Environmental control of energy storage containers

The implementation of an energy storage system (ESS) as a container-type package is common due to its ease of installation, management, and safety. The control of the operating environment of an ESS mainly considers the temperature rise due to the heat generated through the battery operation.

Introduction An energy storage system (ESS) is a system that has the flexibility to store power and use it when required. An ESS can be one of the solutions to mitigate the intermittency effect of variable renewable energy (VRE), such as photovoltaic and wind power [1, 2, 3].

The indoor temperature of the ESS container can be controlled to maintain the battery temperature below the target temperature. Generally, economical and simple forced air convection systems (FACS) are used to manage the indoor temperature of ESS containers .

The operating environment of an ESS must be managed within the operating range provided by the manufacturer. It is recommended that the ESS container used in this study be operated at 35~75% humidity and 18~28 °C. Figure 2 shows an example of the relative humidity, temperature of the container, and battery cell temperature during summer.

In this study, temperature and humidity monitoring and management issues were addressed for a container-type ESS by building sensor-based monitoring and control systems. Furthermore, a rule-based air conditioner control algorithm was proposed for temperature and humidity management.

The general configuration of an ESS container is shown in Figure 1. It consists of a power conversion system (PCS), battery protection unit (BPU), battery management system (BMS), and battery. The PCS converts AC power to DC power during charging and vice versa during discharging.