Sevcon Dragon8 - Motor Characterisation; Supported Motor Algorithms; Determining Motor Parameters; Speed Limit Tuning

Doc. # 177/52705
Rev. 1.0
50
Motor characterisation
Ensure you have completed the CANopen network setup process.
Supported motor algorithms
The firmware within the controller supports multiple motor control algorithms and which can be
selected using object 0x4639, 0:
• Permanent magnet AC
• Induction (flux vector)
Determining Motor Parameters
Key motor parameters for permanent magnet ac and induction motor are adjustable in 0x4641.
Contact Sevcon for more information on how to set up the Dragon8 controller for supported motor types.
Speed Limit Tuning
The speed limit is controlled using PI loops, which can be configured in the Object Dictionary at index
4651h. The following parameters can be configured:
• Standard proportional and integral gains (4651h, 1+2). Used to configure the loops during normal
operation.
• Low speed proportional and integral gains (4651h, 3+5). Used to configure the loops at low speeds
(<50 RPM) and during hill hold. These are normally set lower than the standard gains to dampen
oscillation as the vehicle comes to a stop.
• Roll back integral gain (4651h, 4). Used to boost the integral term to prevent vehicle roll-off down
inclines, particularly when Hill Hold is enabled. Normally, this gain is higher than the standard
integral gain.
• dw/dt gain (4651h, 6). For speed mode this is used to boost the torque output in speed mode, when
a large increase in speed demand occurs. For torque mode this is used to apply compensatory torque
to damped oscillations induced from the vehicle drive train. Not used in torque mode.
• Integral initialization factor (4651h, 7). Used to initialize the integral term on entry to speed limit
in torque mode. This factor is multiplied by the actual torque to set the integral term. Not used in
speed mode.
• Speed filter pole (4651h, 8). Used to filter speed used by speed limit loop.
• Speed pre-limit threshold (4651h, 9). Speed limit algorithm will start cutting back torque when
speed is within this threshold of the maximum.
I/O configuration
Ensure you have completed the CANopen network setup and Motor Characterization processes
described above.
The individual characteristics of the I/O in your application need to be setup. Setup each hardware I/O
object, including wire-off protection.
I/O control is managed using the I-Protocol. Refer to the I-Protocol documentation for more
information.