Tuning the Kelly KLS-72701-8080i

Understanding the Settings

After about a year of using the Kelly KLS72701-8080I BLDC sinusoidal controller (Hall Input) with the Motenergy ME1306, I spent time experimenting with different settings available in the Kelly PC app.  Here is a summary of the settings did to the performance of the car.  The goal was to optimize acceleration from a stand-still on level road.  One indicator of performance is how the battery amps changed (not phase amps).

1. Increasing IQ-Kp and ID-Kp to 6000 from the previous setting of 4500 resulted in a hum from the motor at about 300 rpm.  Increasing these to 9000 increased the hum.  No performance difference.
2. Increasing IQ-Ki and ID-Ki to 5000 from previous setting of 500 resulted in low hum from the motor.  No performance change.   Reverted both back to 1000 to resolve the hum.  No performance.
3. Decreasing IQ-Ki and ID Ki to 0 and 10, resulted in the motor not starting to turn from a stop.
4. Increasing Torque Kp & Ki from 4500 to 10000 resulted in noticeable improvement in acceleration from a stop.  The battery amps appeared to increase faster when accelerating.
5. Decreased Speed Error to 50 from 200 and the acceleration was very sluggish.     
6. Increase Speed Error to 4000 and observed improved performance.
7. Lowered PWM frequence from 20k to 6k. High hum with no real motor spin.
8. Lowered Maximum Output Frequency from 1000 to 100.  No change to acceleration but in 2nd gear, the controller shutdown with no error message.  Resumed once RPMs returned to 0.
9. Increased acceleration time from 1 to 100 (0.1ms to 10 second) - Noticeable reduction in acceleration rate.

Overall, with the Torque Kp & Ki changes and the Speed Error increases, the acceleration is improved with no other observable issues or problems.

Bottom Balancing

Started the annual bottom balancing the drive pack.  Using a custom discharger which is set to connect each cell to a 1/4-ohm resistor network, pulling about 10A (3v/0.25 ohm).  A voltage meter is set to connect the network when the cell's voltage is above 2.8v.  As the pack SOC moves down the shoulder of the voltage curve, the voltage with oscillate around 2.8v until the pack is finally discharged to a stable 2.79v and no longer recovers to above 2.8v.