Design Of Power Quality Cloud Monitoring System Based On Internet Of Things

Electricity as one of the most popular energy,already and the country’s economic lifeline tightly together,and with a lot of impact load,the nonlinear load access,for the safe and stable operation of power system has brought the huge impact,power quality problems highlighted increasingly,so the development of power quality monitoring system,is an urgent thing.In view of the shortcomings of traditional power quality detection devices in cumbersome wiring and remote monitoring,this paper designs a set of power quality cloud monitoring system based on Internet of Things according to the requirements of national standard.It has the features of low cost,high precision,remote real-time monitoring and other functions,and can meet different power quality detection occasions.The specific work of the paper is as follows:The calculation and measurement principle of power quality parameters in national standard are discussed.Aiming at the detection of harmonic parameters,the harmonic detection principle and application of Fourier transform and wavelet transform are deeply analyzed.Through the analysis of simulation experiment,the advantages and disadvantages of the two harmonic detection methods are compared,and the more suitable windowed fast fourier transform is adopted as the harmonic detection algorithm of the project.The hardware circuit with "ARM chip + energy metering chip" as the core is designed to speed up the acquisition and calculation of power quality parameters.Special three-phase power metering chip RN8302 is selected for the power metering chip,which can calculate most of the power quality parameters and reduce the calculation of the main control chip to a certain extent.ARM chip adopts STM32F205VGT6 with low cost and outstanding computing capability,which can meet the requirements of harmonic calculation and communication between modules.In addition,the corresponding current and voltage acquisition circuit,storage circuit,WIFI module circuit and power supply circuit are designed.Using UCOSII real-time operating system,the software program of main control module is designed.According to the system function,the software is divided into several subprograms,and the RN8302 data acquisition program,harmonic calculation program,WIFI module communication program is designed.Baidu Cloud Internet of Things platform has been built to enable devices to access the Internet of Things with network communication functions.Considering that the micro program is easy to use and develop,the micro program is developed as the monitoring interface of power quality parameters to realize real-time remote monitoring.After the system is developed,the performance and function of the system are tested.The test results show that the precision of the monitoring system designed in this paper can meet the requirements of the current national standard,and the function meets the design requirements.