Research And Application Of On-line Monitoring System For Capacitive Equipment In Substation

Power system plays an important role in the development of national economy,it is very important to ensure the safe and stable operation of power system.There are many types of capacitive equipment in substation,and the total number accounts for more than half of the electrical equipment in substation.Based on the field investigation of various voltage level substations in Taizhou City,Jiangsu Province,the fault detection technology of capacitive equipment still adopts the off-line detection mode,which can not monitor the operation status of capacitive equipment online in real time.In order to ensure the safe and stable operation of capacitive equipment,a set of on-line monitoring system for capacitive equipment is developed based on the technical requirements of on-line monitoring of capacitive equipment.After successful application,the on-line monitoring technology of other electrical equipment will be popularized.The main work of this paper is as follows:Firstly,the 220 k V substation under Taizhou is investigated to obtain the type and quantity of capacitive equipment and understand the on-site monitoring requirements.The relevant theoretical basis and the factors affecting the on-line monitoring of capacitive equipment is summarized in this paper,and the monitoring theory of dielectric loss factor is studied,and the measurement method of dielectric loss is obtained.Then the system implementation scheme is designed,and the front-end field monitoring unit and background server unit are developed.The core processor of the front-end field monitoring unit selects DSP chip,which is responsible for the control of the whole monitoring terminal.A small current sensor is choosen,which is responsible for acquiring the current signal of the end screen of capacitive equipment.The output signal of the sensor is amplified,filtered and converted by the signal processing unit.The field monitoring unit and the background server unit interact with each other through Ethernet.The background server can receive the data of the field monitoring unit,and display the collected data by calling.The hardware related functions are realized and the background display software is developed in this paper,the design results in Taizhou substation current transformer and transformer bushing for test.After several months of operation,the system can accurately monitor the on-line capacitive equipment,and the design meets the requirements of engineering application.