Power Quality Monitoring System In Wind Farm Based On LabVIEW

Now the world is suffered from the shortage of energy. Wind energy, as a new energy, is inexhaustible and free. It's the most attractive new energy for its advantages of renewable and without-pollution. It arouses the attention of many countries. China is also one of them, and it enhances its research and utility on wind energy.Among with the continuous increasing of power capacity in future wind energy generation programming, the harm to the connected power grid, which is caused by the wind farm, will become to be more important and not allowed to be neglected. It will even damage the safety and stability of weak power grid when the harm is serious. Hence, the research and development of wind power generation supervising system and its related control technology appears to be more urgent. Thereby, it's necessary to excogitate a power quality monitoring system for the wind farm to analyze and evaluate the power quality of the present win farm, which is a very important meaning for the research of the grid-connected wind power generation unit and the harmonious development between wind power and grid.First of all, this thesis introduced the trend of wind energy generation inside and outside of the world, and the necessity of monitoring the power quality of the win farm. Secondly, by analyzing the wind turbine structure and operating characteristics, summarizing the power quality problems of wind farm and its characteristics. then combined the characteristics of the power quality of the wind farm, the hardware and methods are appropriately chosen. According to the situation that voltage fluctuations of wind farms are mainly in the low frequency band, the arithmetic which is now widely used has a lower accuracy in this band, this thesis used the arithmetic by counteracting the fundamental wave to test voltage fluctuation and flicker, then simulated this method to prove it has high accuracy in low frequency band. At last, with these hardware and methods the power quality monitoring system in wind farm is developed using LabVIEW in this thesis, which collects voltage and current signals and tests voltage deviation, frequency deviation, harmonics, unsymmetrical, voltage sag, voltage fluctuation and flicker. The hardware composition and software programming are expounded, the plans of the client computer and the host computer are particularly introduced, and the main functions of the system are described. The main modules and the key technical measures of the system are explained.This system has the advantages of short development cycle, high accuracy, interactive interface with good visualization and its function and scale can be changed and modified easily, which provides a high mobility and has the advantages of easy control.