Optimal allocation of ELC in microgrid using droop controlled load flow

Abstract

The increased renewable-based sources penetration in the microgrid (MG) has given rise to issues related to the voltage (V) and frequency (f) surpassing their tolerance limits, especially during off-peak hours. The fluctuations in V and f could be handled by available real-time control schemes within a specified range. Owing to the wide generation-load mismatch in the high-penetration scenario, deviations in V and f cannot be sorted out using available real-time control schemes and seeks further developments. An electronic load controller (ELC) in the MG can consume excess generation to regulate V and f. Hence, this work presents an analytical study to understand the significance of ELC in highly penetrated MGs in V and f regulation at off-peak hours. The problem is formulated as single- and multiple-optimisation problems, which are solved using heuristic techniques viz. particle swarm optimisation and non-dominated sorted genetic algorithm-II. To incorporate the effect of P–f and Q–V droop characteristics as exhibited by distributed generations in the power flow, a special load flow method is used. The analysis is conducted on IEEE 33-and 69-bus test systems modified as autonomous MGs. The results show that proposed method is capable of minimising V and f deviation.