Here is the technical English translation:
Decoding the Technical Vocabulary of Energy Storage
In a BESS, whether using LiFePO4, NMC, NCA, LCO, or LTO cells, the PCS operates in VSG mode under EMS command, while the BMS monitors SOC, DoD, and SOH to enable charge/discharge cycles and enforce power limits. In Grid-Forming (GFform) mode, the PCS maintains VSG and the EMS adjusts SOC/DoD targeting RTE; in Grid-Following (GFollo) mode, the PCS synchronizes with the existing grid and the BMS updates SOH based on charge/discharge cycles. In a BESS, active power (P) is defined by the EMS setpoint and applied by the PCS within BMS constraints (SOC, DoD, SOH), while reactive power (Q) is defined by the PCS voltage/power factor control for grid voltage support. Frequency (f) is impacted by active power variation (ΔP) and, in modes such as VSG/GFform, the PCS can contribute to frequency support via droop and VSG control, adjusting P in response to frequency deviation (Δf).
Glossary of Acronyms and Technical Terms
- BESS — Battery Energy Storage System; a battery-based energy storage system integrated with the grid and/or load.
- LiFePO4 — Lithium Iron Phosphate
- NMC — Lithium Nickel Manganese Cobalt Oxide
- NCA — Lithium Nickel Cobalt Aluminum Oxide
- LCO — Lithium Cobalt Oxide
- LTO — Lithium Titanate Oxide
- PCS — Power Conversion System; a bidirectional converter that controls power, voltage, and current between the battery and the grid.
- VSG — Virtual Synchronous Generator; a control strategy that emulates the dynamic behavior of a synchronous generator (droop/virtual inertia).
- EMS — Energy Management System; optimizes system operation and defines setpoints (e.g., P) according to operational strategy and system constraints.
- BMS — Battery Management System; monitors and protects the battery pack, calculates SOC/SOH, and enforces operational limits.
- SOC — State of Charge; instantaneous charge level (%) and available energy at a given moment.
- DoD — Depth of Discharge; discharge depth associated with a given cycle and operational window.
- SOH — State of Health; aging condition of the battery (in terms of capacity, power, and impedance) relative to its initial rated condition.
- GFform — Grid-Forming; operating mode in which the converter establishes the voltage and frequency reference for the grid or microgrid.
- GFollo — Grid-Following; operating mode in which the converter synchronizes with an existing grid and injects current/power accordingly.
- RTE — Round-Trip Efficiency; the efficiency of a complete charge/discharge cycle (energy delivered / energy absorbed).
- P — Active power (W / kW / MW); the component that performs real work/energy transfer and influences the system frequency balance.
- Q — Reactive power (var / kvar / Mvar); the component associated with voltage control and reactive power flow.
- f — Electrical frequency (Hz); a system stability variable and the target of ancillary frequency services.
- ΔP — Active power variation; used to describe transient response and frequency control dynamics.
- ΔQ — Reactive power variation; used to describe voltage support and control response.
- Δf — Frequency deviation; the typical control signal for droop response and frequency support services.
- V — Voltage (V); the PCS control variable for voltage support and reactive power flow regulation.
- I — Current (A); the quantity controlled by the PCS for active and reactive power injection/absorption, subject to thermal limits.
Flavio Marqueti – Engenheiro e Diretor da EVENERGY