Novel Frequency-Domain Hybrid Circuit-Computational Electromagnetic Modelling of Photovoltaic Module Impedances

Abstract

<p>A novel circuit-computational electromagnetic (CEM) hybrid simulation methodology, which results in vast improvements in the accuracy of high-frequency photovoltaic (PV) modelling between 1 Hz and 50 MHz, is proposed. At low frequencies, the impedance of a PV module is dominated by the behaviour of the PV cells, while at high frequencies it is dominated by the layout of the inter-cell connections. The proposed methodology considers both the low and high-frequency behaviour of a PV module in a single simulation. Firstly, the impedances of two PV modules are carefully measured using two vector network analyser configurations. Secondly, literature-based models of PV modules are adapted to the proposed methodology. Thirdly, improved models of each PV module are introduced in four ascending levels of complexity. These improved models comprise additional novel aspects, including distributed cell layouts and implicit CEM-calculated self-inductances. Fourthly, a feature-selective method is used to compare the measured results with the literature-based and improved models. This analysis yielded comparable error reductions of up to a factor of 400 -- highlighting the value of the improved methodology and models. Penultimately, the required level of computational resources is introduced, and the trade-off between simulation time and accuracy is discussed. Finally, a review discussion is presented.</p>