Title :
Analysis of steep-fronted voltage distribution and turn insulation failure in inverter-fed form-wound AC motor
Author_Institution :
Motor Technol. Center, Emerson Electr. Co., St. Louis, MO, USA
Abstract :
As a potential source of turn insulation failure, the steep-fronted voltage at the motor terminal generated by pulsewidth modulation drive switching or cable ringing is not uniformly distributed among the coils of the windings and among the turns of the coils. This paper presents a detailed electromagnetic analysis of the parameters of a transient model of coil and coil group which includes iron loss, skin, and proximity effects. The finite-difference method is applied to solve the model for the interturn and intercoil voltage distributions. The simulation is compared to a simplified lattice diagram analysis and to test results. A turn insulation surge-withstanding capability study is then presented with a flexible insulation test system that models the repetitive steep-fronted voltage stress and temperature stress
Keywords :
AC motors; PWM invertors; coils; electromagnetic fields; finite difference methods; losses; machine insulation; machine theory; skin effect; voltage distribution; cable ringing; coils; electromagnetic analysis; finite-difference method; flexible insulation test system; intercoil voltage distribution; interturn voltage distribution; inverter-fed form-wound AC motor; iron loss; motor terminal; proximity effect; pulsewidth modulation drive switching; repetitive steep-fronted voltage stress; simplified lattice diagram analysis; skin effect; steep-fronted voltage distribution; temperature stress; transient coil model; turn insulation failure; turn insulation surge-withstanding capability; Cable insulation; Coils; Drives; Power cable insulation; Power cables; Pulse generation; Pulse modulation; Space vector pulse width modulation; Stress; Voltage;
Journal_Title :
Industry Applications, IEEE Transactions on
