dv/dt Filters

Since the rise time of IGBTs are in the range of a few tens of nanoseconds (between 50ns-200ns), even short cables between PWM motor drives and motors can cause voltage doubling at the motor terminals due to Travelling Wave Phenomenon such as in transmission lines. If sufficient precautions are not taken, the insulation of motor windings are prone to failure due to high voltage spikes.

dV/dT Output Filter Modules effectively protect motors against these high voltage spikes due to the use of motor cables between IGBT-based motor drives and motors.




  • Reduction of dv/dt stress on the motor windings
  • Extension of equipment lifespan
  • Compliance with standards of general purpose motors up to 100 m cable length
  • Economic and compact solution for short cable applications
  • Reduction of EMI on surrounding equipment


Typical Applications


  • Motor Drives with short motor cables
  • Motor Drives with existing motors
  • Process Industry
  • Oil & Gas
  • HVAC
  • Water and Waste Water
  • Irrigation




Technical Specifications
Motor drive input power ratings 0.3-630 kW (parallel operation for higher power ratings)
Operation voltages Standard voltages up to 690V
Operating frequencies 50Hz - 60 Hz (without derating)
Rated currents 1A - 1200A
Minimum switching frequency 1.5kHz - 4kHz (depending upon filter rating)
Maximum switching frequency 8kHz
Overload capability 1.6 x rated current (1 min/hour)
Protection degree IP20 (upper protection degrees upon request)
Ambient temperature -30°C to +50°C
Altitude < 1000m