Hi.
I am working on a high voltage HW using IGBTs and I have issues measuring the resistance of the motor. My guess is that the forward voltage of the IGBTs causes problems during the measurement and that one should compensate for the forward voltage drop during the measurement. I tried to just subtract a fixed voltage in mcpwm_foc_measure_resistance. It helps to improve the measurement a bit, but I suspect it is the wrong approach.
Does somebody have an idea how I should compensate for the IGBT forward voltage drop during the measurement?
This is a known problem, and it should be possible to do something about it. I just don't have any IGBT hardware to do any testing. I'm planning on adding support for a low pass filter on the phase voltage inputs that can be switched on and off with a pin, which should help a lot on hardware with IGBTs during low speed operation and detection. The reason that it cannot be on all thee time is that BLDC mode and thus flux linkage measurement won't work with it.
OK, thank you for the info!
I will try to find a solution for the issue. If, in the mean time, you have an idea how one could solve it best, please let me know!
Does anyone have solution for this problem?
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