On-Board EV Charging With High-Power AC Handshake
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Solution Overview
Problem
Existing electric vehicle charging systems are unable to efficiently provide AC power in excess of 19.2 kW, as both EVSEs and on-board vehicle charging systems lack the necessary hardware and communication protocols to support high-power charging using connectors like the North American Charging System (NACS).
Innovation Solution
Upgrading EVSEs with high-power rated relays and thicker busbars, and implementing a handshake protocol between the EVSE and vehicle charging system to initiate the supply of AC power exceeding 19.2 kW, followed by conversion to DC power using on-board chargers capable of handling higher currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If existing EVSEs and on-board chargers are used, then charging infrastructure compatibility is maintained, but charging power is limited to 19.2 kW or below
Solution Approach 1:
The patent changes the electrical parameters (current rating, power output) of the EVSE and on-board charger to support higher power charging. By upgrading these components to handle increased current and power levels, the system achieves charging power in excess of 19.2 kW while maintaining compatibility through standardized connector interfaces.
2Productivity
If DC fast charging is used, then charging speed is improved, but battery degradation and installation costs increase
Solution Approach 1:
The patent uses the on-board charger as an intermediary device that converts AC power to DC power for battery charging. This intermediary approach allows the system to achieve fast charging speeds while avoiding the direct DC injection that causes battery degradation, as the on-board charger provides controlled, regulated power conversion.
3Power
If high-power connectors are implemented, then AC power supply capability is improved, but communication protocol compatibility challenges arise
Solution Approach 1:
The patent implements a universal handshake protocol that performs multiple functions: it negotiates power capabilities, verifies connector compatibility, and establishes communication parameters. This single communication routine handles various scenarios (different connector types, power levels, vehicle models) making the system universally compatible despite the complexity of high-power connections.
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 efficient charging of electric vehicles, reducing charge time by approximately half without requiring new infrastructure, while avoiding the drawbacks of DC fast charging such as battery degradation and high installation costs.
Implementation Method 1
The AC power can be converted to DC power in excess of 19.2 kW by at least one on-board charger in the vehicle charging system
Data Source
AI summary
Described herein is a method of high-power direct current (DC) charging of at least one vehicle battery. The method includes connecting an electric vehicle supply equipment (EVSE) to a vehicle charging system using a high-power connector. A handshake is performed between the EVSE and the vehicle charging system to initiate supply of AC power from the EVSE to the vehicle charging system via the high-power connector. The AC power is converted to DC power in excess of 19.2 kW by at least one on-board charger in the vehicle charging system. At least one vehicle battery is charged using the DC power in excess of 19.2 kW.