Monitor System Of Power Quality And FACTS Applications Based On Virtual Instrument

The increasing application of power electronics and a lot of nonlinear loads in power system deteriorate power quality and make it a problem attracted more and more concern. The studies of power quality mainly focus on two factors: the one is to install monitor system at specified spots to monitor the parameters in power system; the other is to prevent power quality from worsening by applying every feasible technology and devices such as FACTS and DFACTS in power system. At the same time, monitor system is also needed in such devices to monitor the operation conditions.This thesis employs virtual instrumentation software - LabVIEW as the design tool, studies several pulse modes and adopts a method of cycle buffer to solve the problem of DAQ. Based on LabVIEW, the thesis analyzes and designs the monitor of power parameters in power system. The harmonics and reactive power, which are two main parameters in analysis of power parameters, are objects of monitor. As to the analysis of harmonics, the thesis studies methods of FFT, short FFT, and wavelet transformations, and designs a program to compare the performance. The thesis analyzes the instantaneous reactive power theory to computer the reactive power, which is designed in a program.On the basis of analysis of power parameters, the thesis designs and develops monitor systems of FACTS/DFACTS devices, which are DC Active Power Filter to eliminate harmonics, and Statistic Var Compensator to compensate reactive power. After study the structure of APF and SVC, the thesis puts forward the requirements of and whole frameworks of monitor systems. Monitor systems are made of two parts: hardware and software. The part of hardware adopts data acquisition system which is composed of signal conditioning and DAQ. The part of software adopts the idea of functional modules, designing a lot of functional modules separately to fulfill the whole function by combining them. The results of monitor system operating on the practical devices demonstrate that the monitor system realize the functions of monitoring power parameters and FACTS/DFACTS devices.