Topology Of Parallel Hybrid Active Power Filter And Measurement Method Of Harmonics

The traditional method of governing harmonic pollution is to install the LC Power Filter (PF), and it has been implied widely. But the compensation capability of this kind PF is not very good, as the development of full-controlled components such as GTO thyristor, BJT and IGBT, all kinds of Active Power Filter (APF) with power electrical technology have quickly developed. Governing harmonic with Active Power Filter has better compensation performances than with Passive Filter.The fundamental principle of Active Power Filter is to measure the harmonic current from the compensation object, the compensation installation will generate a compensation current that equal to the harmonic current but the polarity is opposite, so the electric network current only contains fundamental component. This kind of filter can bail and compensate the harmonic whose frequency and amplitude value all change, and the compensation capability is not affected by the parameters of electric network, it deles the danger of generating harmonic between filter and the impedance of electric network, it has many excellence such as the character of high controlled and response quickly, and it can tail and compensate all the harmonic, and will generate the required variable reactive power, its character is not affected by the system, it isn't have the danger of harmonic magnify, its comparatively bulk and weight is small, its filter performance is excellent and it costs very little, so it becomes an important method of power harmonic prohibiting and reactive power compensation. This paper studies the topology structure of active power filter in detail.According to the connecting method between APF and electric network, it can be divided into many types APF and parallel type APF. Because both the control methods have merit and disadvantages, in recent years people develop and try to let the APF and PF used mixed in great deal. The control strategies are mixed APF and parallel mixed APF, and the method of using APF and APF mixed.This paper focus on the fundamental principle and topology of APF, and discuss the topology of parallel mixed APF in detail and analogy, the filter principle with the system preference of the reference, the simulation results of MATLAB indicate that compensate the electric network with the mixed active power filter installation the harmonic distortion will reduce greatly. Compared with the passive filter installation, the active filter performance and compensation performance is better than the passive...