Flyback Isolation Power Circuit With Demagnetization Iteration Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional flyback isolation power supplies face challenges with slow system response due to lagging high-frequency transformer control signal transmission and right-half-plane zero issues, which affect stability and dynamic response.
Innovation Solution
An isolation type power conversion method based on demagnetization iteration control, utilizing a high-frequency transformer with adaptive turn-on time control and demagnetization time iteration, enables real-time signal coupling and iterative demagnetization time calculation to improve response speed and eliminate right-half-plane zero.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If control signal is transmitted by main high-frequency transformer, then electrical isolation is achieved, but system response lags behind one switching cycle
Solution Approach 1:
The patent segments the control signal transmission path into two independent channels: a primary side control channel using high-voltage isolation capacitor for fast response, and a secondary side control channel using optocoupler for electrical isolation. This segmentation allows each channel to perform its specialized function without compromising the other.
Solution Approach 2:
The patent introduces a high-voltage isolation capacitor as an intermediary component to transmit control signals from the primary side to the secondary side. This intermediary enables fast signal transmission while maintaining electrical isolation, resolving the contradiction between speed and isolation.
2Reliability
If control signal is transmitted by optocoupler, then electrical isolation is maintained, but transmission speed is slow affecting system response
Solution Approach 1:
The patent divides the control signal transmission into two segments: urgent control signals are transmitted through the high-voltage isolation capacitor on the primary side for fast response, while non-urgent signals use the optocoupler on the secondary side. This segmentation optimizes overall system response by handling time-critical signals through the faster path.
Solution Approach 2:
The patent implements partial action by using the optocoupler only for non-critical control signals while reserving the high-voltage isolation capacitor path for urgent signals. This partial utilization of the slower optocoupler channel maintains electrical isolation without compromising overall system response speed.
3Stability of the object's composition
If loop bandwidth is reduced to solve stability problem of right-half-plane zero, then system stability is improved, but dynamic response speed becomes slow
Solution Approach 1:
The patent extracts the right-half-plane zero issue from the control loop by implementing a fixed turn-on time control mode on the primary side. This extraction removes the stability-problematic element from the feedback loop, allowing the loop bandwidth to be increased for faster response without compromising stability.
Solution Approach 2:
The patent implements self-service by using the secondary side to detect its own output voltage and generate control signals that are transmitted back to the primary side. This self-regulating mechanism eliminates the need for external stability compensation and enables faster dynamic response.
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 enhances system dynamic response speed, stabilizes the power supply, and reduces system cost by eliminating the need for current sampling resistors and improving reliability through high-voltage isolation and ripple injection methods.
Implementation Method 1
An isolated power converter realizes energy transfer through an electromagnetic conversion mode of the high-frequency transformer
Implementation Method 2
the high-frequency transformer charging a secondary side power supply capacitor in a charging capacitor circuit electrically connected to a secondary side of the high-frequency transformer
Data Source
AI summary
Disclosed are an isolation type power conversion method based on demagnetization iteration control and a power conversion circuit. The power conversion circuit comprises a high-frequency transformer, wherein a primary side of the high-frequency transformer is electrically connected with a primary side power tube in a power switch tube circuit, a secondary side of the high-frequency transformer is electrically connected with a charging capacitor circuit and an output feedback circuit through a secondary side synchronous rectifier tube, and the primary side and the secondary side of the high-frequency transformer are electrically connected with a power conversion integrated control chip. The present invention provides a novel demagnetization time iteration loop control architecture, which controls the switching of the primary side power tube by iteratively calculating the demagnetization time, and the method eliminates the right-half-plane zero of a flyback isolation power supply, increases the loop bandwidth and improves the response speed of the system. The influence of signal noise interference during high-speed dynamic response is eliminated through a ripple injection method, and a voltage adaptive turn-on time control technology is adopted, so that a primary side current sampling resistor is omitted, the system cost is reduced, and the system reliability is improved.