http://i0.wp.com/www.researchgate.net/profile/Akhtar_Kalam/publication/228558086/figure/download/fig4/AS:341781829963780@1458498546412/Power-network-with-underground-subtransmission-and-distribution-system-respectively-2.png?_sg=2kNIPQNbsxkYj1JTYxbRIUefhdoOc2-h8gMSilReiK_kiKIGiEHBtMGzqMmcdlB4OaZ2U99iwXw?quality=80&strip=all