Design procedure for brushless doubly-fed machine used as a limited speed-range pump drive

The continuing desire of industry to further improve process efficiency, through tighter control and energy conservation, has prompted users to pay closer attention to Adjustable Speed Drives (ASDs). The conventional ASDs consist of induction or synchronous motors controlled by power electronic controllers through the adjustment of supply frequency and line voltage. The drawback of these conventional ASDs lies in the high cost of the power electronic controllers which have the same rating as that of the machine itself. The Brush less Doubly-Fed Machine (BDFM) ASD has proven, both analytically and experimentally, to provide a cost effective and a wide range of precise speed control. The experimental BDFM prototypes built to date were designed and constructed individually based on designers' experience with self-cascaded machines. The success with these prototypes has promoted the idea of standardizing the design procedure for all future BDFMs. This thesis offers a general design procedure for the BDFM, which can serve as a first step in standardizing the manufacturing process of this machine. The procedure is presented in the form of a demonstration, by applying it to the design of a 60-hp, 600 to 900 r/min, 460-volts BDFM pump drive to replace the currently utilized conventional 60-hp wound rotor induction motor ASD. An ideal design, which determines machine details such as physical dimensions, slot specifics and conductor details based on conservative magnetic and electric loading assumptions, is one form of the design procedure. The other form, the practical design, involves utilizing a specified physical dimensions and slot details to determine the associated conductors' details and to insure the compliance of machine loadings with up-to-date industrial standards. In both procedures, the design will be made to satisfy, if not to exceed, the existing conventional drive performance