LED Lighting Device Modelling Voltage Profile
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Solution Overview
Problem
LED lighting devices require a stable AC power supply to function efficiently, as they are sensitive to voltage fluctuations, which can lead to flickering and uneven light emission when using AC power sources like those found in aircraft, where voltage frequencies and amplitudes can vary.
Innovation Solution
An LED lighting device with a rectifier circuit and a control system that uses a modelled voltage profile, based on measured AC voltage parameters, to adjust the circuit states of the LEDs, ensuring consistent light emission by synchronizing the LED current with the AC voltage profile, thereby minimizing flickering and maintaining high power factor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If LED lights are operated directly from AC power supply without voltage stabilization, then the device complexity is reduced, but the light emission becomes uneven and flickering occurs due to voltage fluctuations
Solution Approach 1:
The patent applies preliminary action by pre-modelling the voltage profile of the AC power supply before the LED operation. The control device creates a model of the voltage profile in advance and uses this model to proactively adjust the LED circuit states, rather than reacting to voltage fluctuations after they occur. This allows the system to maintain uniform light emission by anticipating voltage variations.
Solution Approach 2:
The patent implements dynamics by making the LED circuit configuration adjustable and adaptive. The control device dynamically switches between different circuit states (series/parallel LED configurations) based on the modelled voltage profile. This dynamic adaptation allows the system to maintain optimal light emission uniformity across varying AC voltage conditions without requiring complex stabilization hardware.
2Illumination intensity
If the LED circuit states are frequently adjusted to match instantaneous voltage values, then the light emission uniformity is improved, but the switching losses and heat generation increase
Solution Approach 1:
The patent applies partial action by adjusting the LED circuit states to match the modelled voltage profile rather than attempting to track every instantaneous voltage fluctuation. The control device strategically switches between circuit states at optimal points in the voltage cycle, achieving sufficient light emission uniformity without the excessive switching required for perfect instantaneous tracking. This reduces switching losses while maintaining acceptable performance.
3Ease of operation
If a rectifier circuit is used to convert AC voltage, then the LED operation is simplified, but the power factor decreases and energy efficiency is reduced
Solution Approach 1:
The patent implements feedback by using the modelled voltage profile as a reference for controlling the LED circuit states. The control device continuously compares the modelled profile with actual operation conditions and adjusts the circuit states accordingly. This feedback mechanism allows the system to maintain high power factor by synchronizing LED switching with the voltage waveform, reducing energy losses while keeping the operation simple through automated control.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides a stable and uniform light emission even under unstable AC power conditions, ensuring high reliability and efficiency by aligning the LED circuit states with the modelled voltage profile, thus maintaining a high power factor greater than 0.98.
Implementation Method 1
a rectifier device (5) which produces, in particular rectifies, a rectified AC voltage (11) from the mains voltage (2)
Data Source
AI summary
An LED lighting device for supplying a main voltage by an AC power supply is provided. The device has a rectifier for producing a rectified AC voltage from the main voltage, an LED light unit having multiple of LEDs and a circuit arrangement, and a control device for controlling the circuit arrangement. The circuit arrangement switches the LEDs to different circuit states, in which the LED light unit has different forward voltages. The control device controls the circuit arrangement, in such a way that the forward voltage of the LED light unit is adjusted to the voltage profile of the rectified AC voltage. The device also has a modelling device for modelling a modelled voltage profile. The control device controls the circuit states based on the modelled voltage profile. The modelled voltage profile is modelled based on measured variables for describing the real voltage profile of the main voltage.