Cascading DC Machines to Obtain New Torque/Speed Characteristics and Save Energy in Their Applications

ABSTRACT

The representation of torque/speed characteristics of each type of DC machine has a fixed shape, but in industrial applications not all the required DC load torque/speed characteristics can be loaded by existing DC machines. To build a DC machine to fulfill each required torque/speed characteristic is expensive, unreliable, and time-consuming. From this point of view, came the idea of coupling the shafts of DC machines in cascade. This article investigates the new characteristics obtained from different cascaded sets of DC machines. It compares the new characteristics of each cascaded set with the use of one DC machine that has the same rating in order to show the advantages of the process of cascading. The article proceeds to investigate the degree of success of this idea by applying it in DC machines used in mining, then investigating the energy saved.

Keywords::

• energy conversion
• DC motors
• cascaded motors
• torque/speed characteristics
• applications in mining
• energy savings.

Additional information

Notes on contributors

Eyhab El-Kharashi

Eyhab El-Kharashi received his Ph.D. degree from the University of Newcastle upon Tyne, UK in 2003 and his B.S. (first class honors) and M.S. degrees in electrical power and machines engineering from Ain Shams University, Cairo, Egypt, in 1994 and 1997, respectively. He is now an associate professor in the Department of Electrical Power and Machines, Faculty of Engineering, Ain Shams University, Cairo, Egypt. His research interests include energy conversion, conservation, engineering, and management; power system distribution, analysis, planning, modeling, and simulation; control of electromechanical drive systems; electrical traction and neural network theory; and the analysis and design of novel electrical machines. He can be reached at 1 El-Sarayat Street, Abdou Basha Square, Abbasia, 11517 Faculty of Engineering, Electrical Power & Machines Department, Ain Shams University, Cairo, Egypt. Email: [email protected].

M. A. El-Dessouki

Maher M. El-Dessouki received his Ph.D. degree from Warsaw University of technology in 1994 in the dynamic study of power systems, considering electrical machines as dynamic loads. He is now an assistant professor in the Department of Electrical Power and Machines, Faculty of Engineering, Ain Shams University, Cairo, Egypt. His research interests include modeling, simulation, and control of electrical machines; power systems dynamics, stability, reconstruction, and distribution; design of novel electrical machines; and the use of artificial intelligence in the control of both electrical machines and power systems. He has supervised many research projects and teaches many courses on electrical machines and power systems, both inside and outside Egypt in various universities.