Parallel Battery Pack Heating Control to Prevent Circulating Current
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In parallel-connected battery packs, heating each battery pack using its own power can generate a circulating current, potentially damaging the cells, especially in low-temperature conditions.
Innovation Solution
A heating control system that includes relay units and management units to selectively connect or disconnect battery packs and heating elements, allowing only one pack to operate in self-powered heating mode under low temperatures, preventing circulating currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If each battery pack is heated by using power supplied by itself, then the battery can be pre-heated in low-temperature environment, but a circulating current is generated that may damage battery cells
Solution Approach 1:
The patent introduces an inverter as an intermediary power source for heating battery packs in parallel connection. Instead of each battery pack heating itself (which causes circulating current), the inverter acts as a mediator to provide heating power to one or more battery packs, eliminating the harmful circulating current while achieving the heating objective
Solution Approach 2:
The patent inverts the conventional self-heating approach by having the battery packs heated by an external power source (inverter) rather than by their own power. This reversal of the heating power direction eliminates the circulating current issue inherent in parallel-connected self-heating systems
2Power
If battery packs are connected in parallel to increase power supply capacity, then the system can provide more power, but circulating current between packs causes safety issues
Solution Approach 1:
The inverter serves as an intermediary that manages power distribution to parallel-connected battery packs during heating operations. By controlling which pack receives heating power from the inverter, the system maintains parallel connection benefits while preventing circulating current through centralized control
Solution Approach 2:
The battery management units monitor battery pack states and communicate with the inverter control unit, creating a feedback loop that dynamically adjusts heating operations. This feedback mechanism ensures safe operation by preventing circulating current while maintaining the parallel connection configuration for enhanced power capacity
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
Prevents damage from circulating currents by controlling the connection of battery packs and heating elements, ensuring safe and efficient pre-heating in low-temperature environments.
Implementation Method 1
a first heating element... configured to heat the first battery unit when the temperature of the first battery unit is less than a first threshold
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present application provides a heating control system for parallel-connected battery packs, including first and second battery packs. In response to temperatures of first and second battery units being less than a first threshold, each of first and second battery management units issuing a first heating request, and a voltage of the second battery unit being greater than that of the first battery unit, the first battery management unit controls a second relay unit to enable a second heating element and the second battery unit to be electrically connected; and controls a first relay unit to enable a first heating element and the first battery unit to be electrically disconnected. Adopting the present application may resolve a charging problem due to a circulating current between parallel-connected battery packs under a low-temperature condition.