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5.3.4.5. G5 BMS Firmware Features
The following section details the software features of the G5 High-Voltage BMS
Continuous Balancing
G5 High-Voltage BMS introduces a new passive balancing operation which will increase the
operational time of a battery stack and minimize the time spent balancing cells. Traditional voltage
based balancing requires that the cells maintain a difference in voltages to identify the cells requiring
balancing. This voltage difference must be maintained to allow balancing to act on the cells of the
highest voltages. Such an operation can cause the battery stack to be offline for hours to allow the
cell balancing to complete.
Continuous balancing is a new algorithm that minimizes this operational downtime by the following
procedure:
1. A Nuvation Energy BMS continuously provide estimates on the imbalance in cells of a stack. The
best results of imbalance estimations are often at the top of a charge cycle of a battery stack but
can vary by the battery chemistry.
2. After the imbalance estimates have been captured, the software will begin to apply passive
balancing to the cells with the highest imbalance. A stack can resume its operation while this
balancing occurs.
3. BMS software provide status on the amount of imbalance remaining for the cells. After the
imbalance has been removed, it is suggested that the stack could repeat its charge cycle to
capture the next cell imbalance estimates.
4. This process is repeated while until the imbalance estimates are small and no longer trigger any
balancing actions.
Cell imbalance estimations are periodically persisted and will recover after a reboot
of the G5 Stack Switchgear
Cell balance estimations will be using confidence intervals and are only updated
when there is a high confidence in the imbalance estimation. The best confidence
estimates for imbalance are at the top of the charge cycle in the final few SoC
percentages before a stack is full. It is highly suggested that the stack is controlled
using a properly configured BMS current limits to approach the full state of a stack.
Cell Imbalance Estimations Configuration
Cell imbalance estimation is configured using the following registers:
Register
stack_soc_distribution_estimato
r[0]. enabled
stack_soc_distribution_estimato
r[0]. measurement_error
Document ID: NE-DS-011
Nuvation Energy G5 High-Voltage BMS - NUVG5 Product Manual
Table 19. Cell Imbalance Estimation Configuration
Suggested Value
1
3
Description
Enables the estimation of SoC distribution used
in the new balancing algorithm.
Standard deviation of the noise in the voltage
measurements.
73
Rev 1.0, 2023-05-19
G5 Faraday
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