I have tried the methods of institutes in Nurmberg/Erlangen and Torino, but get failures to the worths of Ld(id,iq) and Lq(id,iq) the producer gives to us.
I want to create a Lookup-Tables of Ld(id,iq),Lq(id,iq), PsiPM(id,iq).
Steps to determine Inductance(Ld)
1. Align the rotor to phase A. Phase A is connected to the positive potential (+) and phase B and C are grounded (-).
2. Lock the rotor shaft.
3. Apply negative step voltage. Phase A is grounded (-) and phases B and C are connected to the positive potential (+).
Usual level of the current is about 10% of the rated phase current.
4. Measure the step response of the current by a current probe.
5. Calculate inductance Ld
Steps to determine Inductance(Lq)
1. Align the rotor to the q-axis. Connect the phase B terminal to the positive potential (+) of the voltage source and phase
C is grounded (-). Phase A terminal is floating.
2. Lock the rotor shaft firmly because current step response in q-axis creates torque.
3. Generate a current step response in this configuration: phase A is connected to the positive potential (+) of the voltage
source and phases B and C are grounded.
4. Calculate inductance Lq
Thanks for your answer, but i think, this is not what i really look for.
I look for a method, so I can calculate Ld and Lq dependent on my currents id and iq.
I can generate currents id and iq with my inverter into the machine. Unfortunately I have no other kind of power supply at the moment.
Can anybody help me please, if somebody know something, let me know :)
Are there any specialists here? ;)
As you can apply D,Q currents, you just need to lock the rotor and apply desired currents, and read the step response, then calculate the Ld, Lq.
If you lock the rotor as described earlier, you just need to apply desired constant current to phase A and negative half of its value to the B and C phases. In first case, due to the alignment, the A current will be actually applied in D axis, in second case, it will be applied in Q axis. Then again, just read the step response and calculate the Ld, Lq.
But if you can apply the DQ currents directly, I assume the second paragraph just describes what the inverter does for you when you asking for DQ current - it just applies the Prak/Clark transformation based on the rotor position.
The Problem is, I have a three-phase voltage inverter. So i can apply D, Q currents at locked rotor, but what step response I choose?
There is no real chance to create DC voltage (duty cycle is max. 0.55).
And Mr. Bajpai, I know the paper of freescale, you copy and paste it from.
But I want a simple solution how to measure the values at my dSpace test bench.
I have no FEM-Model, the producer only give us some data, but it has to be verified and the values are without cross-coupling effects.
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