Buck-Boost Topology With Active Holdup for Inverted Output Continuity
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Solution Overview
Problem
Conventional power conversion systems lack the ability to provide negative holdup voltage, which is essential for ensuring power continuity in modular power supplies, particularly in applications like aircraft where certain components require a guaranteed 28 Volts even during power interruptions.
Innovation Solution
A buck-boost power converting system with a voltage source input, multiple switches controlled by a controller, and a holdup capacitor that provides positive holdup voltage, capable of switching between non-inverted and inverted modes to maintain power delivery regardless of the input power availability, utilizing a single inductor and six switches with specific switching sequences for PWM control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional power conversion topologies are used, then the system structure is simple, but the ability to provide holdup voltage during power interruption is insufficient
Solution Approach 1:
The patent combines the holdup capacitor charging function with the main power conversion function into a single integrated circuit topology. The holdup capacitor is charged during normal operation through the same power conversion circuit that supplies the load, merging two functions (holdup and power conversion) that could otherwise be separate systems.
Solution Approach 2:
The power conversion circuit is designed to perform multiple functions: during normal operation it converts input voltage to output voltage for the load, and during power interruption it transfers energy from the holdup capacitor to maintain output voltage. The same switches, inductor, and control logic serve both the holdup charging function and the power conversion function.
2Reliability
If a holdup capacitor is added to provide positive holdup voltage, then power continuity is improved, but the device complexity increases
Solution Approach 1:
The holdup capacitor is integrated into the existing power conversion circuit rather than being added as a separate standalone system. The capacitor shares the same inductor and switch network, eliminating the need for separate magnetics and control circuits that would increase complexity.
Solution Approach 2:
The holdup capacitor serves dual purposes: it acts as an energy storage element for holdup voltage during interruptions, and simultaneously functions as part of the power conversion process during normal operation. This multi-functionality reduces the need for dedicated holdup circuitry.
3Adaptability or versatility
If the system must support both inverted and non-inverted modes, then versatility is improved, but the control complexity increases
Solution Approach 1:
The system dynamically switches between inverted and non-inverted output modes based on control signals. The controller adjusts the switching sequences of the power switches to change the output polarity, allowing the system to adapt its behavior rather than requiring separate fixed circuits for each mode.
Solution Approach 2:
The output mode (inverted or non-inverted) is changed by modifying the switching parameters and sequences of the power switches. The controller varies the duty cycles and timing of switch activation to produce different output polarities from the same hardware configuration.
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
The system effectively generates and maintains positive holdup voltage, enabling continuous power supply to critical components by charging a holdup capacitor and switching between non-inverting and inverting output modes, reducing the need for custom magnetics and enhancing reliability with dual switches in the forward power path.
Implementation Method 1
A holdup capacitor with a holdup voltage output is operatively connected to the plurality of switches to provide positive holdup voltage for output if power to the voltage source input is interrupted
Data Source
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AI summary
A buck-boost power converting system includes a voltage source input (102) for connecting a voltage source for power conversion. A plurality of switches are electrically connected to the voltage source input (102). Each switch is connected to a controller configured for control of the switches. A load output is operatively connected to the switches to provide non-inverted output voltage relative to the voltage source input (102) in a non-inverted mode and to provide inverted output voltage relative to the voltage source input (102) in an inverted mode. A holdup capacitor with a holdup voltage output is operatively connected to the plurality of switches to provide positive holdup voltage for output if power to the voltage source input (102) is interrupted, regardless of whether the load output is in the inverted mode or the non-inverted mode.