Analytical evaluation of output current ripple amplitude in three-phase three-level inverters
2014 (English)In: IET Power Electronics, ISSN 1755-4543, Vol. 7, no 9, 2258-2268 p.Article in journal (Refereed) Published
Nowadays, three-phase multilevel inverters are widely employed in medium and high-power applications, increasing the power ratings, improving the output voltage quality and reducing the conducted electromagnetic interferences. Despite of numerous pulse-width modulation (PWM) techniques have been developed for multilevel inverters, a detailed analysis of the output current ripple amplitude has not been reported yet. In this study, the peak-to-peak current ripple distribution over a fundamental period is analysed in details specifically for three-level three-phase voltage source inverters for both motor-load and grid-connected applications. In particular, the peak-to-peak amplitude of the current ripple is determined analytically as a function of the modulation index. The centred PWM strategy is considered in all the developments, implemented either by carrier-based or space vector (SV) PWM methods. With this modulation, the dc bus utilisation is maximised in a simple and effective way, and a nearly-optimal behaviour is obtained to minimise the current ripple rms. The results obtained in different cases and sub-cases identified in the proposed analytical approach are verified by experimental tests with reference to three-phase three-level neutral-point clamped configuration.
Place, publisher, year, edition, pages
2014. Vol. 7, no 9, 2258-2268 p.
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:uu:diva-236636DOI: 10.1049/iet-pel.2013.0837ISI: 000343973600008OAI: oai:DiVA.org:uu-236636DiVA: diva2:764822