Nidec Unidrive M200 User Manual page 49

Safety Product Mechanical
information information installation
Pr 38 {05.012} Autotune
There are two autotune tests available in open loop mode, a stationary and a rotating test. A rotating autotune should be used whenever possible so
the measured value of power factor of the motor is used by the drive.
• A stationary autotune can be used when the motor is loaded and it is not possible to remove the load from the motor shaft. The stationary test
measures the Stator Resistance (05.017), Transient Inductance (05.024), Maximum Deadtime Compensation (05.059) and Current At
Maximum Deadtime Compensation (05.060) which are required for good performance in vector control modes (see Control Mode later in this
table). The stationary autotune does not measure the power factor of the motor so the value on the motor nameplate must be entered into Pr 09.
To perform a Stationary autotune, set Pr 38 to 1, and provide the drive with both an enable signal (on terminal 11) and a run signal (on terminals
12 or 13).
• A rotating autotune should only be used if the motor is unloaded. A rotating autotune first performs a stationary autotune, as above, then a
rotating test is performed in which the motor is accelerated with currently selected ramps up to a frequency of Motor Rated Frequency (Pr 39) x
2/3, and the frequency is maintained at that level for 4 seconds. Stator Inductance (05.025) is measured and this value is used in conjunction
with other motor parameters to calculate Motor Rated Power Factor (Pr 09). To perform a Rotating autotune, set Pr 38 to 2, and provide the
drive with both an enable signal (on terminal 11) and a run signal (on terminals 12 or 13).
Following the completion of an autotune test the drive will go into the inhibit state. The drive must be placed into a controlled disable condition
before the drive can be made to run at the required reference. The drive can be put in to a controlled disable condition by removing the signal from
terminal 11, setting the Drive Enable (06.015) to OFF (0) or disabling the drive via the Control Word (06.042) and Control Word Enable (06.043).
Pr 41 {05.014} Control Mode
There are several voltage modes available which fall into two categories, vector control and fixed boost.
Vector control
Vector control mode provides the motor with a linear voltage characteristic from 0 Hz to Motor Rated Frequency, and then a constant voltage above
motor rated frequency. When the drive operates between motor rated frequency/50 and motor rated frequency/4, full vector based stator resistance
compensation is applied. When the drive operates between motor rated frequency/4 and motor rated frequency/2 the stator resistance
compensation is gradually reduced to zero as the frequency increases. For the vector modes to operate correctly the Motor Rated Power Factor
(Pr 09), Stator Resistance (05.017), Maximum Deadtime Compensation (05.059) and current at Maximum Deadtime Compensation (05.060) are all
required to be set up accurately. The drive can be made to measure these by performing an autotune (see Pr 38 Autotune). The drive can also be
made to measure the stator resistance automatically every time the drive is enabled or the first time the drive is enabled after it is powered up, by
selecting one of the vector control voltage modes.
(0) Ur S = The stator resistance is measured and the parameters for the selected motor map are over-written each time the drive is made to
run. This test can only be done with a stationary motor where the flux has decayed to zero. Therefore this mode should only be used if the motor
is guaranteed to be stationary each time the drive is made to run. To prevent the test from being done before the flux has decayed there is a
period of 1 second after the drive has been in the ready state during which the test is not done if the drive is made to run again. In this case,
previously measured values are used. Ur S mode ensures that the drive compensates for any change in motor parameters due to changes in
temperature. The new value of stator resistance is not automatically saved to the drive's EEPROM.
(4) Ur I = The stator resistance is measured when the drive is first made to run after each power-up. This test can only be done with a stationary
motor. Therefore this mode should only be used if the motor is guaranteed to be stationary the first time the drive is made to run after each
power-up. The new value of stator resistance is not automatically saved to the drive's EEPROM.
(1) Ur = The stator resistance and voltage offset are not measured. The user can enter the motor and cabling resistance into the Stator
Resistance (05.017). However this will not include resistance effects within the drive inverter. Therefore if this mode is to be used, it is best to
use an autotune test initially to measure the stator resistance.
(3) Ur_Auto= The stator resistance is measured once, the first time the drive is made to run. After the test has been completed successfully the
Control Mode (Pr 41) is changed to Ur mode. The Stator Resistance (05.017) parameter is written to, and along with the Control Mode (Pr 41),
are saved in the drive's EEPROM. If the test fails, the voltage mode will stay set to Ur Auto and the test will be repeated next time the drive is
made to run.
Fixed boost
The stator resistance is not used in the control of the motor, instead a fixed characteristic with low frequency voltage boost as defined by Pr 42, is
used. Fixed boost mode should be used when the drive is controlling multiple motors. There are three settings of fixed boost available:
(2) Fixed = This mode provides the motor with a linear voltage characteristic from 0 Hz to Motor Rated Frequency (Pr 39), and then a constant
voltage above rated frequency.
(5) Square = This mode provides the motor with a square law voltage characteristic from 0 Hz to Motor Rated Frequency (Pr 39), and then a
constant voltage above rated frequency. This mode is suitable for variable torque applications like fans and pumps where the load is
proportional to the square of the speed of the motor shaft. This mode should not be used if a high starting torque is required.
(6) Fixed Tapered = This mode provides the motor with a linear voltage characteristic with a tapered slip limit.
Unidrive M200 / M201 Control User Guide
Issue Number: 2
Electrical Getting Basic
installation started parameters
Running the NV Media
Optimization
motor Card
Onboard Advanced
Diagnostics
PLC parameters
UL Listing
49