Measurement-based parameter identification of non-linear polynomial frequency domain model of single-phase four diode bridge rectifier

Abstract

The increasing use of energy from renewable sources entails significant changes in power systems. On the generation as well as the load side more and more power electronics devices are in operation, leading to an increase of harmonics in power systems. For simulating modern power systems in steady-state, linear modeling approaches in the frequency domain are not sufficient for accurate simulations or a reliable stability assessment. A non-linear frequency domain modeling approach could take the generation of harmonics into account, while enabling simulations entirely in the frequency domain that are more efficient than hybrid or time domain simulations for steady-state analysis. In this paper, a common non-linear power electronics device, a single-phase four diode bridge rectifier, is modeled entirely in the frequency domain. A non-linear multivariate polynomial model in the frequency domain is used to take the harmonics generated by the exemplary component into account. The parameters of the non-linear model are identified by measurements at power level in the laboratory. Therefore, this modeling technique is enabled mainly by the availability of measurement setups including power amplifiers with sufficient bandwidth. Furthermore, simulations for validation of the presented measurement and modeling approach are performed.