Pergamon Plh SQ~I0-131S(~-9 Compumn EdJer.Vol, 28. No. 3, pp. 15.5-164, 1997 O 1997 Blmvier Science LM All dStdS restored. Printed in Great Britain 0360-1315/97 $17.00+0.00 TEACHING TRANSIENT BEHAVIOR OF ELECTRICAL MACHINES WITH PERSONAL COMPUTERS MEHMET AKBABA Departmentof ElectricalEngineering, The Univm, sity of Bahrain.p.o. Box 33547,It, Town,Stateof Bahrain (Receh,ed I December 1996; accepted I March 1097) Ahetnaet--This paper discussesthe use of pm-aonai computers in teaching the transient and steady-state behavior of electricalmachines,it explainshow computer simulationshelp stodenm to get betterunderstandingand pin in-depth knowledge of the physicalconcepts they studyin the lecture.Emphasisis givento the use of personal computers in teachingthe responseof electriml machinesresultingfrom many complexphenomenaand it is explainedthat this developsstudentscreativity and ability in analyzing and designingthe engineering systems. Formulation of electrical machines for computationalpurpose is demonsuated for induction machines and selected sample simulation results are demonstratedto emphasizethe impommceof the approach. 0 1997 ElsevierScience Ltd LIST OF SYMBOLS • • • • iq., |din |qo gdr V., Vq. V. R.,R~X,,X, Xm X,~,X,, Po J TL stator and rotor q--d axis currents respectively stator and rotor q-d axis voltages respectively stator and rotor windings resistances and reactances respectively magnetizing reactance stator and rotor leakage reactances respectively base angular velocity which is chosen as the angular velocity of the supply voltage rotor angular velocity number of pole pairs of the motor inertia of the shaft system load torque INTRODUCTION One of the most maths-intensive courses in the electrical engineering educational experience is in the area of electrical machines, especially the analysis of their transient behavior. With use of hand calculators it is almost impossible to analyze the transient behavior or even, in some cases, the detailed steady-state performance of electrical machines, as the time required would be prohibitively long and as a result, the task would be prohibitively tedious. For this reason it is difficult to motivate students to learn the transient behavior of electrical machines. Usually the details of the perfonnance cham~ristics are shown in the form of sketched graphs which is not very informative for the students. Tber~ore use of computers for this purpose becomes a necessity. Nowadays with "high tech" facilities available at universities it would be short-sighted to ignore the advantages inherent in electronic information processing. It is for this reason that ~ Power Engineering Education Committee recommends use of personal cornpu~,rs in every course at university level [I ]. Several publications have been devoted to demonstrating the benefits gained from the use of compulms in engineering education [2--7]. There are a number of comn~c~l software packages such as EMTP (Electromagnetic Transient Program) [8] that are useful in analyzing the behavior of electrical machines. However use of such software packages as learning tools is rather limited for the following reasons. I. The costs usually are beyond the financial capability of students, as student versions of these packages are not available. 2. Such packages need computers with large memory and with large storage requirements and many students may not afford such expensive computers. 3. Tune taken to grasp the use of such packages is usually long and tedious and therefore students lend to be less motivated to learn and use of such commercial software packages. 155