Study of the discrete vector controller for current regulation of flexible grounding compensation method

Abstract

The active and high-frequency harmonic current are compensated by introducing power electronics converter of the flexible grounding, which achieves full compensation of the single-phase to earth current to achieve a fast arc extinction. Thus, the flexible grounding is promising in the distribution network. Regarding the active and harmonic current control, this paper proposes to design the controller in the discrete-time domain based on the discrete model of the plant, which deals with the one-sample delay directly. The discrete complex current controller is developed which achieves AC current regulation in the stationary reference frame without steady-state error. With regard to the proposed controller, a tuning method based on critical damping is proposed based on the discrete root locus analysis, which avoids overshoot and optimizes the settling time. The simulation results have verified the effectiveness of the proposed controller and the tuning method.

Keywords

• flexible grounding
• current compensation
• discrete complex controller
• critical damping