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Control of Active Power
Active power can be controlled by the PMC via MODBUS messages at the output of the ACS. The flow of
active power into the battery has a negative sign, the flow of active power out of the battery has a
positive sign.
Table 4-4 Active Power Modbus Addresses
MESSAGE
ACTIVE POWER SET POINT %
The total energy exported by each inverter can be read though a Modbus variable. No variable exists to
measure the imported energy.
Table 4-5 Real Lifetime Energy Exported Addresses
MESSAGE
REAL LIFETIME ENERGY EXPORTED
4.5.1
Active Power Limit
The active power set point can be further curtailed by the PMC via a MODBUS message for the active
power limit. This feature applies to the charging as well as the discharging of the battery, and is used to
limit the charge rate of the inverters, for instance in very cold weather.
Table 4-6 Active Power Modbus Addresses
MESSAGE
INSTANTANEOUS REAL POWER LIMIT
[W]
4.5.2
Volt-Watt configuration
If the Volt-Watt feature is enabled, the inverters will first reduce the amount of active power that they
output, and then actively absorb the power from the grid. This feature overrides the active power set
point and is not meant to run constantly, but rather as an emergency function to reduce the voltage at
the point of interconnection temporarily. The Volt-Watt-delay feature allows customers to coordinate
the voltage response with other voltage regulating assets on the grid. Your local utility can help you with
the correct settings. The following MODBUS messages can be controlled by the PMC:
Yaskawa Solectria Solar
MODBUS ADDRESS DATA TYPE
40985
Float32
MODBUS ADDRESS DATA TYPE
40249
MODBUS
ADDRESS
40295
DOCR-071070
SCALE FACTOR
-
SCALE FACTOR
Acc64
1000
DATA TYPE
SCALE FACTOR
Float32
-
Page 25 of 30
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