Research On Three-phase Shunt Active Power Filter

In recent years, along with applications of a large number of power electronicdevices, harmonic and reactive power has caused serious harm to the grid, leadingto a decline in the quality of the grid. Due to its high-performance in harmonicsuppression and reactive power compensation capabilities, active power filterbecomes a research hotspot and has broad development prospects.Two harmonic control methods are introduced since the harmonics and reactivepower make serious pollution on the grid. The first is the transformation ofharmonic source to reduce harmonic; the second is the installation of active powerfilter. Compared with the passive power filter, the active power filter has manyadvantages, such as operating without the influence of grid parameters and beingable to compensate for each harmonic, and becomes an important research directionof harmonic governance.The classification, topology and their advantages and disadvantages of activepower filter are described in this paper, and a mathematical model of three-phaseshunt active power filter is also derived. A strong feasible harmonic detectionmethod of ip-iqbased on instantaneous reactive power theory is selected with theanalysis of several common methods of harmonic detection. The fixed switchingfrequency PWM current control strategy, which can simplify control system design,is also selected. The design process of control system is described in detail.Considering the disadvantages of delay and poor anti-interference ability etc ofhardware phase-locked cicuit, a new digital phase-locked technique based oninstantaneous reactive power theory is used to improve the reliability of system.MATLAB/SIMULINK is used to simulate and analyze the three-phase shuntactive power filter system. A three-phase shunt active power filter experimentalplatform is build with the TI TMS320F2812DSP as the control chip. Theexperimental results show that the system can compensate the harmonic and reactive current well, which also prove the feasibility and effectiveness of thissystem.