Impact of hybrid electrical energy storage system on realistic deregulated power system having large-scale renewable generation

Abstract

Frequency stabilization in the deregulated power system (DPS) becomes more significant because of increased complexities and uncertainties due to higher penetration of renewable energy sources (RESs) among other operational challenges of the system. Variable generation due to RESs and frequent load deviations impact the supply and demand balance which causes huge frequency deviations in the system. The issues associated with the grid due to RES can be effectively tackled by maintaining power balance using different types of energy storage and advanced control mechanism. This article evaluates the suitability of hybrid electrical energy storage (HEES) and a novel (1 + TDF)-PI cascade controller to tackle the frequency regulation issues of the two-area DPS. The DPS has a power generation capacity of 2000 MW in each area integrated with RESssuch as geothermal power plant (GPP) and realistic dish-sterling solar thermal system (RDSTS). To resemble the practical operational situation of the DPS, several contract transaction scenarios and nonlinearities have been considered and examined. The HEES is a combination of a Super-Capacitor (SC) and redox flow battery (RFB). The SC is very fast responding and it can counter immediate variations in the power whereas, the RFB system can counter large variations of the power as needed in the system. The supremacy of the proposed controller has been confirmed by equating its performance with other well-known controllers. Compared to the state-of-the-art approaches, with the proposed controller smaller setting time has been achieved i.e. 10.72 s and 10.579 s for area-1 and area-2 frequency and 1.25 s for tie-lie power under the BBT scenario. Moreover, the system performances and capabilities to handle system nonlinearities have been prominently enriched due to precise control and a quick response provided through the proposed HEES.