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6F3A4768
In the three-level inverter, three levels of voltage (P-potential, C-potential, and N-potential) can be output by
turning on/off four IGBTs from 01 (IGBT1) to 04 (IGBT4). Fig. 5.1.7 shows the inverter output (phase) voltage
waveform and IGBT status. Fig. 5.1.8 shows the output voltage (rectangular wave) and average voltage (sine
wave) of the inverter.
Fig. 5.1.7 Average Output Voltage
Fig. 5.1.8 PWM Waveform of Three-level Inverter
(1) + voltage output
0 voltage output
−
voltage output
Regular cycle
Q1 and Q2 are ON
+900V
0V
Q2 and Q3 are ON
+900V
0V
Q1 and Q2 are ON
Q2 and Q3 are ON
Q3 and Q4 are ON
0V
-900V
Q1 and Q2 are ON
Q3 and Q4 are ON
V
U-0
V
V-0
V
U-V
Phase voltage
Motor line-to-line voltage
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