On-Board Charger Current Control for Battery Charging

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

During battery charging in electric vehicles, high-power components connected in the charging path consume some current, leading to prolonged charging times and the risk of supplying excess current to the battery due to varying operating states of these components.

Innovation Solution

A current control method and device that classifies high-power components based on their ability to calculate current consumption based on operating states, allowing for precise calculation and adjustment of the charging current to prevent excess current supply to the battery, thereby reducing charging time and ensuring efficient energy distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the on-board charger outputs the sum of current necessary to charge the battery and current consumed by the high-power component, then the charging time of the battery is shortened, but there is a risk of supplying excess current to the battery when the operating state of the high-power component changes

Engineering Contradiction:
Improvecharging timeVSAvoidcurrent supply accuracy
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The control device determines the current consumption of the high-power component before the operating state changes, and pre-adjusts the output current of the on-board charger. This preliminary action ensures that when the high-power component's current consumption decreases, the charger has already reduced its output to prevent excess current from reaching the battery, thus maintaining reliability while enabling faster charging response.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control device continuously monitors the operating state of the high-power component and uses this feedback information to dynamically adjust the output current of the on-board charger. By establishing a feedback loop that tracks current consumption changes, the system can real-time optimize the charging current to prevent both excess current supply and charging delays.

Inventive Principle:
Principle #23Feedback

2Productivity

If high-power components operate during battery charging, then the battery charging time becomes long due to current consumption by high-power components, but increasing the output current risks supplying excess current to the battery

Engineering Contradiction:
Improvecharging speedVSAvoidexcess current risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The control device acts as an intermediary between the on-board charger and the battery, intelligently managing current distribution. It calculates the optimal current allocation by considering both the battery's charging needs and the high-power component's current consumption, thereby enabling high charging speed while preventing excess current from reaching the battery through precise current management.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically changes the output current parameter of the on-board charger based on the operating state of high-power components. By adjusting the current parameter in real-time according to actual consumption patterns, the system achieves both fast charging and prevents harmful excess current conditions.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3767774B1Current control method and current control device for on-vehicle battery chargers
Publication Date: 2022.11.30 NISSAN MOTOR CO LTD
  • EP3767774B1 patent drawingFigure 1~2
  • EP3767774B1 patent drawingFigure 3

AI summary

By using the current control method and the current control device for an on-board charger according to the present invention, when an on-board charger is controlled that supplies current to high-power components and a battery, current control is executed to supply output current to the high-power components and the battery, wherein the output current is the sum of the drive current to be supplied to high-power components configured to compute current consumption based on their own operating states and the charging current to the battery.