A design study of silicone insulated transformers

Abstract

In recent years the Navy has become very interested in any method that will decrease the size of various types of electrical rotating and stationary machinery and also to increase their reliability under normal operating conditions. An examination of data from Naval new construction vessels will indicate why this has become important. These new vessels are almost twice the size of their pre World War II prototypes. Much of this increase in size may be attributed to the large amount of electronic, sonar, and radar equipment which have been placed upon them, no small part of which is electrical equipment, which is, of course, the power source for the equipment. If some method could be devised to decrease the size of this equipment, it would be advantageous to the Naval Constructors in their search of methods to keep their new construction vessels within their respective size requirements. Two methods have been advocated as possibilities in this matter. Both are theoretically excellent possibilities, but both would involve major changes in our present shipboard electrical layouts. The first of these methods is an increase in the voltage and frequency values to 1000 volts and 400 cycles. The second method is the introduction of higher operating temperatures in electrical machines by the use of new type insulating materials, the most promising of which seems to be the silicone family of insulation products. In 1948 as partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in Electrical Engineering at the United States Naval Postgraduate School, Lieutenant Commander James Mercer, U. S. Navy and Lieutenant Commander Harborough Irwin Lill, Jr., U. S. Navy, made a comparison of 400 cycle 1000 volt transformers to 60 cycle 450 volt transformers. The purpose of this thesis is to extend the work of Mercer and Lill so as to include comparisons of silicone insulated transformers, both 60 and 400 cycle, to ordinary 60 and 400 cycle transformers, and to each other. The work on this thesis was done in the early months of 1949 at the United states Naval Postgraduate School, Annapolis, Maryland under the direction and guidance of Professor C.V.O. Terwilliger, Head of the Department of Electrical Engineering.