With AC connected, MPPT will reach the maximum
motor speed. Power is shared between AC grid and
PV modules, according to their actual capacity.
In this condition, DC voltage stays naturally close to
rectified AC voltage (V3.24.1.1).
DC voltage will increase in case the modules can
sustain the needed full power.
When switching Off condition is reached (high
irradiation), motor speed is decreased until DC
voltage increases above (V3.24.1.1 + P3.24.1.4).
That is the working point aligned with present power
available from PV module. Relay is switched Off
afterwards.
It is possible to activate Identification of minimum
irradiation threshold. It means that the value of
parameter is internally adjusted, so that the AC
switching On condition always happens when the
motor is close to a programmable speed. This
compensates the changeable ratio between
irradiation and power, that is function of temperature.
P3.24.3.1 Irradiation Signal
Selection between AI1 and AI2.
P3.24.3.2 Max Irradiation
Value of irradiation at maximum signal.
P3.24.3.3 AC On Irradiation
Threshold for irradiation, below which AC relay is
switched On.
P3.24.3.4 AC Off Irradiation Offset
Value added to P3.24.3.3 to determine the threshold
for switching AC Off.
P3.24.3.5 Irradiation Stabilization Time
Irradiation has to stay below/above thresholds for this
time, to activate switching On/Off.
P3.24.3.6 Identification
P3.24.3.7 Identification Frequency
When active, identification adjust the value of
P3.24.3.3, to align the conditions of low irradiation
and desired minimum power from the PV modules
(defined as minimum frequency, set in P3.24.3.7).
If irradiation goes below P3.24.3.3, but present motor
frequency is higher than P3.24.3.7, than the value in
P3.24.3.3 is reduced. This will avoid switching to AC,
when the power from PV modules is still enough.
On the other hand, if irradiation is still higher than
P3.24.3.3, but MPPT regulation decreases the
frequency below P2.24.3.7, present irradiation value
is used to update P3.24.3.3. This will activate the AC
switching On.
Mode 2 Sensorless
In mode 2, relay for AC supply is activated when the
pump is running below a certain speed.
AC relay is switched On also in case of Low Power
alarm at start or Under voltage fault. And in case DC
voltage was already below the threshold (M3.24.1.1 +
P3.24.1.4) when external Start command is given.
With AC connected, MPPT will reach the maximum
motor speed. Power is shared between AC grid and
PV modules, according to their actual capacity.
In this condition, DC voltage stays naturally close to
rectified AC voltage (V3.24.1.1).
DC voltage will increase in case the modules can
sustain the needed full power.
If the threshold (V3.24.1.1 + P3.24.1.4) is reached,
AC is switched Off.
Besides this, when AC switch is On, the drive
periodically decreases the motor speed to a
programmable level, to check if PV modules can
sustain at least that reduced power. If DC voltage has
increased above the threshold, AC is switched Off.
Otherwise MPPT will go back to max speed. This DC
voltage check can be disabled by digital input (RTC
channel possibility).
P3.24.4.1 AC On Frequency
AC relay is switched On if motor frequency stays
below threshold, for delay time.
P3.24.4.2 AC On Delay
AC relay is switched On if motor frequency stays
below threshold, for delay time.
P3.24.4.3 DC Check Reference
Frequency reference at which DC voltage is checked,
for possible switching Off. Higher values mean to use
PV modules alone only if they have a good power
availability.
P3.24.4.4 DC Check Period
Time for periodic DC voltage check, at reduced
frequency. It can be disabled by means of digital input
set in P3.5.1.60. This can be connected to RTC
channels, for time of the day related actions.
P3.24.4.5 DC Check Stabilization Time
DC voltage must stay above the threshold for this
time (both at maximum and reduced speed), to
activate AC switching Off.
166
English (GB)
To Next Page
Loading...
