NOVAR 2600 Operating Manual
The choke control limit power factor parameter setting is irrelevant for this control mode, therefore it is
not displayed.
The non-mixed mode cannot be set together with the 3p+1p control strategy.
4.3.1.9 Choke Control Limit Power Factor (for Mixed Choke
Control)
In mixed choke control mode, this parameter specifies power factor value at which the controller starts
using, besides capacitive sections, inductive compensation sections for compensation as well –
chokes (if available).
If the power factor measured is more inductive (current more lagging) than the value specified in this
parameter, the controller uses only capacitive sections (capacitors) to control compensation.
If the power factor in the power system changes so that it is more capacitive (current more leading)
than the choke control limit value, the controller starts using combination of capacitive and inductive
compensation sections for compensation.
Exception: This rule does not apply when offset control (see below) is activated ! In this case,
the value of measured power factor is not essential and the controller uses both capacitive
and inductive sections, regardless of its value. This is true even if the offset power value is
set to zero.
4.3.1.10 Offset Control
In some cases it may be necessary to control "shifted" by a certain value of reactive power. A typical
example is an installation of a power transformer compensating capacitor permanently connected to
the transformer before the controller CT, or an installation of long power cable with not-negligible
parasitic capacity. In such cases, so called
offset control
can be used.
As default, the parameter is off (
). In this setting, the offset control is disabled and the controller
maintains the preset target power factor value.
If you set it to
, the offset control is activated with following consequences:
•
OFFSET
message appears in the info folder of the data & status panel which indicates that
the offset control is active
•
offset power for tariff 1
(and , optionally,
for tariff2
too) parameters appear and can be set in
the PFC control setup group of parameters
•
after the power factor control deviation ( i.e. reactive power difference to achieve target power
factor) is evaluated, the controller adds to it appropriate preset offset power value.
Therefore, it controls to this “shifted” reactive power.
Example
:
A compensation capacitor with a nominal value of 5 kvars is permanently connected to a power
transformer, which is before the controller CT. It is required to control the target power factor of 1.00,
which is to be registered by an electricity meter, measuring whole transformer load. Then the
controller must then set as follows:
•
set target power factor to 1.00
•
turn the offset control on (
)
•
set the offset power to 5 kvars
30
Содержание NOVAR 2600
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Страница 88: ...NOVAR 2600 Operating Manual NOVAR 2600 4 RS485 Remote Communication Connection 88...
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