Industrial Engineer · phase 11 of 16 · noun
Torque Boost
Additional low-frequency voltage used to compensate stator resistance and improve starting or low-speed torque.
The Explain card
- Plain English
- Torque boost adds extra voltage at low frequencies, above the plain volts per hertz line. It makes up for the voltage lost in the stator resistance, which matters most when the frequency and voltage are both small.
- Example
- A screw conveyor stalls trying to start at 3 hertz in V/Hz mode. A few percent of torque boost puts enough flux in the motor to break it loose.
- Why it matters
- Boost is a fix for weak starting in scalar control. Too much of it saturates the motor and overheats it at low speed, and vector modes do the same job automatically, so if you find yourself cranking boost up, the control mode is probably the real problem.
- Hook
- A little extra voltage where the curve runs 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 increased Torque Boost until the motor started the loaded conveyor smoothly without an overcurrent trip.
Why these words
- torque Latin torquere, to twist, through French names the turning effect being adjusted
- boost American English boost, a lift or increase marks an added amount intended to strengthen performance
Where it came from
- Origin
- an English engineering compound formed from torque and boost
- Entered the language
- 20th century
- What changed
- Torque moved from the general idea of twisting to rotational engineering, while boost developed from a physical upward push into a technical increase.
How it is spelled
- Pattern
- Both words are spelled as single closed forms in the compound.
- Pattern
- The final silent e in torque accompanies the written qu sequence.
- Pattern
- The vowel pair oo in boost represents the long oo sound.
- Breaks the pattern
- Torque ends in que, but the final ue is not pronounced.
Spelled like
- unique
- technique
- roost
- cool
Broken into chunks
-
torque
- torsion
- torque wrench
-
boost
- voltage boost
- pressure boost
What it sits beside
Same subject
- V/f control
- motor nameplate
- acceleration ramp
- current limit
- overcurrent fault
Same shape
- voltage boost
- torque limit
- speed reference
VFD tuning parameters
- Torque Boost
- acceleration time
- deceleration time
- current limit
motor control quantities
- torque
- speed
- current
- frequency
Where it sits in the deck
Phase 11: VFD Control Modes and Tuning
How a drive decides what to send the motor, from plain volts per hertz up to closed loop vector control, and how each mode is tuned.
