Vibroakustična karakterizacija elektromotorja z zunanjim rotorjem

Rihtaršič, Matija (author), Slavič, Janko (mentor)

Ena od pomembnih lastnosti elektromotorjev je hrup, ki ga oddajajo med obratovanjem. To magistrsko delo se ukvarja z analizo hrupa serijskega sinhronskega elektronsko komutiranega (EC) elektromotorja s trajnimi magneti nameščenimi na zunanji rotor. Pri obravnavanem motorju smo pri določenih vrtljajih v delovnem območju elektromotorja zaznali moteč hrup. Najprej smo z eksperimentalno meritvijo preverili vpliv spremembe krmilnih parametrov pulzne širinske modulacije (PŠM) na hrup elektromotorja. Izkazalo se je, da na tak način na hrup elektromotorja ne moremo vplivati. V nadaljevanju smo eksperimentalno določili, da je vzrok za povišan hrup lastna frekvenca ene od komponent elektromotorja. To kritično frekvenco, pri kateri se je pojavljal neželeni hrup, smo z meritvijo zvočnega tlaka med zagonom elektromotorja podrobneje identificirali in jo s pomočjo eksperimentalne modalne analize povezali z rotorjem EM. V nadaljevanju smo nato s pomočjo numerične analize raziskali vpliv komponent na lastno dinamiko rotorja. S pomočjo numerične analize smo pripravili nabor konstrukcijskih rešitev, ki bi spremenile lastno frekvenco rotorja dovolj, da bi se izognili pojavu resonance. Ugotovili smo, da se s preprosto konstrukcijsko spremembo rotorja ne moremo izogniti motečemu hrupu v celotnem delovnem območju elektromotorja, lahko pa prestavimo kritično točko, v kateri se pojavi ta hrup.

• Language: Slovenian
• Keywords: elektromotorji, elektronska komutacija, pulzno širinska modulacija, hrup, lastne frekvence, modalna analiza
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [M. Rihtaršič]
• Year: 2023
• Number of pages: XXII, 95 str.
• PID: 20.500.12556/RUL-148972
• UDC: 621.313.13:534.83:519.6(043.2)
• COBISS.SI-ID: 166611715
• Publication date in RUL: 02.09.2023

RIHTARŠIČ, Matija, 2023, Vibroakustična karakterizacija elektromotorja z zunanjim rotorjem [online]. Master’s thesis. Ljubljana : M. Rihtaršič. [Accessed 22 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=148972

Secondary language

• Language: English
• Title: Vibro-acoustic characterization of external rotor electric motor

Abstract

One of the important characteristics of electric motors is the noise they emit during operation. This master's thesis deals with the analysis of noise from a series-produced electronically commutated (EC) synchronous electric motor with permanent magnets mounted on the external rotor. With the motor under consideration, we detected disturbing noise at certain rotational velocity within the motor's operating range. Initially, we conducted experimental measurements to assess the impact of changing pulse width modulation (PWM) control parameters on the motor's noise. It was determined that this approach does not influence the motor's noise. Subsequently, through experimental measurements of sound pressure during motor startup, we identified that the elevated noise was caused by the resonant frequency of one of the motor's components. This critical frequency, at which the undesired noise occurred, was further identified and connected to the EM rotor through experimental modal analysis. In continuation, we employed numerical modal analysis to investigate the influence of components on the rotor's inherent dynamics. Using numerical analysis, we generated a set of design solutions aimed at altering the rotor's resonant frequency sufficiently to avoid resonance phenomena. We found that through a straightforward rotor design change, complete mitigation of disruptive noise throughout the motor's operational range is not achievable. However, it is possible to shift the critical point at which this noise manifests by doing so.

• Keywords: electric motors, electronic commutation, pulse width modulation, noise, natural frequencies, modal analysis