Modelado e implementación de un manejador eléctrico para un motor de inducción trifásico

Abstract

This paper gives a detailed description of a non-conventional speed-variation linear model intended for a conventional three-phase induction motor. The proposed architecture consists in a single-phase unit-power-factor tap (PFC) followed by three-phase inverter, which feeds the motor by using the scalar-control technique. The whole system is digitally-controlled by a Digital Signal Processor (DSP). In order to obtain the model, non-conventional use of the average operator is suggested, which involves a calculation time span that depends on the target dynamics. This type of analysis simplifies the development of lossless models in terms of model precision. The project was divided into three methodological stages. Stage one established target dynamics for each of the electric-driver parts as well as providing linear models by means of a well-defined stage-specific mobile average operator. Stage two served to validate the models through simulation-based experiments. Finally, controllers were designed and the driver was implemented so as to validate the design process experimentally. The system that was implementing through this modeling process corresponds to a speed-variation unit for a 0,5-HP reduced-voltage (22V) induction motor. The implemented system was characterized in terms of the total power-factor correction, a speed regulation level lower than 5 %, and power-processing-unit efficiency (PFC-Inverter) of 82 %.

Keywords

• variable speed drives
• linear feedback control systems
• power conversion
• power system modeling