Pulse Width Modulation (Pwd) Output Method; Switching Frequency For Low Motor Noise - Siemens MICROMASTER Eco Reference Manual

ECO REFERENCE MANUAL
7.

PULSE WIDTH MODULATION (PWD) OUTPUT METHOD

0V
Pulse Width Modulation
SWITCHING FREQUENCY FOR LOW
MOTOR NOISE
• PWM (pulse width modulation) switching
frequency adjustable from 2kHz to 16kHz
• 16kHz above audible frequency
• The pulse width modulation (PWM) switching
frequency used is proportional to the heating
and energy losses within the inverter. The
higher the switching frequency the greater is
the amount of heat produced by the inverter
output devices (IGBTs). An overtemperature
trip can result if the inverter is operating close
to its maximum rated temperature and is fully
loaded.
• The Eco unit automatically optimizes switching
frequency whenever possible for motor noise
reduction
• Lowers switching frequency if heat sink
temperature exceeds limits
• Once heat sink temperature returns to normal,
switching frequency returns to setting
Voltage
Current
Larger MIDIMASTER Eco units may be restricted
from operating above 4kHz. Refer to parameter
P076 which shows output current restrictions
associated with switching frequency.
Time
7-1