Control of SRM Drive
The switched reluctance machine (SRM) has strong similarity to series-excited dc and synchronous reluctance machines, but in control it is very remotely connected to these machines and therefore analogous control development is not possible. This chapter explains the derivation of a linearized model of the SRM. It presents the validity of the current controller design, nonlinear dynamic simulation of the drive system. The chapter describes the system model, the need for linearization and decoupling becomes evident and a method to achieve them. It introduces the concept of control from the machine characteristics of inductance vs. rotor position for a fixed excitation. The chapter discusses the variables of control such as advance rise and commutation angles are recognized and their dependence on machine inductance, speed, and the requirement to maximize torque. It prvoides a low-performance, closed-loop, speed-controlled SRM is considered and a complete step-by-step design and implementation of the control system.