Static power conversion from self-excited induction generators

Schemes based on synchronous generators and high-voltage d.c. transmission are often used to exploit remote natural energy resources. However, unless the provision of synchronous power at the sending end is essential, such schemes are unnecessarily complex. The paper describes an alternative solution using self-excited induction-generator/controlled-rectifier units, which eliminate the problems of voltage and frequency variations inherent in self-excited induction machines. Theoretical and experimental results are provided showing that the self-excited induction generator can operate in the linear region of the magnetisation curve while feeding a variable d.c. load at constant voltage. It is also shown that the unit can be used to feed controllable power into an existing a.c. network through a d.c. transmission link.