Interleaved Boost Converter Phase Control for Input Ripple Compensation
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Solution Overview
Problem
Interleaved boost converters face challenges in maintaining a 180-degree phase difference between converters, especially at low switching frequencies and with smaller filter capacitors, leading to input voltage ripple issues that affect power factor correction and efficiency.
Innovation Solution
A phase compensator system that compares duty cycle measurements from both converters to generate a phase compensation, adjusting the switching times of the converters to maintain a 180-degree phase difference, using a differential ON time generation circuit and cycle controller to synchronize the switching signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If interleaved boost converters operate at low switching frequencies with smaller filter capacitors, then device size and cost are reduced, but phase difference stability deteriorates leading to input voltage ripple issues
Solution Approach 1:
The patent implements a feedback mechanism where the controller continuously monitors the actual phase difference between the two converters and adjusts the switching timing accordingly. This closed-loop control ensures that the phase difference remains stable at 180 degrees even when operating at low switching frequencies with smaller capacitors, thus resolving the contradiction between reduced size and maintained stability
Solution Approach 2:
The patent dynamically adjusts switching parameters (timing and duration) based on operating conditions. By modifying the switching timing parameters in response to detected phase deviations, the system maintains stable phase difference while operating with reduced capacitor sizes and lower switching frequencies, achieving both size reduction and stability maintenance
2Loss of energy
If interleaved boost converters operate at low switching frequencies, then switching losses are reduced improving efficiency, but phase synchronization becomes more difficult to maintain
Solution Approach 1:
The controller uses feedback from phase difference detection to continuously correct timing deviations. This ensures reliable phase synchronization is maintained even at low switching frequencies where synchronization is more difficult, allowing the system to operate at lower frequencies for reduced switching losses without sacrificing synchronization reliability
Solution Approach 2:
The system employs dynamic adjustment of switching timing parameters based on real-time phase difference measurements. This dynamic control approach enables the converters to adapt to varying operating conditions and maintain reliable synchronization across different frequency ranges, permitting operation at lower frequencies for improved efficiency
3Ease of operation
If the phase difference between converters deviates from 180 degrees, then individual converter operation may be simplified, but input voltage ripple increases affecting power factor correction
Solution Approach 1:
The controller continuously monitors phase difference and provides feedback to adjust switching timing. This ensures the phase difference is maintained at the optimal 180 degrees, minimizing input voltage ripple and improving power factor correction, while the control mechanism itself remains relatively simple through duty cycle or timing adjustments
Data Source
AI summary
A method and apparatus are described for compensating input voltage ripples of an interleaved boost converter using cycle times. In an embodiment, a phase compensator receives a first duty cycle measurement of a first converter and a second duty cycle measurement of a second converter, compares the first duty cycle to the second duty cycle and generates a phase compensation in response thereto. A phase combiner combines a phase adjustment output and the phase compensation and produces a phase control output, and a cycle controller is coupled to the first and the second converters to generate a first drive signal to control switching of the first converter and to generate a second drive signal to control switching of the second converter, wherein a time of the second drive signal is adjusted using the phase control output.