Frozen Permeability
 | 158 - Superimposed Direct Current Characteristic Analysis of a Reactor That Accounts for Minor Hysteresis Loops
| Module:FQ,ST | 2012-07-31 | High-frequency reactors used in equipment like DC-DC converters have a high-frequency current accompanying the switching direct current. The reactor's performance requires a stable inductance in a wide direct current region that is superimposed by alternating current components. If there is only a direct current, the magnetic flux is generated against the external magnetic field, following the magnetic steel sheet's DC magnetization curve. However, when there is a current waveform whose high-frequency components are superimposed on the direct current component, the response displays a minor loop against the external magnetic field. The values of the inductance in the reactor can have significant differences depending on the method used to measure them. This can make it difficult to carry out a performance prediction during an actual state of operation.
In order to handle the responsiveness of a magnetic field against a current waveform that is superimposed by a higher harmonic with a small amplitude for the direct current component, a magnetic field analysis that accounts for material modeling needs to be carried out. With a magnetic field analysis, it is possible to analyze the machine characteristics from the magnetic flux density distribution.
This Application Note presents the use of the frozen permeability condition to obtain the superimposed direct current characteristic that includes minor hysteresis loops of a high-frequency reactor.
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  | 156 - Segregation Analysis of Torque Components for an IPM Motor
| Module:DP | 2012-06-08 | IPM motors are often used as high performance motors because they are highly efficient and their structure makes it possible to achieve a wide range of operation. They are able to achieve high efficiency because they obtain maximum total torque by using their controls to adjust their magnet and reluctance torques. For this reason, it is important to find out the distribution of both of these torques during operation when the IPM motor is being designed. The motor's detailed geometry and the material's nonlinear magnetic properties need to be taken into account to obtain the torque characteristics, and it is even more difficult to segregate the torque into two components by using manual calculations.
In order to proceed with the design while looking into how much each one contributes, it needs to be studied with an electromagnetic field analysis that uses the finite element method (FEM).
In this Application Note, the torque components are separated and the magnetic flux density distributions created by each magnetomotive force are confirmed.
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