5motor control (mctrl) – Lenze 8400 TopLine User Manual

Page 279

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Lenze · 8400 TopLine · Reference manual · DMS 6.0 EN · 06/2014 · TD05/TD14

279

5

Motor control (MCTRL)

5.10

Parameterisable additional functions

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Example: Voltage increase in the DC bus when field weakening is switched off
(For instance by an active setting of the controller inhibit or by tripping a fault or error at high motor

speed.)

[5-28] Example: Possible DC-bus voltage > 800 V if field weakening gets lost

Field weakening

Speed n

Motor voltage peak value

Switched off

4000 rpm

560 V

5700 rpm

800 V

6000 rpm

840 V

Switched-on

6000 rpm

560 V

• If pulse inhibit occurs at 6000 rpm and switched-on field

weakening, the DC bus is loaded to more than 800 V ().

• A speed limitation to 5700 rpm is required since this speed

causes a DC-bus voltage of 800 V if field weakening is

switched off.

n

U

4000

840 V

560 V

6000

> 800 V

Œ

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