1. Global Market Outlook 2019-2023 – Solar Power Europe (2020). http://www.solarpowereurope. org/global-market- outlook-2019-2023/. Accessed 22 July 2020
2. Effect of high shares of renewables on power systems, Publications Office of the EU (2020). https://publications.europa. eu/en/publication-detail/-/publication/01c456f4 - 7144 -11e9- 9f05-01aa75ed71a1/language-en/format-PDF/source-96288175. Accessed 22 July 2020
3. Voltage control with on-load tap changers in medium voltage feeders in presence of distributed generation;Viawan;Electric power systems research,2007
4. The online voltage control of ULTC transformer for distribution voltage regulation;Choi;International Journal of Electrical Power & Energy Systems,2001
5. Dieter Dohnal (2020) On-load tap-changers for power Transformers. https://www.reinhausen.com/de/Xparo Download. ashx?raid=58092. Accessed 8 August 2020