Onboard DC Charging Control Without Pre-Discharge Switching

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Solution Overview

Problem

The charging speed of electric vehicle battery packs is slow due to the need to discharge the battery pack before charging and switch from low-voltage to high-voltage power-on during the charging process.

Innovation Solution

A vehicle-mounted charging control method that allows charging when the battery management system is in a high-voltage power-on state, determining connection to a DC charging pile, and controlling the charger to enter DC charging mode for fast charging, without requiring a discharge or low-to-high voltage switch.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the battery management system requires discharge before charging and switches from low-voltage to high-voltage power-on, then the system ensures safety and proper initialization, but the charging speed becomes slow

Engineering Contradiction:
Improvesystem safetyVSAvoidcharging speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent applies preliminary action by detecting the DC charging pile connection status before initiating the charging process. The battery management system checks whether the charging socket is connected to a DC charging pile in advance, and based on this detection, directly enters DC charging mode without requiring discharge first or voltage switching. This preliminary detection enables the system to bypass unnecessary steps and achieve fast charging while maintaining safety through proper initialization sequences.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If the system switches from low-voltage power-on to high-voltage power-on during charging, then the system ensures proper power management, but the charging process takes longer time

Engineering Contradiction:
Improvepower managementVSAvoidcharging time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent applies dynamics by making the power-on state configurable based on real-time conditions. Instead of a fixed low-voltage to high-voltage switching sequence, the system dynamically determines the appropriate power state based on the detected charging pile type. When a DC charging pile is detected, the system can operate in high-voltage mode from the start, adapting the power management strategy to the specific charging scenario to reduce charging time while maintaining proper power control.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the battery management system requires discharge completion before charging, then the system ensures proper battery state, but the overall charging process becomes slower

Engineering Contradiction:
Improvebattery state managementVSAvoidcharging efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies parameter changes by modifying the charging initiation conditions based on the detected charging pile type. The system changes the operational parameters (discharge requirement, voltage switching) according to whether a DC charging pile is detected. When DC charging is available, the system adjusts its parameters to allow direct charging without mandatory discharge, thereby improving charging efficiency while still ensuring proper battery state management through monitoring and control.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4667280A1Vehicle-mounted charging control method and apparatus, vehicle, system, and storage medium
Publication Date: 2025.12.24 BYD CO LTD
  • EP4667280A1 patent drawingFigure 1~2
  • EP4667280A1 patent drawingFigure 3
  • EP4667280A1 patent drawingFigure 3

AI summary

A vehicle-mounted charging control method and apparatus, a vehicle, a system, and a storage medium are provided. The method includes: when a battery management system of a target vehicle is in a high-voltage power-on completed state, determining whether a charging socket of a vehicle-mounted charger of the target vehicle is connected to a DC charging pile; and if the charging socket of the vehicle-mounted charger of the target vehicle is connected to the DC charging pile, controlling the vehicle-mounted charger to enter a DC charging mode to quickly charge a battery pack of the target vehicle. The apparatus includes a determining unit and a processing unit. The charging system includes an electric vehicle and a charging pile. The electric vehicle includes a vehicle body, a charging control module, and an energy storage module.