Techno-Economic Analysis of Impact on the Distribution Feeder with Capacitor Placement as per NEA’s Regulations and Optimum Scenario

Abstract

With the aim of distribution loss reduction, Nepal Electricity Authority has brought regulation to install the capacitor with size equivalent to approx. 30% of the load demand. Throughout the period of 5 years, the partial implementation of this regulation is practically achieved. This paper compares the techno-economic impact of the placement of the capacitor as per NEA's regulations and the other case for the optimal placement and sizing with the cost minimization function of genetic algorithm. The voltage improvement and reduction in the overall loss can be achieved with the placement of the capacitor banks. In case of the IEEE-33 bus system, the voltage profile with optimal placement was better 0.924pu as compared to the case with NEA regulation which is 0.921pu. However, the overall system loss was lower for the optimal placement of the capacitor. With active loss being 163.28kW and 154.43kW respectively with the capacitor placed as per NEA’s guidelines and optimal scenario respectively. So, voltage can be better for the utility feeder dominated with the private consumers. Melamchi feeder taken into account, the base case minimum voltage and loss was obtained as 0.732pu and 14.79% respectively. The minimum voltage with the capacitor placement as per NEA's regulation and Optimal capacitor placement (OCP) are 0.774pu and 0.817pu with loss 12.30% and 10.16% respectively. Moreover, from the financial analysis for the comparison of the two cases, it was evaluated that the IRR, BCR & discounted payback periods are 19.78%, 2.20 & 4.96 years and 23.76%, 2.46 & 4.41years for the placement with NEA’s guidelines and optimization respectively. This majorly indicates that the optimal placement of the capacitor is a bit more cost effective than the other case. From both the techno-economic perspective, the capacitor placement in the distribution feeder at the optimal locations was determined more suitable than the installation at the private consumer’s point as per the NEA’s guidelines. So, the private consumers can aid the system voltage and mitigate loss with the collaborative evaluation of the optimal location and sizing of the capacitor in the utility’s distribution feeder.