A research on control strategy of APF combined with TSC

Active power filter (APF) often combines with thyristor switched capacitor (TSC) for the purpose of reducing cost. Traditional full-bandwidth control method of APF contains system´s parallel resonant point and the harmonic of power grid will be amplified. To address this problem, a novel fractional frequency control strategy with lead compensation is proposed. This method can obtain arbitrary order harmonic reference to compensate using synchronous rotating coordinate transform method. Instruction value of APF can be achieved by adding the amplitude limited fundamental reactive power reference to the finite harmonics reference. In this way which can improve the stability of hybrid compensation system, output spectrum of APF will become numbered discrete spectral line. And a synchronous rotating coordinate transformation based lead compensation is also proposed. By adding a leading angle in the inverse transformation matrix, compensation effect is improved. And proposed methods have all been verified in experiments and practical debugging in field.