Wavelet analysis of electric adjustable speed drive waveforms

Dariusz Czarkowski, Alexander Domijan

Research output: Contribution to journalConference articlepeer-review


The three most common adjustable speed drives (ASDs) used in HVAC equipment, namely, pulse-width modulated (PWM) induction drive, brushless-dc drive, and switched-reluctance drive, generate non-periodic and nonstationary electric waveforms with sharp edges and transients. Deficiencies of Fourier transform methods in analysis of such ASD waveforms prompted an application of the wavelet transform. Results of discrete wavelet transform (DWT) analysis of PWM inverter-fed motor waveforms are presented. The best mother wavelet for analysis of the recorded waveforms is selected. Data compression properties of the selected mother wavelet are compared to those of the fast Fourier transform (FFT). Multilevel feature detection of ASD waveforms using the DWT is shown.

Original languageEnglish (US)
Pages (from-to)559-569
Number of pages11
JournalASHRAE Transactions
Issue numberPt 1A
StatePublished - 1998
EventProceedings of the 1998 ASHRAE Winter Meeting. Part 1 (of 2) - San Francisco, CA, USA
Duration: Jan 18 1998Jan 21 1998

ASJC Scopus subject areas

  • Building and Construction
  • Mechanical Engineering


Dive into the research topics of 'Wavelet analysis of electric adjustable speed drive waveforms'. Together they form a unique fingerprint.

Cite this