Battery Self-Heating Control Using Bidirectional AC Charging
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Solution Overview
Problem
Current battery charging technologies are inefficient due to the need for external heating structures, which increase weight, reduce energy density, and have low heating efficiency, thereby prolonging charging times for electric vehicles.
Innovation Solution
A charging and heating apparatus that uses a unidirectional/bidirectional conversion unit to output a first bidirectional alternating current to the battery, allowing it to self-heat without additional heating devices, and controls the mode based on real-time temperature and SOX parameters to optimize charging efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a heating structure is provided on the battery to heat the battery, then charging efficiency is improved, but weight of the battery increases and ratio of stored power to mass decreases
Solution Approach 1:
The battery uses its own internal resistance and the charging current to generate heat through Joule heating, eliminating the need for external heating structures. The battery essentially heats itself during the charging process by utilizing its inherent electrical properties rather than requiring separate heating components.
Solution Approach 2:
The patent replaces the mechanical/thermal heating system (heating structures, heaters, thermal conduction paths) with an electrical field-based heating mechanism. By applying alternating current or pulsed current, the battery generates heat through electrical resistance, substituting a thermal field approach with an electrical field approach that is more efficient and lighter.
2Productivity
If a heating structure is provided on the battery to heat the battery, then charging efficiency is improved, but heating efficiency is low
Solution Approach 1:
The patent replaces inefficient thermal conduction heating with direct Joule heating through electrical current. This substitution of heating mechanism dramatically improves heating efficiency by generating heat directly within the battery electrodes and electrolyte through electrical resistance, rather than attempting to transfer heat from external heating elements through thermal conduction.
Solution Approach 2:
The patent changes the heating parameter from thermal conduction (external heat source) to Joule heating (internal heat generation through current). By controlling current parameters (amplitude, frequency, pulse width), the system optimizes heating efficiency and can precisely control the heating process to match charging requirements.
3Temperature
If a heating structure is provided on the battery, then battery temperature can be increased, but charging time is prolonged due to low heating efficiency
Solution Approach 1:
The battery generates its own heat during charging through internal resistance, eliminating the time delay associated with external heating. The heating occurs simultaneously with charging rather than sequentially, as the charging current itself produces the necessary heat through Joule heating, thus not extending the overall charging time.
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 eliminates the need for external heating structures, improves heating efficiency, increases energy density, and reduces charging time by allowing the battery to self-heat under controlled conditions, thereby enhancing overall charging efficiency.
Implementation Method 1
control the unidirectional/bidirectional conversion unit to output the first bidirectional alternating current to the corresponding power unit, such that the battery self-heats under excitation of the first bidirectional alternating current
Data Source
AI summary
A charging and heating apparatus includes a power unit configured to be connected to a battery to be charged/discharged and perform voltage conversion on a received voltage and current and output a converted voltage to the battery, a unidirectional/bidirectional conversion unit connected to the power unit and configured to output a bidirectional alternating current or a preset current to the power unit, and a control unit connected to the unidirectional/bidirectional conversion unit and configured to, in response to the battery being in a heating mode, control the unidirectional/bidirectional conversion unit to output the bidirectional alternating current to the corresponding power unit, such that the battery self-heats under excitation of the bidirectional alternating current, and in response to the battery being in a charge/discharge mode, control the unidirectional/bidirectional conversion unit to output the preset current to the power unit, such that the battery is charged/discharged.