Industrial Engineer · phase 8 of 16 · noun

DC Bus / DC Link

Intermediate DC power section between the rectifier and inverter that stores and smooths energy.

The Explain card

Plain English
The DC bus is the middle of the drive, the DC section between the rectifier and the inverter. It is where energy is stored and smoothed before it is chopped back into AC.
Example
The two heavy bars or terminals marked plus and minus inside a drive are the bus. On a 480 volt drive they sit around 650 volts DC, and they stay dangerous for minutes after power is removed.
Why it matters
Almost every drive fault code that mentions voltage is about the bus, too high on deceleration or too low on a sag. Its voltage is the one number to watch when the drive misbehaves.
Hook
The reservoir between what comes in and what goes out.

Word knowledge

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

In a sentence

During commissioning, the technician measures the DC Bus voltage at the drive terminals before testing the inverter stage.

Why these words
  • DC English initialism of direct current identifies the electrical form associated with the phrase
  • Bus English bus, shortened from Latin omnibus, for all names a shared electrical pathway
  • Link Middle English link, a ring or segment in a chain presents the alternate term as a connecting section
Where it came from
Origin
English engineering compound formed from DC, direct current, and electrical bus, with DC link as a parallel compound
Entered the language
20th century
What changed
Bus moved from a shared conductor to broader power-distribution uses, while link moved from a chain connection to an electrical connection between converter stages.
How it is spelled
Pattern
DC is written as an uppercase initialism without periods.
Pattern
Bus is spelled with one final s in the singular and becomes buses in the plural.
Pattern
DC Bus and DC Link are open compounds.

Spelled like

  • AC bus
  • DC motor
  • data bus
  • communication link
Broken into chunks
  • DC
    • DC motor
    • DC drive
  • bus
    • busbar
    • fieldbus
  • link
    • data link
    • communication link
What it sits beside

Same subject

Same shape

  • AC Bus
  • DC Motor
  • DC Drive
  • Data Link

drive power sections

DC Bus components

Where it sits in the deck

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.

Neighbours in this phase