Stand alone variable speed constant frequency generators
- Univ. of Limerick (Ireland)
The paper discusses three types of stand-alone variable speed constant frequency (VSCF) generators, which do not require power processing equipment in order to generate constant frequency output from a variable speed prime mover. These are the AC commutation generator (ACCG), the synchronous condenser and the programmed pole generator or Roesel machine. In the ACCG, a reference frequency voltage is supplied to the field winding and the output power at constant frequency (single or multiphase) is obtained from the rotor commutators. The characteristic of this machine is similar therefore, to the DC machine with linear torque-speed characteristic. In the synchronous condenser system, the reactive vars of the induction generator and load are supplied by a synchronous machine running at synchronous speed. The DC field current for the synchronous machine can be adjusted in such a way that all its losses are supplied by the induction generator and therefore it will be free running at constant speed without an auxiliary prime mover. The programmed pole generator, or Roesel machine, has no slip rings or commutators but a solid rotor made from iron laminations and ferrite pieces. The stator consists of two windings, the exciter winding and the output winding. As in the ACCG, a reference frequency is supplied to the exciter winding in order to {open_quote}write{close_quote} the number of poles on the rotor in real time. The output winding thus generates a constant frequency power supply to the load independent of the prime mover speed.
- OSTI ID:
- 220093
- Report Number(s):
- CONF-9507190--
- Country of Publication:
- United States
- Language:
- English
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