Phase-Shifted Full-Bridge Converter MPPT Under Variable Input Current
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Solution Overview
Problem
Existing photovoltaic power generation systems face instability and inefficiency in maximum power point tracking due to the inability of current control methods to adapt quickly to varying sunlight conditions, leading to prolonged stabilization times and potential system failures.
Innovation Solution
A phase-shifted full-bridge converter control method that dynamically adjusts the phase angle and switching frequency of switch transistors based on current thresholds, allowing for timely adaptation to varying input currents, thereby improving efficiency and stability in maximum power point tracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If constant cycle control is used for the switch transistor, then the control method is simple, but the system cannot adapt quickly to varying sunlight conditions, resulting in prolonged stabilization time and reduced efficiency
Solution Approach 1:
The patent implements dynamic control by dividing the switching cycle into multiple sub-cycles with different duty ratios. The controller adjusts the duty ratio of each sub-cycle based on the relationship between input voltage and reference voltage, enabling the system to adapt dynamically to varying sunlight conditions and achieve rapid stabilization without sacrificing control simplicity.
2Productivity
If constant phase shift control is used, then the control implementation is straightforward, but the system fails to respond timely to rapid current changes, causing instability in maximum power point tracking
Solution Approach 1:
The patent segments the switching cycle into multiple sub-cycles, where each sub-cycle can have different duty ratios. This segmentation allows the system to respond to current changes more frequently and accurately, improving response speed while maintaining stable maximum power point tracking through precise control of each sub-cycle's contribution to the overall power transfer.
3Adaptability or versatility
If the switching frequency is kept constant, then the design is simple, but the system cannot optimize power extraction under varying sunlight conditions
Solution Approach 1:
The patent changes the duty ratio parameter of each sub-cycle based on the relationship between input voltage and reference voltage. By adjusting this parameter dynamically, the system can optimize power extraction under varying sunlight conditions while maintaining a relatively simple control structure that builds upon conventional phase-shift control.
Data Source
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AI summary
A phase-shifted full-bridge converter, a control method and device thereof, and a medium. The method comprises: after a current input current of a phase-shifted full-bridge converter is obtained, selecting a working mode corresponding to the current input current according to a preset correspondence between an input current and a working mode, and under a current working mode, acquiring a phase shift angle of the phase-shifted full-bridge converter and the switching frequency of a switch transistor in the phase-shifted full-bridge converter according to a maximum power point tracking algorithm to control the switch transistor to execute a corresponding action. By applying the technical solution, when an input current is changed, a switch transistor in a phase-shifted full-bridge converter can be controlled under different modes according to different input currents, and a rapid change of the input current is responded in time, so that the maximum power tracking efficiency and stability are ensured, and the requirements of a system are further satisfied.