Series Resonant Converter Duty Cycle Control for Partial Load Efficiency
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Solution Overview
Problem
Series resonant converters experience efficiency reductions during partial load operations due to standard 50% duty cycle, leading to increased transmission losses and inefficiencies when power transfer is reduced.
Innovation Solution
Adjusting the duty cycle in at least one port to less than 50%, particularly between 10% to 45%, allows for improved efficiency by matching port voltage ratios with transformer ratios, reducing losses and enhancing power transfer efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a duty cycle of 50% is used in standard operation, then full load power transfer efficiency is maintained, but partial load operation efficiency decreases due to mismatched voltage ratios and increased transmission losses
Solution Approach 1:
The patent implements dynamic duty cycle adjustment in series resonant converters, allowing the duty cycle to vary based on operating conditions. Specifically, the duty cycle is adjusted to match the ratio of port voltages divided by transformer turns ratios, enabling optimal efficiency across different load conditions rather than being fixed at 50%.
Solution Approach 2:
The patent changes the operational parameter of duty cycle from a fixed 50% value to a variable parameter that adapts to different operating conditions. By modifying the duty cycle parameter according to the relationship between port voltages and transformer ratios, the system achieves reduced transmission losses and improved efficiency, particularly in partial load operations.
2Productivity
If the duty cycle is reduced below 50% for partial load operation, then efficiency is improved by matching voltage ratios, but control complexity increases
Solution Approach 1:
The patent employs feedback control mechanisms where the duty cycle is continuously adjusted based on measured port voltages and transformer ratios. This feedback loop ensures that the duty cycle remains optimized for current operating conditions, maintaining high efficiency while managing control complexity through systematic monitoring and adjustment.
Solution Approach 2:
The control system automatically adjusts the duty cycle based on real-time operating parameters without requiring manual intervention. The system self-regulates by calculating the optimal duty cycle from measured voltages and transformer characteristics, reducing the need for complex external control while maintaining high efficiency.
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
This approach significantly increases electrical power transfer efficiency during partial load operations by optimizing duty cycle settings, ensuring equal voltage-time areas across ports and reducing transformer loading, thereby achieving high efficiency even at reduced power levels.
Implementation Method 1
the ports being coupled together with a transformer for transferring electrical power between the ports
Implementation Method 2
a series resonant circuit and a transformer terminal of the transformer for controlling a port voltage applied to the series resonant circuit
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
The invention concerns a method of operating a series resonant converter (1), the series resonant converter (1) having a plurality of ports (2), the ports (2) being coupled together with a transformer (T) for transferring electrical power between the ports (2), the ports (2) each having a switch configuration (4) formed with a plurality of switches, a series resonant circuit (5) and a transformer terminal of the transformer (T) for controlling a port voltage (V1, V2, V3) applied to the series resonant circuit (5) with switching of the switch configuration (4). To achieve a high efficiency, in particular in partial load operation, at least one of the ports (2) is operated with a duty cycle of less than 50 %. Furthermore, the invention concerns a series resonant converter (1).