This paper analyzes the phase-shifting carrier PWM techniques in case of multilevel cascaded H-bridges with non-equal DC-link voltages. In the past it has been demonstrated that these techniques succeed in cancelling the sideband harmonics in the produced multilevel voltage only if the DC-link voltages are equal. Two different approaches can be used to modulate the reference signal in multilevel converters when the DC-link voltages are different and in a non-integer ratio: the theory of symmetric polynomials and resultants, and the generalized hybrid modulation (GHM) technique, which extends the hybrid modulation technique to non-integer DC-link ratio. This paper extends the original PSC-PWM technique proposing a method to obtain the proper shifting angles in view of reducing the overall output voltage WTHD under every possible de-link voltages. The proposed new approach is compared, in simulation with the original phase-shifted cascaded multilevel technique
Multilevel Phase-Shifting Carrier PWM Technique in Case of Non-Equal DC-Link Voltages / Liserre, Marco; Monopoli, Vito Giuseppe; Dell'Aquila, A.; Pigazo, A.; Moreno, V.. - (2006), pp. 1639-1642. (Intervento presentato al convegno 32nd Annual Conference of the IEEE Industrial Electronics, IECON 2006 tenutosi a Paris, France nel November 6-10, 2006) [10.1109/IECON.2006.347669].
Multilevel Phase-Shifting Carrier PWM Technique in Case of Non-Equal DC-Link Voltages
LISERRE, Marco;MONOPOLI, Vito Giuseppe;
2006-01-01
Abstract
This paper analyzes the phase-shifting carrier PWM techniques in case of multilevel cascaded H-bridges with non-equal DC-link voltages. In the past it has been demonstrated that these techniques succeed in cancelling the sideband harmonics in the produced multilevel voltage only if the DC-link voltages are equal. Two different approaches can be used to modulate the reference signal in multilevel converters when the DC-link voltages are different and in a non-integer ratio: the theory of symmetric polynomials and resultants, and the generalized hybrid modulation (GHM) technique, which extends the hybrid modulation technique to non-integer DC-link ratio. This paper extends the original PSC-PWM technique proposing a method to obtain the proper shifting angles in view of reducing the overall output voltage WTHD under every possible de-link voltages. The proposed new approach is compared, in simulation with the original phase-shifted cascaded multilevel techniqueI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
