Multiphase Light Fixture Power Conversion Circuit Reduces LED Flicker
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Solution Overview
Problem
LED lighting systems face issues with flicker caused by varying electrical signals, which can be aesthetically displeasing and undesirable, especially when powered by multiphase AC power sources.
Innovation Solution
A power conversion circuit using a multi-pulse, multiphase rectifier and regulator circuit that converts multiphase AC power to a rectified DC output with reduced voltage ripple, minimizing flicker and eliminating the need for filtering capacitors, thereby providing a stable power supply to LED devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional power conversion circuits are used to convert AC power to DC for LED lighting, then the LED devices can be powered, but voltage ripple and flicker occur which are aesthetically displeasing and undesirable
Solution Approach 1:
The power conversion circuit is divided into multiple independent full-wave rectifier bridges (first bridge, second bridge, third bridge) that process different phases of AC input power separately. Each bridge converts one phase to rectified DC output, and the outputs are combined to produce a composite DC output with reduced ripple. This segmentation allows the circuit to maintain stable power conversion while minimizing voltage ripple and flicker through the distributed processing of multiple phases.
2Reliability
If filtering capacitors are added to reduce voltage ripple, then power supply stability improves, but thermal degradation occurs in high temperature environments
Solution Approach 1:
The patent replaces the traditional mechanical/chemical filtering method (using capacitors to smooth voltage ripple) with an electrical method (using multiple phase-shifted rectifier bridges to inherently produce lower ripple through their combined output). This substitution eliminates the thermal degradation issues associated with filtering capacitors while maintaining power supply stability, as the reduced ripple is achieved through circuit topology rather than thermal management of filtering components.
3Use of energy by moving object
If multiphase AC power is used to power LED devices, then power efficiency increases, but flicker caused by varying electrical signals becomes more pronounced
Solution Approach 1:
The patent merges the outputs of multiple full-wave rectifier bridges that process different phases of AC power. By combining the rectified DC outputs from bridges processing different phases, the circuit maintains the power efficiency benefits of multiphase input while the merging process inherently averages out the variations and flicker that would occur with single-phase processing. The combined output provides stable DC power with minimal ripple.
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 effectively reduces voltage ripple and flicker in LED lighting systems, allowing them to operate with minimal percent flicker and reduced harmonic distortion, even in high temperature environments, without the thermal degradation associated with filtering capacitors.
Implementation Method 1
a multi-pulse, multiphase rectifier configured to convert an input multiphase power to a rectified output power
Implementation Method 2
Light emitting diode (LED) lighting systems can include one or more LED devices that become illuminated as a result of the movement of electrons through a semiconductor material
Data Source
AI summary
Multiphase lighting fixtures having one or more light emitting diode (LED) light sources are provided. In one example implementation, a light fixture includes one or more light sources, such as LED light sources and a power conversion circuit. The power conversion circuit includes a phase shifting transformer for implementing a phase shift between output phases of secondary windings thereof, a multi-phase rectifier having a first rectifier and a second rectifier connected in parallel for converting a multiphase input power to a rectified output or a six-pulse configuration, a zero sequence blocking transformer for reducing harmonic distortion, an interphase transformer for further reducing harmonic distortion, and a current regulator for providing a constant DC current output to the one or more light sources. In some example implementations, the DC rectified output has a voltage ripple of less than about 7%, or less than about 3%.