| The routine work inspection of the power safety patrol and power safety inspection for State Grid Corporation of China（SGCC）,it’s normally include two important works,the failure detection and power breach inspections.The temperature monitor of key nodes inside the switch cabinet can forecast the faults in time.The power theft action is also a common phenomenon happens in power breach inspections work.For SGCC the investigation of power theft action is an important part of electricity inspection.According to the type of power supply and power consumption,the users are divided to special transformer type and public transformer type.Special transformer type usyally used by enterprises and commercial tenant.Therefore,it is of great significance for the safe and orderly operation of the power grid to detect faults in a timely manner and prevent the theft of electricity in the special transformer power supply system.In this thesis,use surface acoustic wave（SAW）sensor to measure the temperature of the switchgear,and designs an anti-theft detector to mornitor special transformer users.The system achieves real-time transmit data through NB-IoT module.The system is mainly composed of SAW temperature detector,display instrument,metering box side anti-electric larceny detector,vacuum circuit breaker side anti-electric larceny detector,NB-IoT communication module and IoT application.When the temperature measuring system is working,the SAW temperature sensor is excited through the frequency sweep signal.The SAW temperature sensor returns echo signals with different frequencies through normal mode helical antenna at different temperatures.The temperature reader obtains the temperature of the measuring point according to the frequency of the echo signal,and then displays the temperature through the display instrument.The scheme determines whether the power is stolen by monitoring the operating parameters of the power system in real time.To be precise,it determines whether power thefted occurs by compare the vacuum circuit breaker’s current with the power of meter box,at same time it also monitor the status of the meter box.The power data is obtained by reading the smart electricity meter and the smart switch controller.In the thesis,briefly describe the research background and significance,describes the design principles of SAW temperature measurement and anti-theft,it’s introduces the design of hardware and the flow map of software.Through data analysis the system has great of value to measure the temperature of the switch cabinet and monitor against electric theft. |
