Series Power Converter Control for Natural Voltage Equalization
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Solution Overview
Problem
Existing power conversion apparatuses formed by combining multiple units face challenges in achieving natural voltage equalization, leading to complex control and reduced reliability due to uneven voltage distribution among the units.
Innovation Solution
A power conversion apparatus and method that includes a control unit connected to each power conversion unit, inputting control signals to ensure equal voltage across all units, utilizing a digital control system for simplified hardware design and enhanced flexibility, and implementing a hybrid PWM modulation scheme for efficient power conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple power conversion units are combined to improve power capacity and efficiency, then power density and conversion efficiency are improved, but voltage equalization becomes difficult to achieve and control complexity increases
Solution Approach 1:
The patent implements a feedback control mechanism where the control unit continuously monitors the voltage output of each power conversion unit and adjusts the duty cycle of each unit accordingly. This closed-loop feedback system ensures that voltage differences between units are detected and corrected in real-time, achieving natural voltage equalization without complex external intervention.
Solution Approach 2:
The patent employs dynamic duty cycle adjustment for each power conversion unit based on its instantaneous voltage output. By making the control parameters dynamic rather than static, the system adapts to changing operating conditions and automatically balances voltage distribution across all units, resolving the equalization problem while maintaining high power density.
2Loss of energy
If multiple power conversion units are combined to improve power capacity, then power conversion efficiency is improved, but control complexity increases and reliability decreases
Solution Approach 1:
The patent designs a universal control unit that manages multiple power conversion units through a unified control algorithm. This single control unit performs multiple functions including voltage monitoring, duty cycle calculation, and signal generation for all units, eliminating the need for separate control circuits for each unit and thereby reducing overall control complexity while maintaining high conversion efficiency.
Solution Approach 2:
The patent changes the control parameter from fixed duty cycles to dynamically adjusted duty cycles based on real-time voltage measurements. This parameter change enables the system to optimize conversion efficiency by adapting to load variations and unit performance differences, while the centralized control approach keeps the control architecture manageable despite the increased number of units.
3Ease of manufacture
If traditional control methods are used for multiple power conversion units, then device structure is simple, but voltage equalization cannot be achieved naturally and reliability is low
Solution Approach 1:
The patent introduces a centralized control unit as an intermediary between the power supply input and the multiple power conversion units. This control unit acts as a mediator that coordinates the operation of all units, ensuring voltage equalization through unified management. The intermediary structure maintains relative simplicity in the overall device architecture while dramatically improving reliability through intelligent control.
Data Source
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AI summary
Provided are a power conversion apparatus and a method for controlling a power conversion apparatus. A power conversion unit group and a control unit are provided. The power conversion unit group includes at least two power conversion units which are connected in series, the power conversion unit group is connected in series to an inductor unit and a power supply unit, and an output of at least one of the power conversion units is used as a power conversion result of the power conversion apparatus. The control unit is respectively connected to each of the power conversion units, and inputs corresponding control signals to the power conversion units respectively. The control signal enables the power conversion units to have a same voltage.