Evaluation of nanocrystalline materials, amorphous metal alloys, and ferrites for magnetic pulse compression applications

Abstract

A magnetic pulse compressor test stand was developed to evaluate the switching and loss properties of magnetic core materials that included ferrite and several alloys of nickel-iron, Metglas, and the nanocrystalline material Vitroperm. The test stand generated 1 − cos͑t͒ voltage pulses across the core under evaluation to simulate the magnetic excitation encountered in pulse compressors. Pulse amplitude and repetition rate were user controlled in order to vary the initial time to saturation while keeping magnetic core temperature constant. Switching losses were calculated directly as ͐͑i͒dt, and an advanced figure of merit was utilized to compare test results. The test stand, data acquisition and analysis, and test results are discussed.

Modified multistage semiconductor-Fitch generator topology with magnetic compression

“…Digital oscilloscope registered rise time values (10% -90% of the waveform amplitude) shown an improvement from 690 ns for the voltage rising slope before the magnetic compressor to 300ns after compression, better results are obtainable when dedicated nanocrystalline or amorphous materials can be used [12].…”

Magnetic core test stand for energy loss and permeability measurements at a high constant magnetization rate and test results for nanocrystalline and ferrite materials

“…8 are not sufficient for relative core-tocore comparisons because the saturation induction, which is an important material parameter relevant to any magnetic switching application, is not taken into account. From Table I, the saturation induction for the nanocrystalline core and the ferrite core differ by approximately 2 T. A figure of merit known as the loss factor has been used in past studies of energy losses in magnetic cores to make relative core-to-core comparisons, 6 and the same figure of merit will be used here.…”

“…[2][3][4][5][6] In the present experimental study, the test stand generates a square voltage pulse across the winding on the magnetic core under evaluation, i.e., a linear magnetic induction and a constant magnetization rate, that replicates the magnetic excitation inherent to the pulsed power applications discussed previously. The magnetization rates achieved in the present study vary from approximately 5 to 50 T / s, which are faster than those of any previous studies located by the authors.…”

Study on a Solid-State Pulse Generator Based on Magnetic Switch for Food Treatments by Pulsed Electric Field (PEF)

“…A phase control thyristor with rated voltage and current of 4.2kV and 4.32kA, respectively, is selected as the semiconductor switch balancing the performance and the cost [18]. As the working frequency of magnetic switch is 25kHz approximately, Fe-based amorphous magnetic cores are selected for their high flux density change and relatively lower price [19][20][21]. Double parallel winding are rolled around the cores for decreasing the stray impedance and improving magnetism uniformity [22].…”