Bidirectional DC-DC Converter for Wide Input Voltage Efficiency
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Solution Overview
Problem
The efficiency of insulated DC-DC converters decreases with a wide input voltage range, which is exacerbated by the voltage fluctuations of high-voltage main batteries in electric vehicles, and existing solutions struggle to maintain high efficiency across a wide range while managing voltage fluctuations for low voltage auxiliary equipment systems.
Innovation Solution
A power supply device incorporating a bidirectional DC-DC converter that receives the high voltage from the main battery and outputs a link voltage, which is then adjusted by a chopper to optimize the input to an insulated DC-DC converter, thereby maintaining efficient power supply to both the main battery and the load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the input voltage range of the insulated DC-DC converter is widened to accommodate main battery voltage fluctuations, then the converter can handle a broader operating range, but the conversion efficiency decreases
Solution Approach 1:
The patent divides the voltage conversion function into two separate converters: a non-insulated DC-DC converter and an insulated DC-DC converter. The non-insulated converter handles the wide input voltage range from the main battery, while the insulated converter operates with a narrower, more efficient voltage range. This segmentation allows each converter to be optimized for its specific operating conditions, maintaining high efficiency across the overall wide input voltage range.
2Device complexity
If the conversion magnification of the insulated DC-DC converter is fixed, then the converter structure is simplified, but the ability to adapt to output voltage fluctuations is reduced
Solution Approach 1:
The patent combines two DC-DC converters in series to achieve both fixed magnification benefits and output voltage adaptation. The non-insulated converter with variable magnification compensates for output voltage fluctuations, while the insulated converter maintains fixed magnification for structural simplicity and high efficiency. Together, they provide both adaptability and structural advantages.
3Loss of energy
If a two-converter configuration is used to improve overall efficiency, then conversion efficiency is improved, but the system complexity increases
Solution Approach 1:
The non-insulated DC-DC converter serves multiple functions: it adapts to the wide input voltage range from the main battery, compensates for output voltage fluctuations, and provides insulation between the high-voltage and low-voltage sides. This multi-functionality reduces the need for additional components and simplifies the overall system despite using two converters.
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 configuration allows for a highly efficient power supply that maintains efficiency across a wide input voltage range, reducing voltage fluctuations and minimizing losses, thus effectively addressing the challenges of voltage management and efficiency in electric vehicle power systems.
Implementation Method 1
a bidirectional DC-DC converter that receives the voltage of a main battery 5 and outputs a link voltage
Implementation Method 2
a chopper that receives the link voltage and outputs a direct current to be input to an insulated DC-DC converter
Data Source
AI summary
An object of the present invention is to provide a highly efficient power supply device.A power supply device 1 according to the present invention includes a bidirectional DC-DC converter 3 and an insulated DC-DC converter 4. The bidirectional DC-DC converter 3 receives a main battery 5 and outputs a direct-current link voltage Vlink. The insulated DC-DC converter 4 receives the link voltage Vlink and supplies power to a load 7. The link voltage Vlink, which is an output of the bidirectional DC-DC converter 3, changes according to the output voltage of the insulated DC-DC converter 4.