Modular Multi-Level Converter Topology with Dynamic Series-Parallel Reconfiguration
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Solution Overview
Problem
Conventional power converters face challenges such as increased complexity, high discharge currents leading to destruction, and inefficient energy storage due to the need for even voltage distribution and protective measures, especially at high voltages, and they require oversized components for maximum power handling.
Innovation Solution
A power converter system comprising multiple individual modules with internal switching elements and energy storage elements that can be connected either in series or parallel, allowing for flexible energy storage configuration without additional external switches, reducing internal resistance and enabling efficient power delivery across a wide range of voltage and current levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If conventional converters use series connection of power semiconductors to achieve high voltage, then voltage handling capability is improved, but device complexity increases due to requirements for even voltage distribution and protective measures
Solution Approach 1:
The converter is divided into multiple independent modular units, each capable of operating autonomously. Each module contains its own power semiconductor switches and energy storage elements, allowing the system to achieve high voltage through series connection of modules while maintaining individual module simplicity. This segmentation eliminates the need for complex voltage distribution control across the entire system.
Solution Approach 2:
The converter topology enables dynamic reconfiguration of modules between series and parallel connections through control of switching elements. This dynamic capability allows the system to adapt to varying voltage and power requirements, optimizing performance while simplifying protection schemes compared to fixed series connections.
2Stress or pressure
If conventional converters use series connection of power semiconductors for high voltage, then voltage handling is improved, but reliability deteriorates due to high discharge currents causing destruction from mechanical forces and arcing
Solution Approach 1:
By segmenting the converter into modular units with distributed energy storage, the patent isolates fault conditions to individual modules. High discharge currents are confined to local capacitor banks within each module rather than flowing through the entire series string, reducing mechanical forces and arcing damage risks.
Solution Approach 2:
Each module is equipped with its own energy storage capacitor that serves as a local energy buffer. This beforehand cushioning prevents high discharge currents from propagating through the entire converter system, protecting switches from destructive mechanical forces and arcing.
3Power
If conventional converters use fixed series connection to handle maximum power, then power handling capability is improved, but adaptability deteriorates due to oversized components and inefficient energy storage
Solution Approach 1:
The converter employs dynamic switching control that allows modules to be reconfigured between series and parallel connections based on real-time voltage and power requirements. This dynamic adaptability enables the system to handle varying power levels efficiently without requiring oversized components designed for maximum continuous power.
Solution Approach 2:
The system changes its effective impedance and voltage output parameters by reconfiguring the connection topology of modular units. By altering the series/parallel arrangement, the converter can adapt to different voltage levels and power demands, eliminating the need for fixed oversized component design.
4Stress or pressure
If conventional converters use PWM conversion with variable duty factors for voltage control, then voltage regulation is improved, but energy efficiency deteriorates due to large voltage differences resulting in unfavorable pulse duty factors
Solution Approach 1:
The converter uses segmented modular units with individual energy storage capacitors, allowing voltage synthesis through discrete level combination. This segmentation enables more favorable pulse duty factors compared to conventional PWM, reducing switching losses and improving energy efficiency while maintaining voltage regulation capability.
Data Source
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AI summary
The present invention describes an electrical converter system for power supplies, comprising at least two identical individual modules connected in series, characterized in that each individual module has at least four internal switching elements, at least one energy storage element and at least four connections, wherein in each case two of the connections are used as first and second terminal pairs; the internal switching elements of each individual module are designed in such a way that said switching elements can connect either one or both connections of each terminal pair to the energy storage element; at least two individual modules are connected in series in such a way that in each case the connections of the second terminal pair of a preceding individual module are connected to the connections of the first terminal pair of the respectively following individual module, and at least one terminal of the first terminal pair of the first individual module in the series circuit and at least one terminal of the second terminal pair of the last individual module in the series circuit act as terminals of the series circuit; and wherein the switching elements of the respective individual modules in the series circuit of the at least two individual modules connect the respective energy storage elements thereof to the terminals of the series circuit in such a way that there is either a series circuit or a parallel circuit of the energy storage elements.