Open AccessDesign of an inverter‐side current reference and controller for a single‐phase LCL‐based grid‐connected inverter
Author(s) -
Escobar Gerardo,
MartinezRodriguez Panfilo R.,
Ho Carl N. M.,
Sosa Jose M.
Publication year - 2018
Publication title -
international transactions on electrical energy systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.428
H-Index - 42
ISSN - 2050-7038
DOI - 10.1002/etep.2476
Subject(s) - inverter , control theory (sociology) , total harmonic distortion , controller (irrigation) , grid tie inverter , harmonic , compensation (psychology) , computer science , electronic engineering , engineering , voltage , electrical engineering , maximum power point tracking , physics , control (management) , agronomy , artificial intelligence , biology , psychology , quantum mechanics , psychoanalysis
Summary This paper presents the design of a current reference used in an inverter‐side current controller for a grid‐connected single‐phase transformerless inverter with an Inductive‐Capacitive‐Inductive of LCL filter. The idea is to indirectly control the inverter‐side current, by directly acting on the grid‐side current. Furthermore, it can be shown that the simple proportional term guarantees damping injection. However, the design of the current reference for such a controller is a more involved process, which turns out to be even more challenging in the case where the grid voltage signal is subject to harmonic distortion. In this case, the distortion propagates into the converter through the LCL filter. Therefore, an inverter‐side current reference must be proposed to be as distorted as necessary to assure indirect tracking of the grid‐side current towards its corresponding reference, which is built as a sinusoidal with a given phase displacement to allow reactive current injection. The inverter‐side controller must then include a harmonic compensation mechanism, to assure perfect tracking of the inverter‐side current towards its distorted reference, and thus, achieve an adequate performance under harmonic distortion. Experiments are performed in a prototype to evaluate the performance of the proposed controller.