Synchronous Motor Line; Absolute Encoder With Rssi Board; Absolute Encoder - WEG MVW3000 Series User Manual

5 SYNCHRONOUS MOTOR LINE

In order to allow driving synchronous motors, the MVW3000 introduces a number of software functions and new
hardware elements for commanding and controlling these motors.
Figure 5.1 on page 5-1 presents the general diagram for driving the synchronous motor using the MVW3000.
For more details on the excitation control system and the direct connection of the motor to the line, refer to the
electrical project of the inverter.
Supply line

5.1 ABSOLUTE ENCODER WITH RSSI BOARD

In synchronous machine drive applications, it is necessary to use an absolute encoder so as to obtain the exact
rotor position in relation to the stator, since the incremental encoder is not able to provide such information.

5.1.1 Absolute Encoder

The synchronous motor control requires the use of an absolute encoder, which must follow the following
specifications:
Synchronous Serial Interface (SSI) communication protocol with RS-485 communication channel, with clock and
16 bit word size in the following format:
14 data bits
1 ZERO bit
1 even parity bit
Auxiliary line
Y
RSSI
MVW3000
Interlocked
Figure 5.1: General diagram of the inverter for synchronous motor
Synchronous Motor Line
AC/DC converter
Y
MVC3
Excitation
control
system
MVC4
Crowbar
- +
E
MS
MVW3000 | 5-1 MVW3000 | 5-1
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