Three major design challenges that battery energy storage systems need to overcome

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Three major design challenges that battery energy storage systems need to overcome

Posted Date: 2024-01-15

Solar and wind energy bring renewable energy to the grid, but the imbalance between supply and demand has become a major limiting factor in the utilization of this energy. Although solar energy is plentiful at noon, electricity demand is not high enough at this time, so consumers' electricity costs remain high.

Grid energy storage, home energy storage, and commercial and industrial energy storage systems (ESS) can collect energy from renewable sources such as solar and wind during the day and release the stored energy during peak demand periods or when grid electricity prices are high. By storing energy for use during peak times, energy storage systems can stabilize the grid and reduce energy costs.

Design challenges associated with battery energy storage systems (BESS for short, which is the more common type of energy storage system) include: 1) safe use; 2) accurate monitoring of battery voltage, temperature, and current; and 3) battery to battery and battery Powerful balancing capabilities between packages. These challenges are detailed below.

Challenge 1: Security

The first challenge is maintaining battery safety throughout the entire life cycle of the battery energy storage system, which typically exceeds 10 years. Battery energy storage system applications typically use lithium-ion (Li-ion) batteries, especially lithium iron phosphate (LiFePO4) Battery.

When the voltage, temperature and current exceed the maximum limit, lithium-ion batteries are prone to smoke, fire or explosion, so the monitoring and protection of battery voltage, temperature and current data are crucial. Therefore, the possibility of battery and battery management system failure should be considered and analyzed.

Figure 1 shows the architecture of a battery energy storage system. Texas Instruments Stackable Battery Management Unit for Energy Storage Systems reference design describes a stackable battery management unit (BMU) that monitors system issues by using the BQ79616 integrated redundant battery information detection, while the battery for energy storage systems The control unit reference design demonstrates a battery control unit (BCU) that ensures system safety through a reliable switch driver design.

Figure 1: BESS architecture

Challenge 2: Accurate battery monitoring

Accurate battery data ensures safety and improves battery energy utilization. Considering that lithium iron phosphate (LiFePO4) The charge and discharge curve has a wide plateau area, and even a small battery voltage measurement error will lead to a huge remaining power error. Therefore, accurate battery voltage and battery pack current measurement is very important for accurate power estimation. Accurate power information is the key to avoiding incorrect battery balancing. Over-balanced charging and over-balanced discharging will destroy the maximum available capacity of the battery.

Another important measurement is temperature. Most battery fires and explosions are caused by battery thermal runaway.

Figure 2 shows Texas Instruments’ stackable battery management unit reference design.This design uses the BQ79616 battery monitor, which can be

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