Waveform Library Control Based On Parallel Active Power Filter

For growing concerns about the ecological environment and the green energy, a smooth environment of power system is required. As the main factor affected the power quality, the elimination extent of harmonic has become an important standard of green power electricity, which can be effectively coped with an Active Power Filter.The fast response speed of waveform-library control is very fit for APF, of which the core is sample model. Because of non-linear model in most actual circuit, based on the circuit of buck and boost, this paper summarized a set of modeling ways adapt to non-liner systems as well as liners, and a solution of smoothly filtered sample model to fix the high frequency harmonic and switching ripple of the real circuit. In realization, the assembler FIR program advertised by TI company is used to improve the execute speed of control algorithms.L-type and LCL-type are two widely used kinds of parallel APF topology. On the ground of mathematical model analysis, this paper proposed a waveform-library controlling current-sampling model between modulation signals and offset current, which is used to design controller and achieve parallel APF. However, there are some limitations in the controlling of the model, so an improved control program of LCL-type parallel APF, the output voltage sampling model which compensates sample current is presented. In order to improve the effect, considering the advantage of predictive-current control, easygoing and high speed, a compound control scheme combined waveform-library controlling the output voltage of APF and predictive-current controlling offset current of the grid connection is figured out, which enhanced the tracking accuracy of harmonic current source again. The compound schemes proposed in this paper were proved on a three-phase parallel APF controlled by TMS320F2812. Advantages and problems of the compound schemes as well as suggestions for the future research were also presented.