Island operation of the variable speed induction generator

The power generation system with a doubly fed induction generator operating autonomously is described in the following paper. A simplified topology of the power electronics converter connected to the rotor was applied. The subsynchronous range of speed is mainly possible for this system, but in the negative rated slip range it can operate also. The external source is used for initial excitation of the generator and next the excitation power source is switching to the stator. The space vector theory is used in the control algorithm. The stator voltage vector components in x and y axes in the rotating reference frame are responsible properly for the stator voltage amplitude and frequency. In this way the stator voltage frequency and amplitude are mechanical speed independent. A better stability of the power system is achieved by the proportional rotor current feedback loop using. PSIM software was used for regulators quick designing and tuning. A laboratory system with 1.5 kW slip-ring machine was build and tested. As a controller the floating point processor Share/spl trade/ with a programmable unit ALTERA/spl trade//FPGA support was used. Results of the simulation tests and oscillograms from the laboratory setup are presented in the paper.