HPM3000 motor overheating

[Stinky]

Hi,

I have bought a 3kW motor (HPM03KW) and controller EZ-A48400. I have connected everything and started the motor. Everything works fine BUT the motor heats up very quickly. In 1 hour it is 80 degree Celsius. There is no load on the output shaft. It is rotating freely. The bus voltage is 48 V and bus current is around 2 amps. Is this normal?

Also it is not possible to run the motor in forward direction when operated from CAN. Backwards works fine.

0C01EFD0#800C187903000001 (-1000RPM)  This command works, rotates the motor
0C01EFD0#800CE88003000001 (1000RPM)   This command does not work, motor does not start.

[Bikemad]

Hi Stinky andto the forum.

I'm not sure what shape the cooling fan blades are on that motor but they may be optimized for maximum airflow in the forward direction at higher rpm.
If you have just been running the motor at a set speed of 1,000 rpm, and also in the reverse direction, this might explain why is is getting so warm.

Your 2 Amp current draw (~100 Watts of power) seems reasonable to me, considering that the Dynomometer data indicates a current draw of 14.87A @ 4489 rpm with a shaft load of just 0.7Nm.

After checking the VEC controllers' default settings, I would say that your motor is not "overheating" if it has only reached 80 degrees after an hours use.  The VEC controllers will only start limiting the current when the motor temperature exceeds 120 degrees, and will eventually cut the power completely if the motor temperature exceeds 150 degrees to protect against overheating.

Unfortunately, I have no experience with any of the EZ Kontrollers (or CAN-BUS protocol), so I don't know why your motor does not run in the forward direction when using the 0C01EFD0#800CE88003000001 (1000RPM) CAN-BUS command.

You may need to contact GM China (sales@goldenmotor.com) for further assistance with the CAN-BUS related problem.

Alan
 

[Stinky]

Hi Bikemad,

Thank you for your answer. It seems that the motor is not very efficient when running with low load and low speed. When looking at Dynomometer data it is seen that efficiency is around 50% when producing 371W mechanical power. That is around 371W heat. Best efficiency (92%) is at 3180 W mechanical power which uses 3458 W electrical power. The heat is 278W. So it runs cooler when the load is high? Have I misunderstood something or is this really the case?

 I will check if the cooling fan works as expected specially in revering direction. 

[Stinky]

It seems that I found the reason why motor got so hot. The EZ-A48400 controller was configured wrong. It was set to AC motor instead of BLDC. When changing this parameter the motor runs much cooler.

I still have problems to control the motor from CAN. It runs in backwards direction but not forward. Does anyone else use the CAN protocol to control the EZ-A48400 controller?