Title :
Multi-sampled carrier-based PWM for multilevel active shunt power filters for aerospace applications
Author :
Odavic, Milijana ; Biagini, Veronica ; Sumner, Mark ; Zanchetta, Pericle ; Degano, Marco
Author_Institution :
Dept. of Electr. & Electron. Eng., Univ. of Nottingham, Nottingham, UK
Abstract :
Active power filters create sideband harmonics over a wide frequency range around the multiple carrier-frequency harmonics and these can encroach into the low frequency range. This issue is particularly critical when low carrier-fundamental frequency ratios are used such as in aerospace applications, where high fundamental frequencies exist. A multilevel Active Shunt Filter with a low switching frequency is proposed to mitigate the lowest order carrier frequency terms. However low carrier frequencies lead to reference voltage phase delay and attenuation and can introduce significant baseband harmonics. These effects cannot be hidden by employing multiple modulator converters. In order to overcome these problems, a multi-sampled modulation approach is proposed, which allows duty cycle updating (n-1) times per switching period for each H-bridge of one phase of the n-level converter (rather than only once or twice as in the regularly sampled PWM). The proposed modulation approach was combined with predictive current control in order to enhance the system performance. The control loop performance compared to regularly sampled PWM is experimentally verified by employing a five-level ASF in a 400Hz power network.
Keywords :
active filters; aerospace engineering; electric current control; modulators; power harmonic filters; power system harmonics; predictive control; pulse width modulation; H-bridge; aerospace application; control loop performance; duty cycle; low carrier-fundamental frequency ratio; low switching frequency; multilevel active shunt power filter; multiple carrier-frequency harmonics; multiple modulator converter; multisampled carrier-based PWM; multisampled modulation approach; n-level converter; predictive current control; sideband harmonics; significant baseband harmonics; voltage phase attenuation; voltage phase delay; Harmonic analysis; Power harmonic filters; Pulse width modulation; Switches; Voltage control;
Conference_Titel :
Energy Conversion Congress and Exposition (ECCE), 2011 IEEE
Conference_Location :
Phoenix, AZ
Print_ISBN :
978-1-4577-0542-7
DOI :
10.1109/ECCE.2011.6063956