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SPX advanced – description of parameters
SPX ADVANCED APPLICATION MANUAL
SVCH0203—October 2017 www.eaton.com
5.8.3.1 I/f Control
I/f-control can be used to start the motor using a constant
current control. This is useful especially, if the motor
stator resistance is low, which makes the motor current
sensitive for u/f-curve tuning at low speed area. I/f-control is
activated by setting AdvancedOptions2.B9 = 1 (P1.10.6) for
PM-motors. Also software modulator is required.
I/f Start Current
I/f Control
Limit
Output Frequency
Time [s]
Motor Current
Code
ID
Description
Notes
P1.8.6.6
1693
I/f current “I/f current”
This parameter defines the current level during I/f control, in percent of the motor
nominal current
Zero position with incremental encoder and Z-Pulse
In closed loop control utilizing the encoder z-pulse, defines also the current level used
in starting before the z-pulse is received to synchronize with.
DC Start Angele identification
This parameter defined DC Current level when Start Angle Identification Time is set
greater than zero. See P1.8.5.5
Start Angle Identification Time.
I/f Current parameter is used for
several different purposes.
P1.8.6.7
1790
I/f control limit “I/f control lim”
This parameter sets the frequency limit for I/f-control in per cent of the motor nominal
frequency. I/f-control is used if the frequency is below this limit. The operation
changes back to normal when the frequency is above this limit with 1 Hz hysteresis.
5.8.3.2 Flux current controller
The flux current controller is used with a PMS motor when
running in closed loop control in the field weakening area.
This function controls negative Id current to PM motor in
the field weakening area that motor terminal voltage do not
increase above maximum level (set by field weakening point
voltage, maximum drive output voltage).
Field weakening area operation depends on motor
construction and motor construction may prohibit operation
above field weakening area.
If there is instability in the field weakening area, gain can be
decreased and/or time constant increased.
Code
ID
Description
Notes
P1.8.6.8
551
Flux current Kp “FluxCurrent Kp”
Defines gain for the flux current controller when using a PMS motor. Depending on
motor construction and the ramp rate that is used to go to field weakening area high
may be needed that output voltage do not reach maximum limit and prevent proper
motor control. Too high gain may also lead to unstable control. Integration time is more
significant in this case for control.
I/f Current parameter is used for
several different purposes.
P1.8.6.9
652
Flux current Ti “FluxCurrent Ti”
Defines the integration time for the flux current controller when using a PMS motor.
Depending on motor construction and the ramp rate that is used to go to field
weakening area, short integration times may be needed that output voltage do not
reach maximum limit and prevent proper motor control. Too fast integration time may
also lead to unstable control.
P1.8.6.10
1730
ExtIdRef ”ExtIdRef”
This reference value can be used for the external control of the motor id-current i.e.
reactive current. Normally there is no need for that as the control uses already the
optimal value. This reference value is additive to drive internal values but, for example,
field-weakening controller can override the given reference in field-weakening
operation.
P1.8.6.11
654
EnableRsIdentifi “EnableRsIdentifi”
This parameter enables the Rs identification during DC brake current operations and in
closed loop control for every start. If the identification run was made successfully it is
recommended to keep this parameter disabled.