Greenfield planning approach for the city of Mumbai leads to optimal future network development

The Indian utility Reliance Energy Ltd. (REL) operates the power supply for its Mumbai supply area with 1200 MW peak load by 220/33/22/11 kV networks. On the distribution level with more than 4000 distribution substations medium to low voltage the supply situation was characterized by high losses and frequent interruptions. The network had grown over years and some replacement works as well as expansion work to meet the load growth were urgently necessary. At this stage in 2003 the management decided to carry out a major system study for network optimisation, distribution automation and automatic meter reading together with Siemens in order to optimise the upcoming investments and to define the priorities. The paper shows the approach of network optimization with the identification of weak points in the existing network as well as the selection of the target network structure and its verification with principle networks and concrete modeling in Mumbai area.