Battery Heating System Using Motor-Generated AC Current

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Solution Overview

Problem

Lithium batteries experience degraded discharge capacity and inability to charge at low temperatures, necessitating heating, but existing external heating methods are inefficient and costly.

Innovation Solution

A battery heating system that integrates switches, a motor, and a controller within a single housing to generate continuous alternating current, heating the battery pack internally.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If external heating methods (air heating, liquid heating, phase-change material heating) are used to heat the battery pack, then the battery can be heated in low temperature environments, but the heating efficiency is low and the cost is high due to requiring dedicated thermal cycle vessels and special structural components

Engineering Contradiction:
Improvebattery temperatureVSAvoidheating efficiency
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The battery pack uses its own power system to generate heating current through the motor and controller, eliminating the need for external heating sources. The motor acts as a generator to produce alternating current that flows through the battery, generating heat internally through resistance, thus the system serves itself for heating without external thermal cycle vessels or special structural components

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces mechanical/thermal external heating systems with an electrical heating system. Instead of using external heaters, thermal cycle vessels, or phase-change materials, the system uses electrical current generated by the motor-controller assembly to heat the battery internally, substituting a mechanical thermal management approach with an electrical one that is more efficient and cost-effective

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Temperature

If external heating methods are used with dedicated thermal cycle vessels, then the battery pack can be heated, but the device complexity and cost increase due to special structural components

Engineering Contradiction:
Improvebattery temperatureVSAvoidstructural complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The motor and controller assembly serves dual functions: it acts as the drive system for the vehicle and simultaneously serves as the heating system when needed. The same electrical components that control motor operation are repurposed to generate heating current, eliminating the need for separate dedicated thermal cycle vessels and special structural components, thus reducing device complexity while maintaining heating capability

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the heating function with the existing motor-controller system. Instead of having separate external heating components, the heating functionality is integrated into the motor-controller assembly, combining multiple functions into a single system and reducing overall structural complexity

Inventive Principle:
Principle #5Merging (Combining)

3Temperature

If the motor operates during heating, then heating can be provided, but the motor must be stopped for heating to occur safely

Engineering Contradiction:
Improvebattery temperatureVSAvoidoperational flexibility
Core Design Contradiction:
TemperatureVSEase of operation

Solution Approach 1:

The system uses periodic switching of the motor controller to generate alternating current for heating. The controller periodically switches the motor windings to create AC current flow through the battery, enabling heating while maintaining the ability to quickly transition to motor operation when needed, thus balancing heating effectiveness with operational flexibility

Inventive Principle:
Principle #19Periodic action

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

Improves heating efficiency and reduces costs by directly heating the battery pack from the inside, enhancing performance in low-temperature conditions.

Implementation Method 1

heat the battery pack using an alternating current generated in a circuit formed by the first switch, the second switch, the switch component, the motor, and the battery pack

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3675273B1Battery heating system and control method thereof
Publication Date: 2021.05.12 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD
  • EP3675273B1 patent drawingFigure 1
  • EP3675273B1 patent drawingFigure 2
  • EP3675273B1 patent drawingFigure 3

AI summary

The disclosure provides a battery heating system and a control method thereof. The system includes a first switch (K1) connected to a positive electrode of the battery pack (E), a second switch (K2) connected to a negative electrode of the battery pack (E), a switch component (K3) connected between the first switch (K1) and the second switch (K2), a motor (M) connected to the switch component (K3), and a main controller (P); wherein: the first switch (K1), the second switch (K2), the switch component (K3) and the main controller (P) are integrated in a same housing; the main controller (P) is configured to determine, based on a state parameter of the battery pack (E), whether the battery pack (E) needs to be heated, and to send a battery heating request to a vehicle controller when it is determined that the battery pack (E) needs to be heated, so as to enable the vehicle controller to send a battery heating instruction to the main controller (P) according to the battery heating request in a case where it is determined that a vehicle is in a static state and the motor (M) is not operating; and the main controller (P) is configured to control, based on the battery heating instruction, the first switch (K1), the second switch (K2) and the switch component (K3) so as to heat the battery pack (E). Based on the embodiments of the disclosure, cost can be reduced and heating efficiency can be improved.