June 15, 1997
June 15, 1997
June 18, 1997
2.398.1 - 2.398.6
Teaching Three-Phase Power ... A Low-Voltage Approach
Thad B. Welch ASEE/United States Air Force Academy
Any electrical power systems course that includes demonstrations and/or laboratory exercises would benefit from a low-voltage three-phase power supply. Providing a low-voltage three-phase power supply allows classroom demonstrations and “hands-on” student participation in laboratory exercises without the danger associated with a 240 VAC system. Faculty and student surveys indicate that students would benefit from a “hands-on” approach and are more comfortable working with the safe low-voltage supply. Additionally, the flexibility and capabilities of the low-voltage three-phase power supply allow the instructor to implement demonstrations and laboratories that would not be possible on an energized 240 VAC system.
The United States Air Force Academy (USAFA) teaches a first course in Electrical Power Systems. This course includes several labs and demonstrations designed to involve the student in the learning process. Three phase electrical power generation, distribution and use have been a particularly difficult group of concepts for most students to fully understand. A demonstration of three-phase alternating current circuits at 240 volts (VAC) was already provided; however, it was felt that a “hands-on” lab would provide a better learning opportunity for the students. Discussion with the faculty stressed that the need for “hands-on” lab experience must not compromise student safety. Additionally, it was felt that a student’s concern for his/her own personal safety would hinder the learning experience offered by the lab if it were conducted at 240 VAC.
II. A STUDENT SURVEY
These faculty concerns appear to be shared by most students. In August of 1996, a survey consisting of three multiple choice questions was administered to the 42 students just starting the Electrical Power Systems course. Electrical Power Systems is a required course for all Electrical Engineering, Civil Engineering, Physics, and Computer Science majors. Of the 42 students starting the course only 2 were Electrical Engineering majors. A majority of the Electrical Engineering majors take this course during the Spring semester. The questions, a partial listing of the possible responses and the average numerical response to the questions are provided below.
1. How comfortable would you be working on an energized three-phase 240 VAC circuit?
1. Very Comfortable 2. Moderately Comfortable
Welch, T. (1997, June), Teaching Three Phase Power ... A Low Voltage Approach Paper presented at 1997 Annual Conference, Milwaukee, Wisconsin. 10.18260/1-2--6826
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