Unidrive M702 User Guide
121
Issue Number: 3
8.1.2 RFC-A mode
Induction motor with Position feedback
Pr 00.046 {05.007}
Motor Rated Current
Defines the maximum motor continuous current
The motor rated current parameter must be set to the maximum continuous current of the motor. (See section 8.2
page 127, for information about setting this parameter higher than the maximum Heavy Duty current rating.) The motor rated current is used in the
following:
•
Current limits (see section 8.3
on page 127, for more information).
•
Motor thermal overload protection (see section 8.4
on page 127, for more information)
•
Vector control algorithm
Pr 00.044 {05.009}
Rated Voltage
Defines the voltage applied to the motor at rated frequency
Pr 00.047 {05.006}
Rated Frequency
Defines the frequency at which rated voltage is applied
The
Rated Voltage
(00.044) and the
Rated Frequency
(00.047) are used
to define the voltage to frequency characteristic applied to the motor (see
Open Loop Control Mode
(00.007), later in this table). The motor rated
frequency is also used in conjunction with the motor rated speed to
calculate the rated slip for slip compensation (see motor
Rated Speed
(
00.045), later in this table).
Pr 00.045 {05.008}
Rated Speed
Defines the full load rated speed of the motor
Pr 00.042 {05.011}
Number Of Motor Poles
Defines the number of motor poles
The motor rated speed and motor rated frequency are used to determine the full load slip of the motor which is used by the vector control algorithm.
Incorrect setting of this parameter has the following effects:
•
Reduced efficiency of motor operation
•
Reduction of maximum torque available from the motor
•
Reduced transient performance
•
Inaccurate control of absolute torque in torque control modes
The nameplate value is normally the value for a hot motor; however, some adjustment may be required when the drive is commissioned if the
nameplate value is inaccurate. Either a fixed value can be entered in this parameter or an optimization system may be used to automatically adjust
this parameter (see
Motor Parameter Adaptive Control
(05.016), later in this table).
When Pr
00.042
is set to 'Automatic', the number of motor poles is automatically calculated from the motor
Rated Frequency
(00.047), and the
motor
Rated Speed
(00.045).
Number of poles = 120 x (Motor
Rated Frequency
(00.047 / Motor
Rated Speed
(00.045) rounded to the nearest even number.
Pr 00.043 {5.10}
Rated Power Factor
Defines the angle between the motor voltage and current
The power factor is the true power factor of the motor, i.e. the angle between the motor voltage and current. If the
Stator Inductance
(05.025) is set
to zero then the power factor is used in conjunction with the motor
Rated Current
(00.046) and other motor parameters to calculate the rated active
and magnetising currents of the motor, which are used in the vector control algorithm. If the stator inductance has a non-zero value this parameter
is not used by the drive, but is continuously written with a calculated value of power factor. The stator inductance can be measured by the drive by
performing a rotating autotune (see
Autotune
(Pr 00.040), later in this table).
Output
voltage
Pr
/ 2
00.044
Pr
00.044
Pr
/ 2
00.047
Pr
00.047
Output
frequency
Output voltage characteristic
Summary of Contents for Unidrive M702
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