ORIGINAL ARTICLE Improvement of power quality in grid-connected inverter through adaptation-based control strategy M. Momeni 1 • A. H. Mazinan 2 1 Department of Control Engineering, South Tehran Branch, Islamic Azad University (IAU), No. 209, North Iranshahr St., P.O. Box 11365/4435, Tehran, Iran 2 Department of Control Engineering, Faculty of Electrical Engineering, South Tehran Branch, Islamic Azad University (IAU), No. 209, North Iranshahr St., P.O. Box 11365/4435, Tehran, Iran Received: 14 May 2018 / Revised: 11 January 2019 / Accepted: 14 January 2019 Ó The Joint Center on Global Change and Earth System Science of the University of Maryland and Beijing Normal University 2019 Abstract This paper describes power quality improve- ment, which has attracted the attention of the electricity distribution companies and subscribers. The idea of improving power quality is considered as the universal concept for various types of the power system disturbances. These aforementioned disturbances include noise, low voltage, overvoltage and middle harmonics, in general. The key goal of realizing the adaptation-based control strategy in this investigation is to reduce the grid current harmonics, in its efficient manner. It should be noted that there are some traditional and state-of-the-art techniques to improve power quality through the realization of active, passive or hybrid filters, respectively. In accordance with the growing applications of the renewable energy sources in distribution grids, the investigated research proposes the renewable energy sources in the studied grid. In the strategy presented here, the background of this topic is extensively considered and subsequently the above-referenced adaptation-based control strategy is designed, in order to deal with the converter signals, which are connected to the point of common coupling and also the direct current link. In summary, the main contribution of this investigation with respect to the state-of-the-art outcomes is made to improve power quality of the grid side and also to handle the transfer of the power betweenthe renewable energies and the corresponding grid, as well. The validity of the inves- tigated outcomes is tangibly verified by considering the benchmarks, correspondingly. Keywords Power quality Á Grid-connected inverter Á Renewable energy resources Á Point of common coupling Á Harmonics Á Nonlinear and unbalanced loads 1 Introduction Nowadays, supplying power to consumers is important to maintain in terms of the quality standards in different parts of the world. Furthermore, based upon the current position of the renewable energy sources and also the frequent connection of these resources to distribution systems, the topic of power quality can be considered as a new per- spective. These fundamental points are generally made in Santoso et al. (2012) with a focus on the electrical power systems quality. In this regard, Gomez-Exposito et al. (2008) considered the electric energy systems. Shim (2013) proposed synergistic control for enabling dispatch ability of renewable energy sources. Bhadane et al. (2012) noted on the causes of poor power quality in grid-connected wind energy. The details of the aforementioned studies indicate that an active power filter can be realized to improve power quality of the distribution system in the form of the three- phase three-wire system, while a control strategy is cor- respondingly designed to deal with the active shunt filter in the form of the three-phase four-wire system, as well. This filter design uses a tripod inverter and two capacitors par- allel to the inverter. The fourth wire of the distribution system is connected to the point between the two capaci- tors. Furthermore, the control strategy in this area needs to be designed through the inverter model. It aims us to improve the power factor and reduce the disturbance har- monics without measuring the current of the line. Regarding a series of potential investigations, El Shatshat & A. H. Mazinan mazinan@azad.ac.ir; ahmazinan@gmail.com 123 Energ. Ecol. Environ. https://doi.org/10.1007/s40974-019-00111-y