Design of permanent magnets to avoid chaos in PM synchronous machines

This paper analyzes the effect of permanent magnets (PMs) on the occurrence of chaos in PM synchronous machines (PMSMs). Based on the newly derived nonlinear system equation, the bifurcation analysis shows that the sizing of PMs significantly determines the stability of PMSMs. Hopf bifurcation and chaos may even occur in the PMSMs if the PMs are not properly sized. Experimental results of two practical PMSMs are provided to support the theoretical analysis.