Design of an inverter-side current reference and controller for a single-phase LCL-based grid-connected inverter Article uri icon

abstract

  • 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. Copyright © 2017 John Wiley %26 Sons, Ltd.

publication date

  • 2018-01-01