Power Converter Model Fidelity Comparison

This example shows how to use different levels of fidelity in power converters. You change the level of fidelity by changing the values for the Fidelity level, Switching device, and Integral protection diode parameters of the Converter (Three-Phase) block. You also change the inputs to the G port. Using a higher level of fidelity improves the accuracy of the results but it also slows down simulation.

The system contains four converters. The name of the Converter (Three-Phase) block indicates the modelling approach:

• Converter with ideal switches — To achieve a high level of accuracy, this model uses ideal switches and protection diodes at a 10 us sample time.

• Converter with averaged switches and averaged pulses — To yield accurate results even though you undersample the model at 50 us sample time, this model uses averaged switches with averaged pulses.

• Converter with averaged switches and modulation waveforms — To further increase the sample rate and to operate as an ideal averaged converter, this model uses averaged switches and modulation waveforms instead of gate pulses.

• Converter with equivalent model option — To reduce simulation time even further, this model uses the equivalent model option which does not model the individual switching devices, but returns similar results to the converter with ideal switches.

The Control subsystem contains a three-phase, two-level PWM waveform generator. The Scopes subsystem contains Scope blocks that allow you to see the simulation results.

Model

Simulation Results from Simscape Logging

Plot the comparison of the DC currents, as well as the AC a-phase currents.

Plot the comparison of the DC voltage, as well as the AC a-phase voltage.