• P-ISSN 0974-6846 E-ISSN 0974-5645

Indian Journal of Science and Technology


Indian Journal of Science and Technology

Year: 2020, Volume: 13, Issue: 22, Pages: 2272-2281

Original Article

Sizing of dc-link capacitor for a grid connected solar photovoltaic inverter

Received Date:25 April 2020, Accepted Date:11 June 2020, Published Date:28 June 2020


Objective: To determine the optimum size of a dc-link capacitor for a grid connected photovoltaic inverter. Methods: Dc-link capacitors are considered as one of the sensitive parts of the grid connected photovoltaic systems and needs effort to design a reliable and optimal size capacitor as its reliability is concerned with the overall system reliability. The double line frequency power flows between the input and outside of a Φ grid connected PV system which produces voltage ripples at the capacitor and dc link. This voltage ripple increases temperature of passive components and dc source which affects the MPP operation of the photovoltaic modules and the system life. Therefore, it is essential to limit the voltage ripples at the input side of the system. The easiest way to limit the double frequency ripple voltage is to connect a capacitor in parallel to the PV module and the inverter which buffers the double line frequency power and supply a constant power to the inverter. This study proposed a general method for sizing a dc-link capacitor for a Φ grid connected voltage source inverter. It is seen that the capacitance is inversely proportional to the nominal dc and ripple voltage. Thus an increase in the nominal system voltage decreases the size of the capacitor and at the same time increases the voltage ripple. Therefore to limit voltage ripple within permissible limits and to ensure better system performance the dc-link capacitor must be appropriately sized. The simulations based on 3kW grid connected PV system are carried out in DIgSILENT Power Factory software. Findings: A capacitor of 410µF is needed to be connected in parallel with a 3kVA inverter having an nominal input voltage of 370V and maintaining a voltage ripple under 8.5%. Novelty: After determining optimized dc-link capacitor size we will limit the voltage ripple under permissible limits and hence improves the system efficiency and life of the grid connected PV system. 

Keywords: Voltage source inverter; voltage ripple; Dc-link capacitor sizing; distributed generation; grid connected PV system


