Control theory; Electric power factor; Feedback; Harmonic analysis; Military data processing; Power electronics; Wave filters; control schemes; Current harmonics; Distortion (deformation); Equivalent expression; Feedforward paths; harmonic disturbances; Internal model principle (IMP); International (CO); Negative feedback (NFB); Odd harmonics; Resonant filtering; Shunt active filters; single delay line; Single phasing; Voltage source inverter (VSI); Active filters