Interleaved Boost Converter Phase Compensation for Input Ripple
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Solution Overview
Problem
Interleaved boost converters face challenges in maintaining a 180-degree phase difference due to input voltage ripples, especially with smaller filter capacitors, leading to misalignment and inefficiencies in power factor correction.
Innovation Solution
A phase compensator is introduced to adjust the ON times of the converters based on differential measurements and phase feedback, compensating for input voltage differences and maintaining a 180-degree phase difference using a phase control loop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If interleaved boost converters are used to reduce converter size and improve performance, then the effective switching frequency is doubled and inductor size is reduced, but input voltage ripples cause misalignment of the 180-degree phase difference between converters
Solution Approach 1:
The patent implements a feedback mechanism where the actual phase difference between the two interleaved converters is continuously measured and compared to the ideal 180-degree phase difference. Based on this comparison, the control system adjusts the switching timing of one or both converters to correct any phase misalignment caused by input voltage ripples, thereby maintaining stable phase relationship despite the reduced inductor size
Solution Approach 2:
The patent dynamically adjusts switching parameters (such as duty cycle or switching timing) of the interleaved converters based on detected phase differences and input voltage conditions. By changing these parameters in real-time, the system compensates for phase misalignment while maintaining the benefits of reduced inductor size achieved through interleaved operation
2Volume of moving object
If smaller filter capacitors are used to reduce converter size, then the converter volume is reduced, but input voltage ripples increase causing phase misalignment
Solution Approach 1:
The patent converts the harmful effect of increased input voltage ripples (caused by smaller capacitors) into a useful signal for phase detection and correction. The ripple information is used to detect phase misalignment and trigger compensatory adjustments, thereby transforming what would be a detrimental effect into a basis for maintaining phase synchronization
Solution Approach 2:
The patent introduces a phase detection and control circuit as an intermediary between the smaller capacitors and the converter switching elements. This intermediary component processes the voltage ripple signals and generates corrective control actions, allowing the system to tolerate smaller capacitors while maintaining stable operation through active compensation
3Productivity
If active PFC control is implemented to maintain phase difference, then power factor correction efficiency is improved, but device complexity increases
Solution Approach 1:
The patent implements a control circuit that performs multiple functions: it detects phase differences between converters, measures input voltage ripple characteristics, generates corrective control signals, and maintains power factor correction. By combining these functions into a single integrated control mechanism, the system achieves high PFC efficiency without proportionally increasing device complexity
Data Source
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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.