Fast and reliable phasor detectors for single phase AC systems by derivative quadrature generation

The detection of amplitude and phase information in a single phase AC system is quite challenging due to the lack of quadrature component available in multi-phase AC systems. To produce the reliable quadrature component of the single phase AC system with harmonic noises, a derivative quadrature generator with appropriate filters is proposed. A low pass filter (LPF) optimizing the reductions of total harmonic distortion (THD) and response time of sensed signals was found, surveying generalized n-th order filters. To nullify phase shift of the LPF, an all pass filter was adopted. By simulations and experiments for the proposed phasor detector at 60 Hz, a fast time response of less than 8 ms was achieved under severe THD of 9.3 %.