Invertek Drives Optidrive ODP-2 User Manual page 51

 Select Sensorless Vector Speed Control mode by setting P4-01 = 0.
 Ensure that the motor is correctly connected to the drive.
 Carry out a motor data Autotune by setting P4-02 = 1.
The Autotune will begin immediately when P4-02 is set regardless of the status of the drive enable signal. Whilst the
autotune procedure does not drive or spin the motor, the motor shaft may still turn slightly. It is not normally necessary to
uncouple the load from the motor; however the user should ensure that no risk arises from the possible movement of the
motor shaft.
It is essential that the correct motor data is entered into the relevant drive parameters. Incorrect parameter settings can
result in poor or even dangerous performance.
8.2.5. Synchronous Motors
Overview
Optidrive P2 provides open loop vector control of the following synchronous motor types.
PM AC Permanent Magnet AC Motors and BLDC Brushless DC Motors
Optidrive P2 can be used to control Permanent Magnet AC or Brushless DC motors without a feedback encoder or resolver. These
motors operate synchronously, and a vector control strategy is used to maintain correct operation. In general, the motor can be
operated between 10% - 100% of rated speed with a correctly selected and configured drive. Optimum control is achieved when the
motor back EMF / Rated speed ratio is >= 1V/Hz. Motors with Back EMF / Rated frequency ratio below this level may not operate
correctly, or may operate only with reduced speed range.
PM AC and BLDC motor control employs the same strategy, and the same commissioning method is applied.
Permanent Magnet motors (including BLDC) produce an output voltage known as the Back EMF when the shaft is rotated.
The user must ensure that the motor shaft cannot rotate at a speed where this Back EMF exceeds the voltage limit for the
drive, otherwise damage can occur.
The following parameter settings are necessary before attempting to operate the motor.
 Ensure advanced parameter access is enabled by setting P1-14 = 101.
 Enter the motor nameplate details into the relevant parameters as follows:
o P1-07 Back EMF at Rated Frequency / Speed (kE)
This is the voltage imposed by the magnets at the drive output terminals when the motor operates at rated frequency or speed.
Some motors may provide a value for volts per thousand RPM, and it may be necessary to calculate the correct value for P1-07.
o P1-08 Motor Rated Current.
o P1-09 Motor Rated Frequency.
o (Optional) P1-10 Motor Rated Speed (Rpm).
 Select PM Motor Speed control mode by setting P4-01 = 3 or BLDC Motor Speed Control by setting P4-01 = 5.
 Ensure that the motor is correctly connected to the drive.
 Carry out a motor data Autotune by setting P4-02 = 1.
o The autotune measures the electrical data required from the motor to ensure good control.
 To improve motor starting and low speed operation, the following parameters may require adjustment:
o P7-14: Low Frequency Torque Boost Current: Injects additional current into the motor to help rotor alignment at low output
frequency. Set as % of P1-08.
o P7-15: Low Frequency Torque Boost Frequency Limit: Defines the frequency range where the torque boost is applied. Set as %
of P1-09.
Following the steps above, it should be possible to operate the motor. Further parameter settings are possible to enhance the
performance if required, please refer to your Invertek Drives Sales Partner for more information.
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