Power Quality Analysis Software Based On LabVIEW

In recent years, the composition and characteristics of grid load has undergone major changes, a large number of non-linear, impact load has been widely used in the production, life, leading to voltage fluctuations, three-phase imbalance, voltage waveform distortion and a series of power quality problems, causing general concern from electricity sector and users. In order to meet the rapidly growing demand for electricity users, while ensuring a good quality of electricity, the development of a power quality monitoring and analysis device which is full-featured, low cost, high accuracy, easy to use is very important.This paper firstly analyzes the research and development of power quality monitoring and analysis domestic and international, and national standards related to power quality. Then it makes research and analysis on the measurement of steady and transient power quality indicators and analysis methods, providing a theoretical foundation for the development of power quality analysis software. What’s more, this artle compares virtual instruments and traditional instruments, and bring virtual instrument technology into the field of monitoring and analysis on power quality parameters, and then used the USB2831 data acquisition card from Beijing Altai company to obtain voltage and current signals. Furthermore, it designed a intelligent, modular power quality analysis software under the environment of virtual instrument software development platform--Lab VIEW.The correlation function modules of power quality analysis software based on Lab VIEW include: password module, data acquisition module, waveform playback module, the voltage deviation module, voltage dip module, over-current module, total harmonic analysis module, current RMS(Root mean square) and imbalance module, current and voltage sequence components and imbalance module, exceeding data extraction and storage module. Among them, the paper focuses on the data acquisition module and voltage dip module. Data acquisition module section gives detailed introductions on the main parameters of USB2831 card, USB device-specific functions and continuous data acquisition function achievement under Lab VIEW environment. Voltage dip module section discusses the voltage dip detection problem, articulates the principle of short time Fourier transform algorithm used in this paper and how it applies to voltage dip problems.Finally, experimental tests verifies the reasonableness of the software design solutions, and it shows that software functions and targets have achieved the relevant national standards.