Title :
A comparison of multicarrier PWM strategies for cascaded and neutral point clamped multilevel inverters
Author :
McGrath, B.P. ; Holmes, D.G.
Author_Institution :
Dept. of Electr. & Comput. Syst. Eng., Monash Univ., Clayton, Vic., Australia
Abstract :
Analytical solutions of pulse width modulation (PWM) strategies for multilevel neutral point clamped (NPC) and cascaded inverters are presented. These solutions show that the alternative phase opposition disposition (APOD) PWM strategy for NPC inverters produces the same spectral components as the phase shifted carrier PWM (PSCPWM) strategy for cascaded inverters, when the carrier frequencies are adjusted to achieve the same number of total switch transitions for each inverter over one fundamental cycle. From this understanding, a method is proposed to apply the harmonically superior phase disposition (PD) PWM strategy for NPC inverters to cascaded inverters, to achieve improved harmonic performance for the modulation of cascaded inverters. Both theoretical and experimental results confirming this understanding are presented
Keywords :
DC-AC power convertors; PWM invertors; harmonic distortion; harmonics suppression; power conversion harmonics; switching circuits; alternative phase opposition disposition PWM strategy; carrier frequencies; cascaded multilevel inverters; harmonic performance improvement; multicarrier PWM strategies comparison; neutral point clamped multilevel inverters; phase disposition PWM strategy; phase shifted carrier PWM strategy; spectral component; switch transitions; Bridge circuits; Frequency; Leg; Phase modulation; Power semiconductor switches; Pulse inverters; Pulse width modulation; Pulse width modulation inverters; Systems engineering and theory; Voltage;
Conference_Titel :
Power Electronics Specialists Conference, 2000. PESC 00. 2000 IEEE 31st Annual
Conference_Location :
Galway
Print_ISBN :
0-7803-5692-6
DOI :
10.1109/PESC.2000.879898
