Hybrid Flying Capacitor Converter Phase-Shift Control for Voltage Balance
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Solution Overview
Problem
Existing multi-level hybrid flying capacitor converters face issues with voltage deviations across the flying capacitor, which affect the operation and require separate regulation of both output voltage and flying capacitor voltage in an efficient and space-saving manner.
Innovation Solution
A control circuit is implemented with a PWM circuit and a phase shift circuit to generate control signals based on output voltage and capacitor voltage references, ensuring precise regulation of both voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate regulation circuits are used for output voltage and flying capacitor voltage, then voltage regulation precision is improved, but device complexity and space requirements increase
Solution Approach 1:
The patent combines two separate regulation functions (output voltage regulation and flying capacitor voltage regulation) into a single integrated control circuit. This control circuit uses one PWM generator that produces multiple PWM signals with different duty cycles, eliminating the need for separate regulation circuits and reducing overall system complexity while maintaining precise voltage control for both the output and the flying capacitor.
Solution Approach 2:
The control circuit is designed with multi-functionality, where a single PWM generator can regulate both the output voltage and the flying capacitor voltage through phase-shifted PWM signals. This universal control approach allows one circuit to perform multiple regulation tasks, reducing the number of components needed while achieving precise control over multiple voltage parameters simultaneously.
2Stability of the object's composition
If multiple separate control circuits are implemented for voltage regulation, then voltage stability is improved, but the converter occupies more space
Solution Approach 1:
The patent merges multiple control functions into a single integrated control circuit that regulates both output voltage and flying capacitor voltage. By combining what would traditionally require separate control circuits into one unified design, the patent reduces the overall converter area while maintaining stable voltage control through phase-shifted PWM techniques.
Solution Approach 2:
The patent introduces phase shift as an additional control dimension, where PWM signals are generated with different phase angles to independently control multiple voltage parameters. This phase-shift approach allows the system to achieve multi-parameter regulation without requiring proportionally more physical space, effectively utilizing the time dimension (phase) rather than just the spatial dimension.
3Manufacturing precision
If phase shift control is used for flying capacitor voltage regulation, then voltage deviation is reduced, but control circuit complexity increases
Solution Approach 1:
The patent uses phase shift as an intermediary control mechanism between the PWM generator and the flying capacitor voltage regulation. By introducing phase shift as an intermediate parameter, the system can indirectly control the flying capacitor voltage with high precision without requiring direct complex control circuits, thus achieving precise voltage control through a relatively simple phase-shifting approach.
Data Source
AI summary
In accordance with an embodiment, a control circuit includes a PWM circuit configured to provide a first control signal dependent on an output voltage of the power converter and an output voltage reference; and a phase shift circuit configured to phase shift the first control signal to generate a second control signal. A phase shift introduced by the phase shift circuit is dependent on a voltage across the flying capacitor and a capacitor voltage reference.