14 December 2011
Transformer and ac line reactor finite element design software
Cobham Technical Services claims that the development of new generations of transformers and line reactors is radically simplified and accelerated by a new automated software toolbox from its Vector Fields Software range.
According to the software specialist, its new 3D Transformers Environment (TE3D) provides a graphical user interface for rapidly designing transformers and reactors using the company's Opera-3d finite element electromagnetic simulation package. TE3D is designed to make it easy to employ advanced and precise finite element analysis simulation to evaluate design ideas. Cobham says the software is suitable for both new and experienced transformer engineers, as it simplifies the process of entering design data for industry standard transformer designs and interpreting results.
Users are presented with simple dialog boxes and drop down menus to define a new transformer or reactor design. After entering this data, the software automatically creates a three dimensional finite element model of a reactor or transformer, together with independent drive and load circuits within the circuit editor for subsequent simulation and analysis.
The software allows a variety of common transformer types to be created, including three phase, three and five leg core, and single phase two and three leg core. It accommodates both racetrack and solenoid type single and multiple layer windings and most of the commonly used winding connections specified in the international IEC 60076-1 standard for power transformers. All aspects of transformer design can be modelled through the environment, including multiple air gaps and placement of the core inside a conductive tank. There is also an option to modify the device and circuits following the initial build to enable precise matching of designs, and the analysis options available within the environment can be used to analyse devices not constructed within it.
The simulation analysis phase is also automated. User options include performing open circuit, short circuit and inrush current tests on transformers and mutual inductance tests on reactors. Once an analysis has been completed, the TE3D environment automatically sends the results to the Opera Manager to be solved. In the case of the inrush current test, for example, the calculated results include the Lorentz forces on the primary and secondary windings, eddy currents in any support structures, iron losses in the transformer core, and transformer efficiency. All results can be displayed graphically, presenting users with a clear and unambiguous portrayal of design changes.
The TE3D environment offers fine control of the Finite Element Analysis (FEA) mesh size and distribution within each device, which can be specified by the user before or after the model has been built, to help balance speed with accuracy. The standard Modeller mesh tolerances are converted automatically when any changes are made to length units.
TE3D will also model a diverse range of reactor types, including three-phase three leg, five leg and both horizontal and vertical air core, and single-phase two leg, three leg and air core. Power systems designers will appreciate the benefits of using TE3D from the outset. By modelling the transformer or reactor they can visualise the shape of stray flux and the areas with the highest local loss concentration. Design data can be changed in seconds, allowing 'What-if?' type scenarios to be investigated quickly, so that users can home-in on the optimal design solution to an application more efficiently.
To support design optimisation, TE3D is also fully integrated with Opera-3d's powerful Optimiser tool. This further accelerates design by selecting and managing a comprehensive family of goal seeking algorithms automatically. This is suitable for designers looking to move performance characteristics such as efficiency to new levels, as even a small improvement can bring significant long term economic and environmental benefits. The reduction of electrical losses involves a huge number of design trade offs, which can take considerable time to evaluate fully. By supporting multiple design goals, even when they compete with one another, the Optimiser software minimises the number of simulation runs that are needed and provides an extremely efficient path to design optimisation.
Cobham Technical Services