Self-Excitation Synchronous Rectification Driver Frequency Control
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Solution Overview
Problem
Conventional self-excitation synchronous rectification technologies fail to regulate the self-excitation frequency during zero-load or underload-shutdown stages, leading to abnormal voltage and potential circuit damage due to overlapping switch timings and uncontrolled energy release.
Innovation Solution
A self-excitation synchronous rectification driver that utilizes an external synchronous signal to control the turn-on timings of rectifier switches, incorporating a self-excitation coil, driver, pulse transformer, positive/negative edge detector, and latch unit to limit frequencies and prevent overlap, ensuring normal operation during zero-load or underload conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If self-excitation coil is used to generate self-excitation phenomenon, then rectifier switches can be controlled to turn on, but the turn-on timings of first and second rectifier switches overlap, causing overlap loss
Solution Approach 1:
The synchronous signal provides real-time feedback about the power driver unit's operating phase, enabling the rectification unit to synchronize its switch turn-on timings precisely. This feedback mechanism ensures that rectifier switches turn on at the correct moments relative to the power driver switches, eliminating timing overlaps and reducing energy loss while maintaining efficient rectification operation
Solution Approach 2:
The patent employs periodic synchronous signals that correspond to the operating cycle of the power driver unit. By aligning the rectifier switch turn-on events with these periodic synchronous signal edges (positive or negative), the system ensures proper timing separation between switches, preventing overlap loss while maintaining continuous efficient rectification across operating cycles
2Use of energy by stationary object
If self-excitation frequency is not regulated during underload-shutdown stage, then the power driver unit can be turned off, but abnormal voltage appears due to uncontrolled energy release from main transformer
Solution Approach 1:
The synchronous signal acts as an intermediary control mechanism during underload-shutdown stages. Even when the power driver unit is turned off for energy recycling, the synchronous signal (or its stored state) continues to regulate the self-excitation frequency of the rectification unit, preventing uncontrolled energy release and abnormal voltage generation while allowing safe energy dissipation in the main transformer
Solution Approach 2:
The system prepares for underload-shutdown conditions by maintaining the synchronous signal generation capability or storing its state before the power driver unit is turned off. This preliminary preparation ensures that when energy recycling begins, the rectification unit already has the control mechanism in place to regulate self-excitation frequency and prevent abnormal voltage, enabling safe energy dissipation without harmful effects
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 solution effectively regulates the self-excitation frequency within a normal range, preventing abnormal voltage and ensuring stable operation by alternately turning on rectifier switches and limiting their working frequencies, thus maintaining circuit integrity during varying load conditions.
Implementation Method 1
The rectification unit utilizes a self-excitation coil Lo to generate a self-excitation phenomenon
Implementation Method 2
The pulse transformer obtains a synchronous signal from the synchronous-signal source
Data Source
AI summary
The present invention discloses a self-excitation synchronous rectification driver, which comprises a self-excitation coil, a self-excitation driver, a synchronous-signal source, a pulse transformer, a positive/negative edge detector, and a latch unit. The synchronous-signal source generates a synchronous signal to attain an external synchronous function. When the frequency is abnormal, the first and second rectifier switches of the rectification unit of the power supply are forced to turn on or turn off. Thereby, the first and second rectifier switches can turn on alternately, and the first and second rectifier switches are limited to within the highest and lowest working frequencies during the zero-load stage or the shutdown stage. Thus, the frequency of the synchronous rectification driver is under control, and abnormal voltage will not occur.