes of the current value,the capacitance,the running voltage and the unbalanced current signal of the neutral current under different faults were calculated and analyzed,Provides the data support for the internal fault diagnosis analysis of the capacitor.(5)Combining the actual operation of the parallel capacitor,a fault diagnosis technology based on the difference idea is proposed.This method can eliminate the interference caused by the fluctuation of the voltage fluctuation and the temperature change,and obtain the relationship between the different fault types and the current change interval.The range of current changes can accurately determine the internal component failure.(6)Design a set of power capacitor on-line monitoring system based on embedded technology,real-time monitoring and record the operating parameters of the capacitor,and combine the fault diagnosis technology to diagnose,display,forecast,locate the running status of the equipment.The on-line monitoring system has been piloted in Zibo area,its monitoring accuracy to achieve the desired results,to timely detection of fault defects to provide early warning function.The operation and maintenance personnel can quickly find the fault location and fault analysis according to the monitoring results,carry out targeted maintenance of the defective equipment,and effectively guide the development of the maintenance cycle,and reduce the failure rate and accident rate of the power capacitor.