Part Number: TMS320F280049C
Other Parts Discussed in Thread: TMDSHVMTRINSPIN
Tool/software:
Hello,
We are working on a low inductance, high speed, BLDC motor with InstaSpin F280049 and MotorControl_SDK_4_00_00_00.
It's with a custom board made by following schematic of high voltage kit 'tmdshvmtrinspin'.
The motor data is unknown. Hence we did the parameter measurements as suggested in,
'e2e.ti.com/.../faq-what-are-motor-parameters-why-are-they-needed-and-how-do-i-measure-them'
We are able to run the motor in Lab03, Lab04 and Lab05 also identifies the motor successfully.
The parameters found by following either methods are as follows,
1. By Meter Measurement:
Rs = 0.0967 ohm, LS = 9.765 uH & VpHz = 0.0145
2. Lab05 Identification results:
Rs = 0.06025 ohm, LS = 5.86 uH & VpHz = 0.013475
The set PWM freq is 14kHz.
Our questions are as under,
1. how much variation you expect in measurement and identified values.
2. which of the 2-sets we should use.
2. how much percentage wise difference the InstaSpin algorithms can tolerate as far as Rs, Ls and VpHz
values are concerned
3. Is there any suggested min PWM freq in relation with Ls, as far as following are concerned,
i) faithful motor identification and
ii) having expected Isq control,
4. Is there any recommendations for the ratio for such low inductance motors.
USER_NUM_ISR_TICKS_PER_SPEED_TICK / USER_NUM_ISR_TICKS_PER_CURRENT_TICK
Thanks a lot in advance
