Delta Electronics MVF2000 Series, Product Manual

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2-2 Principles
2-2-1 Main circuit
Fig. 2-9 Topological structure diagram
The typical circuit topological structure diagram of MVF2000 Medium Voltage Drive
series is as shown in Fig. 2-9.
The phase-shift rectifier transformer is a three-phase air-cooled dry-type transformer
directly connected with the incoming high voltage, whereas the secondary windings use
extended delta connection, which can lower the content of the input side current distortion.
The phase-shift angle between the secondary windings can be calculated according to the
following formula:
cells power of Number
angle shift Phase

 
60
The secondary windings of the transformer provide input power for each power cell
respectively. The amount of secondary windings and the phase-shift angle between the
windings are determined according to the voltage level and structure of the MVD, as shown in
Table 2-1.
Table 2-1 Power cell configuration table of MVF2000 medium voltage drive
MVD series
Number of power
cells per phase
System cell
number
Output phase
voltage
Output line voltage
3.3kV 3 9 1905V 3300V
6.6kV 6 18 3810V 6600V
11kV 9 27 6351V 11000V