Three-phase four-wire system of any harmonic component and the reactive current detection method

The present invention discloses a method for detecting three-phase four-wire system of any harmonic component and the reactive current, characterized by: comprising the following steps: Step (1): phase locking to obtain the phase of the fundamental positive sequence voltage θ + (ω0t); step (2): detecting the positive sequence component of the n-th harmonic; step (3): the negative sequence component of the detected n-th harmonic; step (4): the n-th harmonic zero sequence detection component; step (5): detecting the reactive current. A three-phase detection method of the present invention provides a four-wire system according to any of the harmonic and reactive currents, based on the coordinate transformation and the n-th harmonic of the low-pass filtering (the LPF), taking into account the special detected zero sequence current sex; method of phase-locked loop, the phase-locked to ensure accuracy, so as to provide a reliable phase coordinate transformation, the method for the physical concept of clear and simple way to achieve a wide range, the higher detection accuracy and practicality .