| The harmonic propagation, which results from series and parallel resonance between line inductors and capacitors in the feeder, becomes increasingly serious in power systems. Shunt active filter is installed near high capacity nonlinear load to prevent harmonic current from injecting into power system, but can not damp voltage harmonic.The transmission line theory is used to set up distributed parameter model of power system feeders, and analyze the harmonic voltage propagation caused by the background harmonic voltage and harmonic current in power systems. A new discrete frequency of R-APF site slection strategy is proposed to damp the background harmonic voltage propagation in power systems.In order to solve'whack a mole'phenomenon, proposes an over compensation shunt active filter based on grid current detection method to damp harmonic voltage resonance. Both theory and simulation results clarify that installation of the APF based on grid current detection on the end bus of the feeder not only can suppress harmonic propagation but also'whack a mole'is suppressed.Taking advantage that the voltage detection can dump harmonic can cover the shortage of load current detection, proposes a compound control method based on detection of load current and harmonic voltage. In addition, based on the relationship between the rated volt-ampere of APF and the volt-ampere needed to compensate the nonlinear load, the conductance value could auto adjustment, compared with the fixed gain, the auto gain adjusting with the variation of volt-ampere has a clear advantage.Experiments based on TMS320F2812 have been performed to verify the theoretical analysis and demonstrate the effectiveness of the proposed strategies.
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