Battery Energy Storage System Components and Their Functions

Various units comprise a battery storage system, from the batteries to the monitoring and control circuits. This explains battery energy-storage system components. Use it to understand what each part does and how they work together to ensure a properly working setup.

How Does a Battery Energy Storage System Work?

A battery storage system uses electrochemical devices to store electrical energy. It captures energy in a reversible chemical reaction (charging) and releases it when needed (discharging).

The released energy powers an external circuit or electrical piece of equipment, such as the electrical loads of a home, commercial building, or the grid network of a utility company.

You can use various energy sources to charge battery storage. These include the grid and renewable sources like solar and wind. Renewable energy systems require storage batteries more since their power generation is intermittent.

Battery Energy Storage System Components

As we have seen, the operation of a battery storage system, from the charging process to when it discharges to release stored energy, relies on the operation of various components. These include the following:

• Battery cells
• Battery management system
• Power conversion system
• Energy management system
• Thermal management system
• Safety system
• Switchgear and protective devices
• Enclosure
• Communication system

Battery Cells

These refer to the individual units that make up the battery. When combined and enclosed in a frame, several cells make a module. Depending on the required capacity, several modules are joined in stacks to form a rack.

Storage battery cells can be of different types, depending on the chemical compounds in the electrolyte and the types of electrodes used. Popular options are lithium ion and lead acid-based storage systems. Others are sodium-sulfur and flow batteries.

Battery Management System

The energy storage battery management system, BMS, consists of electronics monitoring the battery’s real-time health. It checks the battery’s current, voltage, and other operating parameters such as temperature and charge condition.

The function of the BMS system is to protect the battery cells from damage. It ensures the storage doesn’t overcharge or undercharge, for instance. It also prevents the batteries from overheating by balancing their operation and keeping them within safe levels.

Power Conversion System

Battery storage systems release energy in the form of DC or direct current. In a majority of applications, the load is AC-operated. That requires a conversion system, also shortened to PCS.

The power conversion device changes DC power to AC or alternating current. AC is a more usable type of electrical current when powering electrical appliances or stabilizing the grid output The PCS primarily consists of a device called an inverter.

The typical energy storage system inverter uses a combination of electrical and electronic devices to ensure a smooth transformation of the energy. It also connects to various other parts of the BESS system.

Energy Management System

Controlling energy flow into and out of the storage battery is essential to ensure efficient system utilization. This control requires an energy management system, or EMS in short.

The EMS regulates the inverter’s working as it converts DC to AC, optimizing its performance and the entire system. In other words, these components of a battery energy storage system ensure the whole system works as it should to produce electrical power as needed.

Thermal Management System

With current flowing in its circuits, an energy storage system will undoubtedly heat up. If the heating were to go unchecked, temperatures could reach dangerous levels. The battery’s lifespan would also shorten.

The heat management system cools your storage system, ensuring it operates within a safe temperature range. It comprises fans and other cooling devices or methods, such as liquid cooling and vents.

The type of battery energy storage thermal management system in use depends on the installation size, energy capacity, and other factors such as battery type.

Safety System

Sometimes, the BMS and EMS systems cannot contain the elevated temperature levels. In such situations, a fire suppression system comes in to prevent the flames from propagating.

The fire suppression system may rely on various technologies to know when to come on. Standard options are smoke detectors, heat sensors, and specialized gas detectors.

In some installations, safety measures include housing the storage in a secure room or enclosure and mounting CCTV cameras. These ensure the system’s safe operation and that unauthorized persons do not tamper with its working.

Switchgear and Protective Devices

Any electrical installation must have switchgear and electrical protection devices. The storage system is no exception. These battery energy-storage system components include circuit breakers, switches, and similar equipment.

Protective devices shield the system from electrical faults, and various kinds of switchgear ensure safe connections and disconnections. These BESS components are also helpful when isolating the storage from the grid when needed.

Some switchgear components are manual, while some are automated. Automatic switching devices remove electrical faults to protect the system, while manually operated devices allow maintenance and repair work.

Racks and Enclosure

A battery storage system is primarily a set of batteries connected. These are then placed on racks to secure them after installation. The batteries are large-sized and housed in large enclosures in an industrial battery energy storage system.

Battery enclosures in large installations typically have cooling systems. That’s because such storages generate heat, which, if uncontrolled, could reach catastrophic levels.

Communication System

Various battery energy-storage system (BESS) components, such as the inverter, BMS, or EMS, must communicate to exchange critical information.

The entire BESS might also need to communicate with external systems and equipment like meters and the central control system.

In addition to ensuring the smooth operation of the installation, the communication system allows you to control the entire system or parts and execute various functions such as start/stop, schedule tasks, and carry out diagnostics.

Various components facilitate this information exchange. They include various circuits, monitoring and control software and algorithms, and wireless equipment.

Conclusion

These battery energy-storage components ensure everything operates safely, optimally, and within pre-set levels. More importantly, they protect your storage system, extending its lifespan. As we’ve seen, the components include application-specific algorithms, electronic circuits, and electrical or electronic equipment.