xStorage Large

The built-in peak shaving function of the xStorage Large only supports static peak shaving limits. A higher-level controller, such as Eaton’s Energy Management Software, could be used to determine the proper peak shaving setpoints based on battery state of charge and send these setpoints to the BESS through the communication interface.

There is an internal UPS in the control cabinet to provide backup to the communication and monitoring functions if utility power is lost. The available power is limited by the length of the outage and the level of charge in the battery.

The xStorage Large logs all faults, warnings and events of the system locally and displays immediate alarms and current operational events in the customer’s remote monitoring web interface. The local storage has a running 6 GB capacity.

A 400V-480V double-shielded isolation transformer with Wye (primary) – Delta (secondary) is recommended (available from Eaton; ask your Eaton sales representative for more information). The transformer is required to meet IEEE 1547.4 standards for maintaining the grounding scheme on an island system, preventing or limiting conducted emissions and reducing noise transmission for DC ground fault detection.

The xStorage Large has the following seismic analysis validation:

• Power conversion system (PCS) is rated to ICC-ES AC 156 Sds @ 1.35 G
• Battery cabinet is rated to IEEE 693-2018
• Control cabinet is tested to AC 156 Sds @ 2.0 G

In the very unlikely event of thermal runaway, smoke or fire, the system will operate as follows:

• The control cabinet has an integral fire control panel. Upon signal transmission, a fire suppression agent (Novec 1230 Fire Protection Fluid) is released to reduce damage to the battery cabinets.
• Upon receiving a critical alarm signal from the batteries (smoke/fire detection), the system will immediately send a notice to the customer through the remote monitoring web interface.

The inverter and battery racks independently monitor and self-protect in the event of a critical fault or warning. The stored energy controller adds a layer of monitoring and protection that will shut down the BESS upon loss of signal, fault or critical battery failures (smoke/fire detection). The system inherently cannot operate without a “heartbeat” signal from the components; therefore, loss of communication will shut down the system and all services that were running. (It will not cause blind energy services.) The system has local disconnect methods as well, including a functional emergency stop (E-stop) push button on the front door of the inverter that opens the internal AC and DC contactors, preventing high voltage from flowing between the grid and batteries.

The xStorage Large has a design life of 10+ years. A 95% to 5% depth of discharge at one cycle daily should result in 10+ years of life. Multiple partial discharges per day, extreme ambient temperatures and lower than 5% depth of discharge will affect battery degradation.