Multi-Phase Power Conversion Circuit for Stable Phase Switching
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Solution Overview
Problem
Conventional power conversion devices using single three-phase resonant circuits fail to achieve the desired gain between input and output voltages due to varying voltage and current requirements, leading to overshoot and undershoot when switched to different phases.
Innovation Solution
A multi-phase circuit control method that includes a first and second phase circuit, each with a primary and rectifier side, using a controller to generate control signals to adjust duty cycles and switch between two-phase, single-phase, and three-phase outputs based on detected output voltage levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single three-phase resonant circuit is used for power conversion, then the device structure is simple, but the gain between input voltage and output voltage cannot reach the expected gain and the operating range is limited
Solution Approach 1:
The patent divides the power conversion system into multiple independent phase circuits (first phase circuit and second phase circuit), each capable of operating independently. This segmentation allows the system to provide different voltage gains by selecting different phase combinations, thereby expanding the operating range while maintaining manageable circuit complexity through modular design.
Solution Approach 2:
The patent designs the multi-phase circuit where each phase circuit can serve multiple functions: they can operate individually or in combination, providing different voltage conversion ratios. The same circuit structure can adapt to different output voltage requirements by switching between phases, making the system universally applicable to various voltage demands without requiring separate dedicated circuits for each function.
2Adaptability or versatility
If a three-phase resonant circuit is directly switched to two-phase or single-phase output, then the output configuration is flexible, but the output voltage and current will overshoot and undershoot
Solution Approach 1:
The patent implements preliminary action by setting preset voltages for different phase switching transitions. Before switching between phase configurations, the system compares the current output voltage with these preset values to determine the appropriate switching timing. This preliminary comparison and controlled switching prevents sudden voltage changes, thereby avoiding overshoot and undershoot while maintaining output stability during phase transitions.
Solution Approach 2:
The patent employs feedback control by continuously detecting the output voltage and comparing it with preset reference values. Based on this feedback, the controller adjusts the switching between different phase circuits to maintain the output voltage within the expected range. This closed-loop feedback mechanism ensures stable output voltage and current during dynamic phase switching operations.
Data Source
AI summary
A multi-phase circuit control method includes following steps: generating a first control signal and a second control signal to a first phase circuit respectively by a controller; generating a third control signal and a fourth control signal to a second phase circuit respectively by controller; outputting a two-phase voltage to a output terminal of a power conversion device by first phase circuit and second phase circuit; changing a duty cycle of third control signal to turn off a first switch of a primary side circuit and a rectifier side circuit of second phase circuit by controller when controller is configured to detect that output voltage is lower than a first preset voltage; changing a duty cycle of fourth control signal to conduct a second switch of a primary side circuit and a rectifier side circuit of second phase circuit; and outputting a single-phase voltage to output terminal.