Ripple Current Battery Heating via Impedance Minimization

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Solution Overview

Problem

Secondary batteries face challenges in maintaining sufficient heat generation at low temperatures due to increased impedance, which prevents effective temperature elevation while keeping upper and lower voltage limits, and existing solutions like resonance circuits are bulky and costly.

Innovation Solution

A temperature elevating apparatus using a ripple generator and controller to generate a ripple current at a frequency where impedance is minimized, allowing effective heat generation within the battery without additional power sources, utilizing a chopper-type booster with switching elements and reactors to optimize voltage and current flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If resonance circuit is used to elevate battery temperature, then temperature elevation efficiency is improved, but device complexity and cost increase due to additional inductor, capacitor and AC source

Engineering Contradiction:
Improvetemperature elevation efficiencyVSAvoiddevice complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The battery's own internal resistance is utilized to generate heat for temperature elevation, eliminating the need for external heating devices. The control unit activates the battery to operate in a state that generates internal heat through its inherent resistance, achieving self-warming without additional hardware components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The battery serves dual functions: both as the energy storage device and as the heating element for temperature elevation. By leveraging the battery's internal resistance for heat generation, the system eliminates the need for separate heating components, thereby reducing device complexity while maintaining heating effectiveness.

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

2Loss of energy

If resonance circuit is used to elevate battery temperature, then temperature elevation efficiency is improved, but manufacturing cost increases due to additional components

Engineering Contradiction:
Improvetemperature elevation efficiencyVSAvoidmanufacturing cost
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The battery's own internal resistance is utilized to generate heat for temperature elevation, eliminating the need for external heating devices. The control unit activates the battery to operate in a state that generates internal heat through its inherent resistance, achieving self-warming without additional hardware components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The battery serves dual functions: both as the energy storage device and as the heating element for temperature elevation. By leveraging the battery's internal resistance for heat generation, the system eliminates the need for separate heating components, thereby reducing device complexity while maintaining heating effectiveness.

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

3Temperature

If high current is applied to generate sufficient heat, then temperature elevation effectiveness is improved, but voltage limits are exceeded due to increased impedance at low temperature

Engineering Contradiction:
Improvetemperature elevation effectivenessVSAvoidvoltage limit compliance
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The control unit dynamically adjusts the operating parameters of the battery based on real-time temperature and voltage conditions. By continuously monitoring the battery state and modifying the operating point, the system maintains voltage within safe limits while optimizing heat generation, preventing both overheating and voltage exceedance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control unit employs feedback control to monitor voltage and temperature levels, adjusting the battery's operating state accordingly. When voltage approaches limit thresholds or temperature reaches target levels, the control unit modifies the operating parameters to maintain safe operation, ensuring continuous compliance with voltage constraints during the heating process.

Inventive Principle:
Principle #23Feedback

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

Effectively elevates battery temperature by generating heat internally, ensuring sufficient current flow while maintaining voltage limits, even at extremely low temperatures, without inhibiting miniaturization or increasing costs.

Implementation Method 1

electric power is consumed mostly by the internal resistance of the battery at the time of the resonance, and the temperature of the battery is elevated by self heat generation

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP2453514B1Secondary-battery temperature-raising apparatus and vehicle having same
Publication Date: 2017.11.22 TOYOTA JIDOSHA KK
  • EP2453514B1 patent drawingFigure 1~2
  • EP2453514B1 patent drawingFigure 3~4
  • EP2453514B1 patent drawingFigure 5~6

AI summary

A temperature elevating apparatus of a secondary battery (10) includes a ripple generator (20) and a controller (30). Ripple generator (20) is connected to secondary battery (10), and is configured to actively generate ripple current (1) of a predetermined frequency in secondary battery (10). Controller (30) controls ripple generator (20) to elevate a temperature of the secondary battery by generating ripple current (1) in secondary battery (10). Here, the predetermined frequency is set to be a frequency in a frequency region where an absolute value of an impedance of secondary battery (10) relatively decreases based on frequency characteristics of the impedance of secondary battery (10).