Multi-domain LED digital twin generation and its corresponding product digital design flow: Delphi4LED state-of-the-art and outlook

How to accelerate the transition to Industry4.E [1] by reducing development time and cost while maintaining product quality? The Delphi4LED European project ECSEL-JU grant #692465 developed a state-of-the-art methodology to establish a standardized approach for generating and integrating multi-domain LED digital twins from measurement data. An LED multi-domain compact model (MDCM), also called digital twin (DT), simulates the working space of an LED with the advantage that it does not include LED vendor proprietary information. This allows LED vendors to share them with end-users without disclosing their sensitive intellectual property. Major steps consist of 1) characterizing the physical LED in a standardized way that combines thermal/electrical/optical tests in accordance with combined testing standards (JESD 51-51, JESD 51-52, JESD 51-14, CIE 225:2017); 2) reporting the characterized sets of data (Current- Voltage-luminous Flux (IVL) and thermal impedance characteristics) in a standardized way; 3) generating the MDCM LED from the set of data; 4) coupling the MDCM LED to a 3D luminaire CFD (computational fluid dynamics) model. The LED package MDCM consists of 1) a boundary condition-independent compact thermal model (CTM) of the physical LED package and 2) a multi-domain opto-electrical model that describes the LED operation close to the chip level. The former can be created with the help of measured transient thermal impedance, Zth(t), of the LED package, while the parameters of a opto-electrical model can be identified from the isothermal IVL characteristics of the LED device. The paper presents the state-of-the-art LED digital twin creation approach, the importance of standardization and the latest results in terms of accuracy and calculation time gains for a LED luminaire level simulation.