OVERVIEW

Before the development of the polyphase AC concept by Nikola Tesla [1] in 1888, there was a competition between AC and DC systems. The invention of the induction machine in the late 1880s completed the AC system of electrical power generation, transmission, and utilization. The Niagara Falls hydroplant was the first large-scale application of Tesla s poly-phase AC system. The theory of single- and three-phase induction machines was developed during the first half of the twentieth century by Steinmetz [2], Richter [3], Kron [4], Veinott [5], Schuisky [6], B defeld [7], Alger [8], Fitzgerald et al. [9], Lyon [10], and Say [11] just to name a few of the hundreds of engineers and scientists who have published in this area of expertise. Newer textbooks and contributions are by Match [12], Chapman [13], and Fuchs et al. [14, 15]. In these works mostly balanced steady-state and transient performances of induction machines are analyzed. Most power quality problems as listed below are neglected in these early publications because power quality was not an urgent issue during the last century.

Today, most industrial motors of one horsepower or larger are three-phase induction machines. This is due to their inherent advantages as compared with synchronous motors. Although synchronous motors have certain advantages such as constant speed, generation of reactive power (leading power factor based on consumer notation of current) with an overexcited field, and low cost for low-speed motors they have the constraints of requiring a DC exciter, inflexible speed...