Alternating Valley Switching Controller for Power Converter Frequency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Power converters with valley locking operations are limited to lower frequencies to minimize switching losses and electric-magnetic-interference, restricting their ability to operate at high frequencies.
Innovation Solution
An alternating valley switching controller is introduced, comprising a valley detection circuit and an alternating circuit that alternates switching periods based on a blanking-window signal and valley-detection signal, allowing the power switch to operate at specific valleys, thereby reducing switching losses and EMI without frequency limitations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If valley switching is used to reduce switching losses and EMI, then switching losses and EMI are reduced, but the power converter must operate at lower frequencies
Solution Approach 1:
The patent implements periodic valley switching by detecting voltage valleys at regular intervals and switching the power converter on and off at these periodic valleys. This periodic action allows the system to operate at higher frequencies while still capturing the benefits of valley switching, as the periodic nature ensures consistent timing for loss reduction without forcing the entire system to run at lower frequencies.
Solution Approach 2:
The patent dynamically adjusts the switching timing based on real-time valley detection rather than using fixed periodic intervals. The controller monitors the voltage waveform and identifies actual valley points, then triggers switching events dynamically at these optimal moments. This dynamic approach allows the system to adapt to varying operating conditions and maintain high frequency operation while minimizing switching losses.
2Loss of energy
If valley switching is used to reduce switching losses and EMI, then switching losses and EMI are reduced, but the switching control becomes more complex
Solution Approach 1:
The patent introduces a valley detection circuit as an intermediary component that automatically identifies voltage valley points and generates corresponding control signals. This intermediary handles the complex detection and timing logic, freeing the main controller from implementing complex valley-switching algorithms. The valley detection circuit acts as a dedicated mediator that simplifies the overall control architecture by encapsulating the complexity in a specialized subsystem.
Solution Approach 2:
The valley detection circuit operates autonomously to detect voltage valleys and generate switching control signals without requiring complex external control logic. The circuit self-regulates by monitoring the voltage waveform and automatically triggering switching events at the appropriate valleys. This self-service capability reduces the burden on the main controller and simplifies the overall switching control system.
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 enables regular switching of the power switch at specific valleys, reducing switching losses and EMI while allowing the power converter to maintain higher operation frequencies.
Implementation Method 1
The valley detection circuit is coupled to an auxiliary winding of a transformer to generate a valley-detection signal
Data Source
AI summary
An exemplary embodiment of an alternating valley switching controller is provided. The alternating valley switching controller includes a valley detection circuit and an alternating circuit. The valley detection circuit is coupled to an auxiliary winding of a transformer to generate a valley-detection signal. The alternating circuit alternates a plurality of switching periods of a switching signal according to a blanking-window signal and the valley-detection signal. The blanking-window signal switches between a first voltage level and a second voltage level in the plurality of switching periods. The plurality of switching periods includes at least two first periods and at least two second periods which occur alternately in response to the first voltage level and the second voltage of the blanking-window signal.