Dual Battery Power System for Electric Vehicles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current battery management systems in electric and hybrid vehicles face challenges in efficiently managing higher voltage systems, such as 800V, to reduce battery charging time, improve power system efficiency, and ensure fail-operational functionality while maintaining a compact and cost-effective design.
Innovation Solution
A power system architecture for electric vehicles utilizing dual battery packs and a configuration of switching elements that allows for fast charging and multiple driving modes, with a voltage converter and controllers to manage the on/off states of switching elements, enabling the system to adapt to different operational modes and ensure continued operation in case of battery or controller failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If higher voltage (800V) is used to reduce battery charging time and improve power system efficiency, then charging speed and power efficiency are improved, but system complexity and safety requirements increase
Solution Approach 1:
The power system is segmented into multiple independent battery packs (first battery pack and second battery pack) with separate management controllers. Each battery pack can be managed independently, allowing the system to handle higher voltages safely through modular architecture. This segmentation reduces overall system complexity by breaking down the high-voltage management into manageable units.
Solution Approach 2:
A power conversion device acts as an intermediary between the dual battery packs and the powertrain/auxiliary systems. This intermediary component manages the voltage conversion and power distribution, enabling the system to operate at 800V for fast charging while maintaining compatibility with lower-voltage components through controlled voltage transformation.
2Reliability
If dual battery packs with switching elements are used to enable fail-operational functionality, then system reliability is improved, but device complexity increases
Solution Approach 1:
The first and second battery packs are merged into a unified power system with shared power conversion and control infrastructure. This merging allows the system to achieve fail-operational functionality through redundancy while avoiding the complexity of completely separate systems. The switching elements are integrated into a single power conversion device that manages both battery packs.
Solution Approach 2:
The power conversion device serves multiple functions: it manages normal operation with both battery packs, handles fail-operational modes by switching to a single battery pack, and provides voltage conversion for different operating conditions. This multi-functionality reduces the need for separate dedicated systems for each operating mode, thereby reducing overall complexity.
3Loss of time
If 800V fast charging is implemented, then charging time is reduced, but system cost increases
Solution Approach 1:
The system dynamically switches between different voltage modes (400V and 800V) and different battery pack configurations based on operating conditions. During fast charging, the system operates at 800V to minimize charging time. During normal operation or when one battery pack is depleted, it switches to 400V mode. This dynamic operation allows the system to achieve fast charging capability without permanently requiring all components to be rated for 800V, thereby reducing overall system cost.
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 solution enables efficient 800V fast charging and flexible driving modes, reduces system cost and weight, and provides safety mechanisms for battery failures, while maintaining a compact footprint.
Implementation Method 1
a voltage converter coupled to the first battery pack and the second battery pack, and operable to transform the first voltage to the second voltage
Data Source
AI summary
Embodiments include a power device for an electric vehicle. The power device includes a first bus associated with a first voltage, and a second bus associated with a second voltage, different than the first voltage. The power device includes a plurality of switching elements coupled to a first battery, a second battery, the first bus and the second bus. On/off states of the plurality of switching elements control electrical connections to the first bus, the second bus, the first battery and the second battery according to an operation mode.