Isolated DC-DC Converter Architecture for Flexible EV Charging Outputs

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Solution Overview

Problem

Existing DC-DC conversion apparatuses in charging piles face inefficiencies due to varying charging power requirements of electric vehicles, leading to low power utilization and resource waste when high-power units charge vehicles with low power needs, and lack redundancy and flexibility in output connections.

Innovation Solution

A DC-DC conversion apparatus with a single input and multiple independent outputs, utilizing isolated conversion circuits and a primary-side controller, allowing for adjustable power outputs and redundancy, reducing design complexity and costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the maximum output power of the DC-DC conversion apparatus is continuously increased to meet high-power charging requirements, then the charging power capability is improved, but the power utilization efficiency deteriorates when charging vehicles with low power requirements

Engineering Contradiction:
Improvemaximum output powerVSAvoidpower utilization efficiency
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The DC-DC conversion apparatus is segmented into multiple independent DC-DC conversion circuits (first, second, and third circuits) with different power ratings. Each circuit can be independently selected and activated based on the specific charging power requirements of the electric vehicle, avoiding the energy waste associated with using a single high-power circuit for low-power charging tasks.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically selects which DC-DC conversion circuit to use based on real-time charging power requirements. The control unit determines the appropriate circuit configuration (full power, half power, or quarter power mode) to match the vehicle's needs, ensuring optimal power utilization efficiency while maintaining the capability to deliver high power when required.

Inventive Principle:
Principle #15Dynamics

2Power

If a single high-power DC-DC conversion apparatus is used, then the charging power capability is improved, but the system redundancy and backup capability deteriorate

Engineering Contradiction:
Improvecharging power capabilityVSAvoidsystem redundancy
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The DC-DC conversion apparatus is divided into multiple independent conversion circuits that can operate autonomously. This segmentation creates inherent redundancy, as the failure of one circuit does not compromise the entire system. The other circuits can continue to provide charging service, ensuring system reliability and backup capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system is designed with redundant DC-DC conversion circuits before any failure occurs. This prior cushioning ensures that if one circuit fails, the system still has backup circuits available to maintain charging operations, thereby improving system reliability and fault tolerance.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Device complexity

If a single-output DC-DC conversion apparatus is used, then the device structure is simplified, but the number of charging parking spaces and operation efficiency deteriorate

Engineering Contradiction:
Improvedevice structureVSAvoidnumber of charging parking spaces
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The DC-DC conversion apparatus is designed with multi-functionality, where a single apparatus can serve multiple charging connectors simultaneously. The multiple independent DC-DC conversion circuits can be distributed to different charging outlets, enabling the system to support multiple charging parking spaces while maintaining a unified control and input structure.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system merges multiple DC-DC conversion circuits into a single integrated apparatus with a common input from the power supply. This combining approach allows the system to provide multiple output channels for different charging connectors while sharing the input power interface and control unit, thus supporting multiple parking spaces without proportionally increasing overall system complexity.

Inventive Principle:
Principle #5Merging (Combining)

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 wide-range power outputs, enhances power utilization, provides multiple charging points, and improves system redundancy, ensuring efficient operation and resource utilization.

Implementation Method 1

Each isolated DC-DC conversion circuit is configured to perform power conversion on a direct current output by the direct current power supply

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4640476A1Direct current-direct current conversion apparatus for charging pile, and charging pile
Publication Date: 2025.10.29 HUAWEI DIGITAL POWER TECH CO LTD
  • EP4640476A1 patent drawingFigure 1(a)~1(b)
  • EP4640476A1 patent drawingFigure 2
  • EP4640476A1 patent drawingFigure 3

AI summary

Embodiments of this application provide a direct current-direct current DC-DC conversion apparatus for a charging pile, and a charging pile. The DC-DC conversion apparatus for a charging pile includes a group of power terminals, a plurality of groups of load terminals, and a plurality of isolated DC-DC conversion circuits. An input end of each isolated DC-DC conversion circuit is connected to the group of power terminals, and output ends of the plurality of isolated DC-DC conversion circuits are connected to the plurality of groups of load terminals in a one-to-one correspondence, so that the DC-DC conversion apparatus for a charging pile forms an architecture with a single input and a plurality of independent outputs. In this way, the DC-DC for a charging pile can have high power utilization while implementing wide-range power outputs. This helps enable the charging pile to achieve a charging speed of "one second per kilometer", to provide a user with charging experience of "full charging within time for a cup of coffee", and also helps avoid a waste of charging resources and improve operation efficiency of the charging pile.