Chapter 4
Chaos in AC Drive Systems
AC drive systems have been widely accepted for industrial applications. In general, they take the advantages of a higher power density and a higher efficiency than DC drive systems. AC drive systems are composed of two major groups, namely the induction drive systems and synchronous drive systems. Among the induction drive systems, the cage-rotor is almost exclusively used for industrial applications. Among the synchronous drive systems, the permanent magnet (PM) brushless AC drive system (usually termed PM synchronous drive system) is becoming popular, whereas the synchronous reluctance drive system is receiving attention.
In this chapter, chaos is investigated in three representative AC drive systems, namely a cage-rotor induction drive system, a PM synchronous drive system, and a synchronous reluctance (SynR) drive system.
4.1 Induction Drive Systems
It is well known that the motor parameter variations, especially the increase in rotor resistance due to prolonged operation, in field-oriented control (FOC) based induction drive systems may violate the necessary decoupling condition, causing an unexpected speed fluctuation. In recent years, it has been identified that the compensation of this rotor resistance variation may cause chaotic phenomena (Gao and Chau, 2003a). Therefore, in this section a practical induction drive system using FOC is first modeled, then Poincaré mapping and bifurcation analysis are conducted. Consequently, computer ...
