Using MATHCAD in Teaching Power Engineering

Students typically use small calculators or personal computer applications such as MATLAB or MATHCAD to perform basic electrical engineering calculations. From the experience of teaching several power engineering courses, the author noted that when using computer software to solve problems, students tend to lose the meaning of the equations, concentrating solely on typing variables and numbers. Some programs are especially inviting for making this error. MATLAB, for instance, does not use any built-in units of measurement, leaving the management of such units to the user. The user’s attention shifts from the problem to the units. Although not as powerful and fast as MATLAB, MATHCAD, on the other hand, has a great potential to help students better understand introductory courses. There are two most important features. First, the screen appearance of the equations matches as closely as possible to the traditional form of the equations and helps the students to become familiar with the concepts. Although a bit difficult to type, the equations written in their natural form help avoid errors. A second feature, the use of built-in measurement units, is particularly helpful because the students can concentrate on the meaning of what they learn and know the transformation will be done properly. A technique for representing magnetization curves in MATHCAD (and the corresponding calculations) is also presented. The technique allows for a computer simulation of “graphical calculations” traditionally used in electrical machine design. The class-related experience has shown that even the simple examples presented in this paper could prove to be difficult for students, especially when choosing a programming language to help with the calculations.