surge generator[′sərj ‚jen·ə‚rād·ər]
a synchronous generator (usually for three-phase current) designed for short-duration operation under short-circuit conditions.
A surge generator is usually an air-cooled, two-pole turbine generator. Such generators are used to test high-voltage apparatus for switching capability and thermal and electrodynamic stability. The apparatus being tested is connected to the surge generator either directly or through a transformer. The short circuit lasts 0.06–0.15 sec, after which the surge generator is cooled for several minutes. The voltage generated is usually in the range from 6 to 20 kilovolts (kV); the power ratings of the largest surge generators range from 3 to 7.5 gigavolts-amperes. Surge generators are driven by asynchronous electric motors with phase-wound rotors, having power ratings of up to 6 gigawatts and excited by a separate source.
Difficulties in the design and construction of surge generators are associated with the high electrodynamic stresses (surge stresses) imposed on the stator winding under short-circuit conditions.