Contents lists available at ScienceDirect Renewable and Sustainable Energy Reviews journal homepage: www.elsevier.com/locate/rser A review of inverter topologies for single-phase grid-connected photovoltaic systems Joydip Jana ⁎ , Hiranmay Saha, Konika Das Bhattacharya Indian Institute of Engineering Science & Technology (IIEST), Shibpur, Center of Excellence for Green Energy & Sensor Systems, Botanic Garden, 711103 Howrah, West Bengal, India ARTICLE INFO Keywords: Photovoltaic (PV) Grid-connected inverter Efficiency Transformer-less inverter Multilevel inverter Soft-switching inverter ABSTRACT The concept of injecting photovoltaic power into the utility grid has earned widespread acceptance in these days of renewable energy generation & distribution. Grid-connected inverters have evolved significantly with high diversity. Efficiency, size, weight, reliability etc. have all improved significantly with the development of modern and innovative inverter configurations and these factors have influenced the cost of producing inverters. In this review work, all aspects covering standards and specifications of single-phase grid-connected inverter, summary of inverter types, historical development of inverter technologies, classifications of inverter topologies are presented in a systematic manner. Finally, some transformer-less topologies based on bridge configuration and multilevel concept, and some soft-switching inverter topologies are remarked as desirable with respect to high efficiency, low cost, and compact structure. Areas of further works including use of advanced semiconductor devices, improvement of de-coupling capacitor etc. are also pointed out to draw attention of inverter designer for further increase of efficiency and lowering the cost. 1. Introduction Renewable energy is increasingly considered essential for meeting current and future energy needs [1]. Photovoltaic (PV) power, as it is clean and unlimited source of energy, is probably the best technology amongst all renewable energy sources and therefore a considerable amount of research has been conducted recently in this field. To better utilize the PV power, grid interconnection of PV system is needed. PV power rendering to the utility grid has been the fastest growing renewable energy technology by far since it attracted the attention of policy makers [2]. The primary constraint to the use of PV power was the cost of the PV modules, which were typically ranged between 30% and 50% of the total cost of the system [3]. Due to the downward tendency in the price for the PV modules, the costs of the inverters were increasingly standing out while calculating the total cost of the grid- connected PV system. In the past 2–3 decades, grid-connected inverters have evolved significantly with high diversity and are considered one of the fastest developing technologies in present power electronics and power systems. Efficiency, size, weight, reliability etc. along with ease of installation have all improved significantly with the development of modern and innovative inverter configuration. These factors have influenced the cost of producing inverters. So many grid- connected PV systems have been installed in recent years mainly due to the downward tendency of the cost of such systems, and policy making and subsidy given by the governments to these kinds of technologies. But pressure to further cost reduction still remains. The factors volume and weight of the inverter are inhomogeneous. It is not always true that inverter with line-frequency transformer has more volume and weight than inverter with high-frequency transfor- mer, and similarly inverter with high-frequency transformer has more volume and weight than a transformer-less inverter [4]. Transformer- less inverters had leakage current problem, which has been solved in some transformer-less topologies up to a certain level. But anyway, transformer-less inverters are being produced mostly in recent days due to high efficiency and low cost [4,5]. Inverter cost further can be reduced if more than two-level output voltage could be generated. For this reason, some multilevel inverter topologies may be beneficial [6]. Another important factor is inverter efficiency which reaches near http://dx.doi.org/10.1016/j.rser.2016.10.049 Received 13 April 2015; Received in revised form 30 August 2016; Accepted 25 October 2016 ⁎ Corresponding author. E-mail addresses: joydipjana02@gmail.com (J. Jana), sahahiran@gmail.com (H. Saha), poopoolee50@hotmail.com (K. Das Bhattacharya). Abbreviations: PV, Photovoltaic; IEC, International Electro technical commission; IEEE, Institute of Electronics and Electrical Engineers; NEC, National Electrical Code; DR, Distributed Resource; DC, Direct Current; AC, Alternative Current; THD, Total harmonics distortion; IGBT, Insulated Gate Bipolar Transistor; MOSFET, Metal Oxide Semiconductor Field-effect Transistor; PWM, Pulse width modulation; VSI, Voltage source inverter; CSI, Current source inverter; BJT, Bipolar Junction Transistor; MPPT, Maximum Power Point Tracking; GEC, General Electric Company; ZVS, Zero voltage switching; ZCS, Zero current switching; ZVT, Zero voltage transition; ZCT, Zero current transition; HERIC, High efficient and reliable inverter concept; EMI, Electromagnetic Interference; SiC, Silicon Carbide; R & D, Research and Development; USA, United States of America Renewable and Sustainable Energy Reviews 72 (2017) 1256–1270 Available online 05 November 2016 1364-0321/ © 2016 Elsevier Ltd. 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