Danfoss VLT CDS 302, Руководство по устранению неисправностей, Страница: 13 / 18

Common drives and motor problems
EMC - Electro Magnetic
Compatibility
Effects of EMI
Sources of EMI
Electro Magnetic compliance or EMC are the
voltage and current which are not sinusoidal but
pulsating.
Electromagnetic Compatibility (EMC) concerns
for typical commercial and industrial equipment.
EMI related disturbances to drive operation are
uncommon, but the following detrimental EMI
effects may be seen:
• Motor speed fluctuations
• Serial communication transmission errors
• Drive CPU exception faults
• Unexplained drive trips
Detrimental Effects To These Systems May
Include The Following:
• Pressure/flow/temperature signal transmitter
signal distortion or aberrant behaviour
• Radio and TV interference
• Telephone interference
• Computer network data loss
• Digital control system faults
Drives utilize Insulated-Gate Bipolar Transistors
(IGBTs) to provide an efficient and cost effective
means to create the Pulse Width Modulated
(PWM) output waveform necessary for accurate
motor control. These devices rapidly switch the fixed DC bus
vo ltage creating a variable frequency, variable
voltage PWM waveform.
This high rate of voltage change [dV/dt] is the
primary source of the drive generated EMI.
13
FRCC.PC.036.A2.02
Check List