Synchronous DC/DC Converter Switching for EV Charging and Export Power
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Solution Overview
Problem
Electrified vehicles face compatibility challenges due to varying battery voltages and voltage ripple issues, making it difficult to simultaneously provide power to external loads and perform DC fast charging, especially when supporting both 400V and 800V external loads.
Innovation Solution
A synchronous switching DC/DC voltage converter with a controller that selectively connects external charging and load terminals to the traction battery, allowing the converter to adjust voltage based on detected voltages and requested loads, enabling both boost and buck operations to accommodate different voltage requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a synchronous switching DC/DC voltage converter is used to support both DC fast charging and external power supply, then compatibility with different battery voltages (400V/800V) is improved, but device complexity increases due to multiple switches and control logic
Solution Approach 1:
The synchronous switching DC/DC voltage converter is designed to perform multiple functions: it can operate in boost mode during DC fast charging, in buck mode during external power supply, and in pass-through mode for direct charging. This multi-functionality allows a single device to handle different battery voltages (400V/800V) and different operating modes, improving adaptability while managing complexity through integrated design
Solution Approach 2:
The converter employs dynamic switching control where the controller selectively connects switches (S1-S6) based on real-time operating conditions. The system dynamically transitions between boost mode, buck mode, and pass-through mode by controlling the switching states of the synchronous switches, allowing the converter to adapt its configuration to match the required voltage conversion ratio and operating mode
2Productivity
If the voltage converter operates in boost mode to charge the traction battery from lower voltage external charging terminals, then charging capability is improved, but power loss increases due to voltage conversion
Solution Approach 1:
The patent replaces traditional mechanical or less efficient voltage conversion methods with a synchronous switching DC/DC converter that uses solid-state electronic switching. This electronic approach minimizes energy losses during voltage conversion by using synchronous rectification and reducing resistive losses, thereby maintaining high charging capability while minimizing power loss
Solution Approach 2:
The converter dynamically adjusts its operating parameters (switching frequency, duty cycle, and mode) based on the voltage difference between the external charging terminals and the traction battery. By optimizing these parameters in real-time, the system achieves efficient voltage conversion in boost mode while minimizing energy losses during the charging process
3Power
If the voltage converter operates in buck mode to supply power to external loads from higher voltage traction battery, then power supply capability is improved, but voltage ripple on external load side increases
Solution Approach 1:
The synchronous switching DC/DC voltage converter acts as an intermediary between the high-voltage traction battery and the external loads. During buck mode operation, it provides galvanic isolation and electrical filtering, acting as a mediator that reduces voltage ripple and electrical noise while maintaining high power supply capability to external loads
Solution Approach 2:
The converter implements local quality control by providing different output characteristics to different loads. It can deliver high power to external loads while simultaneously maintaining clean, stable voltage by using the switching architecture to filter and condition the output, addressing different quality requirements in different parts of the system
4Ease of operation
If multiple switches are used to selectively connect charging and load terminals, then operational flexibility is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges multiple functions into a single integrated DC/DC converter module that combines the voltage conversion capability with the switching control for both charging and power supply operations. By consolidating the switch matrix and control logic into one unified device, the system achieves operational flexibility while reducing the total component count and simplifying manufacturing compared to separate systems
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 solution reduces material and space requirements, enables higher power supply to external loads, and facilitates simultaneous power supply and charging, improving compatibility and efficiency in commercial applications.
Implementation Method 1
a synchronous switching DC/DC voltage converter
Data Source
AI summary
An electrified vehicle includes a synchronous switching DC/DC voltage converter, switches configured to selectively connect external charging terminals to a traction battery, the voltage converter, and external load terminals, and at least one controller programmed to operate the voltage converter and control the switches to connect the external charging terminals to the voltage converter and the external load terminals based on nominal voltage of the traction battery relative to voltage at the external charging terminals and a requested voltage supplied to the external load terminals. An associated method includes controlling the plurality of switches to selectively connect the external charging terminals, the voltage converter, and the external load terminals; and controlling whether the voltage converter operates to increase or decrease voltage based on which one or more of the voltage converter, the external charging terminals, the external load terminals, and the traction battery are connected by the plurality of switches.