Traveling Wave Effects
Keith H. Sueker
Traveling wave effects were once the nearly exclusive domain of communications engineers and electric utility transmission line engineers. However, as variable frequency, pulse width modulated (PWM) motor drives have gone to higher and higher PWM frequencies, standing-wave phenomena have appeared in motor circuits. Traveling waves are now of concern to many power electronics engineers, and an understanding of their effects is necessary for motor protection in installations with long cables or high PWM frequencies. In modern terms, a transmission line is any set of parallel or coaxial conductors of finite length, and they may be printed circuit conductors or miles of overhead wires.