I am having some trouble in reversing the direction of a sensored 10KW BLDC motor. Motor has 36 stator teeth and 40 magnets (20 pole pairs)
Apparently the hall sensors position is set for CW direction, and when rotating the motor CCW, the timing is wrong and efficiency is low.
Timing cannot be adjusted in controller (Kelly controller), so I am re-positioning sensors.
...for CCW correct position (measured with an OSC) position never matches a slot. Motor manufacturer tried to place sensors for CCW rotation like this (illustration, ignore zip tie): This looked ok unloaded, but was creating a lot of heat and consuming too much power as I increased load. I assume this is because the sensor is placed halfway between magnets and one coil, and therefore shows zero reading when coil polarity is same and stronger than magnet passing in front of it - Can anyone validate this theory?
Haven't tested this under load yet, but unloaded test shows the following behavior: While testing unloaded at 20v, RPM increases as current increases up to around 2A, then when increasing throttle more, current drops to around 1.8A, and RPM increases as you increase throttle up to the expected max RPM for voltage.
This also happens on the CCW motors with sensors on top of stator.
On CW motors, current gradually increases to 3A for max RPM.
Can anyone tell why this is happening?
I would appreciate any comments on this arrangement and possible solutions.