WEG MVW3000 A0040 V023, User Manual

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MVW3000 | 3-1
3
MVW3000 | 3-1
Product Characteristics
3 PRODUCT CHARACTERISTICS
A brief theoretical explanation about the operation and a simplified electrical scheme of the power cells and
their connections are presented below. The basic operation of the control system is presented at the end of this
chapter.
The MVW3000 is a frequency inverter designed to control medium voltage motors at the rated values of 2.3 kV to
13.8 kV and for a power range of 150 HP to 5400 HP. Based on a topology where the low voltage cells (< 1000
V) are connected in series to form each inverter phase, its assembly is modular, enabling different configurations
if necessary to drive high power motors.
NOTE!
The characteristics contained in this manual were based on models of the standard MVW3000
intended for applications on 6.6 kV motors. Therefore, the MVW3000 used in the general illustrations
will contain 18 low voltage power cells (six in series per phase). Notice that the MVW3000 can be
engineered to meet the needs and technical specifications of our customers. Contact out technical
team for more details.
3.1 INPUT TRANSFORMER
The MVW3000 inverter has an input transformer, because the cascade cell topology demands the feeding of
each cell to be insulated from each other. This transformer is built so as to meet the different functions for the
MVW3000, such as the necessary insulation for the power cells, cancellation of the harmonic current coming
from the cell input rectifiers, and it also has an auxiliary winding responsible for the system pre-charge.
V phase cells
Medium voltage
input
Auxiliary input
(pre-charge)
W phase cells
U phase cells
U1
U2
Un
V1
V2
Vn
W1
W2
Wn
Figure 3.1: Input phase-shifting transformer diagram