Modeling the Electromechanical Subsystem

Modeling the target electromechanical subsystem

Having developed the motor models, it is now time to consider the modeling of the target electromechanical subsystem, introduced in section 0.1. The motor side of the current amplifier can be modeled by the source in the current-source model of subsection 4.1.2. The operation of amplifiers for driving motors will be considered in section 4.3.

The mechanical side of the motor, its rotor and bearings, can be modeled by the inertial and damping elements of the current-source model of subsection 4.1.2. The flywheel inertia can be lumped with that of the rotor to form a single inertia \(J\), the sum of the rotor and flywheel inertias.

The current-source motor model developed in subsection 4.1.2, then, can be understood to also model most of the target electromechanical system, with the provision that the inertial element \(J\) is understood to model the combined inertia of the rotor and flywheel. We will refer to this as the current-source electromechanical system model.

For a system with an amplifier that behaves as a voltage source, a similar conclusion can be reached. This model is referred to as the voltage-source electromechanical system model. To maintain a broad view of the problems of driving motors and designing controllers for them, we will consider both models in this chapter and the following chapters. The system parameters (e.g., inductance, inertia, motor constant) to be used in the models can be found in appendix A.