Siemens MJ-5, Инструкция по установке и эксплуатации

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6
MJ-5 Control Panel Automatic Mode
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6.2 Overview of Automatic Control
Algorithm
The automatic control algorithm maintains the output
voltage within its prescribed limits while following a
control hierarchy.
Normal algorithm operation is as follows. When voltage
falls outside the allowed range (defined by voltage level set
point ± ½ bandwidth), the delay timer is started. If voltage
is out of range at the end of the delay period, the tap change
motor is energized. When the voltage is back within range,
the tap change motor is deactivated. Hysteresis is included
to prevent oscillations.
In automatic mode, the control program processor controls
the tap changer motor. The control algorithm takes the
following into account:
1.
Calculated or monitored regulator output voltage
2. Voltage-level set point
3. Bandwidth set point
4. Resistance line drop compensation set point
5. Reactance line drop compensation set point
6. Voltage limit control set points
7. Voltage reduction control set points
8. Monitored load current
9. Load power factor
10. Power flow operating mode
11. Power flow direction.
Because coinciding events might introduce conflicts, an
operational hierarchy must be established. This hierarchy
is maintained when the unit is under automatic control.
Manual mode always takes precedence over automatic
control.
Conflicts are resolved according to the following priority
scheme (from highest to lowest):
1.
Automatic tap change inhibit (implemented Comm
Link command).
2. Current inhibit (determined by I % Threshold of
configuration setting; as % of full scale CT rating).
3. Current Bias setting and Bias Percent (see Section
6.5.3)
4. Voltage Limit Control (defined in regulator settings).
5. Voltage Reduction Control.
6.
“Normal” regulator control operation.