Abstract:
This paper presents a variable speed autonomous squirrel cage generator excited by a current-controlled
voltage source inverter to be used in stand-alone micro-hydro power plants. The paper proposes a system
control strategy aiming to properly excite the machine as well as to achieve the load voltage control. A
feed-forward control sets the appropriate generator flux by taking into account the actual speed and
the desired load voltage. A load voltage control loop is used to adjust the generated active power in order
to sustain the load voltage at a reference value. The control system is based on a rotor flux oriented vector
control technique which takes into account the machine saturation effect. The proposed control strategy
and the adopted system models were validated both by numerical simulation and by experimental
results obtained from a laboratory prototype. Results covering the prototype start-up, as well as its
steady-state and dynamical behavior are presented.
