Electrical Machine Analysis
The Opera Simulation Software Suite is a powerful interactive Finite Element Analysis (FEA) software package proven to provide accurate electromagnetic field modelling for all types of machines, including axial flux topologies and linear motion devices.
Electromagnetic and other physics solvers provide different levels of analysis complexity, and offer users the best tools for their requirements. With comprehensive material modelling options (including magnetization, demagnetization in service and full vector hysteresis material model) and easy definition of external drive circuits, Opera facilitates machines design with ease.
The Motional Electromagnetic solver can compute electromagnetic fields including the effects of eddy currents in moving systems in three dimensions, such as motors and generators. Parts of the mesh are allowed to move independently at speeds controlled by the user or calculated as the analysis proceeds. The analysis is transient, with eddy currents being induced in conducting media both through the effects of the moving magnetic fields, and through the time variation of the model sources. Three types of motion are allowed in the 3d solver:
• rotational motion: rotation about the z-axis;
• linear motion: displacement in x, y and z;
• general motion: rotation about z and displacement in z.
The analysis relies upon a remeshing technique. During the transient analysis, before the solution at the next time-step, the position of each moving part is updated to give a mesh with the best quality.
Losses can be calculated and passed to a thermal analysis. Forces and Temperatures can be passed to a stress analysis. The deformed shape can be fed back to the electromagnetic or thermal analysis.
The Machines Environment (ME) is an easy to use, template-driven development tool specifically designed for electrical machines engineers.
The Winding Tool is an application dedicated to electrical machine winding design. It provides output on winding scenarios which can be used directly with Opera FEA software.
The integrated Optimizer provides an efficient route from concept to competitive product.
• Induction machines
• Synchronous machines
• Brushless machines
• SRM and synchrel
• Clawpole generators
• Axial flux
• Commutating machines
• External rotor
• Magnetic gearing
• Linear motion machines
Frequently Asked Questions
Can I calculate a Torque-Speed curve for my Synchronous Reluctance Machine?
Yes. You can use either Opera’s general-purpose user interface, or the Machines Environment, which automates analysis processes for electrical machines. If you use the Opera-3d Machines Environment you can select a Torque-Speed analysis, which uses a flux-linkage technique to generate the torque-speed curve from a series of static runs. This is much more efficient than running a large number of motional analyses.
Can you display a Gorges Diagram for my electrical machine?
The Opera Winding Tool allows several key parameters for electrical windings, including the Gorges Diagram to be calculated and displayed.
Can Opera analyse my electrical machine under fault conditions?
Opera is general-purpose finite element simulation software that is available for 2d and 3d analyses. Opera solves the fundamental equations that describe the intrinsic electromagnetic behaviour of any electrical machine. This formulation means that the software applies equally well to fault conditions and normal operation, and predicts accurately the real-life performance in either state.
How do I account for demagnetization of my permanent magnets in my electrical machine?
Opera was designed with advanced material modelling in mind. It is able to treat a wide range of material properties, from the simplest linear material to full hysteresis models of soft magnetic materials, and the demagnetization of hard permanent magnets. In a demagnetization analysis, Opera records the progress of the material magnetization along the virgin characteristic, until the magnetizing field starts to reduce. Secondary ‘demagnetization’ characteristics are then used to determine the remnant magnetization vector when the magnetization process is complete. In both the magnetization and demagnetization processes, the effect of eddy currents and circuit transients are captured. During demagnetization, the values of the pre-stored values determine which demagnetization (second quadrant) curve each element follows and its direction of magnetization. Again the flux density in each element is monitored and the minimum values are stored in variables. The values can then be transferred to the standard Opera transient solvers. In such a simulation where the applied field from current sources etc are opposing the magnet’s field, the variables will show the operating point of the magnet. In a transient simulation, they will show the lowest operating point that was reached during the transient event. Demagnetization in service can therefore be modelled. The minimum field will be tracked and updated during subsequent simulations, and the appropriate demagnetization curve or recoil permeability will be used.
Can I look at magnetization of my permanent magnets before they are assembled into my electrical machine?
Opera was designed with advanced material modelling in mind. It is able to treat a wide range of material properties, from the simplest linear material to full hysteresis models of soft magnetic materials, and the demagnetization of hard permanent magnets. In a magnetization analysis, Opera records the progress of the material magnetization along the virgin characteristic, until the magnetizing field starts to reduce. Secondary ‘demagnetization’ characteristics are then used to determine the remnant magnetization vector when the magnetization process is complete. In both the magnetization and demagnetization processes, the effect of eddy currents and circuit transients are captured. The result is a magnetized sample, where the magnetization distribution is correctly defined. This can then be used in other simulations to model the performance of the magnetized sample in its designated application (eg. an electrical machine).
Can Opera calculate the losses in my machine?
Iron losses (including eddy current, hysteresis and excess/rotational components) can be evaluated using one of the relevant solvers for any type of machine, using Fourier methods with losses described by Steinmetz based formulations or directly from manufacturers curves.
Copper losses can be calculated simply from the current flowing in simulated windings.
Hysteresis losses including rotational component losses can be explicitly obtained using the hysteresis solver and eddy current losses by explicitly defining the materials’ conductivities.
Any loss quantity can be used as a heat source in thermal analyses.
For further details on Opera please contact us