Title |
Reactive Power Compensator with State Observer and Repetitive Control for Stabilization of Low Voltage Distribution Line |
Authors |
서정진(Joungjin Seo) ; 김영록(Youngroc Kim) ; 차한주(Hanju Ch) |
DOI |
https://doi.org/10.5370/KIEE.2020.69.11.1697 |
Keywords |
Stat observer; Repetitive control; Reactive power; Ripple voltage |
Abstract |
In this paper, a new reactive power control algorithm using a stat observer and repetitive control for voltage adjustment to the low-voltage distribution line is proposed and verified by simulation and experiment. A reactive power compensator has a single -phase full bridge inverter structure and consists of DC voltage controller to maintain a constant DC voltage, and current controller for reactive power generation. A DC ripple compensation method use an output from the state observer and the output is used as the DC voltage controller feedback to regulate the DC voltage constant. In order to inject a stable reactive power, the fundamental component of current is controlled by a PI controller, and a repetitive controller is connected in parallel with the PI controller to compensate for lower-order harmonics. The repetitive controller, as implemented in the synchronous coordinate system, serves to eliminate low-order odd harmonic components. The proposed control technique is experimented with a ±5kVar single phase inverter system and verified the performance of the proposed algorithm by confirming that THD is reduced to 2% from 9%. |