Front Window Heater Control for Lower EV Power Consumption

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Solution Overview

Problem

Conventional heater devices for vehicles, particularly electric vehicles, face significant challenges in reducing power consumption when hot-wire heaters at the front window are energized, as existing systems do not efficiently manage power usage.

Innovation Solution

A power control device that switches between alternating control and entire surface control based on external air temperature and vehicle speed, where alternating control sequentially energizes heaters in different areas and entire surface control simultaneously energizes all heaters, optimizing power distribution and reducing consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If all hot-wire heaters are simultaneously energized to provide effective heating, then heating effectiveness is improved, but power consumption increases

Engineering Contradiction:
Improveheating effectivenessVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The front window heating area is divided into multiple independent heater regions. Instead of energizing all heaters simultaneously, the control device segments the heating operation by selectively activating specific heater regions based on detected fogging or icing conditions in different areas, thereby reducing total power consumption while maintaining effective heating where needed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control device implements periodic scanning of the front window surface to detect the presence and location of fogging or icing. Based on these periodic detections, heaters are energized only when and where required, rather than continuous full-surface heating, reducing power consumption while ensuring heating effectiveness when conditions demand it.

Inventive Principle:
Principle #19Periodic action

2Area of stationary object

If heaters are energized in all areas simultaneously, then heating coverage is improved, but power consumption becomes excessive

Engineering Contradiction:
Improveheating coverageVSAvoidpower consumption
Core Design Contradiction:
Area of stationary objectVSUse of energy by moving object

Solution Approach 1:

The control device applies local quality by detecting specific local conditions (fogging or icing) in particular areas of the front window and energizing heaters only in those specific locations. This localized heating approach maintains adequate heating coverage in affected areas while avoiding unnecessary power consumption in areas that do not require heating.

Inventive Principle:
Principle #3Local quality

3Use of energy by moving object

If sequential energizing of heaters is implemented, then power consumption is reduced, but heating response time increases

Engineering Contradiction:
Improvepower consumptionVSAvoidheating response time
Core Design Contradiction:
Use of energy by moving objectVSLoss of time

Solution Approach 1:

The control device performs preliminary scanning and detection of fogging or icing conditions across the front window surface before initiating heater energization. This preliminary action allows the system to identify all areas requiring heating in advance, then energize those specific heaters simultaneously or in an optimized sequence, reducing overall heating response time while maintaining power consumption benefits.

Inventive Principle:
Principle #10Preliminary action

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 effectively reduces power consumption by adapting to different vehicle conditions, ensuring efficient heating while preventing wasteful energy use, especially in scenarios where the vehicle is stationary or traveling at low speeds.

Implementation Method 1

a power control device and a power control method for controlling electric power of a vehicle which includes hot-wire heaters provided respectively in a plurality of areas which are obtained by dividing a front window

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP4316881B1Electric power control device and electric power control method
Publication Date: 2024.10.09 NISSAN MOTOR CO LTD
  • EP4316881B1 patent drawingFigure 1
  • EP4316881B1 patent drawingFigure 2
  • EP4316881B1 patent drawingFigure 3A

AI summary

A power control device of the present invention controls the electric power of a vehicle which includes hot-wire heaters provided respectively in a plurality of areas which are obtained by dividing a front window. In particular, the power control device of the present invention switches between alternating control and entire surface control based on an external air temperature of the vehicle and a speed of the vehicle, the alternating control being for sequentially energizing each hot-wire heater provided in each of the plurality of areas, and the entire surface control being for simultaneously energizing all the hot-wire heaters provided in the plurality of areas.