TopBench

Download: TopBench Version 2.0 from 23.10.2020 Setup (10,1 MB) | ZIP-File (14,4 MB) | Sourcecode (3,5 MB) License: GPLv3 | Contact: Dr.-Ing. Christian NödingComparison TopBench and Plexim PLECS (PDF)

With the developed program "TopBench" various calculations for DC/DC and DC/AC converters can be performed mostly in real time. For this purpose, all current and voltage signals are calculated via stored formulas, which can be parameterized via input masks. The program uses a semiconductor database to calculate semiconductor losses and efficiencies. The figure shows the editor, which can be used to enter the semiconductor properties. A PDF importer allows parameter curves to be easily imported by mouse input. The entered data points are finally fitted into coefficients for polynomial or logarithmic functions, so that in addition to stepless interpolation, extrapolation of the data is also possible.

A graphical view displays at a glance all important information on forward, on and off losses as well as the calculated junction temperature and chip area.

Using an integrated function plotter, important time functions can be displayed via selectable zoom parameters and, in addition to current and voltage characteristics, semiconductor losses for individual semiconductors can also be displayed as a time function. Effects of parameter changes (e.g. DC link voltage, number of semiconductors connected in parallel or change of gate series resistance) can be viewed directly.

With the help of the integrated chip area optimization, a junction temperature can be calculated in an optimization loop using the thermal resistances stored in the semiconductor database. In order not to exceed a specified maximum junction temperature, a minimum required chip area in cm² is calculated automatically. Optionally, a fraction of a real semiconductor chip can be calculated to achieve a finer granularity for the theoretical comparison of a circuit topology. Finally, this calculated chip area can be added to real semiconductor modules via an option.

The implemented benchmark tool allows a clear presentation of the calculation results. This part of the application allows besides an adjustable automated parameter sweep over the input voltage and the power factor the analysis of the semiconductor losses separately for forward and switching losses as well as switch and diode. The power to be displayed, the input voltage and the power factor can be selected and plotted via selection controllers without recalculation. Selected circuit parameters can be easily controlled in this way and, for example, effects of gap operation at certain voltage ratios can be checked for the selected semiconductors.

In addition to the display of efficiency and power dissipation curves in different variants, the benchmark tool also allows a direct comparison of circuits. The figure shows a possible representation of the European efficiency plotted against the input voltage and the AC output voltage at a total of 66 calculation points. Together with the determined chip area as a reference point for the semiconductor costs, it is thus possible to clearly determine, for example, an optimal output voltage for the set semiconductors.

In addition to the parameter sweep via input voltage and power factor of the benchmark tool, a further parameter sweep via the AC or DC switching frequency is possible. Thus, a complete image of a power electronic circuit can be determined with only a few settings and an optimal design can be found. Since a change in the switching frequency is accompanied by a reconfiguration of, among other things, the magnetic components, the integrated formula parser can be used to store a calculation rule for parameters which are automatically recalculated when the parameter sweep is executed. Finally, several TopBench projects can be automatically calculated in batch processing using all parameter sweeps and the values obtained can be automatically exported as a parameter file for further analyses.

In order to be able to write own program extensions, the program offers additionally a plugin interface, over which own program code can be implemented with into the calculation. During a single calculation step, all settings concerning the circuit and the loss components are made available to the plug-in. The Plugin can compute thus own pass and switching losses and return to the main program. Since the plug-ins consist of conventional 32-bit dynamic link libraries (DLLs), Visual C++, C# or other programming languages that can create Windows 32-bit library files can be used in addition to the Embarcadero "Delphi XE2" programming language used for TopBench. A concrete use case would be, for example, the calculation of choke losses based on a specific stored choke model. Adaptations to the main software are also possible without further ado.