Nissan Leaf motor at 60V, 1/6 the power?

[yabert]

You can also run the motor sensorless.

I have run the motor sensorless, but I've read that efficiency can be compromised and it's less trouble.
I would prefer sensorless but I want to be prepare if I have trouble to output interesting torque from the Leaf motor.

AS5047P

Thanks. Look like a good option.
But how is it supposed to be better, worse or more interesting for the Leaf motor than the two other models?
I have hard time to choose right.

 

[yabert]

One step closer to know the answer to this thread. Motors can be fix together.
Next step the shaft couplings.

 

[eee291]

I have run the motor sensorless, but I've read that efficiency can be compromised and it's less trouble.
I would prefer sensorless but I want to be prepare if I have trouble to output interesting torque from the Leaf motor.


Thanks. Look like a good option.
But how is it supposed to be better, worse or more interesting for the Leaf motor than the two other models?
I have hard time to choose right.

Because there is documentation for it.

 

[yabert]

Ok, the dyno is done and motors shafts spin freely.
Now I need your help to control that.

I have ME1507 motor connected to a Golden motor EZkontrol who don't seem to allow sensorless.
Is anyone know how to connect the RMB29 analogue encoder module to the 6 pin of the EZkontrol?
12V on EZ side and 5V on encoder side don't look good to start.

 

[yabert]

Leaf motor is now spinning with the VESC controller.
Now I expect some help to have the EZkontrol spinning the ME1507 because it don't seem to work sensorless

 

[eee291]

Just connect a large resistor to the controller that is doing Regen instead of the battery. Have it work as a bridge rectifier.

 

[j bjork]

Just connect a large resistor to the controller that is doing Regen instead of the battery. Have it work as a bridge rectifier.

Then measure current and voltage to calculate power? Could work as a test at least

 

[eee291]

You can just measure how much the controller is pushing for now. Worry about the rest later.

For instance if the vesc is showing only 40a battery current then there is really no point in measuring the output especially with a second motor since you don't know the losses.
You might as take what that vesc is reporting and extrapolate the efficiency with the Nissan motor efficiency chart

You would need a brake and weight scale setup to accurately measure output power.

 

[yabert]

Just connect a large resistor to the controller that is doing Regen instead of the battery

I'm all in!
How can I connect the 3 phases of the motor to a resistor? Edit : I read another time... connect to the controller?
After all I simply need to spin de Leaf few sec. and monitor with the VESC.

Ok, I have few 400V dc heater, a complete oven, few 120V heater... ummm
But probably the ME1507 motor at 1000 rpm will give very low voltage.

 

[eee291]

You could try with a 12v battery connected to the controller. It doesn't need to be turned on.

 

[fechter]

You could just short a pair of phase wires on the ME1507 and it will be like starting up on a hill. It will turn really slow and the Leaf motor will be at the current limit (or resistance limit). This would give you a good data point to calculate the power. Things will heat up pretty quickly so don't run longer than you need to make a good measurement.

 

[yabert]

You could just short a pair of phase wires on the ME1507

What? Is that easy?
I can monitor current on those phases wires to stay at resonable level.

 

[fechter]

I wouldn't even worry about the phase current in the "load" motor, but it might be interesting to see what you get. The idea is to test quickly enough that nothing will overheat. Try to keep it down to 5-10 seconds.
The main thing is to find out how much current you can push into the Leaf motor at a given voltage. This will be the maximum current. In actual use, as the motor speed increases, the current will drop off. If you have a graph of the Leaf motor output, you should be able to figure out what it would do at a particular speed.

 

[yabert]

The idea is to test quickly enough that nothing will overheat.

That kind of work.
I have to short ME1507 phase wires when the Leaf is spinning as sensorless don't acelerate well.
At first I obtain poor results and I have to fine tune FOC current and many other parameters to have higher current from the battery.
Still it's only around 50A somewhere in the yellow circle.
Motor current at 200-250A is also strange, so I bet I have many settings wrong.

With FOC current at 0, the motor spin slower, but need few Amps to spin.
On the graph below, with FOC current set to 250A, it need around 30A just to spin

 

[eee291]

Set field weaken to enable at a later duty cycle.

 

[yabert]

Is it possible that the ME1507 motor with shorted phase wires can not provide enough torque to slow down the Leaf motor?
Seem like RPM stay very high even when the phase wires are shorted.

In fact, with some tuning, I'm now able to start the Leaf motor from 0 RPM with the phase wires shorted on the ME1507.
Still, max batt Amps draw are around 45-50A.

 

[fechter]

Try shorting all 3 phase wires.

Still, I bet you get about the same reading. 50A battery will be about all you can get at that voltage. Roughly 3kw. At "normal" operating speed, the power will be less.

At least you can get your VESC dialed in nicely with that kind of load.

 

[yabert]

Try shorting all 3 phase wires...I bet you get about the same reading. 50A battery will be about all you can get at that voltage

I was septical caused the motor spin so fast at only 45-50A.
So I tried to short all 3 phases = 60-70A.
The Leaf motor wasn't able to start with the 3 phases shorted, so I had to connect 2 phases, start the motor and short the third one manually.
It's clear, battery current is around 40-50A with 2 phases shorted and around 60-70A with 3 phases shorted... motor still spinning way to fast to be at peak torque.

To my, this start to look like the load is to weak.
From what I know, the Leaf can output over 250Nm at 400A and the ME1507 only 120Nm at 600A.
This can explain the situation right?
Time to fight a Leaf with another Leaf?

 

[eee291]

You need to keep on tuning the motor settings to get more starting torque. I don't know what to change exactly anymore since it's been a few years since I last did this. I'll hook up my em61 to a vesc and we can compare settings then.

 

[fechter]

Yes, you could be right. Any idea how fast it's spinning? It may be close to what a boat propeller will be.

If you have a big ammeter, you could try connecting 60v across a pair of phase wires on the Leaf motor and see how much current you get (quickly).

 

[yabert]

I'll hook up my em61 to a vesc and we can compare settings then.

Any idea how fast it's spinning? It may be close to what a boat propeller will be.

I have to verify another time, but based on my stobscope tachometer, around 1080 rpm without FOC and around 3000 rpm with FOC.
Still, I would like to set correctly the ERPM on the VESC because at the moment it reach 6000.
For boat propeller, I expect to spin at around 1000 rpm.

 

[yabert]

Still, I would like to set correctly the ERPM on the VESC because at the moment it reach 6000.

Based on search online, ERPM should be = to RPM x pole pair.
Leaf rotor have 8 poles, so 4 pole pair, who mean 6000 / 4 = 1500 rpm
Hope that make sense.

 

[eee291]

Not really since you said your tachometer measured 3k rpm. So the fastest you have showing on vesc is 6000 erpm?

 

[yabert]

Not really since you said your tachometer measured 3k rpm

Well, seem like I'm not able to read correct rpm with my stobscope setup.
Today, VESC give me 3080 erpm without FOC and I effectivly mesure 780 rpm with stobscope.

Edit-1: test another time with another reflective tape, it's around 840 rpm without FOC.
Edit-2: Nope, 840 rpm was with 50A Field Weakening. 780 rpm is right without any FOC.

So the fastest you have showing on vesc is 6000 erpm?

yes.

 

[yabert]

So, without other solution, I think I will need to connect my second Leaf motor to the Leaf motor with VESC.
Can someone explain me what is the relation between torque, RPM and phases wires shorted?
I would like to understand clearly what happen when I will short the phase wires.