EV Charging Connector Temperature Estimation for Fast-Charge Safety

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Solution Overview

Problem

Conventional electric vehicle charging technologies face challenges in providing high-power fast charging due to high temperatures generated by charging guns, posing a fire hazard.

Innovation Solution

A method and apparatus for monitoring the temperature of an electric vehicle charging apparatus by calculating resistance values and using a predetermined temperature coefficient of resistance (TCR) to estimate the temperature, comparing it with an over-temperature threshold, and adjusting the charging current accordingly to prevent overheating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If DC fast charging is used to increase charging power, then charging speed is improved, but temperature of charging connector increases causing safety hazards

Engineering Contradiction:

Improvecharging speedVSAvoidtemperature

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary actions by continuously monitoring resistance values before temperature becomes critically high, calculating temperature trends in advance, and proactively adjusting charging current to prevent overheating while maintaining fast charging capability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements feedback control by continuously measuring resistance values, calculating corresponding temperature values, comparing them against safety thresholds, and dynamically adjusting charging current based on the temperature feedback to resolve the contradiction between fast charging and temperature control

Inventive Principle:

Principle #23Feedback

2Reliability

If temperature monitoring and current adjustment is implemented, then safety is improved, but system complexity increases

Engineering Contradiction:

ImprovesafetyVSAvoidsystem complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system applies self-service principle by using the existing power meter to measure resistance values and automatically calculating temperature values through processor-based algorithms, eliminating the need for separate temperature sensors and reducing overall system complexity while improving safety

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system replaces mechanical/physical temperature sensing with an electrical measurement approach, using resistance value measurements and TCR-based calculations to determine temperature, thereby simplifying the system architecture while achieving reliable temperature monitoring for safety

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Enables real-time temperature monitoring and adjustment of charging current to prevent overheating, ensuring safety while maintaining high-power fast charging services.

Implementation Method 1

calculating an initial resistance value of the charging connector based on the initial current value and the initial power value; calculating a present resistance value of the charging connector based on the present current value and the present power value

Methodology Applied

Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 2

calculating an estimated present temperature value of the charging connector based on a predetermined temperature coefficient of resistance (TCR) that corresponds to the charging connector, an initial temperature value that is related to an ambient temperature, the initial resistance value, and the present resistance value

Methodology Applied

Scientific EffectTemperature coefficient of resistance (TCR): Thermo-resistive Effect

Implementation Method 3

The charging pile is connected to the charging connector, and includes a power meter and a processor. The charging connector is connected to the electric vehicle for providing a charging current from the charging pile to the electric vehicle

Methodology Applied

Scientific EffectElectrical Conduction: Conduction (electrical)

Data Source

PatentUS12583351B2Method for monitoring an electric vehicle charging apparatus, and electric vehicle charging apparatus implementing the same

Publication Date: 2026.03.24 METAL INDS RES & DEV CENT

AI summary

A method for monitoring an electric vehicle charging apparatus is provided. A charging pile that includes a power meter and a processor is used to provide a charging current to an electric vehicle through a charging connector. The power meter detects the charging current to generate an initial current value and an initial power value that correspond to an initial charging time, and a present current value and a present power value that correspond to a present time, so that the processor calculates an initial resistance value and a present resistance value of the charging connector accordingly, and then calculates an estimated present temperature value of the charging connector based on the initial resistance value and the present resistance value. The estimated present temperature value is compared with an over-temperature threshold to determine whether to reduce the charging current.