NORD Drivesystems BU0530 - Manual (Page 20)

Functional safety with NORD SK 500E frequency inverters
20 BU 0530 GB-3712
Sizes 7 - 9
I/O
Emergency stop
Driver µ C
T 5
T 6
T 3
T 4
T 1
T 2
U
V
W
L 1
L 2
L 3
Frequency Inverter
Logic
=
=
=
=
Control voltage
Gate supply
VIS 0V (88)
VIS 24V (89)
VOS 0V (87)
VOS 24V (86)
Primary power
=
=
=
=
PWM-IC
=
=
PWM-IC
=
=
PWM-IC
M
Safe pulse block
The semiconductor switches of the inverter (T1 to T6) are controlled by a highly complex pulse pattern. This
pulse pattern is generated by the microcontroller (µC) and amplified by the driver. The drivers convert the logic
signals on the control voltages of the semiconductor switch. The semiconductor switches are switched via the
control voltage and the pulse pattern is amplified and applied to the motor terminals. Due to the low-pass effect
of the motor, a three-phase pulse width modulated sine wave voltage - a three-phase system, results from the
pulsed voltage. The motor generates a torque.