Output filters for PWM drives with induction motors

摘要: When an induction motor is energized from a pulse width modulated (PWM) inverter, through long connecting cables, its insulation system can be severely stressed. The high dv/dt voltage pulses at the output of inverter cause traveling waves in cable between and motor. wave reaches motor, large impedance mismatch present which leads to reflected that, when added incoming incident wave, reach two times voltage. resulting overvoltage terminals stresses lead reduced life. Various filter arrangements used condition before it applied cable. advantage adding filtering that dielectric stress on charging current both reduced. major disadvantages they represent extra cost, require mounting space, introduce losses system. most commonly types filters are: simple line inductors; limit filter; sine termination filter. These are discussed.