Power system transients on large induction generator installations

For electrical energy recovery schemes there is a case for selecting an induction generator, for both the lower initial cost and reduced equipment complexity. Unexcited generators the least expensive system, but they impose heavy current surges when closed onto the electrical supply. The use of synchronizing equipment with an excited induction generator substantially reduces the synchronizing surges. For soft supplies or transient intolerant systems, self excited induction generators may be used equally as well as synchronous generators. Due consideration must be paid to the transient performance to ensure that safe operation under fault or system disturbance conditions is assured. Particularly severe voltage dips can cause significant problems to generator plant, and careful selection of both mechanical and electrical protection is essential for safe operations. The author discusses synchronisation, excitation capacitors, and system disturbances