Assessment of the DSC Technique for Positive-Sequence Extraction in Power Systems

Abstract

In the context of electrical power systems, where nonlinear loads, power converters, and exogenous disturbances can significantly distort electrical signals, there remains a critical need to accurately extract signal parameters useful for various essential tasks, including monitoring, synchronization, and protection. Traditionally, a positive-sequence filter, often based on the well-established Park filter, has been used to mitigate these disturbances. However, the delayed signal cancellation technique (DSC) has gained prominence as a viable alternative, offering similar advantages to the Park filter, but without the need for phase feedback. This growing interest in DSC has led to numerous studies that aim to refine its original concept. However, these efforts have not comprehensively evaluated the DSC alongside the Park filter to discern and quantify its benefits and drawbacks. Inspired by the fact that the DSC exhibits spectral replica, characterized by high-gain repeating side lobes in its frequency response, this article aims to conduct a thorough comparative analysis between the DSC technique and the conventional Park filter. The primary objective is to quantitatively evaluate both approaches in positive-sequence extraction tasks, thereby shedding light on their practical advantages in scenarios marked by signal distortion and perturbations.