Voltage regulation in active power distribution systems integrated with natural gas grids using distributed electric and gas energy resources

Abstract

Several issues have recently arisen in power distribution systems, stemmed from large penetration of renewable energy resources; among which, voltage regulation is the most salient. A newly emerging technology, referred to as power-to-gas (PtG), has brought about new opportunities to utilize the gas grid for mitigation of some existing and imminent issues in active distribution systems (ADSs). PtG units can convert the surplus electricity into the synthetic natural gas, which is then injected into the gas grid for more useful operations. Distributed gas-to-power (GtP) units, on the other hand, could exploit the gas as the feedstock to generate power, when it is needed during high power demand. A balance between the distributed generation and demand can eliminate the voltage magnitude issues in the system. In this paper, a new algorithm is proposed for optimal real-time scheduling of a PtG-GtP unit, to mitigate over/under voltage issues in ADSs with high penetration of renewables. Besides, using optimization slack variables, two indices are formulated for quantifying the contribution of the PtG-GtP facility towards voltage regulation. Using the proposed algorithm, the facility profits by providing voltage regulation services to the ADSs, in addition to the arbitrage benefit as a merchant function. Real-world data and test systems are employed to numerically validate the efficacy of the proposed algorithm.