Converter Rectifier Diode Control for Light-Load Power Loss
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Solution Overview
Problem
Existing power adapters face challenges in reducing power consumption during light loads, as they continue to incur drive loss and power supply loss due to the rectifier diode remaining active even when no load is present, which contradicts the requirements of sustainable development and energy efficiency standards.
Innovation Solution
A converter control method that determines the load situation by detecting the oscillating voltage of the rectifier diode and turns off the rectifier diode in the next switching cycle when the load is light or null, thereby reducing drive loss and overall power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the rectifier diode remains active during light load operation, then the rectification function is maintained, but drive loss and power consumption increase
Solution Approach 1:
The rectifier diode's operating state is dynamically adjusted based on load conditions. The control circuit detects the load status and dynamically switches the rectifier diode between on-state and off-state, making the system adaptive to varying load requirements rather than maintaining a fixed state
Solution Approach 2:
The electrical parameters of the rectifier diode (conduction state) are changed based on load conditions. During light load operation, the parameter changes from conducting to non-conducting state, reducing energy loss while maintaining rectification capability when needed
2Loss of energy
If the rectifier diode is turned off during light load, then power consumption is reduced, but the ability to handle load changes may be affected
Solution Approach 1:
The control circuit continuously monitors the load status through feedback mechanisms and adjusts the rectifier diode's state accordingly. This feedback loop ensures that the system maintains adaptability to load changes while optimizing power consumption by turning off the rectifier diode only when appropriate
Solution Approach 2:
The control circuit periodically detects the load status and adjusts the rectifier diode state in a periodic manner, ensuring continuous monitoring and timely response to load changes while maintaining energy efficiency during sustained light load conditions
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 effectively minimizes power consumption and improves efficiency by ensuring the rectifier diode is only active when necessary, aligning with energy-saving standards and reducing unnecessary losses in the converter system.
Implementation Method 1
determines a load situation by detecting an oscillating voltage of the rectifier diode
Implementation Method 2
energy is provided for the secondary-side circuit by using the transformer
Data Source
Figure 1~3
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AI summary
Embodiments of this application disclose a converter, applied to the field of power supply technologies, and including a direct current power supply, a first switching transistor, a second switching transistor, a resonant capacitor, a transformer, a secondary-side circuit, and a control circuit. The secondary-side circuit is connected to a secondary-side winding of the transformer, and includes a rectifier diode and a parasitic diode corresponding to the rectifier diode. The direct current power supply, the first switching transistor, and the second switching transistor are connected in series, the resonant capacitor and a primary-side winding of the transformer are connected in series, and a loop formed in series is connected in parallel at two sides of the first switching transistor. The control circuit controls the first switching transistor and the second switching transistor to be turned on or off. An Nth turn-on moment of the second switching transistor to an (N+1)th turn-on moment of the second switching transistor is one switching cycle. The control circuit is further configured to control, based on a quantity of oscillation times of an oscillating voltage of the rectifier diode in a first switching cycle, the rectifier diode to be turned on or off in a second switching cycle, where the second switching cycle is a next switching cycle adjacent to the first switching cycle.