Nonlinear control strategy of single-phase unified power flow controller

Younes Abouelmahjoub, Mohamed Moutchou

Abstract


In this work we propose a nonlinear control strategy of single-phase Unified Power Flow Controller (UPFC), using in order to enhance energy quality parameters of a perturbed single-phase power grid supplying nonlinear loads. The control objectives are: (i) The current harmonics and the reactive power compensation, that ensure a satisfactory power factor correction (PFC) at the point of common coupling (PCC); (ii) compensation of the voltage perturbations (harmonics and sags of voltage) in order to ensure the desired level, of load voltage, without distortion; (iii) DC bus voltage regulation. The considered control problem entails several difficulties including: (i) the high system dimension; (ii) the strong system nonlinearity. The problem is dealt with by designing a nonlinear controller with structure including three control loops. The inner-loop regulator is designed using the Lyapunov technique to compensate the current harmonics and reactive power. The intermediary-loop regulator is designed using the Backstepping technique to compensate the voltage perturbations. The outer-loop regulator is designed using a linear PI to regulate the DC bus voltage. The control stability is proved theoretically and through simulations, these latter show the effectiveness and strong robustness of the proposed control, and prove that the above-mentioned objectives are achieved.

Keywords


backstepping technique; harmonics compensation; lyapunov design; nonlinear control; power factor correction; UPFC system;



DOI: http://doi.org/10.11591/ijece.v11i4.pp%25p
Total views : 0 times


Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

ISSN 2088-8708, e-ISSN 2722-2578