Four-period integration oversampling method (4PIOM) for hardware-in-the-loop power converters with complementary switches

Abstract

This paper addresses aliasing oscillations encountered in hardware-in-the-loop (HIL) simulation caused by inaccurate duty cycle detection in high-frequency power electronic applications. Oversampling has been commonly used as a solution to detect switching events more accurately. Traditional oversampling methods use the extra information obtained by oversampling the inputs for further computations to enhance the precision of the simulation. However, these techniques increase the complexity of the model since they take into account several switch states during each simulation step. To mitigate these complexities, the integration oversampling method (IOM) was introduced as a recent alternative with minimum impact on the model complexity. IOM provides a modified switching pattern that effectively prevents aliasing oscillations while maintaining a single switch-state for each simulation step. It can be implemented as an independent block between the controller and the HIL model, so it keeps the HIL model unchanged. This study highlights the limitations detected in applying IOM to the models with complementary switches, including possible undesired short circuits. To overcome these limitations, a novel oversampling method called 4PIOM is presented. 4PIOM further enhances the IOM algorithm by reducing the simulation step and sampling period. The validity of the new method is demonstrated by comparison with previous proposals and also with the same model without any oversampling. Both experimental and MATLAB simulation results prove its superior performance in attenuating the aliasing oscillations and improving the quality of the simulation.