BMS for industrial Battery Storage Systems

The Stercom Battery Management (BMS) consists of the “Dynamic Cell Balancing” (DCB) boards integrated in the battery module and the higher-level String Management Units (SMU). With large battery stacks, each SMU evaluates up to 32 DCB series or parallel modules, organizes the optimal balancing strategy, controls and monitors the protective components such as fuses, DC isolators, pre-charging or insulation monitoring and communicates with the higher-level energy or charging management.

The DCB recognizes any asymmetries and deviations of Cells, that occur at an early stage and also counteracts them immediately, even during the peak load phase. This ensures that each individual cell is always operated in the optimal and safe area, much faster and more efficiently than any other method.

In large systems, up to 30 such SMUs are connected in a master-slave arrangement to form a battery cluster, with one SMU taking on the master function and being responsible for controlling and monitoring the entire battery cluster.

The extremely precise voltage and temperature measurement of the individual cells by the DCB as well as the highly accurate current / charge measurement in the SMU are the basis for a reliable SoC and SoH determination in the stack. Stercom's battery models allow a precise determination of the aging condition for many Li-cell technologies such as LFP, NMC or LTO cells, but also for SuperCaps. With the differential measurement method, even deviations in the SoH of individual cells in the stack can be detected quickly and reliably.

This enables a careful and adapted charging strategy and the operation of each individual cell in the optimal range.

String Management Unit SMU

  • Communication with the DCBs of the modules via an isolated CellCOM interface
  • Supply via 24V input or from the battery voltage via high-voltage AuxPower Supply
  • Redundant current measurement for precise determination of the string current
  • Safe separation of the string via a two-pole DC isolator
  • Additional DC string fuses
  • Pre-charging circuit to the DC intermediate circuit
  • Integrated isolation detection Up to 32 DCB12 or 384 serial cells per string
  • Suitable for operating voltages up to 1500V
  • Communication to energy or charging management via CAN, ModBus TCP / IP or Ethernet
  • Up to 30 parallel strings in the cluster
  • Automatic configuration and string management with Auto-CatchUp method for parallel connection
  • Functional safety according to DIN 61508 and ISO 26262

Cell monitoring and cell protection with DCB

  • Dynamic Cell Balancing
  • Active cells balancing Typically 5-12 cells per DCB
  • Suitable for all cell technologies from 0 to 5V cell voltage
  • Supply from the module, extremely low internal consumption
  • Isolated communication via CellCOM daisy chain to the SMU
  • Up to 32 DCBs in one string
  • Precise temperature measurement with 4 temperature sensors per DCB
  • Functional safety according to DIN 61508 and ISO 26262