A Novel Scheme for Switching Between a Self-excited Induction Generator and a Series Connected Self-excited Synchronous Generator

This paper proposes a novel switching scheme to operate an autonomous three-phase wound-rotor induction machine (IM) as two self-excited AC generators. The first generator is a self-excited induction generator (SEIG) with short-circuited Y-connected rotor terminals. The second generator is a series connected self-excited synchronous generator (SCSESG) with Y-connected rotor windings in series with its stator windings in different phase sequence. The three-phase IM model is derived to analyze the performance operated as an SEIG or an SCSESG. To validate the proposed IM model switching between an SEIG and an SCSESG under various loading conditions, the simulated steady-state and transient results are compared with the experimental results obtained from a laboratory 1.1-kW wound-rotor IM. It can be concluded from the simulated and experimental results that the proposed model is adequate to simulate the performance of the IM operated as an SEIG or an SCSESG.