Watchdogs And Freshness; Freshness - Nuvation Energy NUV300-BC-12 Product Manual

The effect of the temperature gradient can be attenuated by grouping thermistors orthogonal to the
gradient. During operation, the temperature measurements within this group increase and decrease
and therefore, when a failure occurs, the problematic thermistor will begin to deviate from the rest of
the group.
A second factor that can be considered to minimize the temperature deviation within cell grouping is
battery State-of-Health. It is advantageous to group cells with similar State-of-Health values together
since they would have similar thermal responses to current activity.

7.11. Watchdogs and Freshness

Watchdog timers are employed in Nuvation Energy BMS to ensure specific functions execute
regularly. If a watchdog timer is not periodically reset, the timer will expire and an associated fault
will trip and disconnect the contactors. The watchdog timers are exposed by the BMS through
multiple watchdog components.
wdt.expired
▪
1 indicates that the timer has not been reset within the configured time and is considered
expired
▪
0 indicates the timer has not expired.
wdt.period
▪
The time period within which the timer needs to be reset before it expires
The watchdogs configurations are described below.
Table 28. Nuvation Energy BMS Watchdog Components
Watchdog Component
sc_ram_test_wdt
sc_rom_test_wdt

7.11.1. Freshness

Freshness is a mechanism in Nuvation Energy BMS to guarantee data within the system is up to date.
Measurements such as cell voltage, cell temperatures, and stack voltage are captured and
aggregated on different subsystem. Points of failures in different subsystems can result in data
reported by the BMS to be stale. Regardless of how and where data stops being propagated,
freshness provides a mechanism for the system to detect these failures and perform the necessary
procedures to keep the system safe.
The freshness mechanism is exposed by the BMS through multiple freshness component.
fresh.stale
▪
1 indicates that the associated data has not been updated within the configured time and is
considered stale
Document ID: NE-PM-002
Nuvation Energy Low-Voltage BMS - Product Manual
Notes
Configures the watchdog timer for the RAM testing. Typically period is
60000000 (60 s).
Configures the watchdog timer for the ROM testing. Typically period is
60000000 (60 s).
136 Rev 1.2, 2021-03-03
Curie Update 1