Multipurpose control and planning method for battery energy storage systems in distribution network with photovoltaic plant

Abstract

Battery energy storage systems (BESSs) have attracted much attention as a key device for realizing the installation of photovoltaic plants (PVPs) in distribution networks. To improve the cost-effectiveness of BESSs, multipurpose utilization is required. In addition, the BESSs in a distribution network are generally used over a decade or more, and the role and size of BESSs may change according to the distribution network’s condition, such as the PVP penetration level. Consequently, an ad hoc BESS installation may increase excess BESS capacity, which is detrimental to cost-effectiveness. Therefore, a multipurpose utilization and planning method is desired for BESSs. This paper proposes a multipurpose control and planning (MCP) method for BESSs to cope with the increase of large-scale PVPs in distribution networks. The proposed method executes power smoothing, reverse-power-flow (RPF) prevention, and state-of-charge (SoC) adjustment without interactions between controls, and it determines a suitable BESS site and type based on three indices: (1) BESS capacity, (2) the number of tap operations of an on-load tap changer (OLTC) and a step voltage regulator (SVR), and (3) PVP curtailment. The BESS is used for power smoothing of a substation/PVPs and RPF prevention at the substation. To evaluate the impact of the BESS installation on tap operation and PVP curtailment, the voltage regulation methods of OLTC, SVR, and PVP inverters were implemented. According to the results, the substation was selected as a suitable BESS site regardless of the number of PVPs and BESS type. Furthermore, lithium-ion battery (LiB) was the preferred BESS type when PVP penetration rate (PR) was less than 67%, and redox flow battery (RFB) was selected as the BESS type when the PR was 100%. The simulation results indicate that the MCP method can achieve multipurpose control and determine the suitable BESS site and type.