Chaos in DC Drive Systems
DC drive systems have been widely used for domestic, industrial and vehicular applications because of their technological maturity and control simplicity. In general, the speed control of DC drives can be accomplished by two methods, namely armature control and field control. In the case of permanent magnet (PM) excitation, the PM field is essentially uncontrollable. During normal operation, the armature circuit is fed by a voltage source while adopting either armature voltage control or armature current control. The voltage control has the definite advantage of simplicity and low cost, whereas the current control has the merit of direct torque control.
In this chapter, chaos in both voltage-controlled DC drive systems and current-controlled DC drive systems are investigated. The corresponding modeling, analysis, simulation, and experimentation are also discussed in detail.
3.1 Voltage-Controlled DC Drive System
The investigation into chaos in power electronic circuits was launched in the late 1980s, focusing on various kinds of switching DC–DC converters (Hamill and Jefferies, 1988; Deane, 1992; Tse, Fung, and Kwan, 1996). By extending the work to DC drive systems that involve a speed-dependent load voltage, chaotic behavior in the voltage-controlled DC drive system was first investigated in 1997 (Chau et al., 1997a). Consequently, the corresponding dynamic bifurcation (Chau, Chen, and Chan, 1997b) as well as modeling of subharmonics and chaos ...