A single-phase active power filter for high-order harmonic current compensation is presented in this paper. In modern railway
locomotives, multi-paralleled PWM converters provide unity power factor operation with low THD, but their high-order harmonics
current may provoke interference problems with the railway track signal and public telecommunication lines. A band-pass digital
filter is proposed to extract the harmonic reference currents to be compensated in the active filter. A prediction algorithm to
compensate the delay in the deadbeat current control is also proposed to produce a predicted harmonic reference current. The
effectiveness of the proposed algorithms is verified through simulations and experiments.