This paper presents our approaches to chip level multi-domain LED (light emitting
diode) modelling, targeting luminaire design in the Industry 4.0 era, to support virtual
prototyping of LED luminaires through luminaire level multi-domain simulations. The
primary goal of such virtual prototypes is to predict the light output characteristics
of LED luminaires under different operating conditions. The key component in such
digital twins of a luminaire is an appropriate multi-domain model for packaged LED
devices that captures the electrical, thermal, and light output characteristics and
their mutual dependence simultaneously and consistently. We developed two such models
with this goal in mind that are presented in detail in this paper. The first model
is a semi analytical, quasi black-box model that can be implemented on the basis of
the built-in diode models of spice-like circuit simulators and a few added controlled
sources. Our second presented model is derived from the physics of the operation of
today’s power LEDs realized with multiple quantum well heterojunction structures.
Both models have been implemented in the form of visual basic macros as well as circuit
models suitable for usual spice circuit simulators. The primary test bench for the
two circuit models was an LTspice simulation environment. Then, to support the design
of different demonstrator luminaires of the Delphi4LED project, a spreadsheet application
was developed, which ensured seamless integration of the two models with additional
models representing the LED chips’ thermal environment in a luminaire. The usability
of our proposed models is demonstrated by real design case studies during which simulated
light output characteristics (such as hot lumens) were confirmed by luminaire level
physical tests.
