The Capacity Optimization for the Static Excitation Controller of the Dual-Stator-Winding Induction Generator Operating in a Wide Speed Range

The dual-stator-winding induction generator (DWIG) designed to achieve wide-speed-range operation with reduced capacity of the static power controller is presented. The DWIG consists of a standard squirrel-cage rotor and a stator with two separate windings wound for the same number of poles. This generator has a diode bridge rectifier load connected across to the power winding and a static excitation controller (SEC) to the control winding. Investigations into the reactive power released by the fixed excitation capacitor bank versus rotor speed under various loads represent that the minimal capacity of SEC can be achieved by an appropriate selection of excitation capacitor bank. With the help of instantaneous power theory, the control mechanism for the DWIG system working with a variable rotor speed is analyzed. Moreover, the system control strategy which is fit for the wide-speed-range operation using the stator flux orientation is consequently proposed. An 18-kW DWIG system with a 270-V high voltage DC output is developed. The simulation and experimental results illustrate a desirable performance, and the compact implementation of SEC is obtained.