Design And Implementation Of Three-level Active Power Filter Based On DSP

With the progress of science and technology,power electronic technology has been widely used,a large number of non-linear load access to the power grid has brought harmonic pollution,affecting the power quality in the grid.Active power filter(APF)is a kind of device which can realize harmonic dynamic compensation and improve power quality.In this thesis,the principle and design of three-level active power filter is taken as the research direction,chiefly from the harmonics current detection method,the tracking control of harmonics current,the simulation of the three-level APF system and the hardware part of the development of its research.Firstly,in this thesis,the generation and harm of harmonics,summarizes the classification and development of APF at home and abroad are introduced,and the advantages and prospects of three-level APF is analyzed.The three-level APF is the main research object of this thesis.Secondly,by analyzing the harmonic current detection methods of active power filter,the harmonic current detection method based on the instantaneous reactive power theory is adopted.At the same time,the tracking control strategy of APF is analyzed,and the three-level space vector pulse width modulation(SVPWM)algorithm is used to track the APF.Based on the traditional three-level SVPWM algorithm,a simplified algorithm of three-level SVPWM is adopted by analyzing the current detection method and tracking control strategy of three-level APF.And the solution of the midpoint voltage imbalance of the three-level APF DC side capacitor is proposed.Simulink is used to simulate the simplified three-level SVPWM algorithm and the three-level APF system.The simulation results show that the harmonic compensation is realized,and it is proved that the simplified three-level SVPWM algorithm is effective.Finally,in this thesis,a three-level APF experiment system based on Digital Signal Processor(DSP)TMS320F28035 in combination with theoretical research and simulation experiments is designed.TMS320F28035 as the core of the control system can generate PWM control signal,the control signal sent to the drive circuit,through the drive circuit to control the main circuit to achieve harmonic current compensation.In the end of this thesis,the design and the debugging of three-level APF experiment system is finished,through the experiment of harmonic compensation of the system,the results show that the system can realize harmonic compensation and reach the desired goal.