Industrial Engineer · phase 13 of 16 · noun
Sine-Wave Filter
Output filter that converts the PWM waveform toward a sinusoidal motor voltage.
The Explain card
- Plain English
- A sine wave filter is a larger inductor and capacitor network that smooths the PWM output into something close to a true sine wave. The motor sees clean power, as if it were on the line.
- Example
- A submersible pump 800 meters down a well runs through a sine filter. The cable never sees PWM edges, and the motor is a standard unit rather than an inverter duty one.
- Why it matters
- It solves reflected waves, cable ringing, motor noise and most insulation stress in one piece of equipment. It is large, hot, and it limits how high the output frequency can go, so it is a considered purchase.
- Hook
- Make the drive look like the utility.
Word knowledge
How the word is built, where it came from, and what it sits beside in memory.
In a sentence
A sine-wave filter is installed at the VFD output before commissioning a motor connected by a long cable.
Why these words
- sine Latin sinus, curve or fold identifies the mathematical waveform associated with the phrase
- wave Middle English wave, a moving swell names the repeating signal form
- filter Medieval Latin filtrum, felt used for straining identifies the device class
Where it came from
- Origin
- 20th-century English engineering compound formed from sine wave and filter
- Entered the language
- 20th century
- What changed
- Sine moved from geometry into waveform terminology, while filter expanded from physical straining to selective electrical signal treatment.
How it is spelled
- Pattern
- Sine retains a final silent e that marks the long i sound.
- Pattern
- Sine-wave is hyphenated when it acts as a compound modifier before filter.
Spelled like
- line
- fine
- square-wave generator
Broken into chunks
-
sine
- cosine
- sinusoid
-
wave
- waveform
- wavelength
-
filter
- filtered
- filtering
What it sits beside
Same subject
- dV/dt filter
- output reactor
- variable frequency drive
- motor cable
Same shape
- square-wave generator
- common-mode choke
- low-pass filter
VFD output-conditioning devices
- sine-wave filter
- dV/dt filter
- output reactor
waveform terms
- sine wave
- square wave
- carrier wave
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.
