Program studies materials for use in static inverters and converters. It gives suitable data on the behavior of commonly used materials when excited with square wave power

Frost, R. M.

Mc Vay, R. E.

Pavlovic, D. M.

English

NASA Technical Reports Server

August 1969	 Brief 69-10306 
NASA TECH BRIEF 
NASA Tech Briefs are issued to summarize specific innovations derived from the U.S. space program, 
to encourage their commercial application. Copies are available to the public at 15 cents each 
from the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
--	 y'r'-
Evaluation of Magnetic Materials for Static Inverters and Converters 
The design of lightweight, highly efficient static 
inverters and converters has been seriously hampered 
by the lack of suitable data on the behavior of com-
monly used materials when excited with square wave 
power. 
A program was conducted to study materials for use 
in these static inverters and converters. This program 
included a literature survey of conductor materials, 
and a series of tests on magnetic alloys. 
Tests were performed with square wave excitation 
to evaluate two thicknesses of available types of core 
materials to determine the CCFR (Constant Current 
Flux Reset) properties at room temperature at 400 to 
3200 Hz. AC (400 to 3200 Hz) and DC magnetic prop-
erties at —55°C, room, temperature and 250°C, de-
gradation of magnetic properties resulting from nor-
mal factory processing, and the effects of high vacuum 
at 250°C for 1000 hours. 
The tests made with square wave excitation were 
the first comprehensive compilation of data using a 
square wave form of voltage instead of a sinusoidal 
wave form of voltage. The formation of a square wave 
requires the use of the odd harmonic powers 1, 3, 5, 7, 
9, II, etc. The test equipment was designed to meas-
ure through the 15th harmonic to provide the utmost 
in accuracy. 
The materials evaluated were: 
1) Square hysteresis loop 4% Mo-79% Ni-17% Fe 
alloy.
2) Grain oriented 50% Ni-50% Fe alloy. 
3) Magnetic field annealed 49% Co-2% V-49% Fe 
alloy.
4) Doubly grain oriented silicon steel both with and 
without magnetic field anneal. 
5) Singly grain-oriented silicon steel.
Table I. Potential Application of Materials 
Material 
- -o - 0 
< 
E 
tp L :> 5e •-L 
r ' çu --
-n.y o= Application 
Power Transformers • . • • 
Specialt y Type Transformers I I • I I I 
Current Transformers I I • • • . 
Pulse Transformers • I • I I • 
Reactors (Inductors) I I I • 
Saturable Reactors I • I I • I 
Magnetic Amplifiers • I S S • • 
Flux Counters • • 
• Transductors S • S S S • 
Time Delays • • 
Ri-Stable Switching Devices • . 
Saturating Switching • • 
Devices
Test results follow: 
I) The grain oriented 50% Ni-50% Fe toroid had the 
optimum combination of overall magnetic properties 
for core applications. 
2) The magnetic field annealed doubly grain 
oriented silicon steel had the second most generally 
useful properties.
(continued overleaf) 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19690000305 2020-03-16T18:10:49+00:00Z
3) The square hysteresis loop 4% Mo-79% Ni-17%. 
Fe toroid was best suited for core applications requir-
ing high gain. 
4) The magnetic field annealed 49% Co-2% V-49% 
Fe toroid was best for those applications requiring 
a high saturation. 
5) The singly grain-oriented silicon steel toroid was 
a suitable substitute for the stress relief annealed 
doubly grain-oriented silicon steel. 
The test results and data should enable a designer 
using square wave excitation to select suitable ma-
terials to minimize losses when operating at various 
induction levels and frequencies. 
Potential uses of the materials are shown in Table I. 
Notes: 
I. Documentation is available from: 
Clearinghouse for Federal Scientific 
and Technical Information 
Springfield, Virginia 22151 
Price $3.00 
Reference: TSP69- 10306
2. Technical questions may be directed to: 
Technology Utilization Officer 
Lewis Research Center 
21000 Brookpark Road 
Cleveland, Ohio 44135 
Reference: B69-10306 
Patent status: 
No patent action is contemplated by NASA. 
Source: R. M. Frost, R. E. McVay 
and D. M. Pavlovic of 
Westinghouse Electric Corporation 
under contract to 
Lewis Research Center 
(LEW- 10343)
[II 
. 
Brief 69-10306	 Category Ol


Evaluation of magnetic materials for static inverters and converters

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