Hybrid Electric Vehicle Motor Segmentation for Charging Efficiency

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Solution Overview

Problem

Conventional hybrid electric vehicles experience decreased charging efficiency when using the starter/generator motor to charge the high-voltage battery and compromised drivability when starting movement after charging through the motor while stopped.

Innovation Solution

The method involves using the first drive motor to charge the battery with engine power while stopped, and upon shifting to driving mode, employing a second drive motor independently or in conjunction with the first drive motor based on requested torque and available torque to maintain drivability, ensuring efficient charging and smooth vehicle start-up.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the starter/generator motor is used to charge the high-voltage battery, then charging can be performed while stopped, but charging efficiency decreases by about 10%

Engineering Contradiction:

Improvecharging efficiencyVSAvoiddrivability

Core Design Contradiction:

Loss of energyVSEase of operation

Solution Approach 1:

The patent divides the drive motor into two separate motors: a first drive motor connected to the transmission for vehicle propulsion, and a second drive motor independent of the transmission for charging operations. This segmentation allows the second motor to charge the battery with high efficiency while the first motor maintains drivability during vehicle start-up, resolving the contradiction between charging efficiency and ease of operation.

Inventive Principle:

Principle #1Segmentation

2Ease of operation

If the motor is used to charge the high-voltage battery while stopped, then charging is enabled, but drivability is degraded when the vehicle starts moving

Engineering Contradiction:

ImprovedrivabilityVSAvoidcharging efficiency

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The control unit acts as an intermediary that manages the coordination between the first and second drive motors. During vehicle start-up, the control unit controls the first motor to provide torque while managing the second motor's operation to prevent drivability degradation, enabling both efficient charging and smooth vehicle start-up.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If the engine clutch is locked to charge the battery through the motor, then charging is performed, but the speeds of the engine and motor must be equal which limits flexibility

Engineering Contradiction:

Improvecharging capabilityVSAvoidoperational flexibility

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent divides the drive motor into two separate motors: a first drive motor connected to the transmission for vehicle propulsion, and a second drive motor independent of the transmission for charging operations. This segmentation allows the second motor to charge the battery independently without requiring engine clutch engagement, enabling the engine and motor to operate at different speeds and thus resolving the contradiction between charging capability and operational flexibility.

Inventive Principle:

Principle #1Segmentation

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 approach enhances charging efficiency when stopped and maintains drivability during vehicle start-up by utilizing the second drive motor to manage torque and engine operation, optimizing both charging efficiency and drivability.

Implementation Method 1

performing charging through a first drive motor with power of an engine

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

commencing movement of the hybrid electric vehicle using a second drive motor alone or using at least one of the first drive motor or the engine together with the second drive motor

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

using the power of an engine to perform charging through a first drive motor

Methodology Applied

Scientific EffectCombustion: Combustion

Data Source

PatentUS11584355B2Hybrid electric vehicle and method of controlling the same

Publication Date: 2023.02.21 HYUNDAI MOTOR CO LTD

AI summary

Disclosed is a method of controlling a hybrid electric vehicle having a transmission, an engine, and first and second drive motors. The method includes: performing charging through the first drive motor using the power of the engine by engaging an engine clutch disposed between the engine and the first drive motor while a vehicle is stopped with the gear stage shifted to the parking (P) range; turning off the engine and controlling the clutch of the transmission to enter an open state when the gear stage is shifted to the driving (D) range; and commencing movement of the vehicle using the second drive motor alone or using at least one of the first drive motor or the engine together with the second drive motor based on at least one of requested torque, available torque of the second drive motor, or the speed of the first drive motor.