Impact of pulse width modulation schemes In eccentricity fault detection using current signature analysis

Among various motor issues, eccentricity faults pose significant challenges, leading to vibrations, reduced efficiency, and potential failure if undetected. Motor Current Signature Analysis (MCSA) is a widely used technique for diagnosing such faults, particularly in line-fed motors. However, the effectiveness of MCSA based on the modulation scheme employed in inverter-driven setup is underexplored. This thesis addresses this gap by analyzing the impact of Sinusoidal Pulse Width Modulation (SPWM) and Selective Harmonic Elimination (SHE) on diagnosing eccentricity faults in three-phase synchronous motor drives. The study involves a three-phase, 2 kW, 208 V, 1800 rpm synchronous motor driven by an inverter, which is controlled via a Raspberry Pi Pico2 microcontroller. Using Sinusoidal PWM (SPWM) and Selective Harmonic Elimination (SHE) modulation schemes, the research examines their influence on motor current signatures, focusing on harmonic distortion and the detectability of eccentricity faults. A comprehensive experimental setup is developed to analyze both healthy and fault-induced conditions with varying eccentricity levels. Current signals are processed through Fast Fourier Transform (FFT) to extract fault-relevant spectral features and assess the sensitivity of each modulation method. The results emphasize the differences in the frequency spectra produced by pulse-width modulation systems, uncovering unexpected behaviors and trends as eccentricity increases. They also demonstrate how much easier it is to observe the magnitude and growth of specific fault frequencies when the system is connected directly to the electrical grid, compared to when it operates under pulse width modulation schemes.

Author dc:creator

• Espinoza Velez, Christian Omar

Advisors dc:contributor.supervisor

• Thirumarai Chelvan, Ilamparithi Thirumarai
• Popli, Navneet

• PWM
• Pulse Width Modulation
• Variable Speed Drive
• MCSA
• SPWM
• SHE
• Eccentricity
• FFT

Statement dc:rights

• Available to the World Wide Web

Language dc:language.iso

en, English

Handle dc:identifier.uri

https://hdl.handle.net/1828/23029

OAI identifier oai:identifier

oai:dspace.library.uvic.ca:1828/23029