Integration of Lithium-Ion Battery Storage Systems in Hydroelectric Plants for Supplying Primary Control Reserve

Abstract

Abstract:The ever-growing diffusion of renewables as electrical generation sources is forcing the electrical power system to face new and challenging regulation problems to preserve grid stability. Among these, the primary control reserve is reckoned to be one of the most important issues, since the introduction of generators based on renewable energies and interconnected through static converters, if relieved from the primary reserve contribution, reduces both the system inertia and the available power reserve in case of network events involving frequency perturbations. In this scenario, renewable plants such as hydroelectric run-of-river generators could be required to provide the primary control reserve ancillary service. In this paper, the integration between a multi-unit run-of-river power plant and a lithium-ion based battery storage system is investigated, suitably accounting for the ancillary service characteristics as required by present grid codes. The storage system is studied in terms of maximum economic profitability, taking into account its operating constraints. Dynamic simulations are carried out within the DIgSILENT PowerFactory 2016 software environment in order to analyse the plant response in case of network frequency contingencies, comparing the pure hydroelectric plant with the hybrid one, in which the primary reserve is partially or completely supplied by the storage system. Results confirm that the battery storage system response to frequency perturbations is clearly faster and more accurate during the transient phase compared to a traditional plant, since time delays due to hydraulic and mechanical regulations are overpassed. A case study, based on data from an existing hydropower plant and referring to the Italian context in terms of operational constraints and ancillary service remuneration, is presented.

Effects of Energy Storage Systems Grid Code Requirements on Interface Protection Performances in Low Voltage Networks

“…It is not advisable to implement a delay on the P/f function in providing primary control regulation to the main grid as demonstrated, for instance, in [4,38], showing how a fast and precise active power response directly implicates reductions in the frequency perturbation width. Consequently, for new installations, the Q/V stabilizing function is required to dynamically behave as a first order filter, with time constant configurable in the range of 3-60 s.…”

“…An excessive and unplanned penetration of power electronic interfaced systems in distribution networks, partially replacing the traditional centralized generation making use of rotating machines, reduces the connected regulating energy available in the interconnected network and may consequently affect the network stability in terms of voltage and frequency [4]. In order to counteract this kind of problems, national and international authorities updated their standards and grid codes regarding the connection of active end-users to distribution networks, including both DGs and ESSs.…”

Battery Storage-Based Frequency Containment Reserves in Large Wind Penetrated Scenarios: A Practical Approach to Sizing

“…A more complex economic model of BESS, together with sizing procedure with respect to different operation criteria, is presented in [25]. Furthermore, the authors of [26,27] have performed a techno-economic analysis of the lithium-ion BESS providing FCR. However, the aforementioned studies [23][24][25][26][27] that included an economic evaluation of the BESS unit, were lacking a clear understanding of how the obtained parameters for optimal sizing are influencing the BESS lifetime and subsequently the economic profitability.…”

Review of Voltage and Frequency Grid Code Specifications for Electrical Energy Storage Applications

“…• Bignucolo et al [44] studied the integration of lithium-ion battery storage systems in hydroelectric plants for supplying Primary Control Reserve required by the Grid Code specification. The simulation study of the overall system was carried out to quantitatively analyse the plant dynamic response in the case of network frequency contingencies and to study the technical benefits brought by such integration system to grid stability.…”

“…The simulation study of the overall system was carried out to quantitatively analyse the plant dynamic response in the case of network frequency contingencies and to study the technical benefits brought by such integration system to grid stability. A case study to the technical-economic analysis, based on data from an existing hydropower plant and the Italian context, was presented in [44], mainly on the investment profitability.…”