Smart Control Strategies for Primary Frequency Regulation through Electric Vehicles: A Battery Degradation Perspective

Abstract

Nowadays, due to the decreasing use of traditional generators in favor of renewable energy sources, power grids are facing a reduction of system inertia and primary frequency regulation capability. Such an issue is exacerbated by the continuously increasing number of electric vehicles (EVs), which results in enforcing novel approaches in the grid operations management. However, from being an issue, the increase of EVs may turn to be a solution to several power system challenges. In this context, a crucial role is played by the so-called vehicle-to-grid (V2G) mode of operation, which has the potential to provide ancillary services to the power grid, such as peak clipping, load shifting, and frequency regulation. More in detail, EVs have recently started to be effectively used for one of the most traditional frequency regulation approaches: the so-called frequency droop control (FDC). This is a primary frequency regulation, currently obtained by adjusting the active power of generators in the main grid. Because to the decommissioning of traditional power plants, EVs are thus recognized as particularly valuable solutions since they can respond to frequency deviation signals by charging or discharging their batteries. Against this background, we address frequency regulation of a power grid model including loads, traditional generators, and several EVs. The latter independently participate in the grid optimization process providing the grid with ancillary services, namely the FDC. We propose two novel control strategies for the optimal control of the batteries of EVs during the frequency regulation service. On the one hand, the control strategies ensure re-balancing the power and stabilizing the frequency of the main grid. On the other hand, the approaches are able to satisfy different types of needs of EVs during the charging process. Differently from the related literature, where the EVs perspective is generally oriented to achieve the optimal charge level, the proposed approaches aim at minimizing the degradation of battery devices. Finally, the proposed strategies are compared with other state-of-the-art V2G control approaches. The results of numerical experiments using a realistic power grid model show the effectiveness of the proposed strategies under the actual operating conditions.

Power Grid Integration and Use-Case Study of Acid-Base Flow Battery Technology

“…Not only operational safety is important but also features such as the availability, the mean time between failures (MTBF), and the failure recovery and management. Fully deployed technologies such as Li-ion have provided extensive studies about this issue [38,39]. However, it is necessary to reach enough maturity level of readiness prior to perform such studies.…”

Research on Active Overbalanced Control Strategy for Lithium-Ion Battery

“…If there is no balanced control, the capacity of the battery pack should be limited to the minimum capacity of the monomer during the charging and discharging process, so as to ensure that the battery pack and monomer will not be overcharged or overdischarged. As a result, the capacity utilization rate of the battery pack will be greatly reduced [12][13][14][15][16][17][18]. In order to solve this problem and improve the battery life and capacity utilization, the balance control of lithium batteries is particularly important.…”

Operation Strategy for Electric Vehicle Battery Swap Station Cluster Participating in Frequency Regulation Service

“…Considering the applicability of battery energy storage to participate in FR, some scholars have recently carried out research based on battery degradation. A refined model of the battery degradation principle is given in [20,21]. Based on this, the FR control strategy to minimize the degree of battery degradation is proposed and the accurate calculation method of the battery energy storage FR cost is given, both of which can promote the application of battery energy storage in the FR market.…”