Integrated DC/DC Converter for Battery Pack Energy Balancing
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Solution Overview
Problem
High voltage battery systems in electric vehicles face inefficiencies due to external DC/DC converters, which consume excess power when idle and require external equipment for balancing battery pack voltages, leading to energy wastage and safety concerns.
Innovation Solution
Incorporating a DC/DC converter within the battery pack that can import or export power based on energy balancing needs, controlled by a computing system to manage power flow and balance energy levels among multiple battery packs, eliminating the need for external equipment and reducing idle power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If an external DC/DC converter is used to convert high voltage DC to low voltage DC, then power conversion function is achieved, but the battery contactors must be energized to deliver power which increases electric load and consumes excess power during idle state
Solution Approach 1:
The DC/DC converter is integrated within the battery pack itself, merging the power conversion function with the energy storage unit. This eliminates the need for separate external converters and their associated contactors, allowing power conversion to occur without energizing high-voltage battery contactors during idle state, thus reducing parasitic power consumption.
Solution Approach 2:
The low-voltage DC/DC converter acts as an intermediary between the high-voltage battery system and low-voltage loads. It enables power transfer from high-voltage batteries to low-voltage systems without requiring direct connection through high-voltage contactors, thereby isolating the high-voltage system during idle state and reducing unnecessary power consumption.
2Stability of the object's composition
If external equipment is used to balance battery pack voltages by discharging excess energy, then battery pack imbalance is corrected, but stored energy is wasted in the form of discharged energy
Solution Approach 1:
The battery pack performs self-balancing through its integrated DC/DC converter, which can operate in bidirectional mode to import or export power as needed. This eliminates the need for external balancing equipment and allows the system to redistribute energy internally without wasting stored energy through uncontrolled discharge.
Solution Approach 2:
The DC/DC converter dynamically adjusts power flow parameters (import/export mode, power magnitude) to achieve voltage balancing across battery packs. By controlling the converter's operation mode based on real-time voltage measurements, the system can transfer energy from overcharged packs to undercharged packs, maintaining voltage balance while preserving total system energy.
3Power
If external DC/DC converter is used for power conversion, then high voltage to low voltage conversion is achieved, but safety is reduced because contactors must be energized to deliver power
Solution Approach 1:
By integrating the DC/DC converter within the battery pack, the high-voltage-to-low-voltage conversion occurs inside the protected battery enclosure rather than externally. This allows the high-voltage battery contactors to remain disengaged during idle state while still enabling power conversion through the integrated converter, thereby maintaining safety isolation while preserving conversion capability.
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 enables efficient energy balancing and power management within the battery system, reducing energy wastage and enhancing safety by allowing for in-system rebalancing without external intervention, thereby improving the operational efficiency and maintenance of electric vehicles.
Implementation Method 1
a direct current to direct current (DC/DC) converter configured to at least one of import power to the at least one battery cell from the low voltage bus bar or export the power from the at least one battery cell to the low voltage bus bar
Data Source
AI summary
A battery system may include at least one battery pack including a direct current to direct current (DC/DC) converter and at least one battery cell. A positive terminal and a negative terminal of the at least one battery cell may be electrically connected to a positive terminal and a negative terminal, respectively, associated with the DC/DC converter. The battery system may further include a high voltage bus bar electrically connected to the positive terminal and the negative terminal of the at least one battery cell and a low voltage bus bar electrically connected to the DC/DC converter. The DC/DC converter may be configured to import power to the at least one battery cell from, or export the power to, the low voltage bus bar. The battery system may additionally include a communication bus bar electrically connected to the DC/DC converter.