Design Of Multifunction Network Power Meter With PC Monitoring Software

To meet the urgent needs of establishing green, efficient and sustainable "smart grid" of our nation, A comprehensive electric parameter monitoring system has been developed in this thesis, which consists of multifunction network power meter and PC monitoring software. The scheme could perform real-time measuring of three-phase voltage and current, frequency, power factor, four-quadrant power, harmonic distortion and all other common electric parameters accurately. Besides that, Modbus-RTU communication protocol is also implanted in the instrument, which will realize the real-time communication between the multifunction network power meter and PC monitoring software. All those functions facilitate power sector informed the basic operating conditions of power system timely, and make the right comprehensive assessment of the utility grid performance. The research on this subject will not merely meet the urgent need of "smart grid" but also has good prospects and social value in substation automation, energy management systems, industrial automation, the intelligent buildings.The main achievements of this system that made in the design and debugging process are as follows:First, it described the definition of each electric parameter, put the analog formulas into discrete, obtain its approximate calculations and give out the measurement method of voltage, current, frequency, power, power factor and other parameters. Derived the frequency analysis theory in detail, and some corresponding ameliorative measures is presented aiming at the spectrum leakage and spectrum aliasing phenomenon of FFT. This paper also analyzed the theory of Modbus-RTU communication protocol and Cyclic Redundancy Check.Second, the thesis not only systematically expounded circuit and software design process of the electric parameter monitoring device at the part of hardware and software design but also described the design errors and the anti-jamming measures.Third, it explains the use of Kingview 6.55 software, introduces the functions and design processes of each interface of the PC Monitoring software.Fourth, the thesis summarizes some shortcomings of the program, develops the corresponding improvement measures and makes a prospect to the electric Parameter monitoring system at the end of the paper.After the online debugging, it prove that the multifunction network power meter with its PC systems are stable and reliable, this design reach 0.5 measurement accuracy requirements, the unique spectral analysis and remote communication capability for the electricity sector can provide real-time, accurate grid information.