Terminology
This section lists the terms and abbreviations used in this manual, but it's also a general glossary of XOLTA terms.
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Alternating current
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An air-cooling unit in the battery energy storage system used to absorb and transfer heat inside the battery unit.
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Short for "Application Programming Interface". A set of commands and protocols that enables different software applications to interact and exchange data by defining how requests and responses should be structured.
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A unit containing switches and fuses for battery protection .
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Battery energy storage system
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A system operation mode in which the battery energy storage system independently generates power without external grid support, allowing it to restart other power generation sources and restore grid operations following a blackout. See also “grid forming mode”.
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Battery management system
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Beginning of life
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Battery protection unit
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Short for "Commercial and Industrial" and refers to the larger XOLTA battery systems BAT-79, BAT-80, and BAT-80 AC. It can be a single battery rack or a multirack installation.
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A corrosion category based on ISO 12944, indicating a moderate level of environmental corrosion risk. It applies to urban and industrial areas with moderate sulfur dioxide pollution or coastal areas with low salinity.
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Controller area network
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Cell monitoring unit of n-BMS
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Serial communication protocol developed by Bosch.
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A coupling contactor is a switching device used to connect or disconnect a power source to the main electrical grid. In grid protection systems, it enables safe synchronization and isolation during faults or maintenance.
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Direct current
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To disconnect or isolate the battery energy storage system from any power source to prevent the flow of current. A de-energized battery might still be partially or fully charged.
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Depth of discharge
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Short for "distribution system operator", also known as "electricity distribution company". This is the company responsible for operating, maintaining, and developing the electrical distribution network, ensuring a reliable supply of electricity to end-users, and facilitating the integration of renewable energy sources and other distributed energy resources.
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Energy storage system
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Energy management system
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End of life
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Short for "Frequency Containment Reserve". FCR is a primary frequency response service that stabilizes grid frequency deviations by automatically balancing generation and consumption within seconds after a disturbance. It is the first line of defense to maintain grid frequency near its nominal value.
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Short for "Frequency Containment Reserve for Disturbances". FCR-D is activated during larger, more significant frequency disturbances that fall outside the range of normal operations. It provides a stronger, more targeted response to prevent the grid frequency from falling below critical thresholds.
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Short for "Frequency Containment Reserve - Normal". FCR-N is a subtype of FCR designed to handle smaller frequency deviations during normal grid operation. It ensures continuous frequency stabilization within a defined tolerance band.
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Short for "Fast Frequency Response". FFR provides rapid active power support to counteract significant frequency drops, acting faster than traditional FCR. It is often used to address high-inertia grids or during large, sudden power imbalances.
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A set of technical regulations that power generation systems must comply with to connect to the grid. It defines operational limits for voltage, frequency, and disconnection criteria to ensure grid stability and reliability.
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An operational mode where a battery energy storage system actively controls voltage and frequency, creating a stable grid environment and maintaining power balance, even in the absence of external grid input or under weak grid conditions. See also “black start mode”.
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A grid protection relay monitors the public grid for anomalies and ensures compliance with grid codes by automatically disconnecting and reconnecting the battery system when necessary. Synonyms: "NA Schutz" and "NS protection relay".
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Graphical user interface
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Insulated gate bipolar transistor
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The inverter power rating indicates the maximum amount of power the inverter can deliver to the load or grid under specified conditions. It is measured in kilovolt-amperes (kVA) and determines the system’s capacity to convert and supply electrical energy.
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Ingress protection code according to International Electrochemical Commission
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Short for "low voltage ride through". LVRT is the ability of an electrical device - typically a wind turbine or solar inverter - to stay connected to the grid during short periods of low voltage, such as those caused by faults or disturbances. The purpose is to support the grid by remaining online and helping restore normal conditions.
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A crucial component in photovoltaic systems that optimizes the performance of solar panels by maximizing the power they can deliver under varying conditions. It is typically part of a solar charge controller or inverter.
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Miniature Circuit Breaker
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Main Control Unit of n-BMS
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A digital device that has been physically installed and is awaiting connection to the XOLTA server, measuring and recording real-time electricity consumption, generation, and grid interaction for efficient energy management in a battery storage system. Synonym: smart meter.
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A circuit protection device that protects against overcurrent and short circuits.
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Serial communication protocol developed by Modicon
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Maximum power point tracker
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Battery Management System from Lithium Balance A/S
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Synonym for "grid and system protection" and "NS protection".
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Negative temperature coefficient thermistor
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Short for "over voltage category". The level of transient overvoltage the battery energy storage system can withstand based on its location in the electrical installation. It ranges from OVC I (low exposure, electronic devices) to OVC IV (high exposure, utility connections). Transient protection is achieved through a surge protection device.
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The level of transient overvoltage the battery energy storage system can withstand based on its location in the electrical installation. It ranges from OVC I (low exposure, electronic devices) to OVC IV (high exposure, utility connections). Transient protection is achieved through a surge protection device.
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Short for "Point of Common Coupling". The PCC is the connection point between a generating facility (e.g., a battery system) and the utility grid, where power exchange occurs.
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Power conditioning system
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The process of reducing short-term high power demand (peak loads) by using energy storage or alternative power sources to lower electricity costs and relieve grid stress.
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A technology that converts sunlight directly into electricity. It's a way of generating energy by using solar panels that capture sunlight and turn it into usable power for homes, businesses, or devices.
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The connection point between a generating facility (e.g., a battery system) and the utility grid, where power exchange occurs.
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Power on reset
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Photovoltaic also know as solar energy
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A type of refrigerant used in air conditioning and refrigeration systems.
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Residual Current Breaker with Overcurrent.
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Residual Current Circuit Breaker.
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Residual current device
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A circuit protection device that combines the functions of RCCB and MCB into a single device.
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A circuit protection device that detects earth faults or residual currents.
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A circuit protection device that detects leakage currents and cuts off the power to prevent electric shocks.
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Short for "Registered Jack 45". A standardized connector used for Ethernet networking, featuring an 8P8C (8 Position, 8 Contact) design. It is commonly found on twisted-pair cables like Cat5e and Cat6, enabling connections between devices such as computers, routers, and switches. RJ45 supports high-speed data transmission and adheres to wiring standards like TIA/EIA-568.
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Short for "Rate of Change of Frequency". In grid monitoring relays, it refers to how quickly the electrical frequency is changing over time. It's used to detect unstable grid conditions - especially during events like load shedding or generator disconnection - and can trigger protective actions if the frequency changes too rapidly.
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Site controller
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State of charge
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Short for "Surge Protection Device". A device designed to protect batteries and other electrical components from voltage spikes or surges, for example, because of lightning strikes. It’s installed between the power supply and the battery it’s protecting. When a surge occurs, the device either diverts the excess voltage to the ground or limits it to a safe level that won’t damage the system.
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A type of surge protection device (SPD) used in electrical power systems to limit voltage surges and divert excess current safely to the ground, preventing damage to equipment during events like lightning strikes or switching surges.
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A device designed to protect batteries and other electrical components from voltage spikes or surges, for example, because of lightning strikes. It’s installed between the power supply and the battery it’s protecting. When a surge occurs, the device either diverts the excess voltage to the ground or limits it to a safe level that won’t damage the system.
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Total cost of ownership
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Transmission control protocol
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A pricing model used by utility companies where electricity rates vary depending on the time of day, day of the week, or season. Under TOU, electricity is typically more expensive during peak demand periods (when usage is high) and cheaper during off-peak times (when demand is lower). This pricing structure encourages consumers to shift their energy use to off-peak periods to lower costs and reduce strain on the electrical grid.
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Thermal management system
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Time of Use
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