Research And Development Of Compensation Device Based On APF For The Drilling Rigs

Electric drill system contains a lot of power electronics and inductance type equipment, this will cause severe harmonic pollution and reactive power for power grid.Traditional passive filter cannot fully meet the requirements of power users for the power quality, Active power filter is effective in inhibiting harmonic current of drilling system. It is also good for energy conservation,emissions reduction and increasing the economic benefit.This thesis introduces the research history, current situation and trend on active power filter and analyze the topology and work principle of active power filter briefly,harmonic current detection scheme is designed on the basis of a deep analysis of the instantaneous reactive power theory; the design of current tracking control scheme is based on studying hysteresis comparison,triangle wave comparison and study on SVPWM three control principles. In contrast to hardware and software phase- locked loop principles to complete the program of software phase- locked loop,combined with the filtering requirements of system to calculate the relevant parameters after digital low pass filter selection,I get a scheme of active power filter control full digital system finally. Under the simulation environment of SIMULINK from MATLAB,an active power filter system model is built and using oscilloscope, FFT tools to analyze each link and the compensation effect for the experimental platform to build stage. The thesis designs digital control syste m based on DSP TMS320F28335, control program code is written by c language. Taking full account of factors including power of the system and matching of every device, the scheme identifies hardware parameters such as DC, AC-side inductance and resistance load and purchase the related component, then completes circuit design of hardware such as the main control circuit, power circuit, AD sampling circuits, signal conditioning circuits, driven circuit. The designed PCB Board is printed by professional firms, with chips, sensors, chip capacitors soldered to the printed circuit board. Power supply, load, the main control board, DSP debug Board, host computer are connected into a system, building a whole set APF experiment platform.Simulation and experimental results prove the validity and rationality of ip-iq testing method based on instantaneous reactive power theory, software phase- locked loop, low-pass filter, current tracking control strategy. The basic function of DC side voltage control and harmonic current compensation is completed.