Hysteretic control of grid-side current for a single-phase LCL grid-connected voltage source converter

© 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/This paper proposes a new approach to control the grid-side current of LCL-grid connected voltage source converters using hysteretic relay feedback controllers. The closed loop system is stabilized by designing a local feedback around the relay element. The compensator allows the use of relay feedback controllers by making the controlled plant almost strictly positive real. The article proposes the use of the locus of the perturbed relay system as analysis and design tool and studies orbital stability for several plant and controller conditions. The approach is validated by means of simulation testing.Postprint (author's final draft

A relay controller with parallel feed-forward compensation for a buck converter feeding constant power loads

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.A simple and efficient analog direct voltage control design for improving the performance and stability of a buck converter feeding constant power loads (CPLs) is the main aim of this article. One of the oldest and most spread approaches is to design a relay control system. In these systems, although the hysteretic relay adds non-linearity to the closed-loop system, an adequate controller design procedure will be presented using the locus of a perturbed relay system (LPRS) technique. This work shows how a designer can apply LPRS technique to a converter plant, in this case a buck converter feeding a mixed linear and constant power load (CPL), using a parallel feed-forward compensator (PFC) to obtain a suitable performance in the closed-loop system. That means to enlarge the range of stable behavior with respect to the power in the CPLs, in comparison with the open-loop case, and to regulate adequately the output voltage of the converter in front of input voltage and load power variations. The simulation results with the converter-load non-linear model show the good performance of the designed controller with respect to the above-mentioned disturbances and perturbations.Postprint (author's final draft

Hysteretic control of grid-side current for a single-phase LCL grid-connected voltage source converter

© 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/This paper proposes a new approach to control the grid-side current of LCL-grid connected voltage source converters using hysteretic relay feedback controllers. The closed loop system is stabilized by designing a local feedback around the relay element. The compensator allows the use of relay feedback controllers by making the controlled plant almost strictly positive real. The article proposes the use of the locus of the perturbed relay system as analysis and design tool and studies orbital stability for several plant and controller conditions. The approach is validated by means of simulation testing