Electromagnetic tool speeds up virtual prototyping

Addressing one of the more problematic aspects of almost any embedded control design, Vector Fields Inc. has just released a new version of its Opera electromagnetic simulation tool with sophisticated model parameterisation and scripting capabilities.

According to Vector Fields' Kevin Ward, designer and creator of the tool, the new facilities make it much simpler to perform 'what if?' investigations, to speed up the virtual prototyping of electromagnetic equipment.

Opera is available in numerous variants, with generic 2D and 3D finite element analysis (FEA) solvers for static and time-varying electromagnetic fields, and with application-specific solvers for design work involving rotating machinery, superconducting magnets, particle beams, dielectric insulation and magnetisation/demagnetisation processes. The latest release extends the performance of many of these solvers to enhance simulation fidelity and speed.

According to field the use of an integrated design-simulate-optimise toolchain allows organisations to reach the optimal solution much faster eliminating the huge cost associated with physical design iteration cycles.

Enhanced features
Opera v12 provides users with integrated design-simulate-optimise tools to create design models, simulate electromagnetic behavior (and optionally related physics including temperature and mechanical stress), post-process results and iterate the concept to reach the optimal solution.

Component or system models can be imported from CAD programs, or generated using a powerful, built-in, geometric modeler built around the industry-standard ACIS geometry engine.

To enhance design process efficiency, models may now be parameterised using variables, making it simple to refine ideas. Users can quickly change parameter values in a model and view effects, or macros can be built to automate complicated design tasks.

A related enhancement is the availability of a 'parameterised history stream', allowing models to be easily modified and replayed. This makes it easy to save portions of a complete model, said Ward, as script-like shortcuts for designers who regularly create variations of products, such as electric motor stators or recording heads.

A further time saving feature comes in the form of adaptive FEA meshing, which allows users to employ the most efficient resolution for the accuracy of solution required.

Users can purchase Opera with a wide range of solvers to simulate electromagnetic behavior. There are three generic solvers available depending on the application, for modeling static and low-frequency or high frequency time varying fields.

These are available in both two- or three-dimensional versions, to suit the design need and budget. Application-specific variants are also available. These cater for applications including rotating electrical machinery, the magnetisation/demagnetisation of permanent magnets, the simulation of 'quench' phenomena in superconducting magnets, space charge effects of particle beams, a solver for modeling insulation properties of semiconducting materials, plus extensions to incorporate temperature and mechanical stress effects, and electrical circuits and mechanical loads.

Several of these solvers are radically improved in Opera v12 claims Ward. "For example, the rotating machinery solver features two major enhancements to simplify electric motor and generator design," he said, "a skew modeling facility to enhance the accuracy of designs that employ skewed magnetic fields to reduce 'cogging' torque, and a means to greatly speed the simulation of large machines by simulating just a segment of a symmetrical design."

This latter facility, combined with operation on today's 64bit PCs, can reduce simulation times to hours or even minutes for very complex designs.

Simple analysis
When simulation is complete, Opera includes a purpose-designed post-processor that simplifies analysis of results. As well as displaying electromagnetic field quantities, numerous functions are available to prepare and display results in forms and units familiar to the user such as forces, power loss and stored energy.

For the most demanding applications, Opera v12 introduces an option that is believed to be a first in the electromagnetic modeling marketplace. Optimisation of designs may now be performed automatically using a new tool called Optimiser, an advanced auto-optimisation tool designed specifically to work with finite element methods and to support competing goals.

Unlike current attempts at auto-optimisation, this tool incorporates a number of algorithmic techniques including stochastic, descent, Pareto and Kriging that are automatically selected and managed depending on the problem, and which are able to work out the best solution for one or multiple goals even when goals compete with each other.

Opera v12 is available from Vector Fields in around 20 variants, starting from around Rs.3.44 lakh ($8,500), with discounts for educational or research establishments.

- Bernard Cole
Embedded.com