Experimental characterization of laminated ferromagnetic materials for calculation of pulse width modulation induced iron losses in electrical machines

doctoral thesis

• Title (croatian): Eksperimentalna karakterizacija lameliranih feromagnetskih materijala za izračun gubitaka u željezu električnih strojeva uzrokovanih modulacijom širine impulsa napona
• Author: Igor Sirotić; MBZ: 346585
• Mentor: Stjepan Stipetić (mentor)
• Committee member: Damir Žarko (predsjednik povjerenstva)
• Committee member: Zlatko Hanić (član povjerenstva)
• Committee member: Andrea Cavagnino https://orcid.org/0000-0003-0636-9012 (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; (Department of Electric Machines, Drives and Automation); Zagreb
• Defense date and country: 2023-06-05, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering
• Universal decimal classification (UDC): 621.3 - Electrical engineering

Abstract

The use of inverter-fed electrical machines in industry and even in the small consumer market is prevalent today. With the transition from sinusoidal AC supply to PWM-generated supply, the losses in the entire electrical powertrain increase. The magnetic circuit is also affected by PWM-generated excitation, which is manifested by the occurrence of relatively small remagnetization cycles along the main one: total iron losses increase. Soft magnetic materials are an essential component of any electrical device, and accurate loss data is therefore essential for design purposes. However, data on magnetic materials is still only available for sinusoidal excitation, and there is no generally accepted method for accounting for PWM-induced losses at the design stage. For this purpose, the measurement setup was built and measurements were performed on cores with different geometrical parameters. The effect of the voltage generated by the PWM was analyzed and compared with the results obtained in other research papers which served as validation of the proposed setup. DC bias measurements were performed and data were collected in the form of 3D loss maps. Two methods for calculating the contribution of PWM-induced losses to the total losses AC were proposed and an corresponding algorithms were developed. The obtained 3D loss maps were used as magnetic material data, and the results of calculations using the methods were compared with the results of the performed AC measurements, which served as reference data. The results of the calculations agree well with the measurements.

Abstract (croatian)

U današnje vrijeme u industriji, ali sve više i na tržištu malih potrošača, prevladava upotreba električnih strojeva napajanih putem pretvarača napona i frekvencije. Prijelazom sa sinusnog izmjeničnog napajanja na napajanje generirano modulacijom širine impulsa napona (PWM), povećavaju se gubici cijelog električnog pogonskog sklopa. Tako generiran napon utječe i na magnetski krug što se očituje pojavom relativno malih ciklusa remagnetizacije duž glavnog ciklusa: povećavaju se ukupni gubici u željezu. Meki magnetski materijali su ključna komponenta svakog električnog uređaja i točni podaci o gubicima u materijalu su važni u projektiranju. Međutim, podaci o magnetskim materijalima dostupni su još uvijek samo u uvjetima sinusne pobude i ne postoji opće prihvaćena metoda za proračun gubitaka izazvanih PWM-om u fazi projektiranja. U tu svrhu izrađen je mjerni postav i provedena su mjerenja na prstenastim jezgrama različitih geometrijskih parametara. Utjecaj napona generiranog PWM-om je analiziran i uspoređen s rezultatima drugih istraživačkih radova što je poslužilo u svrhu validacije predloženog mjernog postava. Provedena su i mjerenja u uvjetima istosmjerne magnetizacije materijala i podaci su prikupljeni u obliku 3D mapa gubitaka. Predložene su dvije metode za izračunavanje doprinosa gubitaka izazvanih PWM-om ukupnim izmjeničnim gubicima i razvijeni su odgovarajući algoritmi. Dobivene 3D mape gubitaka korištene su za karakterizaciju magnetskog materijala, a rezultati proračuna uspoređeni su s rezultatima provedenih mjerenja u uvjetima izmjenične pobude. Rezultati proračuna dobro se slažu s mjerenjima.

• Keywords: Experimental characterization of ferromagnetic materials; PWM effects on iron losses; Calculation of the contribution of PWM-induced losses; High-power single winding measurement setup for material characterization; Ring core; DC bias
• Keywords (croatian): Eksperimentalna karakterizacija feromagnetskih materijala; utjecaj PWM-a na gubitke u željezu; izračun doprinosa gubitaka uzrokovanih PWM-om; mjerni postav velike snage s jednim uzbudnim namotom za karakterizaciju materijala; prstenasta jezgra; istosmjerna magnetizacija (DC bias)
• Language: english
• URN:NBN: urn:nbn:hr:168:545054
• Promotion: 2023
• Study programme: Title: Doctoral study programme "Electrical Engineering and Computing"; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, po-dručje tehničkih znanosti (doktor/doktorica znanosti, po-dručje tehničkih znanosti)
• Type of resource: Text
• Extent: xxi, 207 str. : graf. prikazi ; 31 cm.
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-09-18 15:48:03