Research And Design Of New Intelligent Switch Cabinet Real-time Monitoring System

The switchgear is an important control equipment in the power distribution link of the power system.The equipment in the high-voltage switchgear is in the working state of strong magnetic field,large current and high voltage for a long time,so it is very important to monitor and protect its normal operation life cycle.However,at present,the traditional monitoring and control methods,which monitor the temperature of the switch cabinet manually and inspect the operation state,have serious deficiencies in reliability,accuracy and real-time.Therefore,it will be the inevitable trend of the development of intelligent switch technology to develop the switch cabinet to the high intelligent direction of unattended.In this paper,aiming at the large volume,low intelligence and low centralized control of traditional switchgear,an intelligent switchgear monitoring system based on ARM technology is designed.The main contents of this paper are as follows:(1)In order to prevent the operators of high-voltage switchgear from misoperation with electricity,this paper designs a high-voltage live locking display module.When any phase or two phases of the three-phase bus are live,the live locking display will make the electromagnetic lock implement the forced locking operation.The high voltage side is isolated from the low voltage side by the method of signal isolation.The live signal of the high voltage bus is connected to the main control MCU module,and the live state of the bus is displayed in the display screen,and the high voltage signal is accurately uploaded to the cloud platform of the monitoring system in real time.(2)Design a low-power wireless temperature monitoring module.Firstly,analyze the generation and conduction process of heat in the switch cabinet.Analyze the temperature change and the electric field distribution of the heat transfer conductor in the process of temperature conduction at the key temperature measuring points through the COMSOL software.Monitor the temperature change at the key points of the switch cabinet through the low-power temperature sensor,and propose a predictable insulation state model of the key points.Secondly,the module uses keil software to complete the microprocessor RTC timing wake-up temperature sensor to collect temperature,and transmits the data collected by the temperature sensor to the main monitoring module in real time through the wireless module.Finally,the power consumption of the modules with different configurations is calculated.Compared with the current similar design,the power consumption is lower and the running time is longer,which has a certain engineering application value.(3)In order to improve the reliability of wireless temperature monitoring module communication in high voltage,high current and strong magnetic field environment,different distance attenuation and different signals are used to improve the success rate of data transmission.The optimal attenuation signal in short distance and long distance is calculated by experimental test.Secondly,frequency hopping communication mode is adopted in the design,and the simulation analysis of frequency hopping communication system is carried out by MATLAB software.The results show that frequency hopping communication system can improve the anti-interference and data transmission confidentiality of wireless temperature monitoring module.(4)In order to collect the power quality index parameters,an improved FFT algorithm is designed by using the acceleration principle of FFT algorithm.The algorithm uses the power metering chip to convert and collect the secondary current and voltage signals in the transformer.The converted signal data is calculated and analyzed by the improved FFT algorithm.The experimental results show that the Improved FFT algorithm can not only meet the accuracy of index parameter data,but also reduce the calculation error.(5)In this paper,DHT11 sensor is used to collect the change of temperature and humidity in the switch cabinet,verify the measured data,improve the reliability of data collection,control the dehumidification of the heating plate,and ensure that the cabinet environment is dry without condensation.In order to ensure the accuracy of the signal in the system,fully consider the factors of signal interference in PCB design,suppress various signal interference,and improve the influence of electromagnetic interference on each system module.(6)The cloud platform display operation interfaces of multiple monitoring systems are designed respectively.The data and equipment status information collected by multiple monitoring modules are uploaded to the cloud platform of the monitoring system through the network.The data and status information collected by the front-end monitoring of the intelligent switch cabinet that has been put into operation are connected with the monitoring system platform to complete the monitoring and operation management of the monitoring system on the intelligent switch cabinet It can better realize the remote operation,maintenance and management of power equipment by the Internet of things.