Research Of Single-phase Power Quality Monitoring System Based On Virtual Instrument

Today, with the rapid development of science and technology and the constant expansionof industrial scale, electrification degree enhances unceasingly and power quality problemsare also valued seriously. Therefore, it is necessary to take technology means establishing andimplementing the power quality monitoring to ensure power quality. The main part of thetraditional power quality monitoring system which has not many functions is hardware, so itcan’t meet lots of increasingly complex requirements such as real-time, multi-function andintelligent monitoring. The use of the advanced virtual instrument technology, computertechnology and the embedded technology, this paper design and development the electricpower quality monitoring system based on virtual instrument. The system combines the slavemachine which based on the STM32micro controller and the master machine which based onLabVIEW. It can not only measure voltage, current, power, frequency, harmonic contentand other power quality parameters, also realize the simulation test and database managementfunction and has many advantages such as rich function, friendly interface, extensible,portability and low cost.This paper first studied power quality standard and the measurement model of powerquality basic parameter, focus on the harmonic and its measurement principle in the powergrid.It analyzed and reviewed existing several major harmonic measurement methods andtheir advantages and disadvantages. Also, it put forward two new harmonic analysis methodswhich were the harmonic analysis based on support vector machine and the harmonic analysisbased on improve population migration algorithm and TLS_ESPRIT algorithm, thesimulation shows two harmonic analysis methods were effective and practical.This paper expounded the development work of power quality monitoring system basedon virtual instrument. It put forward overall design scheme of the system, adopted STM32series micro controller which was a new generation of microprocessor and introduced by STCompany, completed design and production of the slave machine system hardware circuit andsoftware program based on the STM32; it also designed PC software with LabVIEW whichwas the virtual instrument development platform, finished the modularization program suchas real-time measurement analysis, simulation analysis, database management, designedfriendly human-machine interface. The paper also introduced commissioning of power qualitymonitoring system. Through the whole work of various parts for the system test, the searchand correction of the problems in the system work, the system of the reliability and practical could be improved.Finally, the paper summarized the process of research development and the debuggingof power quality monitoring system, and pointed out some disadvantages of the system andput forward the need to further research.