Bidirectional On-Board Charger Control for Simultaneous EV Outlet Power
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Solution Overview
Problem
Conventional bidirectional on-board chargers (OBCs) in electric vehicles cannot measure the required current of indoor power outlets, leading to power limitations and potential damage to electronic devices due to voltage mismatches, preventing simultaneous power supply to indoor and outdoor outlets during charging or V2G modes.
Innovation Solution
A bidirectional OBC system that branches power to indoor outlets from three-phase AC input lines, using sensors to measure current and a controller to adjust switch operations based on required current, allowing simultaneous power supply to indoor and outdoor outlets while maintaining voltage compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the single-phase AC input line is used for charging, then charging power can be supplied to the high voltage battery, but power cannot be supplied to the indoor power outlet simultaneously
Solution Approach 1:
The patent segments the power supply system by separating the charging function (single-phase AC input) from the indoor power outlet function (three-phase AC input). This allows independent operation of charging and indoor power supply, resolving the conflict where single-phase charging blocked indoor outlet power supply.
Solution Approach 2:
The bidirectional OBC is designed to handle multiple functions: it can process single-phase AC for charging, three-phase AC for indoor outlets, and bidirectional power flow for V2G mode. This multi-functionality enables the system to adapt to different operating modes without conflict.
2Device complexity
If the bidirectional OBC controls power supply without measuring required current, then the system structure remains simple, but the sum of power supplied to indoor and outdoor outlets is limited to 3.7 kW
Solution Approach 1:
The patent introduces current sensors that measure the required current of connected electronic devices and feed this information back to the controller. The controller uses this feedback to dynamically adjust power distribution, enabling the total power supply to exceed the conventional 3.7 kW limitation while maintaining system stability.
3Stability of the object's composition
If the same voltage as EVSE is supplied to indoor power outlet, then voltage compatibility with EVSE is maintained, but electronic devices with different rated voltage may be damaged
Solution Approach 1:
The patent implements voltage transformation capability in the bidirectional OBC, allowing it to convert between different voltage levels. The controller can adjust the output voltage to match the rated voltage of connected electronic devices (e.g., converting 240V EVSE voltage to 120V for compatible devices), preventing damage while maintaining system stability.
4Device complexity
If the line for indoor power outlet is branched from single-phase AC charging line, then system structure remains simple, but required current of indoor power outlet cannot be measured
Solution Approach 1:
The patent separates the power input lines into distinct paths: single-phase AC for charging and three-phase AC for indoor outlets. This segmentation allows independent current measurement for each path using dedicated sensors, enabling precise measurement of indoor outlet current without complicating the overall system structure.
Data Source
AI summary
An embodiment apparatus for an electric vehicle includes an indoor power outlet configured to receive power through one of a plurality of lines except for a single-phase alternating current (AC) charging line among three-phase AC input lines, a sensor configured to measure a required current of an electronic device connected to the indoor power outlet, and a controller configured to control a bidirectional on board charger of the electric vehicle based on the required current.