Research On User’s Power Quality Monitoring System Based On Internet Of Things

With the proposal of the “Three Types and Two Networks” strategic goal of the State Grid,in order to adapt to the construction and deployment of the Internet of things in the State and State Grid,and combined with the actual demand of the user-side power quality monitoring,this thesis studies a distributed user-side real-time power monitoring system based on the Internet of things.Based on the GPRS and Zigbee dual communication method,the relevant quality analysis of the collected power data is carried out,and the model simulation and experimental platform are built to verify and analyze.In this thesis,the overall architecture of the designed electric energy monitoring system is planned,and the functional requirements of the electric energy monitoring system are analyzed.Designed the hardware system of power quality monitoring device based on STM32 as the core processor,Focus on research and design including the transformer and its auxiliary circuit,voltage clamping circuit,anti-aliasing low-pass filter circuit and voltage following conditioning circuit,greatly improving the sampling accuracy;Designed CC2530 circuit and its Babylon matching circuit to realize wireless transmission of local data;The SIM800 C and its peripheral circuits are designed to realize the remote transmission of data.According to the designed circuit schematic diagram,the drawing of the PCB board is completed.Then introduced various power quality indicators and their measurement methods,and completed the discrete calculation of basic power quality indicators.Focus on the algorithm research of harmonic measurement in power system,complete the analysis of harmonic signal based on base 2-fast Fourier transform and db6 wavelet transform,and build the MATLAB simulation model of the algorithm.the feasibility of the algorithm is verified based on the obtained simulation waveform and simulation data.Zigbee technology is used to form a star network topology for local communication.The design of cloud platform server and client software based on proxy server technology and multi-thread technology is proposed,and the program is designed using Python.Finally,for the user-side energy monitoring system based on the Internet of Things designed in this thesis,a system-level simulation was carried out.At the same time,the hardware debugging and the test platform of remote transmission and local wireless transmission are built.The overall verification of the power quality online monitoring system has good response speed and reliability,and the measurement error is small and universal.There are 112 figures,19 tables and 72 references in this thesis.