| Abstract: | ![]()
This paper presents a new PWM scheme for NPC inverters that is suitable for large capacity GTO inverters. In conventional NPC inverters, a pulse of narrow width is needed to synthesize a low-voltage wave. A pulsewidth limitation due to the use of GTOs causes differences between output phase voltages and reference voltages. This paper proposes a scheme in which square waves are added to all three-phase voltage references to enable a low-voltage to be synthesized with no narrow pulses and significant reduction in harmonic components of output voltage results. Also, a new neutral point voltage control is proposed. Finally, a theoretical analysis and experimental results for the proposed scheme are presented. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 118 (1): 93–105, 1997 |
