Projecting a self sustainable Micro-Grid. Kishore Seshadri (IITB)

This research project is on low-voltage AC microgrids to achieve sustainability within a community. A microgrid is an aggregate of distributed energy resources and loads which can operate both in gridconnected and isolated mode. The size of a microgrid is still a topic of discussion in the field of power engineering. An isolated microgrid is being designed at IIT-Bombay as a prototype which aims to power
up the Insulation Diagnostic Lab (estimated load: 12kW) to achieve self-sustenance. Solar and vertical axis wind turbines for rooftop applications will be the primary source of energy for the lab. For energy
storage purposes, a pico-pumped-hydro storage is considered as an alternative to batteries which have a negative impact on the environment. Many towns and villages in India have access to community
tanks, temple ponds and lakes, upstream and downstream back waters and rivers. These hold potential to utilize pumped hydro-storage (PHS) at a small scale. The size of the load will determine the capacity
of water storage for the PHS plant. The existing requirement is for 2 tanks with 10000 liter capacity. A 10000L tank at a height of 20m is capable of storing 0.544kWh of energy. An important role of an energy storage facility, in addition to being an auxiliary power supply, is to provide active and reactive power compensation for a low-voltage AC system. So, one major challenge in using a PHS plant is the mechanical time delay being high for catering to electrical transients. With this solution in hand, to
ensure a secure and reliable power source, a charge controller will be designed to regulate the energy mix based on the load demand variation. The first step to achieving this is to estimate a load demand
cycle of the lab for a typical hot summer’s day in Mumbai, India. Accordingly, the night time requirements (estimated consumption: 53.145kWh, average power: 4.43kW for 12 hrs) and day time requirements
(estimated consumption: 81.7kWh, average power: 6.81kW for 12 hrs) are identified. The major loads are the cooling systems (air conditioners). This will help in deciding the solar, wind and PHS capacity required to power up the lab. The operating strategy can then be decided and the charge controller can be designed accordingly.
Main Discussant:
Mr. Pratik Rao, Lead Control & Protection Engineer, GE Vernova
Research Scholar, IIT-Bombay