Parallel Battery Current Balancing via Thermal Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for controlling current in parallel-connected batteries face challenges such as coarse current control, energy wastage, high cost, and complexity, particularly with hard switching and regulator-based systems, which can lead to inefficiency and reliability issues.
Innovation Solution
A system that controls current by manipulating the temperature of each battery, utilizing temperature controllers and cooling systems to adjust internal resistance and thereby manage current flow, allowing for precise control without adding significant hardware or energy loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If hard switching devices are used to control current between parallel batteries, then current control is achieved, but current control precision is poor and current inrush damage may occur
Solution Approach 1:
The patent changes the control parameter from direct current switching to temperature control. By controlling the temperature of each battery, the internal resistance changes, which in turn controls the current distribution. This indirect control method achieves fine current control without the precision problems of direct switching.
Solution Approach 2:
The patent introduces temperature as an intermediary parameter between the control system and current distribution. Instead of directly controlling current through switching devices, the system controls temperature, which then naturally regulates current flow through changes in internal resistance, avoiding current inrush issues.
2Measurement precision
If regulators are used to actively control power flow in and out of each battery, then current control precision is improved, but system cost, size, weight, and complexity increase
Solution Approach 1:
The patent replaces the mechanical/electrical regulator system with a thermal control system. Instead of using complex regulators with switching devices, magnetic components, and capacitive elements to control current, the system uses temperature control to achieve the same effect through changes in battery internal resistance, significantly reducing system complexity.
Solution Approach 2:
The patent changes the control approach from direct electrical parameter control (voltage, current) to thermal parameter control (temperature). This fundamental parameter change eliminates the need for complex power electronics and reduces system complexity while maintaining control precision.
3Device complexity
If series resistors are used to control current into parallel batteries, then current control is simplified, but energy loss increases significantly
Solution Approach 1:
The patent changes the control mechanism from resistive control to thermal control. By controlling battery temperature, the internal resistance changes, which controls current distribution without the continuous energy dissipation inherent in resistive control. The energy loss is minimized because the resistors are not continuously dissipating power, but rather the battery's own internal resistance is being dynamically adjusted.
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 enables fine-tuned current control with minimal energy loss and reduced system complexity, improving efficiency and reliability by adjusting current values based on temperature, allowing batteries to maintain balanced state of charge and health.
Implementation Method 1
a cooling system which can draw the heat generated in the batteries away from the batteries, in which the rate of heat transfer from each of the batteries can be independently controlled
Implementation Method 2
The resistance is monotonically variable with respect to the battery's temperature within the normal operating temperature range of the batteries
Data Source
AI summary
A method of controlling current in a parallel battery systems includes providing at least two parallel connected batteries, each said battery having an internal resistance and dissipating heat while operating; during operation, measuring at least the temperature and current of each individual battery; and providing instructions to a temperature control system having a temperature control module coupled with each said battery for individually cooling each said battery to adjust temperature of at least one battery in order to maintain the current at a target value.