Bidirectional EV Onboard Charger for Plug-In and Wireless Charging

Solution Overview

Problem

Existing electric vehicles require separate onboard chargers and rectifiers for plug-in and wireless charging, increasing manufacturing cost and weight due to the number of components needed.

Innovation Solution

A bidirectional onboard charger (OBC) that can receive and convert input currents at low and high frequencies, as well as direct current, eliminating the need for a separate rectifier and enabling bidirectional power flow between the vehicle and external power sources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate onboard chargers and rectifiers are provided for plug-in and wireless charging, then charging functionality is comprehensive, but manufacturing cost and vehicle weight increase

Engineering Contradiction:

Improvecharging functionalityVSAvoidvehicle weight

Core Design Contradiction:

Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The patent combines the onboard charger and rectifier into a single integrated unit. The rectifier is integrated within the onboard charger housing, sharing common components such as the control unit, cooling system, and electrical connections. This merging eliminates the need for separate mounting spaces and reduces overall system weight while maintaining both plug-in and wireless charging capabilities.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The integrated onboard charger is designed to perform multiple functions: it can process both plug-in AC charging and wireless power transfer inputs, convert both low-frequency and high-frequency AC to DC, and charge the vehicle battery. This multi-functional design replaces what would traditionally require separate dedicated devices for each charging method.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If separate onboard chargers and rectifiers are provided for plug-in and wireless charging, then charging functionality is comprehensive, but manufacturing cost increases

Engineering Contradiction:

Improvecharging functionalityVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent combines the onboard charger and rectifier into a single integrated unit. The rectifier is integrated within the onboard charger housing, sharing common components such as the control unit, cooling system, and electrical connections. This merging eliminates the need for separate mounting spaces and reduces overall system weight while maintaining both plug-in and wireless charging capabilities.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The integrated onboard charger is designed to perform multiple functions: it can process both plug-in AC charging and wireless power transfer inputs, convert both low-frequency and high-frequency AC to DC, and charge the vehicle battery. This multi-functional design replaces what would traditionally require separate dedicated devices for each charging method.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If conventional OBCs are adapted to receive AC at 50-60 Hz, then plug-in charging is supported, but wireless charging requires a separate rectifier

Engineering Contradiction:

Improveplug-in charging supportVSAvoidnumber of components

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent modifies the onboard charger's circuitry to accept both low-frequency AC (50-60 Hz from plug-in charging) and high-frequency AC (from wireless power transfer). The rectifier circuit is designed with frequency-agile components that can operate across both frequency ranges, eliminating the need for separate rectifiers tailored to specific frequency bands.

Inventive Principle:

Principle #35Parameter changes

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

Reduces manufacturing costs and weight by integrating multiple charging functions into a single component, allowing for cost-effective and efficient charging and discharging of electric vehicle batteries.

Implementation Method 1

The OBC has a rectifier functionality which then converts this input AC to DC

Methodology Applied

Scientific EffectRectification:

Implementation Method 2

A bidirectional onboard charger (OBC) that can receive and convert input currents at low and high frequencies

Methodology Applied

Scientific EffectFrequency conversion:

Data Source

PatentEP4633995B1Onboard charger for electric vehicles

Publication Date: 2026.04.01 CAPACTECH LTD

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AI summary

An onboard charger for an electric vehicle is configured to receive: (a) an input alternating current at a low frequency, (b) an input alternating current at a high frequency, and (c) an input direct current, for charging of an internal electric vehicle battery. The onboard charger is bidirectional, being configured to output direct current for charging of the battery and also configured to discharge the battery outputting alternating current at a low frequency, alternating current at a high frequency, or direct current.