【Iprober 520 current probe】Practical use in motor control

gyp1

【Iprober 520 current probe】Practical use in motor control [Copy link]

Actual use of the probe

This test mainly uses the I-Prober520 probe for actual testing, mainly for motor control. This time, the FOC motor control development board evaluated previously was used, and the motor used was a 24V30W motor with a rated speed of 5000RPM.

The overall connection is as follows:

The current probe can be used in closed magnetic circuit mode and PCB mode.

First, use the closed magnetic circuit mode to run the motor and run it into the weak magnetic zone to observe the phase current.

When the speed reaches 8600 rpm, the phase current amplitude is as shown in the figure below: (blue is PWM voltage, which is SVPWM modulation wave).

The maximum modulation ratio has been set to 100%, so part of the PWM has disappeared in this sampling time state.

At this time, the current probe uses the PCB mode and is calibrated in advance to measure the sampling resistance.

The usual current probe cannot be used for convenient measurement in this case, so the field probe comes into play. The actual waveform is as follows.

Because the sampling resistor is the voltage divider of the phase current to the ground, plus the modulation, the waveform is different from the actual phase current. Zoom in and observe the details:

Probes are very convenient for this situation.

This content is originally created by EEWORLD forum user gyp1 . If you want to reprint or use it for commercial purposes, you must obtain the author's consent and indicate the source