Steady-state analysis of a self-excited induction generator self-regulated by a shunt saturable reactor

The terminal voltage of a self-excited isolated induction generator (SEIG), supplying a fixed load, may increase considerably due to a small increase in speed, excitation capacitance or both. In most developing countries, unregulated wind-turbines are often used due to their lower cost. Under such conditions the voltage may increase to a dangerously high level which may cause machine, load or capacitor damage. This paper examines the steady state analysis and performance characteristics of an isolated SEIG when a saturable reactor is connected across its terminals. As the reactor saturates it absorbs the excess reactive VArs supplied by the excitation capacitance, and limits the increase of the terminal voltage