PROGRAMMING
GUIDE
SOLARDRIVE
PLUS
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107
regulator. If the drive stops due to sudden changes in solar radiation
(clouds) or hydraulic load (flow rate variations when hydraulic valves
are open), adjust the voltage regulator based on the criteria below:
1) Increase integral gain
P814
and proportional gain
P815
. The
integral gain determines the response time of the voltage
regulator: when it is increased, the pump speed is expected
to change rapidly. The proportional gain acts promptly and
timely on the pump speed reference. As a first attempt,
change
P814
and
P815
without changing their ratio (e.g.
double both
P814
and
P815
).
2) Monitor speed reference of pump
M001
. If too noisy or
oscillatory, decrease gains
P814
and
P815.
The regulator is to be adjusted when the motor speed is adjusted to
values lower than the maximum value set in
C029
with MPPT
enabled
P818
=0. When speed is equal to
C029
, power made
available from the PV field is greater than the power absorbed by the
pump and the regulator is inactive. Otherwise, wait for ambient
conditions to become correct (e.g. weaker solar radiation) or
decrease power made available from the PV field (e.g. cut off some
strings).
P822
see 2.6.11
MPPT Initial Voltage Gain
The optimum value for
P822
is the ratio between MPPT voltage and
open-circuit voltage of the PV field. The value obtained is the lower
limit for
P822
.
Example: from the datasheet of the PV panel:
Open-circuit voltage: 38.58 V
Voltage at maximum power: 30.90 V
Minimum value for
P822
= 30.90/38.58*100 = 80.09%.
If
P822
is set to higher values, the maximum power at start takes
longer time to be attained. The closer the value to the theoretical
value, the quicker the maximum power is attained. If
P822
is set too
low, the motor might stop even when solar radiation is strong and the
system might restart frequently at dawn.
It is therefore recommended that a value approx. 5% higher than the
theoretical value be set (as far as the example is concerned,
P822
= 85%).
8) Reset:
If an alarm trips, find the cause responsible for the alarm and reset the drive. Enable
input MDI3 (terminal 16) for some time, or press the
RESET
key
on the
display/keypad.
