Three-phase magnitude detection based on decoupling positive and negative sequences of double d-q transformation

摘要

This paper introduces T/4 time-lapse elimination detection, a novel method of detecting three-phase magnitude based on double d-q synchronous reference frame, functioning in decoupling positive and negative sequences of fundamental wave. When the voltage (or current) fundamental positive and negative sequence components are separated, their magnitudes can be detected respectively, so it is effective to restrain the impact on detection precision from negative sequence component. To verify the performance of this novel method, simulation experiments like transient response under normal grid condition and dynamic response under three-phase unbalance with harmonic pollution condition is finished. The results indicate that the novel method obtains a high precision of measure and a better dynamic property and has advantages on preventing harmonic propagation compared with T/16 time-lapse elimination detection method. Thus it can be wildly applied in three-phase power electronic devices.