Insulation Testing Research And Device Design Of High-power Eletric Heating Elements

China is vigorously promoting the construction and development of nuclear power plants today,but how to ensure the safe and effective operation of nuclear power plants has always been a very important issue.The voltage regulator in the nuclear reactor is a key component for its safe and effective operation.The heating element in the voltage regulator is powered by the IT system.Due to the special working environment of the heating element,It is prone to aging and damage,which leads to problems such as single grounding in the power supply system.If it is not promptly investigated,it may have serious consequences.Therefore,in order to be able to monitor the insulation status of the heating element system in real time,the problem can be found and eliminated in time before serious electrical faults occur.so as to ensure the safe operation of the nuclear reactor.This paper studies and designs the insulation monitoring device,which is suitable for the heating element system of the nuclear reactor regulator.based on the completing of the analysis of the working principle of the heating element power supply system.The system simulation model was established.Through simulation comparison,dual-frequency injection method was selected as the insulation monitoring method of the system.According to the function to be realized,the hardware circuit module of the monitoring device was designed,which mainly includes the power supply module,the injection source generation module,the injection source loop,the acquisition loop,the core module,the display module,and the protection circuit.Verified the correctness of the design.Then according to the circuit design scheme,the circuit schematic diagram was drawn.Combined with the working principle of the device,the software was designed to process the collected signals,and the insulation resistance of the system is calculated in the core module,so that the insulation state of the system can be analyzed.Finally,a test platform was built in the laboratory to simulate the IT system,and offline and online tests were carried out on the sample of the monitoring device.Through analysis of the test data,it was verified that the insulation monitoring sample designed in this subject can achieve the insulation monitoring function and meet the project demand.