Influence of Three-Phase Impulses with Different Sequences and Rise Times on Voltage Distribution Along the Stator Winding of Rotating Machines

The highest amplitude and distribution characteristic of repetitive impulse overvoltage are need to be eliminated for ensuring the stability and reliability of the rotating machines. In this paper, in order to research the influences of PWM three-phase impulse sequences on the voltage distribution characteristic along the stator windings, a laboratory test platform with a 2.5MW permanent magnet synchronous generator under the excitation of a PWM inverter was set up, and a corresponding numerical calculation model was developed to represent these electrical behaviors. The repetitive impulses with different three-phase sequences were measured and calculated, respectively, to analyze their effects on the stator winding voltage distribution. Moreover, the rise time of three-phase impulses was also altered in the calculation model within a range from 0.2 to 2 microsecond to obtain the corresponding voltage distributions. The characteristics of coil (or turn) to ground, coil to coil and inter-turn voltage, respectively, along the stator winding were got and analyzed also.