Design And Research Of Shunt Connected Active Power Filter Equipment Based On The Generalized Instantaneous Reactive Power

In recent years, the harmonic current and voltage have been polluting the public electricity utility grievously, and the power electronic equipment is the principal polluting source. Along with the widely use of power electronic equipment, the harmonic pollution in public supply network becomes more and more severely, and influences the quality of electric energy supply and the safety of use to consumers, so it is increasingly important to harness the harmonic pollution. Because of the shortages of itself the Passive Filter can't meet the need of morden grid. The presentation of Active Power Filter (APF) gives a new way for harmonic cancellation. In china, the studies and exploitations in active power filter is at its beginning stage, but the large capacity mature products have not been come out yet, so the studies and exploitations in active power filter have very important significance.There are two types of harmonic resource in the grid which generate voltage-harmonic and current-harmonic individually. There are two types of APF too, shunt connected and serial connected individually. By analysising the principle and property of the harmonic sources and APFs mentioned above, it can be see that the shunt connected APF is best for current harmonic source and serial connected APF is suitable for voltage harmonic source. Through the voltage harmonic mostly is caused by current harmonic on the resistance of grid, this paper devoted in the research and design of a shunt APF.Firstly, this paper split the load current into two parts, active current and reactive current under the d-q-0 coordinate frame. This paper also proposed the definition of general instantaneous reactive power according to reactiver current. The relative concalusions drawn from the d-q-0 frame are equal to those drawn fromα-β-0 frame. Based on the theory mentioned, the detection arithmetices of obtaining fundmental active current, fundmental reactive current, neg-squence current, pos-squence current and high order harmonic current are introduced. The simulation results of the above arithmetices are given either.