Reserch And Design Of Elctric Power Monitoring Based On The Microcontroller C8051F120

With the application of the nonlinear electrical components, the development of powerelectronic technology,and electric load,asymmetry, impact and nonlinear load capacityincreasing, the situation of harmonics in power system become more and more serious. Inaddition, because of the wide application of control equipment based on computer systemand precision instruments, the requirements for power quality is becoming more and morehigh. Therefore, the electric monitoring instrument gradually cannot meet the requirementsof system performance. The intelligent power monitor is based on microprocessorapplication and network communication technology, which is enough to meet the diverseneeds of the smart grid. In this paper, the research is in this background.According to the requirements of the power monitor technology and the functioncharacteristic,the theory and technology of power monitoring has studied in this paper. It isproposed the calculation method of electric parameter based on Fast Fourier algorithm. Acsampling technique is adopted to realize real-time electrical parameters. The design of thepower monitor system provides a reliable basis for power quality management, which isbased on the one-chip computer C8051F120.The overall design scheme, hardware design and software design are presented in thispaper in detail. The C8051F120microcontroller as the main control unit achieves dataprocessing, data storage and display, and other functions. In addition, a few peripheralcircuit is also designed, including the sampling circuit of voltage and current, man-machineinterface touch screen, data storage, real-time clock, serial communication module andpower supply, etc. A suit of software was designed with the method of modelingprograming, in order to makes the program structure clear, maintain and expand functioneasily and reduce the possibility of error. The various modules are introduced in detail,including initialization program, AD collection program, serial communication programand FFT algorithm program.Matlab/Simulink simulation model of power monitor is set up based on FFT, and thesimulation model is introduced in detail. The Matlab/Simulink model is comparred by thesimulation model’s results and the actual results. The simulation model can prove thevalidity of FFT algorithm but also presents a platform for advanced research.Finally, after testing, the prototype workes well,and is able to accurately monitor allkinds of electric parameters, meet the design requirements, and could achieve harmonicanalysis of power system.