Figure 1. Several operational diagrams of inductions generators found in the literatures, (a) proposed configuration in references [7- 14], (b) proposed configuration in references [15-16]. Several Practical Configurations of a Grid-Tied Induction Generator Constructed from Inexpensive Single Phase Induction Motors Rui Zhang, Student Member, IEEE, Faisal Khan, Member, IEEE, and Marc Bodson, Fellow, IEEE Department of Electrical and Computer Engineering, University of Utah Salt Lake City, Utah, USA Abstract—Three configurations of a unique single-phase power generation system based on inexpensive single-phase induction motors are proposed in this paper. All of these configurations are well suited for residential or equivalent small-scale grid- tied power generation schemes because of their reduced cost, smaller footprint and minimum or no required maintenance. The wind power generation schemes presented in this paper could be used in stand-alone or grid-parallel mode without using any energy storage. Various characteristics of these configurations are summarized in this paper with necessary simulation and experimental results. In addition, an analytical model of the single-phase induction generator is presented to identify its operating characteristics. Keywords-single phase induction generator, voltage source inverter, wind turbines. I. INTRODUCTION DC-motor based residential wind power generators are becoming prevalent these days because their output could be processed and utilized to charge storage batteries. Small scale 12V wind turbines cost around $2/watt including the installation cost where the motor costs around $1/watt. On the other hand, single phase (capacitor start split phase) induction motors are most common type of motors where the price could be as low as 0.1$/watt for a 500W motor. The $/watt number is even smaller for larger sized motors. In addition, induction motors have several advantages compared to other motors such as 1) reduced unit cost and size; 2) ruggedness; 3) brushless operation (in squirrel cage construction); 4) absence of any separate dc sources; 5) ease of maintenance; 6) self protection against severe overloads and short circuits, etc [1-3]. For these reasons, three-phase induction generators with the wound rotor construction occupy over 70% of the total installation capacity in wind energy [4]. However, these units are commonly used in large wind power generation systems with power range of 0.1-10 MW [5, 6]. In contrast, producing power from a single phase induction generator (SPIG) is an unconventional but inexpensive technique with fascinating features, and this method has several limitations and challenges as well. If electric power can be suitably produced from small-scale SPIGs for residential on-site power generation, it will become a technologically viable and economically superior solution. Compared to three-phase induction generators, a small number of technical papers have addressed the potentials of SPIGs for electric power generation. References [7-14] explored modeling, steady-state performance, transient performance, and excitation capacitance requirements for the SPIGs. The topologies presented in these papers are similar, and a typical configuration is shown in Figure 1(a). For a rotational speed lower than the synchronous speed of the motor, the output frequency will be dictated by the equation 120 / N P f × = , where P is the number of poles and N is the shaft speed in RPM. In situations where maintaining the output voltage and frequency is not a prime requirement, this is a simple and practical solution. However the circuit may need a pre-charged capacitor to amplify the residual magnetism in the generator to provide the reactive power at 2011 IEEE International Electric Machines & Drives Conference (IEMDC) U.S. Government work not protected by U.S. copyright 1652