Boundary Conditions
Regardless of the analysis type in an electromagnetic field analysis, the electric potential forming the standard must be set. For boundary conditions other than for electric potential, decide on selections depending on the type of analysis.
Electric Potential Boundary
Can be used with all analysis types. Sets the electric potential for the place that is specified. Electric potential that will become a standard is necessary in electric field analyses, so specify at least one place. Settings are possible for all parts, part surfaces, edges and vertex.
Current Boundary/Current Density Boundary
Can only be used in a current distribution analysis. Specify the inflow and outflow from a specified place. Part faces can be specified. This report describes two divergent examples of current paths. It is possible to confirm that as the current flows from the left the upper current path is long and that most of the current flows on the lower current path (Fig. 2).
Fig. 2 Divergent Current Path Model (left) and Current Density Vector Diagram (Right)
Electric Field Boundary
Useable in static and frequency response analyses. Allows specifying of the electric field in a specified face. In a frequency response analysis, you can also set the phase of an electric field. Part faces can be specified. It is possible to obtain the electric potential distribution to satisfy the specified electric field.
Natural Boundary
Can be used with all analysis types. The specified face will be the face in the direction the current flows in. The part face can be specified. This is used frequently in partial models (Fig. 3).
Fig. 3 The Central Line Forming the Natural Boundary and Electric Potential Contour Settings (Left) and Enlargement of Center Vicinity Electric Field Vector Settings (Right)
Symmetry Boundary
Can be used with all analysis types. The specified face will be the one in which the current can be expelled vertically. A uniform electric potential is set for the boundary. An electric potential phase can also be specified together with its amplitude in a frequency response analysis. The part face can be specified. Usable when creating a partial model. Here is a onequarter model with a central boundary between electrodes fixed at 50 (V) (Fig. 4). Note the electric field distribution is different from that of an example of a natural boundary with upper and lower symmetry (Fig. 3). When there is distribution of electric potential on the boundary surface, avoid using a partial model with a symmetrical boundary.
Fig. 4 Natural Boundary, Symmetrical Boundary and Electric Potential Contour Settings (left) and Enlargement of Center Vicinity Electric Field Vector Settings (Right)
Periodic Boundary (Rotation) and Periodic Boundary (Translation)
Can be used with all analysis types. Specify the model crosssection and periodic angle when the analysis target is a partial model. Narrowing the analysis scope cuts calculation time and the memory needed for calculation.
