Industrial Engineer · phase 8 of 16

IGBT

Insulated-Gate Bipolar Transistor commonly used as a high-speed power switch in a VFD inverter.

The Explain card

Plain English: The IGBT is the transistor that does the inverter's switching. It handles hundreds of amps and hundreds of volts, and it turns on and off in a fraction of a microsecond.
Example: Six IGBTs in a module make up the inverter of a 100 horsepower drive. Each one switches at the carrier frequency, thousands of times a second, for years.
Why it matters: The fast edges that make IGBTs efficient are also what cause reflected waves, bearing currents and radio noise on motor cables. When an IGBT fails it usually fails shorted, which is why an overcurrent trip at power up often means a dead power module rather than a bad motor.
Hook: The switch that made modern drives possible, and modern noise.

How the word is built, where it came from, and what it sits beside in memory.

In a sentence

During commissioning, the technician verifies the IGBT gate pulses before applying full DC-bus voltage to the inverter.

Letter by letter

Where it came from

Origin: English technical coinage formed from the initials of a four-word semiconductor name
Entered the language: 1980s
What changed: The initialism moved from research and patent terminology into standard power-electronics usage as the device became commercially established.

How it is spelled

Capitalisation: Written IGBT in capitals, including mid-sentence
Plural and possessive: Plural IGBTs, singular possessive IGBT's, and plural possessive IGBTs'
Out loud: Spelled out letter by letter.

Same family

Broken into chunks

What it sits beside

Same subject

Same shape

power semiconductor initialisms

Phase 8: VFD Drive Hardware and Power Path

Inside the drive: rectifier, DC bus and inverter, the three stages every variable frequency drive uses to rebuild the waveform a motor sees.