Battery Self-Heating Control to Prevent Switchgear Sintering

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Solution Overview

Problem

Existing battery heating systems in electric vehicles lack accurate control, leading to potential switchgear sintering and impaired battery performance in cold environments, affecting vehicle operation and user experience.

Innovation Solution

A control method for a battery self-heating system that accurately controls battery heating by monitoring temperature and voltage/current information to determine if heating is required, using a switch circuit with transistors and contactors to alternately charge and discharge battery bodies, ensuring safe and efficient self-heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the battery is heated in a cold environment to ensure normal operation, then the battery charging and discharging efficiency is improved, but the switchgear may experience sintering due to inaccurate control

Engineering Contradiction:

Improvebattery charging and discharging efficiencyVSAvoidswitchgear reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent implements a feedback control mechanism by detecting voltage information between the first end and second end of the switch circuit, and current information through the switch circuit. Based on these real-time measurements and temperature information, the control component dynamically adjusts the switching states of switch devices and contactors to prevent sintering while maintaining heating effectiveness

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent applies preliminary action by detecting voltage and current information before actually switching the contactors or switch devices. This allows the system to predict potential sintering risks and adjust switching strategies in advance, ensuring safe operation during battery self-heating

Inventive Principle:

Principle #10Preliminary action

2Device complexity

If the switch circuit is controlled to enable self-heating without accurate voltage and current monitoring, then the heating process is simplified, but the risk of switchgear sintering increases

Engineering Contradiction:

Improvecontrol system complexityVSAvoidswitchgear reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent replaces complex mechanical switching control with intelligent electronic control. The control component uses detected voltage and current information combined with temperature data to make automated switching decisions, substituting manual or simple mechanical control with a smarter electronic system that enhances reliability without proportionally increasing complexity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If the battery bodies are controlled to alternately charge and discharge for self-heating, then the self-heating efficiency is improved, but the control precision requirements increase to prevent sintering

Engineering Contradiction:

Improveself-heating efficiencyVSAvoidvoltage and current measurement precision

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent uses feedback control by continuously detecting voltage information between the first end and second end of the switch circuit, and current information through the switch circuit. This real-time feedback allows the system to maintain precise control over the alternating charge-discharge process of battery bodies, adjusting switching timing and duration based on actual electrical conditions to prevent sintering while maximizing heating efficiency

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

Ensures accurate battery self-heating operations, improving charging and discharging efficiency while preventing switchgear sintering, thus enhancing electric vehicle performance.

Implementation Method 1

the three-phase inverter is controlled to enable/configure the first battery body and the second battery body to alternately charge and discharge, to achieve self-heating of the battery pack

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Data Source

PatentUS20250381887A1Battery self-heating system and control method therefor, and electric vehicle

Publication Date: 2025.12.18 BYD CO LTD

AI summary

A control method for a battery self-heating system, the battery self-heating system includes a three-phase motor, a battery pack, a three-phase inverter, and a switch circuit, and the method includes: acquiring battery pack temperature information; according to the battery pack temperature information, when determining that the battery pack requires self-heating, obtaining voltage information between a first end and a second end of the switch circuit; according to the voltage information between the first end and the second end of the switch circuit, controlling the switch circuit for self-heating of the battery pack; according to the battery pack temperature information when determining that the battery pack does not require self-heating, obtaining current information between the first end and the second end of the switch circuit; and according to the current information between the first end and the second end of the switch circuit, controlling the switch circuit to stop self-heating.