Emerson Mentor MP - Field Weakening Compensation Disable; Motor Saturation Breakpoint 12

Parameter
x.00
Parameter
protocol
Performance
When
the
flux
in
the
motor
is
reduced
below
its
rated
level
the
level
of
torque
producing
current
required
for
a
given
amount
of
shaft
torque
is
higher
See
Pr
5.30
for
description.
When
the
motor
is
operated
in
the
field
weakening
voltage
region,
the
relationship
between
field
current
and
the
level
of
flux
can
be
non-linear.
Menu 5
Parameter
structure
Keypad and
description format
Advanced parameter
descriptions
Serial comms
than the rated level. In speed control the compensation prevents gain reduction at higher speeds. In torque control the compensation maintains the
torque at the correct level for a given torque demand. In some applications using speed control it may be desirable to have a reduction of gain as the
motor flux is reduced to maintain stability. If this is required, Pr 5.28 should be set to one.
The drive can include the effects of saturation by representing the flux producing current to flux characteristic as a series of three lines as shown
below:
flux (%)
100%
Pr 5.30
Pr 5.29
Linear characteristic
(i.e. no saturation)
50 75 100
Field
current (%)
If Pr 5.29 and Pr 5.30 have their default values of 50 and 75, the characteristic becomes one line and there will be a linear relationship between the
drive estimate of flux and the flux producing current. If Pr 5.29 and Pr 5.30 are increased above 50 and 75 the drive estimate of flux can include the
effect of non-linearity. It is unlikely that information will be available to set up these parameters, and so the values are determined during the rotating
autotune test.
78 Mentor MP Advanced User Guide
www.onxcontrol.com Issue Number: 4
5.29
Motor saturation breakpoint 1
Coding
Bit
SP
FI
DE
TE
VM
DP
ND
RA
NC
NV
PT
US
RW
BU
PS
1
1
1
Range
0 to 100 % of rated flux
Default
50
Second motor
parameter
Pr 21.25
Update rate
Background read
5.30
Motor saturation breakpoint 2
Coding
Bit
SP
FI
DE
TE
VM
DP
ND
RA
NC
NV
PT
US
RW
BU
PS
1
1
1
Range
0 to 100 % of rated flux
Default
75
Second motor
parameter
Pr 21.26
Update rate
Background read
5.28
Field weakening compensation disable
Coding
Bit
SP
FI
DE
TE
VM
DP
ND
RA
NC
NV
PT
US
RW
BU
PS
1
1
1
Default
Eur 0, USA 1
Update rate
Background read