Optimal Location and Capacity of Distributed Generators in Expanding Load Distribution in Smart Cities

Abstract

The efficacy of a smart city relies on robust infrastructure, particularly a reliable electric power distribution system. As urban centers transition from fossil fuel vehicles to electric vehicles and experience economic growth, strategies are required to foster cleaner environments. The rapid increase in feeder loads can lead to overloading, resulting in degraded electricity quality, including voltage drops and significant power losses. Limited power supply from substations exacerbates the challenge of meeting feeder demands. Integrating distributed generators (DGs) powered by renewable energy sources offers a viable solution to these issues. Maintaining optimal power supply conditions for consumers is essential, even amid fluctuating loads. Real-time monitoring of electricity quality on each feeder is critical for evaluating operational status and determining the need for additional power injection. Voltage drop calculations can be effectively performed using feeder current data alone, simplifying assessments compared to traditional measurement and power flow methods that require detailed load data. This facilitates the identification of optimal DG locations and capacities, focusing on minimizing losses. The method's accuracy has been validated through simulations involving seven feeder nodes and applied to the IEEE 21-node feeder, expanded to 26 nodes. The implementation of five public EV charging stations demonstrates the method's practicality. Without DG power injection post-SUPB-EV expansion, voltage drops increased from 3.260% to 5.323%, and losses rose from 2.41 to 1.47. To maintain normal feeder operation, power injections of 300.7 kVA, 186.8 kVA, and 173.4 kVA are required at nodes 4, 5, and 6, respectively.