28-01-2013, 12:14 PM
A Close Loop DC Motor Speed Control Simulation System Using SPICE
Abstract:
This paper presents a complete close loop DC motor speed control system model in SPICE. The results are validated comparing them with the data produced by a testing system. Traditionally, the DC Motors and the associate close loop control systems used to drive them have been modeled using classic control theory techniques, based on transfer functions or state equations. These models are adequate to modcl the servo system (DCmotor plus close-loop control) overall behavior and calculate the output variables (sped and position). Difficulties arise when other parts of the drive system, such as the current and speed controllers, and current and Speed transducers must be included in the model. The traditional techniques are also inadequate to model the power stage behavior at the component level, so even if the servo system is modeled at the design stage, a lot of testing is required to evaluate the complete system (power stage, control circuits, sensors, DC motor and mechanical load) operation. Additionally, the DC Motor models become too complex if other non-linear aspects of its behavior, such as magnetic saturation and Eddy currents have to be taken into account