Hello,
We are currently implementing FOC using both TMS320F28388D and BOOSTXL-DRV8323RS gate to control PMSM motors.
Our setup is very simple and contains nothing else than the control card, the motor drivers, the motors and encoders.
The motors characteristics are the following ones:
Motor: Tmotor antigravity4004 kv300
Measured resistance between two phases: 0.65 Ohm
Measured inductance between two phases: 270 uH
Here is the pin assignment map if necessary:
But when we look at the currents we clearly see a current overshoot that can become a problem in certain cases.
Here it is:
The different channels are:
Yellow: Gate High side PWM
Blue; Gate Low side PWM
Green; Real phase current (measured thanks to a current probe)
Purple: DRV ISENA pin (filtered current sense pin)
We see here that each time the transistors are switching, an overshoot or an undershoot occurs in the motor phases.
However the current should remain constant because of the induction of the motor phase.
Also, the undershoot over the low side shunt resistor shouldn't happen when the low side transistor is open, the current should go to zero very quickly.
Here is the same measurement zoomed on the transition:
Also, I measured the bus voltage and only saw small peaks whose amplitude was around 1.5V peak to peak (With a 12V supply voltage) during MOSFET switch.
Do you have an idea of what is causing this ?
PS: I already posted this issue but in a wrong forum:
Thanks in advance.
