Charge Discharge System Regenerative Power Management
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Solution Overview
Problem
Conventional charge/discharge systems for electric vehicles risk undercharging secondary batteries due to prioritizing capacitor charging, which can lead to reduced battery life and inefficient energy use.
Innovation Solution
A charge/discharge system that includes a capacitor and a secondary battery, with an electric power converter and controller to manage voltage and direct regenerative power storage between the two components, ensuring the secondary battery remains sufficiently charged by shifting power storage from the capacitor to the battery when its state of charge falls below a preset threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If regenerative electric power is stored in the capacitor prioritized to prepare for instantaneous high power requirements, then the capacitor charging amount is sufficient, but the secondary battery charging amount becomes too low
Solution Approach 1:
The system dynamically switches between capacitor-only charging and combined capacitor-battery charging modes based on real-time SOC monitoring of the secondary battery. When SOC falls below the first threshold, the controller activates the electric power converter to charge the battery while maintaining capacitor charging, ensuring adaptive power distribution that prevents battery undercharging while preserving instantaneous power capability.
Solution Approach 2:
The controller changes the charging parameter distribution by adjusting the charge/discharge voltage of the secondary battery through the electric power converter. By monitoring SOC and switching between different charging modes (capacitor-only vs. capacitor-and-battery), the system optimizes the parameter allocation of regenerative power to satisfy both instantaneous power requirements and battery charging needs.
2Productivity
If frequent charge/discharge operations are performed on the secondary battery, then the storable capacity utilization is improved, but the battery life is shortened
Solution Approach 1:
The system performs preliminary monitoring of the secondary battery's SOC and establishes a first threshold value before excessive discharge occurs. By detecting SOC trends and switching to combined charging mode in advance when SOC approaches the threshold, the system prevents deep discharge cycles that would otherwise shorten battery life, while still maintaining high productivity through optimized power utilization.
3Productivity
If the electric power converter is used to increase/decrease charge/discharge voltage of the secondary battery, then the power distribution optimization is achieved, but the device complexity increases
Solution Approach 1:
The electric power converter serves as an intermediary device between the capacitor and secondary battery, enabling voltage matching and power flow control. The converter's control unit acts as a mediator that monitors SOC and automatically switches between charging modes, optimizing power distribution efficiency while managing the complexity through automated control logic that reduces manual intervention requirements.
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 approach maintains a stable secondary battery state of charge, prolongs battery life, and enhances energy efficiency by optimizing power distribution between the capacitor and battery, preventing battery failure and reducing unnecessary charge/discharge losses.
Implementation Method 1
an electric power converter placed between the capacitor and the secondary battery to increase/decrease charge/discharge voltage of the secondary battery
Data Source
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AI summary
A charge/discharge system is capable of supplying electric power to an electric motor generator and capable of charging with regenerative electric power from the electric motor generator. The charge/discharge system includes: a capacitor connected to the electric motor generator; a secondary battery connected in parallel to the capacitor; an electric power converter placed between the capacitor and the secondary battery to increase/decrease the charge/discharge voltage of the secondary battery; and a controller to control the electric power converter. If the SOC of the secondary battery is equal to or greater than a preset first setting value, the controller controls so that regenerative electric power of the electric motor generator is stored in the capacitor only, and if the SOC of the secondary battery falls below the first setting value, a part or an entire of the regenerative electric power of the electric motor generator is stored in the secondary battery.