Industrial Engineer · phase 10 of 16
Carrier Frequency
Rate at which inverter power devices switch, affecting audible noise, motor heating, cable effects, drive losses, and possible derating.
The Explain card
- Plain English
- The carrier frequency is how many times a second the inverter switches to build its PWM output. Typical values run from around 2 kilohertz up to 16 kilohertz.
- Example
- A drive at 4 kilohertz makes the motor whine at a pitch you can hear. Raised to 12 kilohertz the whine goes above hearing, and the drive runs warmer for it.
- Why it matters
- Higher carrier means a quieter motor and a smoother current, and it costs drive losses, derating, and more stress on long motor cables. It is a parameter, and the default is a compromise the drive maker chose without seeing your installation.
- Hook
- The pitch of the drive's hum, and the price of silence.
Where it sits in the deck
Phase 10: VFD Electrical and Motor Fundamentals
The physics under the parameters: slip, torque, flux, and the relationship between frequency and voltage that every drive is really controlling.
