Harmonic Elimination And Energy Conservation Of The Electric Traction Based On DFACTS

Electric and electron devices are everywhere in our life, from air-condition, variable-frequency fridge to steelmaking furnace, metallurgical furnace and electric locomotive in industry. The problem of Harmonic pollution has become severe in recent years. As we all know that massive usage of electric and electron devices can create heavy harmonics to the power grid. Harmonics will decrease the power factor of the grid, which will cause both line loss and transformer loss. The problem of harmonics has become the main disadvantage influence to power quality. Active Power Filter (APF), proved to be the most effective way to solve harmonics pollution, has been paid more and more concerns and researches.In this thesis, we firstly discuss the principle of the APF, its circuit structure and its prospect. Then we choose single phase APF as a basic model, build the model structure in MATLAB through simulation and prove APF's ability of eliminating harmonic current in the grid and increasing the power factor as well.Secondly, we select fast control chip TMS320F2812 as the data platform to achieve the detection of harmonic current and choose hysteresis as the control method. Then a prototype has been set. Through experiments, we can see the changes after APF has been put into the system.At last, electric locomotive used APF has been designed, which is used to eliminate the harmonics caused by electric locomotive. Besides improve the power quality, we also analyze the energy-saving effect of APF. Therefore, the potential of APF has been explored in low-carbon power system.