The Economics for Selection of Drives---AC Motors or Steam Turbine Mechanical Drives

Applying mechanical-drive turbines is an option when the opportunity exists for cogeneration. Conversely, new developments in the technology of variable-speed ac drives have enhanced motor application for drive systems when a wide range of speed control is required. Since selection between the two types of drives spans both mechanical and electrical engineering disciplines, some biases can be present that will affect the final choice. Engineers tend to be more comfortable with choices which are within their sphere of experiences. When examined in more fundamental terms, the potential economic value of the proper choice should transcend other reasons for preference. Analysis of the factors influencing the selection and the methods permitting the best economic choices are described. Curves to aid the selection process are presented.