Industrial Engineer · phase 13 of 16
DC Link Choke
Inductor in the DC link used to smooth current and reduce stress and line harmonics.
The Explain card
- Plain English
- A DC link choke is an inductor in the DC bus, between the rectifier and the capacitors. It smooths the current into the capacitors and reduces the line harmonics in much the same way a line reactor does.
- Example
- Many mid sized drives ship with a DC choke built in. Their input current is cleaner than a bare six pulse drive without any external reactor.
- Why it matters
- A drive with a built in choke may need no line reactor for harmonics, though it still gains transient protection from one. Knowing whether the drive has one changes what you specify and what the harmonic study assumes.
- Hook
- The reactor that lives inside the drive.
Where it sits in the deck
Phase 13: VFD Power Quality, Wiring, and Motor Protection
Harmonics, reflected waves, shielded cable and bearing currents: the side effects a drive inflicts on everything around it.
