Design Of On Line Monitoring System For Distributed Capacitive Equipment In Substation

Capacitive equipment refers to the electrical equipment which adopts the principle of capacitance in its insulation design.There are many high voltage capacitive equipment in substation.It occupies more than 50% of substation equipment.It is an important component of the transformer substation.It takes on an important task.Once the insulation,leakage and other faults,will lead to serious consequences.In the traditional way of work,the insulation detection of this kind of equipment is carried out under the condition of equipment outage.This will result in a large area of the line outage,causing inconvenience to the people's production and life.In this paper,an on-line insulation monitoring system for capacitive equipment is designed.It refers to the principle of transformer condition based maintenance.It will change the traditional maintenance mode of power failure into condition based maintenance.It makes it possible to predict the running state of the insulation according to the real-time monitoring results of the insulation state.It makes it possible to predict the fault in time without any leakage in the insulation state,so as to avoid the leakage accident.The TMS320F28335 controller is used as the main processor in the project design.It uses a dedicated 16 bit ADC controller for analog acquisition,and ensures the accuracy of leakage monitoring.At the same time,it increases the detection of environmental parameters,introduces environmental parameters into the insulation monitoring,and reduces the interference of environmental problems on the accuracy of insulation detection.Firstly,this paper introduces the related technologies used in the design of capacitive equipment insulation monitoring system.It discusses the insulation leak detection scheme.It analyzes the working principle of the current sensor.Among them,it focuses on the detection principle and method of dielectric loss.Secondly,it studies the overall design of the insulation on-line monitoring system.It analyzes the overall structure of the system and the working principle of the insulation monitoring unit.It discusses its basic realization principle and monitoring process.It performs the overall structure design of the insulation monitoring unit of capacitive equipment.It draws the block diagram of the terminal circuit and studies the application of the hardware interference.This paper focuses on the hardware unit design of capacitive equipment on-line monitoring terminal.It introduces each unit function of the on-line monitoring terminal,and draws the functional structure diagram of the hardware unit.It makes a comparative analysis of the ADC conversion scheme,and confirms the scheme of using a dedicated ADC conversion chip.It discusses the processor circuit,voltage and current acquisition unit circuit,PLL circuit and ADC control circuit design,and formulates the system power design.It gives detailed circuit schematic design of each part.Finally,the software design of the insulation on-line monitoring unit is accomplished,and the monitoring unit is debugged.It designs the main program design of the insulation on-line monitoring terminal.It draws the flow chart of the main program and the flow chart of the ADC control program.It introduces the debugging process of the insulation on-line monitoring unit,completes the debugging of the circuit board connection,the circuit basic function debugging and the sample precision test.By comparing with the standard equipment of the Electric Power Research Institute found that high precision insulation on-line monitoring system in the design,to meet the use requirements.