Question

Why dc bus voltage in vfd increases in floating network?

Answer 1

$\huge{Hey Mate!!!}$

☆☞ Here is ur answer ☜☆

✔✔ DC Bus Over Voltage.

✔✔ AC Drives are fed by AC mains and produce an AC power output for the motor.

✔✔ Common VSD's use a simple bridge rectifier to create the DC bus voltage.

✔✔ Rectifying 3 phase AC voltage increases the dc voltage by a fixed ratio of 35%.

HOPE IT HELPS!

Answer 2

Cause: As the speed of the motor increases, and/or as the load on the motor increases, the DC bus voltage is dropping and the motor current is increasing, while the main input voltage stays the same or drops very slightly. When you measure the incoming voltage with a voltmeter, you are measuring the RMS voltage.