DV/DTfilter
When the PWM inverter directly drives the motor, it will generate
a higher common-mode voltage of dv/dt, and thus generate bearing
current and common mode leakage current and severe
electromagnetic interference (EMI).Due to the influence of the
distribution parameters in the cable, voltage reflection occurs
at the motor end, resulting in coil insulation failure.The dv/dt
filter reduces the attenuation rate of the motor cable
transmission line, minimizes the peak voltage, and effectively
reduces the high output voltage dv/dt of the IGBT
converter.
Product application
dV/dT filter is for protecting the motor.Due to the long running cable between the inverter and the motor, it will cause a peak voltage that has a devastating effect on the motor.The length of the cable depends on the number of switchings of the power semiconductor and the size of the motor.If the cable is as short as 2.5 meters, the peak voltage of the motor will exceed the rated value.If the cable is too long, the problem is even bigger.In this case, a dV/dT filter is required to protect the motor from the devastating effects of the peak voltage.