Electric Vehicle Power Source Selection Method

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Solution Overview

Problem

Existing electric vehicle power management systems face issues with short battery life, high fuel consumption, and poor energy-saving performance due to relying solely on a power follower as the energy source.

Innovation Solution

A power source system for electric vehicles that includes a power battery as the main energy source, an auxiliary energy apparatus, and a controller to selectively switch between multiple driving modes, such as using the power battery alone, the auxiliary energy apparatus alone, or both simultaneously, to optimize energy usage and extend battery life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of stationary object

If the power follower is used as the main energy source to charge the power battery, then the battery capacity can be reduced and weight decreased, but the battery service life is shortened and fuel consumption increases

Engineering Contradiction:
Improvebattery capacity and weightVSAvoidbattery service life
Core Design Contradiction:
Weight of stationary objectVSReliability

Solution Approach 1:

The patent implements dynamic switching between two driving modes based on real-time battery state of charge (SOC) monitoring. When SOC is high, the system operates in electric-only mode; when SOC drops below a threshold, it switches to hybrid mode where the power follower charges the battery. This dynamic adaptation optimizes battery utilization, extending service life while maintaining reduced battery capacity and weight benefits.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters by adjusting the switching threshold between driving modes. By monitoring battery SOC and dynamically adjusting when to switch from electric-only to hybrid mode, the system optimizes the balance between battery size reduction and service life extension, allowing the battery to operate in a favorable charge range that reduces degradation.

Inventive Principle:
Principle #35Parameter changes

2Weight of stationary object

If the power follower is used as the main energy source, then small battery capacity and light weight are achieved, but fuel consumption increases and energy-saving performance deteriorates

Engineering Contradiction:
Improvebattery weightVSAvoidfuel consumption
Core Design Contradiction:
Weight of stationary objectVSUse of energy by moving object

Solution Approach 1:

The system employs periodic switching between driving modes based on battery charge state. The power follower periodically charges the battery when SOC drops below the threshold, creating a cyclical pattern of electric-only operation followed by hybrid operation. This periodic action ensures the battery maintains optimal charge levels, improving overall energy efficiency and reducing fuel consumption compared to continuous hybrid operation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The power follower serves dual functions: it can directly drive the traction motor and simultaneously charge the power battery. This continuous useful action maximizes energy utilization by capturing waste heat from the power follower and converting it to electrical energy, thereby reducing overall fuel consumption while maintaining the benefits of small battery capacity.

Inventive Principle:
Principle #20Continuity of useful action

3Device complexity

If the power battery operates alone to drive the traction motor, then the auxiliary energy apparatus is deactivated, but the driving range is limited when battery power is low

Engineering Contradiction:
Improvesystem operation simplicityVSAvoiddriving range
Core Design Contradiction:
Device complexityVSSpeed

Solution Approach 1:

The power follower is designed with multi-functionality, capable of both directly driving the traction motor and charging the power battery. This universal design allows the system to extend driving range by providing direct mechanical power when needed while simultaneously replenishing battery charge, effectively solving the limited driving range problem without adding complex additional components.

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 approach reduces the frequency of battery use and fuel consumption, prolongs battery life, and improves energy-saving performance by alternately using the power battery and auxiliary energy source, while ensuring sufficient power during special conditions and detecting potential faults.

Implementation Method 1

a power battery used to output electric power as a main energy source to drive a traction motor of the electric vehicle

Methodology Applied
Scientific EffectBattery (electricity): Battery (electricity)

Implementation Method 2

The power follower comprises an engine and an electric generator, and the power follower can not only charge a power battery, but also directly drive a traction motor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3505411B1Power source for electric vehicle and power source selection method
Publication Date: 2022.05.18 ZHEJIANG GEELY NEW ENERGY COMML VEHICLES CO LTD
  • EP3505411B1 patent drawingFigure 1
  • EP3505411B1 patent drawingFigure 2
  • EP3505411B1 patent drawingFigure 3

AI summary

Disclosed are a power source (100) for an electric vehicle and a power source selection method. The power source (100) comprises: a power battery (11), an auxiliary energy apparatus (130) and a controller (140). The controller (140) is used to select any one mode to control the operation of the power battery (11) and the auxiliary energy apparatus (130) from multiple driving modes, wherein the multiple driving modes comprise: a first driving mode and a second driving mode; the controller (140) is configured to select the second driving mode when the remaining electric quantity of the power battery (11) is not greater than a pre-set nominal value, until the remaining electric quantity of the power battery (11) rises to a value which is not lower than a pre-set intermediate value; and to select the first driving mode when the remaining electric quantity of the power battery (11) is not lower than the pre-set intermediate value, until the remaining electric quantity of the power battery (11) is reduced to a value which is not greater than the pre-set nominal value, wherein the pre-set intermediate value is a value which is between a pre-set maximum value and the pre-set nominal value. The method prolongs the battery life, reduces fuel consumption and improves the energy-saving performance.