DC Power Converter SRC-LLC Switching for Hold-Up and Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing DC power converters face challenges in balancing efficiency, selection of low withstand voltage rated components, and hold-up time, particularly in resonant converters like SRC and LLC converters, which have limitations in maintaining optimal efficiency and stable output voltage across varying input voltages.
Innovation Solution
A mixed-mode operation method is applied to DC power converters, switching between SRC and LLC modes based on input voltage thresholds to maintain fixed switching frequencies and output voltages, optimizing efficiency and component selection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a DC power converter operates in a single resonant mode (SRC or LLC), then the structure is simple and easy to implement, but the efficiency and output stability cannot be optimized across the full input voltage range
Solution Approach 1:
The patent implements dynamic mode switching between SRC and LLC resonant converters based on input voltage levels. The system transitions from a static single-mode design to a dynamic multi-mode system, where the control unit automatically selects the appropriate operating mode (SRC or LLC) according to real-time input voltage conditions, thereby optimizing efficiency across the full voltage range while maintaining relatively simple converter structures.
Solution Approach 2:
The patent changes the operating parameters of the resonant converter by switching between different resonant modes (SRC and LLC) based on input voltage thresholds. This parameter change allows the system to adapt to varying input conditions, maintaining high efficiency and stable output across different voltage ranges without requiring complete redesign of the converter structure.
2Adaptability or versatility
If the input voltage range is expanded, then the adaptability of the converter is improved, but the output voltage stability becomes difficult to maintain
Solution Approach 1:
The system dynamically adjusts its operating mode based on input voltage levels to maintain output stability. When input voltage varies within the expanded range, the control unit switches between SRC and LLC modes appropriately, ensuring that the output voltage remains stable despite the wide input range, thus resolving the contradiction between adaptability and stability.
Solution Approach 2:
The patent employs feedback control mechanisms where the control unit monitors the input voltage and automatically selects the appropriate resonant mode (SRC or LLC) based on predefined voltage thresholds. This feedback-based mode switching ensures that output voltage stability is maintained across the expanded input voltage range by continuously adapting to changing input conditions.
3Adaptability or versatility
If high-voltage rated components are selected to handle maximum input voltage, then the converter can operate at full voltage range, but the cost and device complexity increase
Solution Approach 1:
The patent segments the input voltage range into different operating zones, each handled by a specific resonant mode (SRC or LLC). This segmentation allows the use of components rated for lower voltage in each segment, rather than requiring all components to handle the maximum voltage. The control unit directs operation to the appropriate mode based on voltage levels, reducing overall component specifications and cost.
Solution Approach 2:
The system changes operating parameters by switching between SRC and LLC modes to match different voltage ranges. This parameter change strategy allows components to be selected based on the specific voltage range they need to handle in their designated mode, rather than requiring all components to withstand the maximum input voltage, thereby reducing device complexity and cost.
4Productivity
If the switching frequency is increased to improve power conversion speed, then the productivity increases, but the switching losses increase and efficiency decreases
Solution Approach 1:
The patent dynamically adjusts the switching frequency and resonant mode based on operating conditions. By utilizing resonant switching in both SRC and LLC modes, the system achieves high power conversion speed while maintaining low switching losses. The dynamic selection of operating mode ensures that the converter operates at optimal frequency points that balance speed and efficiency requirements.
Solution Approach 2:
The patent employs resonant vibration principles in both SRC and LLC modes to achieve high-frequency operation with minimal losses. By operating at or near the resonant frequency of the tank circuit, the system achieves fast power conversion while the resonant nature of the operation minimizes switching losses, effectively resolving the contradiction between productivity and energy loss.
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 method achieves improved efficiency, reduces the need for high-voltage rated components, and extends hold-up time by stabilizing output voltage within defined limits, combining the advantages of both SRC and LLC modes.
Implementation Method 1
Resonant converters can use resonant tanks to shape the waveforms of switching voltage and/or switching current to minimize switching losses and enable high-frequency operation
Data Source
AI summary
A mixed-mode operation method is applied to a DC power converter. The DC power converter receives an input voltage, and the input voltage is between a minimum voltage and a maximum voltage. The method includes steps of: operating the DC power converter in a SRC mode when the input voltage is greater than a lower threshold voltage and less than an upper threshold voltage; operating the DC power converter in an LLC mode when the input voltage is less than the lower threshold voltage; operating the DC power converter in the LLC mode when the input voltage is greater than the upper threshold voltage.