Integrated EV Power Conversion Circuit for Charging and Motor Drive

Solution Overview

Problem

The existing electric vehicle control circuits have a complex structure, low integration, large volume, and high costs due to the separation of battery charging and motor drive circuits.

Innovation Solution

An energy conversion apparatus incorporating an inductor, a bridge arm converter, a voltage transformer, and a bidirectional H-bridge, which allows for time-sharing operation between drive and charging modes, reusing the bridge arm converter to simplify the circuit structure and improve integration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If battery charging circuit and motor drive circuit are separated and independent, then each circuit can complete its function reliably, but the overall control circuit structure becomes complex, integration is low, volume is large, and costs are high

Engineering Contradiction:

Improvecharging and driving function completionVSAvoidcontrol circuit structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the battery charging circuit and motor drive circuit into a single integrated control circuit. The charging port connects to the inductor, which connects to the bridge arm converter that serves both charging and motor drive functions. This consolidation eliminates the need for separate independent circuits, reducing overall structural complexity while maintaining both charging and driving capabilities through shared components.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The bridge arm converter is designed to perform multiple functions: it can operate as a charging circuit when receiving power from the charging port, and as a motor drive circuit when powering the motor. This multi-functional design allows a single circuit to replace what would traditionally require separate dedicated circuits, thereby reducing device complexity and improving integration without sacrificing reliability of either function.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If battery charging circuit and motor drive circuit are separated and independent, then each circuit can complete its function reliably, but the overall control circuit integration is low and volume is large

Engineering Contradiction:

Improvecharging and driving function completionVSAvoidcontrol circuit volume

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The patent merges the battery charging circuit and motor drive circuit into a single integrated control circuit. The charging port connects to the inductor, which connects to the bridge arm converter that serves both charging and motor drive functions. This consolidation eliminates the need for separate independent circuits, reducing overall structural complexity while maintaining both charging and driving capabilities through shared components.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The bridge arm converter is designed to perform multiple functions: it can operate as a charging circuit when receiving power from the charging port, and as a motor drive circuit when powering the motor. This multi-functional design allows a single circuit to replace what would traditionally require separate dedicated circuits, thereby reducing device complexity and improving integration without sacrificing reliability of either function.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 reduces the volume and costs of the control circuit while maintaining efficient motor drive and battery charging functions, enhancing the overall integration and simplicity of the system.

Implementation Method 1

an inductor, where a first end of the inductor is connected to an external charging port

Methodology Applied

Scientific EffectElectrical energy storage in inductor: Inductor

Implementation Method 2

a voltage transformer, where an input end of the voltage transformer is connected to the second phase bridge arm and the third phase bridge arm

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS11855543B2Energy conversion device, power system and vehicle

Publication Date: 2023.12.26 BYD CO LTD

AI summary

An energy conversion apparatus includes: an inductor, where a first end of the inductor is connected to an external charging port; a bridge arm converter, connected between an external battery and the external charging port, where the bridge arm converter includes a first phase bridge arm, a second phase bridge arm, and a third phase bridge arm connected in parallel, and a second end of the inductor is connected to the first phase bridge arm; a voltage transformation unit, where an input end of the voltage transformation unit is connected to the second phase bridge arm and the third phase bridge arm; and a first bidirectional H-bridge, connected between an output end of the voltage transformation unit and the external battery. The external battery is connected to and drives an external motor. The external charging port is connected to a power supply and charges the external battery.