Conext SW4048 4,000W 48V Installation

Grid-interactive and Other Features
975-0638-01-03 1–9
Enhanced AC Support
Enhanced AC Support (EnhancedACSup) works when power systems are DC
coupled with a Xanbus-enabled MPPT Solar Charge Controller. This means that
DC power from a renewable source such as an MPPT Solar Charge Controller is
used to charge the battery bank while simultaneously utilizing its power (by way
of inverting) to power loads. Entry and exit to enhanced AC support are
controlled by the MPPT charger so that they can control the state-of-charge of
the batteries. AC power from the grid is utilized only when load demand exceeds
power available from the MPPT charger for charging and supplying the loads.
When enhanced AC support mode is enabled, the Conext SW automatically
tracks the MPPT solar charge controller’s charging voltage as it transitions from
bulk to absorption to float. By tracking the voltage, the Conext SW is then able to
execute and finish the charging cycle using DC power from the solar charge
controller while converting its excess DC power to AC power to support the grid
by supplying more current. Conext SW only uses excess DC power not required
by the battery to support the grid thus, it prioritizes charging the battery before
supporting the loads. Battery health is improved because the system always
executes a three stage charging of the battery that ensures battery SOC is as
close as possible to 100% at all times. Systems that use a fixed voltage for AC
support (or similar) start to support loads sooner and may not fully charge the
battery bank, leaving the battery in a partial SOC. Prolonged periods of partial
SOC can degrade battery performance. Enhanced AC support limits this
degrading effect.
Figure 1-3 AC Support Mode using SOC
Battery
Monitor
Conext SW
Battery
Bank
SCP
AC Loads
AC OUTAC IN
DC
Grid
NOTE: Entry and exit into AC Support
Mode is determined by the SOC. In this
case, AC support mode is engaged.
15 A< 2 A*
> 13 A
SOC Entry = 80%
actual SOC = 75%
SOC Exit = 50%
* To prevent injecting current into the grid from the inverter, there is less than 2 amps of offset allowed
from the grid to flow into AC IN under all conditions.
Figure 1-4 Enhanced AC Support
MPPT Solar
Charge
Controller
Conext SW
Battery
Bank
SCP
AC Loads
AC OUTAC IN
DC
Grid
Solar Array
NOTE: Entry and exit into
Enhanced AC Support is
determined by the MPPT.
15 A< 2 A*
> 13 A
* To prevent injecting current into the grid from the inverter, there is less than 2 amps of offset allowed
from the grid to flow into AC IN under all conditions.