Parameter
structure
Keypad and
display
Parameter
x.00
Parameter
description format
Advanced parameter
descriptions
Macros
Serial comms
protocol
Electronic
nameplate
Performance RFC mode
Menu 5
Unidrive SP Advanced User Guide
129
Issue Number: 10 www.controltechniques.com
The level of slip compensation is set by the rated frequency and rated speed parameters. Slip compensation is only enabled when this parameter is
set to 1 and Pr
5.08
is set to a value other than zero or synchronous speed.
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
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. It should be noted that although field weakening is possible
in servo mode, gain compensation is not applied in this mode.
The rated level of flux in most induction motors causes saturation. Therefore the flux against flux producing current characteristic is non-linear. The
effects of saturation are to cause a step increase in torque when operating in torque mode as the speed increases into the field weakening region.
5.27
Enable slip compensation
Drive modes
Open-loop
Coding
Bit
SP
FI
DE Txt VM DP
ND
RA NC NV
PT
US RW BU
PS
1
1
1
1
Default
Open-loop
1
Update rate
Background read
5.28
Field weakening compensation disable
Drive modes
Closed-loop vector
Coding
Bit
SP
FI
DE Txt VM DP ND RA NC NV
PT
US RW BU
PS
1
1
1
Default
Closed-loop vector
0
Update rate
Background read
5.29
Motor saturation breakpoint 1
Drive modes
Closed-loop vector
Coding
Bit
SP
FI
DE Txt VM DP
ND
RA NC NV
PT
US RW BU
PS
1
1
1
Range
Closed-loop vector
0 to 100 % of rated flux
Default
Closed-loop vector
50
Second motor
parameter
Closed-loop vector
Pr
21.25
Update rate
Background read
5.30
Motor saturation breakpoint 2
Drive modes
Closed-loop vector
Coding
Bit
SP
FI
DE Txt VM DP
ND
RA NC NV
PT
US RW BU
PS
1
1
1
Range
Closed-loop vector
0 to 100 % of rated flux
Default
Closed-loop vector
75
Second motor
parameter
Closed-loop vector
Pr
21.26
Update rate
Background read
Summary of Contents for unidrive sp
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