Research On DC Insulation Detection Technology Of Substation Based On Internet Of Things

The DC system is an important part of the substation.Its main function is to supply power to various protection devices and operating circuits in the substation.Whether the DC system can work normally will have a serious impact on the safe and s Tab operation of the power system.For substation DC systems,branch grounding is a relatively common insulation failure fault.Generally,a single point of grounding has no serious impact on the normal operation of the DC system;but if the location of the fault cannot be found in time,a single point of grounding fault It may evolve into a multi-point grounding fault during operation.Multi-point grounding is a more serious insulation degradation fault.The malfunction of the protection equipment or the short circuit of the power supply caused by the protection equipment will cause the consequences of the line not to be underestimated,and the equipment may be burned in severe cases.Or cause an accident.Therefore,in order to ensure that the system can alarm in time when a point of ground fault occurs,and avoid causing more serious electrical accidents,real-time detection of the system is extremely important and has full practical significance.This article fully analyzes the types of DC insulation faults,and lays a theoretical foundation for the design of DC insulation detection systems in substations.The normal operation of the insulation detection part of the DC system is of great help to the safe operation of the substation.By comparing several traditional and commonly used DC system insulation detection methods,this paper briefly introduces the AC injection method and the bridge balance method,and finally decides to improve the DC leakage current detection method through the Internet of Things technology,using the basic switch combination control The detection principle is to establish the circuit structure under different conditions,and list the linear equations of the sampling voltage under different circuit structures.The various devices in the system are modularized,and the modular programming is performed independently on the basis of the main program.Improve the accuracy of data collection.Take advantage of the wireless conduction of the Internet of Things to replace the original conduction module of the system,complete the integration of system data,and finally transmit the collected and calculated bus voltage values and the resistance values of the positive and negative electrodes to the ground to the terminal for analysis.This article focuses on the design and development of the hardware and software of the insulation detection device based on the Internet of Things in the DC system of the substation.The hardware part of the device can be roughly divided into Zig Bee communication circuit,terminal node and DC leakage current sensor architecture circuit diagram,minimizing single-chip circuit,sampling circuit and display circuit.The PIC16F1947 universal chip is used as the core controller,and the functional modules are designed.Hardware circuit,each module cooperates with each other to realize the function of DC system insulation online detection.Complete the software design according to the requirements of the system and the functions required by the device,and compare and analyze the experimental data at the end of the article.By comparing the magnitude of the leakage current and the measured value of the resistance with the calculated value,it can be judged whether the DC system is well insulated.This design It greatly improves the accuracy of leakage current detection and improves the wireless communication method,and proposes a new and efficient method for DC system insulation detection.