Simulation Research Of Parallel Connection Active Power Filter

This research project is aimed at elimination of harmonic and reactive power compensation in power system, which belong to one financed project of science and technology office, Guangdong Province in 2002. This project addressed itself how to eliminate load harmonic and compensate reactive power under perfect three-phase AC voltage and typical harmonic load current, as to stabilize node voltage.At first the summary in this thesis expounds a heated topic of power system researches?flexible AC transmission system (FACTS), when the power system is becoming more and more complicated, super-high voltage big-volume and long-distance transmission power nets are developing, other new technology are applying , these factors are causing some side-effects , which are hard to solve through traditional measurement and technology . So the emergence of FACTS is just for the purpose of solving these problems of power system .As a branch of FACTS, active power filter (APF), a new power and electric equipment, its function is to eliminate load harmonic and compensate system line reactive power, damp system surge of node voltage, decrease power waste of system line.Chapter 2 particular expounds the basic theory for elimination of harmonic and compensation of reactive power instantaneous reactive power theory. In order to instantly and real time eliminate harmonic and compensate reactive power, the definition of traditional reactive power, an integral average during a period, which is confined to apply under some circumstances. For example, when the load power varies swiftly, it will lead to can' t compensate reactive power rapidly. Japanese scholar Akagi H. put forward instantaneous reactive power theory in 1980S, 20 century, meeting the demand for real time and instantaneousness. Based on introduction of the previous chapter, Chapter 3 expounds carefully thehardware structure of APF and work principle, focusing on the method about how to measure the harmonic current and reactive power current, here introduces p-q ip-iq and d-q 3 measurement ways , and compares their merit and flaw.Chapter 4 introduces the discreet hardware structure control principle and mathematics modeling for APF. This kind of novel parallel connection APF is different from traditional APF, the primary question is to how to reduce the volume of APF and eliminate the high harmonic during pulse width model (PWM). The last chapter 5 gives out the simulation pictures of APF under power system circumstances through Borland C++, the result proves that the new APF can efficiently compensate system line reactive power, the high harmonic during PWM can be controlled in acceptable scope.At last the conclusion is drawed at, and some flaw is pointed out.