A novel harmonic current detection technique based on a generalized dqk coordinate transform for active power filter and fault protection of power system

The paper proposes a novel method of current detection for an active power filter and power system, which is based on a generalized dq_k coordinate transform. The so-called dg_k generalized coordinate is defined as the coordinate frame rotated at the angle frequency kω of the kth harmonic current. This method can effectively and accurately detect the fundamental current, its active and reactive components and any term harmonic current component of a three-phase circuit. Simulation results are carried out to verify the method of current detection.