Research And Design Of Electric Leakage And Insulation Monitoring System In Medical Electric Place

With the rapid development of science and technology,the degree of electrification in the hospital is becoming more and more high.The hospital is inseparable from all kinds of electrical equipment.If there is a leakage or even a power outage,the consequences will be unimaginable.Therefore,it's very important to ensure the reliable operation of medical electrical equipment and ensure that hospital personnel are not injured by a leakage accident.Based on the monitoring of single-phase earth leakage and insulation faults in medical electrical sites,combined with the current research status of insulation and leakage protection in distribution networks at home and abroad,this paper proposes a fault location method for medical distribution system.And using the current communication technology,judge the medical insulation and leakage accidents,and achieve rapid and online positioning.According to the control requirements,the residual current monitoring is used for the neutral point grounding system in the general ward,based on the principle of node current,monitoring the unbalanced current of each out of the line.In recent years,many kinds of signal injection methods have been put forward to the insulation fault monitoring and analysis applied to IT system.Combine the characteristics of the single frequency and dual frequency method,obtain the measured capacitance and resistance.It overcomes the shortcoming of inaccurate insulation resistance measured by single frequency method,which can ensure the accuracy of the system and reduce the use of hardware.The main control chip of this design is CC2530 micro controller.The system is mainly divided into:insulation detection module,leakage detection module,electric energy metering module,temperature and humidity detection module,LCD display,power management and self-inspection.The leakage current can be collected by the current transformer.The insulation resistance detection module can monitor the insulation resistance in real time.And can complete overload protection and temperature detection through the measurement of other electrical quantities.In the event of failure,the system can monitor the fault signal in time and complete the alarm function.Among them,ATT7053AU electric energy metering chip is selected to measure current and voltage in the insulation detection part.After conversion,a more accurate resistance value can be obtained.It improves the former method of detecting current value first and then converting it to voltage value through current and voltage converter,and obtaining the measuring voltage,which eliminating the error caused by transformation.The software algorithm is used to improve the input error of sampling signal in the design.And the system can communicate with the host computer through the ZigBee communication module,sending real-time signals to the main system in time,keeping pace with the development of modern smart-grid.