A comparison between line-start synchronous machines and induction machines in distributed generation

The phenomenon of the self-synchronisation in line-start synchronous machines can be suitably used in distributed generation plants. With a simple control equipment based on contactors, it is possible to overcome the restrictions imposed to the synchronous generators in some countries. The paper shows that synchronous machines can be suitable also when both stand-alone and grid-connected operations are involved. The paper reports finally a comparison with an equivalent system based on induction machines by means of experimental tests on sample test benches with the target to put in evidence the different characteristics of the two plant typologies