EV Charging Contact Impedance Verification for Soiled Connectors
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Solution Overview
Problem
Existing electric vehicle charging systems face issues with unreliable electrical connections due to contaminated or soiled contacts, leading to power losses, longer charging times, and safety concerns, particularly in harsh weather conditions.
Innovation Solution
A device with a contact arrangement that includes a secondary contact to measure the impedance between electrical contacts and the vehicle's contact surface, ensuring a reliable connection by determining and reducing contact impedance before power supply, using a movable contact frame and actuator for engagement, and applying currents to clear high impedance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a movable contact frame with actuator is used to engage electrical contacts with the vehicle, then the ease of connecting and disconnecting is improved, but the reliability of electrical connection deteriorates due to contaminated or soiled contacts
Solution Approach 1:
The system performs a preliminary impedance measurement check before initiating power transfer. The control unit measures the impedance of the electrical connection between the charging device and the vehicle, and only allows power transfer when the impedance is below a predetermined threshold, ensuring connection reliability before operation begins
Solution Approach 2:
The patent replaces mechanical contact quality assessment with an electrical impedance measurement system. Instead of relying on mechanical engagement quality alone, the system uses electrical measurements to objectively verify connection quality, substituting mechanical assessment with electrical detection
2Productivity
If high current levels are used for quick charging, then the charging speed is improved, but the safety deteriorates due to overheating risks from bad contacts
Solution Approach 1:
The system performs preliminary impedance verification before high-power charging begins. By measuring connection impedance in advance and ensuring it meets safety thresholds, the system prevents overheating risks associated with bad contacts while enabling high-speed charging operation
Solution Approach 2:
The control unit continuously monitors impedance during charging operation and can adjust or terminate charging based on measured values. This feedback mechanism ensures safety by detecting deteriorating contact conditions and responding appropriately to prevent overheating
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
The solution provides a reliable and safe electrical connection by ensuring impedance is within a predetermined threshold before power is supplied, reducing the risk of overheating and improving charging efficiency.
Implementation Method 1
measuring the electric impedance between the electrical contact of the contact arrangement and the vehicle's contact surface
Implementation Method 2
applying currents to clear high impedance
Data Source
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AI summary
The invention relates to a device (10) for charging an electric vehicle (12), comprising: a plurality of electrical contacts (20), at least two of them coupled to a power supply (14), and each electrical contact (22, 23, 24, 25) of the plurality of electrical contacts (20) is arranged for contacting a different contact surface (30, 34) of the electric vehicle (12); and a secondary contact (28) forming a contact arrangement (29) with one of the electrical contacts (24) of the plurality of electrical contacts (20), wherein said electrical contact (24) and the secondary contact (28) of the contact arrangement (29) are arranged to contact the same contact surface (34) of the vehicle (12).