Dual Link Power Converter Soft Switching Ripple Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current power conversion technologies face limitations in achieving efficient, high-bandwidth active control, reducing ripple voltage, and minimizing filtering requirements, especially in applications requiring variable frequency and voltage operations.
Innovation Solution
The use of multiple soft-switched power modules connected in parallel, each comprising bi-directional conducting and blocking semiconductor switches, an inductor, and a parallel capacitor, allows for efficient energy transfer and soft turn-off, enabling reduced ripple voltage, increased power density, and high-bandwidth control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple power modules are connected in parallel, then power density and control bandwidth are improved, but device complexity increases
Solution Approach 1:
The power converter is divided into multiple independent power modules connected in parallel, each module containing its own switches, inductor, and capacitor. This segmentation allows each module to operate semi-independently, achieving higher power density and control bandwidth while maintaining manageable complexity through modular design.
Solution Approach 2:
Multiple power modules are merged in parallel configuration to achieve cumulative power output. The modules share common input and output connections while maintaining individual energy storage elements, combining their capabilities to increase overall power density without proportionally increasing control complexity.
2Adaptability or versatility
If bidirectional switches are used for full bipolar connection, then power transfer versatility is improved, but device complexity and loss increase
Solution Approach 1:
Bidirectional switches are implemented in each power module to enable universal power transfer capability in both directions. Each switch can conduct current in either direction and block voltage in both polarities, providing full bipolar connection capability that allows the converter to operate in multiple modes (rectification, inversion, power factor correction) without requiring separate circuits.
Solution Approach 2:
The bidirectional switches utilize the inherent properties of the power modules themselves to achieve versatile operation. The switches leverage the energy storage in inductors and capacitors to naturally enable bidirectional power flow and multiple operating modes without requiring additional external components or complex control circuitry.
3Speed
If link inductor current is rapidly switched, then power transfer speed is improved, but voltage ripple and electromagnetic interference increase
Solution Approach 1:
Energy is pre-stored in the inductors and capacitors of each power module before rapid switching occurs. This preliminary energy storage allows the switches to transfer power rapidly when needed while the energy storage elements act as buffers that smooth out voltage and current ripples, reducing electromagnetic interference during high-speed operation.
Solution Approach 2:
The switching frequency and duty cycle are dynamically adjusted to optimize power transfer speed while maintaining acceptable voltage ripple levels. The control system modifies switching parameters in real-time based on load conditions, allowing rapid power transfer when required while reducing switching activity when lower power levels are needed, thereby minimizing voltage ripple and EMI.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in reduced ripple voltage, increased power density, and high-bandwidth active control, while minimizing filtering requirements and achieving bi-directional power transfer, suitable for various applications including motor drives and solar power systems.
Implementation Method 1
a link inductor, 108, and a link capacitor, 112, connected in parallel with each other, forming a link, 110, which acts as a resonant circuit
Implementation Method 2
The switches alternately connect the reactance between said portals, such that energy is transferred into the inductor from one or more input portals and/or phases, then transferred out of the inductor to one or more output portals and/or phases
Data Source
AI summary
Methods and systems for transforming electric power between two or more portals using multiple power modules. Any or all portals can be DC, single phase AC, or multi-phase AC. Individual power modules comprise a plurality of bi-directional conducting and blocking semiconductor switches, and an inductor and parallel capacitor (reactance). The switches alternately connect the reactance between said portals, such that energy is transferred into the inductor from one or more input portals and/or phases, then transferred out of the inductor to one or more output portals and/or phases, with said parallel capacitor facilitating “soft” turn-off, and with any excess inductor energy being returned to the input. Dual power modules can operate 90 degrees out of phase. This configuration allows use of the same I/O filter capacitors as with a single power module, while achieving twice the total power produced by the power converter, reducing ripple voltage and doubling ripple frequency.