CY8CKIT-037 Sensorless FOC Motor_i32IuvwAmplifierFactor

[MiRe_1322481]

Hello,

we don't understand why in the example Sensorless FOC Motor the amplification factor

Motor_i32IuvwAmplifierFactor is set to 4.16 (customer_interface.c , line 66).

The actual configuration of the amplifier circuit should result in a factor of exactly 5.

We would like to understand the reason for the difference since we have to adapt

the firmware to our own hardware and need to be sure to calculate the factor

correctly for our board.

Best regards

Michael

[Vasanth]

Hi Michael,

Motor_i32IuvwAmplifierFactor: is the factor of amplification multiples in amplification circuit as you have understood. I hope you are referring to  this application note too. Meanwhile I am checking why there is a difference in the factor value from the actual circuit value. I will update you at the earliest.

Best Regards,
Vasanth

[Vasanth · Accepted solution]

Hi Michael,

As per the circuit, opamp non-inverting configuration is used- the gain calculation should also include the feedback capacitor in the design. ( One correction when the circuit is purely resistive the gain should be 6).

To set this parameter accurately in your design you could use the oscilloscope to see the phase current value and compare with the  value read  on phase current value in IAR live watch. Calculate if the value read matches the measured value then adjust the gain set in project accordingly.

Best Regards,
Vasanth