Hysteretic Power Converter Frequency Synchronization
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Solution Overview
Problem
Hysteretic power converters, widely used in Solid State Lighting applications, face challenges in multi-phase configurations due to their variable switching frequency and lack of defined frequency, leading to increased complexity and cost in filtering, especially in LED matrix applications where output voltage changes frequently.
Innovation Solution
An apparatus comprising multiple power converters with real or artificial hysteresis, controlled by a control circuit that adjusts the magnitude of hysteresis based on phase or frequency differences, allowing these converters to operate at the same frequency with a desired phase difference, thereby reducing current ripple through multiphase configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If hysteretic power converters are used in multi-phase configurations, then current ripple is significantly reduced, but the variable switching frequency and lack of defined frequency increase filtering complexity and cost
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the hysteresis magnitude of power converters based on detected phase or frequency differences. The control circuit modifies the hysteresis parameter in real-time to maintain synchronized operation, enabling multi-phase configuration without requiring complex filtering solutions. This dynamic parameter adjustment allows the system to achieve both low current ripple and simplified filtering.
2Device complexity
If hysteretic power converters operate with fixed hysteresis magnitude, then the converter structure is simple, but the switching frequency varies frequently and over a wide range causing filtering complications
Solution Approach 1:
The patent implements feedback control by detecting the phase or frequency difference between power converters and using this information to adjust the hysteresis magnitude. The control circuit continuously monitors the operating state and modifies the hysteresis parameter accordingly, creating a closed-loop system that stabilizes switching frequency while maintaining simple converter structure. This feedback mechanism enables the system to adapt to changing conditions without increasing structural complexity.
3Object-generated harmful factors
If large filter capacitors are used to achieve low ripple current in hysteretic converters, then current ripple is reduced, but the output voltage changes frequently requiring more complicated and expensive filtering
Solution Approach 1:
The patent extracts the frequency stabilization function from the filtering circuitry by implementing it within the power converter control itself. Instead of relying on large filter capacitors and complex external filtering, the invention modifies the hysteresis parameter to inherently stabilize the switching frequency and reduce current ripple at the source. This extraction of the stabilization function eliminates the need for complicated filtering structures while achieving the desired low ripple current performance.
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
Enables efficient operation of multiple power converters in multiphase configurations, significantly reducing current ripple and simplifying filtering, which is beneficial for applications like LED arrays by stabilizing the switching frequency and phase, thus enhancing performance and reducing costs.
Implementation Method 1
a first power converter with real or artificial hysteresis; a second power converter with real or artificial hysteresis; wherein the apparatus is configured such that a magnitude of hysteresis of at least one of said first and second power converters is controlled by said control signal
Data Source
AI summary
An apparatus is described, comprising: a first power converter with real or artificial hysteresis; a second power converter with real or artificial hysteresis; and a control circuit configured to output a control signal dependent on a phase difference or frequency difference between the first and second power converters; wherein the apparatus is configured such that a magnitude of hysteresis of at least one of said first and second power converters is controlled by said control signal.