Three-Level Voltage Bus Switching for Wide AC Input Ranges
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Power supply systems face challenges in maintaining efficiency and reducing voltage variation across downstream converters due to wide input voltage ranges, which can lead to increased voltage stress and inrush current, especially when operating in different countries with varying AC supply voltages.
Innovation Solution
A three-level voltage bus configuration that reconfigures inputs of downstream converters either in series or parallel, using switches and capacitors to adjust voltage thresholds, reducing voltage variation and stress on switches, and employing a controller to manage switch operation based on input voltage levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the power supply system operates with a wide input voltage range to support different countries' AC supply voltages, then the adaptability of the power supply system is improved, but the voltage variation range applied to downstream converters increases causing increased voltage stress and inrush current
Solution Approach 1:
The power supply system is segmented into multiple voltage bus levels (first voltage bus, second voltage bus, third voltage bus) with different voltage thresholds. The first voltage bus operates at a higher voltage threshold for high input voltage conditions, while the second and third voltage buses operate at lower voltage thresholds for low input voltage conditions. This segmentation allows the system to adapt to different input voltage ranges while maintaining appropriate voltage stress levels on downstream components.
Solution Approach 2:
The system dynamically switches between different voltage bus configurations based on the input voltage level. A controller monitors the input voltage and selectively activates appropriate voltage buses and switches. When input voltage is high, the first voltage bus is activated; when input voltage is low, the second and third voltage buses are activated. This dynamic reconfiguration optimizes voltage stress on switches and capacitors across different operating conditions.
2Adaptability or versatility
If the power supply system uses a wide input voltage range to support different countries' AC supply voltages, then the adaptability of the power supply system is improved, but the inrush current during startup increases
Solution Approach 1:
The startup process is segmented into different phases based on input voltage level. The controller detects the input voltage and selectively activates appropriate voltage buses during startup. By segmenting the startup process into high-voltage-mode startup (using first voltage bus) and low-voltage-mode startup (using second and third voltage buses), the system limits inrush current to appropriate levels for each voltage condition.
Solution Approach 2:
The system dynamically controls the activation of voltage buses during startup based on detected input voltage levels. The controller monitors input voltage and selectively enables appropriate switches and voltage buses during the startup sequence. This dynamic control ensures that capacitors charge through appropriate voltage levels, limiting inrush current while maintaining adaptability to different input voltage ranges.
3Adaptability or versatility
If the power supply system uses a wide input voltage range to support different countries' AC supply voltages, then the adaptability of the power supply system is improved, but the system efficiency decreases due to increased voltage variation
Solution Approach 1:
The system segments the operating voltage range into multiple discrete voltage bus levels. Each voltage bus is optimized for specific input voltage ranges. By segmenting the operation into high-voltage-mode (first voltage bus) and low-voltage-mode (second and third voltage buses), the system maintains optimal efficiency in each operating range rather than operating across a wide continuous range where efficiency would degrade.
Solution Approach 2:
The system dynamically switches between different voltage bus configurations to maintain optimal efficiency across different input voltage conditions. The controller monitors input voltage and transitions between voltage bus modes at optimized thresholds. This dynamic optimization ensures that downstream converters receive voltage within their optimal operating range, minimizing energy losses while maintaining adaptability to different input voltages.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
An apparatus includes a first switch and a first capacitor connected in series between a first voltage bus and a second voltage bus, a second capacitor and a second switch connected in series between the first voltage bus and the second voltage bus and a diode coupled between a common node of the first switch and the first capacitor, and a common node of the second capacitor and the second switch.