| With the advancement of science and technology,many distortion loads in the Power system.resulting grid current distortion.The decline in power quality has caused some high-precision electronic equipment to not work normally.With the development of modern industry,more and more equipment is dedicated to improve power quality.Active power filter has the function of suppressing harmonics and improving grid current distortion.Nowadays,shut active power filter is one of the most widely used equipment.(1)Investigate active power filters.First,the impact of harmonics on the power grid and the research significance of the subject are introduced.The working principle of APF is discussed in detail,and then mathematical modeling is carried out.And introduce the topological structure commonly used at present.(2)Research on harmonic detection algorithm,current tracking control strategy and DC side voltage stabilization control strategy theory.Use MATLAB/Simulink to simulate and analyze the ip-iq algorithm,simulate and verify the effects of the current tracking control algorithm and the PI control DC side voltage stabilization algorithm,and verify the feasibility of the theory.(3)Hardware-in-the-loop simulation is completed by RT-LAB.RT-LAB simulation model is built,which is responsible for simulating the real-time operation of power circuits,power systems in real time.The RT-LAB simulation model is debugged with the main control board to verify the feasibility of the control algorithm and the overall hardware system.(4)An active power filter hardware system with a rated current of 30 A is designed.The main control board is composed of DSP and FPGA.The hardware circuit boards mainly include analog signal acquisition boards,analog signal processing boards,and IGBT drive boards.The main circuit also includes fuse,LCL filter,DC side capacitor,IGBT and other devices.(5)The control program of active power filter is designed.The program design includes DSP program and FPGA program,DSP program is designed on the CCS6.0,which realizes the functions of analog signal sampling,DC side voltage stabilization control,calculation of command current,compensation current tracking command current control,fault alarm.FPGA program is designed on the Quartus II,which realizes comparing the modulation wave generated by DSP with the triangular carrier to output PWM.(6)Human-computer interaction interface is completed.This part mainly completes the fault alarm interface,main operation interface,spectrum analysis interface,etc.After debugging the whole machine and observing the experimental data,the experimental prototype can effectively control grid current distortion and suppress harmonics. |
