Design And Application Of Active Power Filter

Application of the power electronic devices are increasing day by day, a lot of harmonic is caused by nonlinear power electronic devices, serious pollution of the power system, Also has great harm to the stable operation of electrical equipment and communication system. The cost of traditional passive power filter is relatively low, relatively mature technology, low running cost, simple structure, but it also has some shortcomings, for example, only few harmonics suppression fixed, and of a harmonic will produce resonance with the grid impedance under certain conditions, can cause the harmonic amplification. Currently on the market the use of active power filter is gradually becoming the preferred method of harmonic suppression, research on the related technology also becomes research hotspot.This article first elaborated the situation of power operation of Tianjin city, point out the necessity of energy saving and management, then it lists the sources of power grid harmonic and some common quality problem now in power grid.Through the comparison of passive power filter and active power filter principle and structure, put forward the active power filter is the best way of harmonic control. Then a comparison of several common topologies and their respective advantages and disadvantages of APF, introduced the working principle of active power filter, analysis of feed forward control and proportional control of current loop in the control strategy, the harmonic detection method based on instantaneous reactive power theory and method, also introduced in detail the SVPWM and the SPWM two kind of strategy.Finally the article introduces the development process of the shunt active power filter, including the structure design, principle analysis, contains the design of the main circuit, the advantages and disadvantages of selection and the DC side voltage tracking current mode control and distinguish it from other types of filter. And has enumerated the application case of an active power filter in practical engineering.