Three-Phase Transformer Switching for Wide EV Charging Voltage

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Solution Overview

Problem

Existing charging piles face challenges in adapting to a wide range of electric vehicle charging voltages due to limited adjustment range of the switching frequency in inverter circuits, leading to inefficiencies and reduced practicality.

Innovation Solution

A power supply apparatus with a three-phase transformer circuit and rectifier bridge circuits, utilizing a turns ratio switching circuit and connection relationship switching circuit to adjust the output voltage range by switching the turns ratio of the transformer and the connection manner of the rectifier bridge circuits, allowing for a wide range of efficient output voltages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the switching frequency of the inverter circuit is adjusted to change output voltage, then the output voltage can be adapted to different electric vehicle requirements, but the conversion efficiency deteriorates due to frequent switching frequency changes

Engineering Contradiction:
Improveoutput voltage adaptation rangeVSAvoidconversion efficiency
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent divides the output voltage range into multiple voltage ranges, with each range corresponding to a specific switching frequency. By segmenting the voltage adjustment into discrete ranges rather than continuous adjustment, the system maintains high conversion efficiency within each range while still providing broad voltage adaptability across all ranges.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent dynamically switches between different switching frequencies based on the required output voltage range. The control system selects the appropriate switching frequency corresponding to the target voltage range, enabling the system to adapt to different electric vehicle charging requirements while maintaining optimal conversion efficiency for each operating condition.

Inventive Principle:
Principle #15Dynamics

2Loss of energy

If the switching frequency adjustment range is limited, then the conversion efficiency is maintained, but the output voltage range becomes insufficient to meet diverse electric vehicle charging requirements

Engineering Contradiction:
Improveconversion efficiencyVSAvoidoutput voltage range
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent segments the overall voltage adaptation requirement into multiple discrete voltage ranges, each optimized for a specific switching frequency. This segmentation allows the system to maintain a limited switching frequency adjustment range for each segment while collectively covering a wide voltage range through multiple segments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the switching frequency parameter to match different output voltage ranges. By establishing correspondence between specific switching frequency values and specific voltage ranges, the system achieves wide voltage adaptability through discrete parameter changes rather than continuous adjustment, maintaining efficiency while expanding capability.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If a wide range of output voltages is implemented through switching frequency adjustment, then various electric vehicle charging requirements can be met, but the conversion efficiency deteriorates

Engineering Contradiction:
Improveoutput voltage range coverageVSAvoidconversion efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent divides the wide voltage range into multiple segments, with each segment handled by a dedicated switching frequency. This segmentation strategy allows the system to cover a broad voltage range for diverse electric vehicle requirements while maintaining high conversion efficiency within each segment by avoiding frequent switching between frequencies.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements wide voltage range coverage through discrete parameter changes (switching frequency selection) rather than continuous adjustment. The control system selects from a set of predefined switching frequencies corresponding to different voltage ranges, achieving both wide adaptability and high efficiency through optimized parameter selection.

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

This solution enables the charging pile to efficiently handle various electric vehicle charging voltages by dividing the output voltage range into multiple ranges, reducing the need for frequent switching frequency adjustments and enhancing overall efficiency and adaptability.

Implementation Method 1

a three-phase primary winding of the three-phase transformer is configured to receive a three-phase alternating current. A three-phase secondary winding of the three-phase transformer is configured to output a three-phase alternating current

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4383545A1Power supply apparatus, three-phase transformer circuit, and charging pile
Publication Date: 2024.06.12 HUAWEI DIGITAL POWER TECH CO LTD
  • EP4383545A1 patent drawingFigure 1A~1B
  • EP4383545A1 patent drawingFigure 2
  • EP4383545A1 patent drawingFigure 3

AI summary

This application provides a power supply apparatus, a three-phase transformer circuit, and a charging pile. The power supply apparatus includes a turns ratio switching circuit, a connection relationship switching circuit, a three-phase transformer, and two three-phase rectifier bridge circuits. A three-phase primary winding of the three-phase transformer is configured to receive a three-phase alternating current. A three-phase secondary winding of the three-phase transformer is configured to output a three-phase alternating current to each of the two three-phase rectifier bridge circuits. A running mode of the three-phase transformer includes a first turns ratio mode and a second turns ratio mode. The turns ratio switching circuit is configured to switch a quantity of turns of the three-phase primary winding, to switch the running mode of the three-phase transformer. A quantity of turns of a primary winding of each phase includes a first quantity of turns and a second quantity of turns. The second quantity of turns is greater than the first quantity of turns. The first quantity of turns corresponds to the first turns ratio mode. The second quantity of turns corresponds to the second turns ratio mode. The connection relationship switching circuit is configured to switch a connection relationship between the two three-phase rectifier bridge circuits. The two three-phase rectifier bridge circuits are connected in series or in parallel through the connection relationship switching circuit.