Fast Estimation of Phase Angle for Three-Phase Voltage Systems Under Distorted Conditions

This article proposes a fast and robust technique for instantaneous phase angle estimation of three-phase voltage systems under unbalanced and distorted conditions. It mainly relies on the Clarke transformation, the Teager energy operator, and the delayed signal cancellation (DSC) approach. Unlike an adaptive DSC-based synchronous-reference frame phase-locked loop (PLL), the proposed technique avoids interdependent loops, thus increasing the overall stability and easing the tuning process. Moreover, it removes the phase loop of the PLL and, hence, eliminates the requirement of an in-loop filter (low- pass filter) and/or a loop filter (proportional–integral controller). As a result, the tuning of these filters is not required, and a quicker response is produced. The proposed technique also avoids inverse trigonometric function operation. In addition, it shows harmonics immunity at steady state and can generate a fast dynamic response with a settling time less than one nominal fundamental cycle. Both simulation and experimental results are presented to reveal the benefits of the technique.