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Littelfuse circuit protection products for BESS


A Battery Energy Storage System or BESS is a large-scale battery system connected to the electrical gridfor both power and energy storage. lts components include:

Littelfuse circuit protection products for BESS

Architecture of battery energy storage system

A Battery Energy Storage System or BESS is a large-scale battery system connected to the electrical gridfor both power and energy storage. lts components include:

■ Individual battery cells, that are contained in a battery system, convert chemical energy intoelectrical energy

■ Battery modules are made up of cells arranged in series and parallel combinations. The batterymodule also contains the module battery management system (MBMS) that monitors and controlsthe operations of these cells

■ The rack holds a number of modules connected in series and the battery protection unit (BPU)-also known as the battery rack controller.

*The battery protection unit includes the rack battery management system (BMS) and monitorsthe voltage, temperature and the state of the charge of the battery. lt also regulates thecharging and discharging cycles of the battery

■ The container can hold several racks in parallel and may have additional components that help tomanage or control the environment within the container

■ The power conversion system (PCS) or bi-directional inverter converts direct current (dc)produced by the batteries into alternating current (ac) supplied to the grid (facilities or end users)lt also charges the batteries by pulling power from the grid when needed

A BESS may also contain some safety systems such as a fire control system, a smoke detector, and atemperature control system or even cooling, heating, ventilation, and air conditioning systems. What isincluded will depend on what is needed to maintain a safe and efficient BESS operation.





There are two general ways the components of an energy storage system are wired together--eitheby altemating current (ac) coupling or direct current (dc) coupling. The difference lies in the path theelectricity takes once it is produced. Although solar panels generate dc electricity and solar batteriesstore electricity in dc, end-users need ac electricity. Thus, a conversion must happen and there aredifferent paths to get there. See below for the pros and cons of each system.



■ Includes two inverters

□ Solar inverter

□ Bi-directional inverter with battery

■ Offers higher flexibility

■ Easier installation, especially for retrofits

■ Can retain grid-tied inverter to save costs

■ The system is less efficient since the energy used by the batteries isinverted multiple times

■ ldeal for retrofits

□ This method is more cost effective if there is an existing PV system



■ Utilizes a single inverter to power loads which saves money

■ Fewer components reduce costs and maintenance

■ Has higher efficiency since the power is not inverted multiple times

■ Shorter cables between BESS and PV help reduce losses

■ Not ideal for retrofits

□ Need to replace existing inverter

□ In many cases PV array wiring needs to be reconfigured

□ Complex installation with an existing PV system





High speed square fuse

The customer needs of energy storage systems for higher DC voltage, current and breaking capacity fuses to protect batteries and DC circuits, Lite PSX and PSR series square fuses can provide higher response speed, higher DC voltage and breaking capacity to prevent costly catastrophic failures due to overcurrent, while the small case size facilitates the design of more compact high power density systems. PSX series up to 1500Vdc, breaking capacity 2500KAdc, PSR series up to 1000Vdc breaking capacity 150 kA dc.

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Arc protection

Arc protection relays quickly detect an arcing flash that is forming by sending a trip signal to the circuit breaker, reducing arc extinguishing time and possible damage. They enable a fast response by providing the output of a circuit breaker that directly activates the electrical system, which directly cuts off the current that generates the arc. The installation of arc relays can greatly reduce the arc extinguishing time and the energy released by the arc, effectively preventing equipment damage and personnel injury.


CNN 48V DC fuse

CNN fuses are designed for heavy loads associated with DC battery-powered devices such as battery systems. Its compact size saves space and provides design flexibility. The CNN fuse has an observation window on the product body, which can intuitively display the status of the fuse, which greatly increases the convenience.


Energy storage cabinet protects fuses

The ESR series of energy storage cabinet protection fuses is designed to protect battery cabinets in energy storage systems, inverters and other DC applications. This 1500 V DC high-speed square fuse is available up to the aBat level, has extremely fast fuse breaking action in some ranges, excellent short-circuit protection and low minimum breaking capability (MBC), covering a range of overcurrent protection requirements that traditional high-speed fuses cannot protect.


Ground fault protection

The presence of various factors in a battery energy storage system can lead to ground faults, and even some unidentified low leakage current ground faults can cause serious damage. Battery energy storage systems are typically non-grounded systems that may continue to operate after the first ground fault, resulting in voltages above ground on the trouble-free bus but no current flowing. However, from the perspective of equipment protection and worker safety, any ground failure can have disastrous consequences. Therefore, battery energy storage systems that are not grounded or even grounded need ground fault detection and protection to maintain the safe operation of the system.


SMD small fuse

LIT 501A series automotive grade fuses are specially designed to protect battery cell monitoring in battery energy storage systems.


Surge protection devices

Surge protection devices (SPDs) can provide microsecond surge protection for battery energy storage systems. SPDs devices can limit overvoltage events on equipment by responding quickly, greatly reducing costly unplanned downtime due to surges.


TLS compact fuse

LIT TLS series fuses can operate at voltages up to 170 V dc, providing current-limiting short-circuit protection for cables and components in DC distribution circuits, such as modules in battery energy storage systems. The compact design and multiple mounting options of the TLS series make it extremely convenient for a wide range of applications.


UL listed fast fuses

The rated current of Lite's small size Class T fuse can be as high as 30A, and the volume is less than 1/3 of Class R. According to NEC standards, Class T fuses provide fast overload and short-circuit protection for non-inductive circuits and equipment.


Sample Request


Samples are available, please feel free to tontaact local sales or send email to sales@szapl.com or call +86-4008-860-626.



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