Multi-pole generator

 The conventional two-pole generator had to be operated at the synchronous rotation speed (3000/3600 rpm) in order to generate a 50 or 60 Hz output.

 In general, in the case of a small engine the maximum output-producing rotation speed is higher than the synchronous rotation speed. Accordingly, the conventional two-pole generator could not use the engine's maximum output fully (The output corresponds to each point on the operating line in the figure shown below (left)).

 The multi-pole generator newly equipped with an "inverter" can operate within the shaded region of the figure shown below (right) where it can produce sufficient output necessary to generate a constant-voltage fixed frequency sine-wave output.

For these reasons

  • A smaller engine can be used (because it can be operated even in a higher rotation speed range beyond the synchronous rotation speed).
  • At light load, it is possible to perform silent operation by lowering the rotation speed.

 In addition, the weight of a multi-pole generator is about a half of the weight of a two-pole generator. The reasons for this lightweight are that its coils are directly wound around the multi-pole cores and therefore sufficient cooling is achievable by air ventilation, which leads to the increase in the current density of coils and also its high rotation speed.

Sawafuji Electric can provide the multi-pole generators with an output power range of 1 to 8 kW.


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