Research And Simulation On The Active Power Filter Based On The Three Level SVPWM

In recent years,the types of power electronic devices have become increasingly varied,and the harmonic pollution caused by them has become increasingly serious.The existence of harmonics has seriously affected the power quality of the power grid.In order to reduce the impact of harmonics on the operation of the entire power grid,it is necessary to use active power filters in the power grid.The traditional harmonic suppression devices use passive filters.With the development of power electronics,active power Filters have been widely studied and applied.This paper focuses on active power filters based on three-level SVPWM.Firstly,the topological structure and working principle of active power filter are analyzed in detail.The diode-clamped three-level inverter circuit is selected,and the primary parameters of the inverter circuit are selected.Secondly,the control strategy of the three-level active power filter is studied.Several harmonic detection algorithms are introduced.Finally,a harmonic detection method based on instantaneous reactive power theory is selected.In the current tracking control process,dead-beat control is selected.Focusing on the SVPWM modulation algorithm,the traditional SVPWM modulation algorithm based on the coordinate system and the SVPWM modulation algorithm based on the coordinate system are respectively described.Based on the reason analysis of neutral point potential imbalance and the SVPWM modulation algorithm,the method of controlling neutral point potential balance was studied.Afterwards,the theoretical part of the research is verified and a simulation model of the three-level active power filter is built in MATLAB.The simulation test of the harmonic detection module and tracking control module of the three-level active power filter is performed.The influence of different parameters on the compensation effect is compared,and the parameters that make the power filter compensation effect optimal are selected.In the simulation results,the compensated harmonic distortion rate can meet the requirements of the public power grid and the compensation effect is satisfactory.It can be demonstrated that the proposed control strategy is feasible.Finally,the power filter is designed with hardware and software.The hardware part completes the design of the main circuit,sampling conditioning circuit,and the like.The prototype experiment was completed in the laboratory.The software part completed the design of the main program and harmonic calculation subroutines.Finally,a prototype experiment platform was built in the laboratory.Experimental results verify the effectiveness of the three-level active power filter designed in this paper.