Effect of subharmonics on the operation of ultrahigh speed induction machines

Stumpf, Péter; Varga, Zoltan; Bartal, Peter; Jardan, R.K.; Nágy, I.

doi:10.1109/iecon.2009.5414960

Cited by 7 publications

(3 citation statements)

References 10 publications

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“…The high switching frequency of SiC transistors, which allows voltage modulation frequencies higher than 50 kHz to be achieved, makes it possible to properly generate a voltage with a fundamental harmonic frequency significantly higher than that obtained in inverters with silicon IGBTs. According to [34], the voltage modulation factor is defined as follows:…”

Section: Methodsmentioning

confidence: 99%

Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator

Breńkacz¹,

Bagiński²,

Adamowicz³

et al. 2022

Eksploatacja i Niezawodność – Maintenance and Reliability

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Due to ongoing research work, a prototype test rig for testing high speed motors/generators has been developed. Its design is quite unique as the two high speed machines share a single shaft with no support bearings between them. A very high maximum operating speed, up to 80,000 rpm, was required. Because of the need to minimise vibration during operation at very high rotational speeds, rolling bearings were used. To eliminate the influence of higher harmonics of supply voltage and current on the formation of torque oscillations on the shaft and excessive losses in the form of heat, a voltage source inverter with high switching silicon carbide (SiC) power transistors characterizing high precision of the output voltage generation with a fundamental harmonic frequency of several kilohertz has been used. During the first start-ups, it turned out that the system was not stable, and a failure occurred. The paper presents the consequences that may arise when a machine operating at a speed of about 70,000 rpm fails. The article contains pictures of a generator failure that occurred at a high rotational speed.

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Section: Methodsmentioning

confidence: 99%

Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator

Breńkacz¹,

Bagiński²,

Adamowicz³

et al. 2022

Eksploatacja i Niezawodność – Maintenance and Reliability

View full text Add to dashboard Cite

show abstract

“…Expression (8) can be expanded using (7) taking into account (4) and (6). After a transformation of the cosine products appearing in (8) and rearranging, it can be written as:…”

Section: Surface Current Densitymentioning

confidence: 99%

“…For high-speed machines, a very high switching frequency might be required. This may represent a challenge, not only due to the high switching losses in the inverter, but often also because of unavailability or high cost of the appropriate hardware which can support such a fast switching [6]. Since the rotor losses in the PM machines are highly dependent on the harmonic content of stator currents, modeling and prediction of these losses in the context of the inverter switching algorithm becomes very important.…”

Section: Introductionmentioning

confidence: 99%