A Simulation-Assisted Teaching Practice: Teaching AC Variable Speed Systems Using Simulation Models Library

Abstract

Different modulation modes of PWM technology and inverters can be selected for different types of the motors, a variety of AC variable frequency variable speed system structures can also be derived based on the same control principle. So it brings a great challenge to teaching AC variable speed systems. We have identified four factors that hinder students’ learning in this topic: 1) the abstraction of the mathematical logic behind the control theory; 2) the complexity of system structures; 3) the diversity of implementation methods; 4) lack of motivation to explore more engineering applications due to boring textbook contents. To facilitate and inspire student learning, we developed an innovative way to teach the AC Variable Speed Systems course using the simulation models library. The library was implemented based on MATLAB/Simulink to assist students in studying five different types of AC variable speed systems. We assessed the effectiveness of our new teaching practice by evaluating students’ cognitive and affective behavior under both the traditional lecture-based teaching environment and the new simulation-assisted teaching environments. The practice assessment tools that take into accounts the in-class performance (attendance accounts for 10% and the experimental reports account for 20%), the lab assignments computer operation score (30%) includes software operation (10%) and system constitution and design (20%), and the final exam (40%) are designed to assess the students’ understanding of AC variable speed systems. The student group learning under the simulation-assisted teaching environment delivered a superior performance in all measures including the noticeable improved scores on the final exam. We also developed a survey to evaluate the students' affective behavior by measuring their motivation for learning and their perceptions of effectiveness of practice. Ninety percent of students reported that the new teaching practice using the simulation models library is much more interesting and inspiring than the traditional lecture-based teaching approach.