Bardac PLX - Pin 1 0 3; Pin 1 0 4; Pin 1 0 5; Pin 1 0 6

CHA NGE PARA METERS 111
6.9.6.5 FLD WE A KENING MENU / Field w eakening feedback derivative time constant PIN 10 7
This affects the armature voltage overshoot when accelerating rapidly through base speed. An increasing
ratio of 107)FLD W K FB DRV ms parameter to 108)FLD WK FB INT ms parameter (D/I) tends to reduce
overshoots. A ratio of unity has no affect and a ratio of 3 or more tends to instability.
The absolute values of the 2 parameters have only a 2
nd
order effect on the response.
6.9.6.6 FLD WEA KENING MENU / Field w eakening feedback integral time constant PIN 108
This affects the armature voltage overshoot when accelerating rapidly through base speed. An increasing
ratio of 107)FLD W K FB DRV ms parameter to 108)FLD WK FB INT ms parameter (D/I) tends to reduce
overshoots. A ratio of unity has no affect and a ratio of 3 or more tends to instability.
The absolute values of the 2 parameters have only a 2
nd
order effect on the response.
6.9.6.7 FLD WEAKENING MENU / Spillover armature voltage % PIN 109
Note. The rated armature voltage is set in the C ALIBRA TION menu.
6.9.6.8 FLD WEAKENIN G MENU / Minimum field current % PIN 110
Note. When setting the minimum % allo w an extra 5% margin below the desired minimum to accommodate
a response transient. If the minimum is belo w 10 % there may be a field failure alarm caused by undershoot.
WARNING. The feedback loss protection afforded in field weakening mode is limited to total feedback loss
only. This is because the speed / AVF relationship is not maintained in field weakening mode. If a partial loss
of feedback occurs the motor may run to excessive speed. When the field has been completely weakened
and is at its minimum leve l, the armature overvoltage trip will come into operation. This may only occur at a
dangerous speed. It is therefore recommended that a mechanical device and or back up system be utilised to
protect against this possibility. Correct setting of 110)MIN FIELD CURRENT will ensure that the overvolts
TRIP occurs just above the maximum operating speed.
FLD WE A KENING MENU 4
107)FLD WK FB DRV ms
107)FLD WK FB DRV ms
100
PARA METER RANGE DEF AULT PIN
FLD WK FB DRV ms 10 to 500 0 ms 100 107
Sets the feedback derivative
time constant in milliseconds.
FLD WE A KENING MENU 4
108)FLD WK FBK INT ms
108)FLD WK FBK INT ms
100
PARA METER RANGE DEF AULT PIN
FLD WK FBK IN T ms 10 to 5000 ms 100 108
Sets the feedback integral time
constant in milliseconds.
FLD WE A KENING MENU 4
109)SPILLOVER A V F %
109)SPILLOVER A V F %
100.00 %
PARA METER RANGE DEFAULT PIN
SPILLOVER A VF % 0 to 100 % of rated A V 100.00 % 109
Sets armature voltage % at
which field w eakening begins.
FLD WE A KENING MENU 4
110)MIN FLD CURRENT
110)MIN FLD CURRENT
10.00%
PARA METER RANGE DEFAULT PIN
MIN FLD C URRENT 0 to 100% of rated IF 10.00% 110
Sets the minimum field current
as a % of the rated field amps.