Toshiba T90S3S08KS6XSN Manual page 145

TOSHIBA G9000 UPS White Paper
FIGURE 6
Equivalent circuit of
a multilevel (3-level)
3-phase inverter
circuit
TABLE 2
Pattern of the
line-to-line output
voltage for a 3-level
inverter
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synthesize the line-to-line output voltage increases as well. Consider the
circuit shown in Figure 6. Pattern of the line-to-line voltage (Table 2) shows
nine possible combinations and five resulting voltage levels (+E, +E/2, 0,
-E/2 and –E Volts). A train of variable-width pulses for a 3-level power
processor is shown in Figure 7. The resulting output waveform tracks the
sinusoidal much better than in the case of the conventional inverter.
Line-to-
Terminal Terminal
U V Voltage
E E
+ +
2 2
E
+ 0
2
E E
+ -
2 2
E
0 +
2
0 0
E
0 -
2
E E
- +
2 2
E
- 0
2
E E
- -
2 2
Line
(U - V)
0
E
+
2
E
E
-
2
0
E
+
2
- E
E
-
2
0
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UPSG9000WP081201