Keywords: small hydro, self-excited induction generators, isolated AC power supply, wound rotor induction generators, micro hydro, simulation, generator control, voltage control
Voltage controlled stand-alone microhydro induction generator system
The paper discusses simulated control cases of the wound rotor self-excited induction generator WRSEIG. The generator external controller is designed to regulate the output voltage and frequency for constant or variable speed operation of the prime mover and has the inherent capability of protecting the load from short circuit, which permits voltage collapse under heavy loads. WRSEIG is self-excited using one set of excitation capacitance connected across the generator stator side. At the rotor side, a PWM controlled resistor is connected to the rotor windings through the rotating slips and act as a slip power controller. The controller can be configured to regulate the voltage as the speed or the load changes. The presented system has the capability to generate good quality AC power source with minimum controlling elements and can operate under constant or adjustable prime mover speed that suits many microhydro electricity-generating plants.