Other Parts Discussed in Thread: LAUNCHXL-F280049C, , C2000WARE
Dear all：
My EVM kit is LAUNCHXL-F280049C+BOOSTXL-DRV8320RS
MotorControl_SDK Version : C2000Ware_MotorControl_SDK_3_03_00_00
I use it to control a drone motor，The drone motor has 7 pole pairs,1700kv，DC bus voltage is 12V
I test the example projects from “is05 Motor id lab” to “is09 Flying Start lab”，the Motor Parameters can be Identificated, and I can use is09 Flying Start lab to make motor run to about 1000Hz electrical frequency.
But when I try to increased motor speed,I found that my motor speed can’t improve over 1000hz. My motor has 7 pole pairs ,1000Hz electrical frequency means that my motor only run at about 8500rpm,this speed is too slowly to a drone motor! Because “Six step” algorithm ESC module can easly run this motor over 20000rpm.
When I set speedref over 1000Hz，The motor began to make a big noise, the motor current increased from 0.35A to 3.5A，motor speed reduce to 500Hz instead of rising to 1000Hz.
I change USER_MAX_VS_MAG_PU from 0.5 to 0.57,and finally,I set it to 0.66，but I found it no useful，the motor still can’t run over 1000Hz.I check overmodulation function and variables,I found the variable “svgencurrent.ignoreShunt” and “svgencurrent.compMode” never changed.It seems like The Overmodulation function never start,but I can’t increase motor speed!
In order to verify the correction of my program，I change drone motor to a general BLDC motor,the BLDC motor has 2 pole paris and rate speed is 3000rpm. The 2 pole paris BLDC run successfully with my program.when I change USER_MAX_VS_MAG_PU from 0.5 to 0.57,I found motor speed increased.and Overmodulation function start!
So the test show my program has no problem ,just can not support 7 pole pairs drone motor very well.
I found a reference document ：TIDUCF1《High-Speed Sensorless-FOC Reference Design for Drone ESCs》.This document use a 6 pole pairs drone motor，and just test to 1200Hz(12000rpm).12000rpm is still not a very high speed for a drone motor ,and 1200Hz for my 7 pole paris motor ,the speed will decrease to about 10000rpm.
By the way ,When I test the “Lab10 Dual Motor Sensorless Velocity Control”,I found my motor can just only run at about 450Hz……It seems like if I use one chip to control dual motor ,the max speed decrease to half of 1000Hz…. Is this right?
So my questions are:
- Can Instaspin-Foc support high speed Drones motor very well?
- What is maximum electrical frequency of Instaspin-Foc?
- Can Instaspin-Foc run a 7 pole paris motor over 2000Hz or over 20000rpm? Or it only support 2 or 4 pole pairs motor run to about 1000~1200Hz?
- If my setting is not correct , how can I run a 7 pole paris drone motor over 20000rpm?