  1. Eren S, Pahlevani M, Bakhshai A, Jain P. An Adaptive Droop DC-Bus Voltage Controller for a Grid-Connected Voltage Source Inverter With LCL Filter. IEEE Transactions on Power Electronics. 2015;30(2):547–560. Available from: https://dx.doi.org/10.1109/tpel.2014.2308251
  2. Saidi AS, Slimene MB, Khlifi MA. Transient stability of photovoltaic system with experimental shading effects. Engineering Technology and Applied Science Research. 2018;8(6):3592–3597. Available from: https://doi.org/10.5281/zenodo.2532664
  3. Guerrero JM, Matas J, Vicuna LGDVD, Castilla M, Miret J. Wireless-Control Strategy for Parallel Operation of Distributed-Generation Inverters. IEEE Transactions on Industrial Electronics. 2006;53(5):1461–1470. Available from: https://dx.doi.org/10.1109/tie.2006.882015
  4. Kjaer SB, Pedersen JK, Blaabjerg F. A Review of Single-Phase Grid-Connected Inverters for Photovoltaic Modules. IEEE Transactions on Industry Applications. 2005;41(5):1292–1306. Available from: https://dx.doi.org/10.1109/tia.2005.853371
  5. Alsafasfeh Q, Saraereh OA, Khan I, Kim S. Solar PV grid power flow analysis. Sustainability. 2019;11(6):1–25. Available from: https://doi.org/10.3390/su11061744
  6. Watanabe H, Sakuraba T, Furukawa K, Kusaka K, Itoh Ji. Development of DC to Single-Phase AC Voltage Source Inverter With Active Power Decoupling Based on Flying Capacitor DC/DC Converter. IEEE Transactions on Power Electronics. 2018;33(6):4992–5004. Available from: https://dx.doi.org/10.1109/tpel.2017.2727063
  7. Mohamed SR, Jeyanthy PA, Devaraj D, Shwehdi MH, Aldalbahi A. DC-Link Voltage Control of a Grid-Connected Solar Photovoltaic System for Fault Ride-Through Capability Enhancement. Applied Sciences. 2019;9(5):952. Available from: https://dx.doi.org/10.3390/app9050952
  8. Latreche AS, Essalam M, Khemliche. Implementation of MPPT algorithm and supervision of shading on photovoltaic module. Engineering Technology and Applied Science Research. 2018;8(6):3541–3544. Available from: htpps://doi.org/10.5281/ZENODO.2532638
  9. Soreng B, Behera P, Pradhan R. Design of A Grid Integrated PV System with MPPT Control and Voltage Oriented Controller using MATLAB/PLECES. IOP Conference Series: Materials Science and Engineering. 2017;225:012249. Available from: https://dx.doi.org/10.1088/1757-899x/225/1/012249
  10. Ertasgin G, Whaley DM, Ertugrul N, Soong WL. Analysis of DC Link Energy Storage for Single-Phase Grid-Connected PV Inverters. Electronics. 2019;8(6):601. Available from: https://dx.doi.org/10.3390/electronics8060601
  11. SHAYESTEGAN M. Overview of grid-connected two-stage transformer-less inverter design. Journal of Modern Power Systems and Clean Energy. 2018;6(4):642–655. Available from: https://dx.doi.org/10.1007/s40565-017-0367-z
  12. Jana J, Saha H, Bhattacharya KD. A review of inverter topologies for single-phase grid-connected photovoltaic systems. Renewable and Sustainable Energy Reviews. 2017;72:1256–1270. Available from: https://dx.doi.org/10.1016/j.rser.2016.10.049
  13. Marcos VMM, Martinez MAG, Gonzalez FB, Montero MIM. A grid-connected photovoltaic inverter with battery-supercapacitor hybrid energy storage. Sensors. 2017;17(8):1–18. Available from: htpps://doi.org/10.3390/s17081856
  14. Liang W, Liu Y, Ge B, Abu-Rub H, Balog RS, Xue Y. Double-Line-Frequency Ripple Model, Analysis, and Impedance Design for Energy-Stored Single-Phase Quasi-Z-Source Photovoltaic System. IEEE Transactions on Industrial Electronics. 2018;65(4):3198–3209. Available from: https://dx.doi.org/10.1109/tie.2017.2750630
  15. Wang H, Blaabjerg F. Reliability of Capacitors for DC-Link Applications in Power Electronic Converters—An Overview. IEEE Transactions on Industry Applications. 2014;50(5):3569–3578. Available from: https://dx.doi.org/10.1109/tia.2014.2308357
  16. Hu H, Harb S, Kutkut N, Batarseh I, Shen ZJ. A Review of Power Decoupling Techniques for Microinverters With Three Different Decoupling Capacitor Locations in PV Systems. IEEE Transactions on Power Electronics. 2013;28(6):2711–2726. Available from: https://dx.doi.org/10.1109/tpel.2012.2221482
  17. Wang B, Hinkel P, Song Y. Single phase VSI with reduced-size dc-link capacitor. 4th International Conference on Power Engineering, Energy and Electrical Drives. 2013;p. 1427–1430.
  18. Lalitha A, Subramanyam M, Shobbha M, Narendra B. Series voltage compensator modeling and design for reduction of grid-tie solar inverter dc-link capacitance. International Research Journal of Engineering and Technology. 2017;4(12):1091–1095.
  19. Mnati MJ, Abed JK, Bozalakov DV, A. Van den Bossche. Analytical and calculation DC-link capacitor of a three-phase grid-tied photovoltaic inverter. In: IEEE 12th International Conference on Compatibility. (pp. 1-6) Power Electronics and Power Engineering. 2018.
  20. Memon MA, Bhutto GM. Effect of optimum sized solar pv inverter on energy injected to ac grid and energy loss in Pakistan. Indian Journal of Science and Technology. 2020;13(8):954–965.
  21. Shi Y, Liu L, Li H, Xue Y. A single-phase grid-connected PV converter with minimal dc link capacitor and low frequecy ripple-free maximum power point tracking. IEEE Conference on Energy Conversion Congress and Exposition. 2013;p. 1–5. Available from: https://doi.org/10.1109/ECCE.2013.6647006. 2385-2390


© 2020 Memon, Bhutto, Buriro. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Published By Indian Society for Education and Environment (iSee)


Subscribe now for latest articles and news.