Keywords: bifurcation diagrams, chaotic behaviour, Poincare map, scalar drives, induction motors, chaos, stability analysis
Chaotic behaviour analysis in induction motors with scalar drive systems
In this paper, the existence of the bifurcation and chaos phenomena in scalar drives of induction machines are investigated. It is shown that there is an unstable region in the plane of voltage-frequency based on the speed controller gain. The unstable region is different for closed or open loop scalar drive systems. Constant and periodic loads are considered in system analysis. When load is constant, modelling of the scalar drive is autonomous in synchronous reference frame accordingly, eigenvalues analysis and bifurcation diagrams of the autonomous systems in any fixed point reveal chaotic behaviour. When load is periodic, such as a compressor, the system will be autonomous and have periodic response. As such, for stability analysis, Poincare map is applied to the systems equations. Existence of drives behaviour may highly be predicted by calculation of eigenvalues of Poincare map in the systems.