Research And Design Of Hybrid Active Power Filter For The Electrified Railway

With the continuous progress of China’s electrified railway process,the power quality problems,which is caused by the increasingly serious,mainly for the load current harmonic current and reactive current content,is high.It will damage the electrical equipment and the normal operation of the electric locomotive impact.And it also interferes with communication lines and causes pollution to the grid.This paper,relying on the Hebei Provincial Department of Education key project "the research of rail vehicle adaptive harmonic suppression device " hosted by Shijiazhuang Railway University,studies for the electrified railway harmonic compensation hybrid active power filter,harmonic Wave detection,control strategy,hardware and software design and other key technologies have been studied.Firstly,the basic principle of the active filter and several typical topologies are analyzed.Combined with the characteristics of the electrified railway load,the topology of the APF coupled into the power grid after the coupling transformer and the passive filter are determined.The control method of detecting the harmonic current on the load side is determined by the equivalent circuit.The method of setting the APF parameters is also given.Secondly,the harmonic detection algorithm of single-phase circuit is studied.The current source model of electric locomotive is built by MATLAB,and the harmonic detection algorithm is simulated.Then the harmonic detection method based on active current separation is improved,and the simulation results show that the improved harmonic detection algorithm has faster detection speed and is more suitable for the harmonic detection of electrified railway.The control strategy of mixed APF,including current tracking control method and DC side voltage control method,is studied,and the feasibility of the two control methods is verified by simulation.Then the whole hybrid APF system is simulated.The simulation results proves that it has good harmonic compensationperformance.Finally,the TMS320F2812 chip as the control center of the APF hardware and software have been designed,in which the signal acquisition circuit uses AD chip ADS8556.Then setting up a prototype in the laboratory to test,the results verify the correctness of topology,detection algorithm and control strategy.This paper has made some research results.And it has a certain theoretical value and practical significance.At the last part of the paper,it gives the summary of the system and the direction of further study.