Magnetics Design Module (MDM)

SIMPLIS MDM is accessible using the Level 2 model of the Multi-Level Lossy PWL Inductor.

MDM provides an intuitive interface to build an inductor by selecting a core material, core shape and size, wire material, wire shape and size, bobbin, and number of turns and their arrangement. The user can select standard sizes from the catalogue or define custom sizes, including the custom placement of air gaps for certain core shapes.

Using the B-H curves of the selected material stored in MDM's database, a reluctance model of the defined core, and an accurate 3D model of the airgaps, a PWL inductance for the inductor is calculated and used in the SIMPLIS circuit simulation.

MDM is accessible using the Level 3 model of the Multi-Level Lossy Transformer.

MDM allows for the design of each transformer winding in detail. Each turn can be placed precisely, allowing for the modeling of interleaved, bifilar wound, and split windings; split bobbins; high leakage and planar transformers. Foils, rectangular wires, litz wires, and solid round wires can be combined in a single design.

Many core shapes (PQ, RM, P, EPC, ERI, etc.) are available. Multiple air gaps per core leg can be precisely placed using the EE core shape. A reluctance (magnetic circuit) model is simulated directly inside the SIMPLIS schematic to obtain accurate currents and voltages for each winding and accurate fluxes in each part of the transformer core.

A large part of inductor and transformer losses are non-linear and cannot be accurately represented simply by a constant resistance in the circuit schematic. Therefore, SIMPLIS MDM provides a post-processing option to accurately calculate DC and AC winding losses (including skin and proximity effect, and the proximity losses due to the core air gaps) as well as core losses accounting for the effect of different waveshapes, DC current, and temperature. Once the circuit simulation is complete, MDM uses the resulting waveforms to calculate the inductor or transformer loss and temperature.

The detailed loss calculations can be performed assuming a constant device temperature. Alternatively, the user can define a detailed cooling arrangement for the inductor or transformer, including sides exposed to heat flow, the presence of heat sinks, the ambient temperature, the usage of natural or forced convection, the speed of air flow, and the orientation of the component.

MDM's database can be edited and extended by the user to add new material and standard core and wire definitions. It will also be updated periodically with new data with program updates.