Dedicated DCDC Conversion for Vehicle Key-Off Loads

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Solution Overview

Problem

Existing electric vehicles face inefficiencies in providing power to key-off functions, leading to increased battery wear and energy wastage, as they either continuously cycle the 12V battery or keep the DCDC converter active, resulting in reduced vehicle range and higher maintenance costs.

Innovation Solution

A dedicated DCDC conversion system that includes a micro DCDC converter to supply power to key-off modules from the propulsion battery when the vehicle is turned off, reducing power consumption and eliminating the need for a 12V battery by downconverting high voltage to 12V only when required.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the DCDC converter is kept active to supply key-off loads from the propulsion battery, then power availability for key-off functions is improved, but energy consumption increases and vehicle range decreases

Engineering Contradiction:

Improvepower availabilityVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent divides the power conversion system into two separate DCDC converters: a main DCDC converter for propulsion battery management and a dedicated key-off DCDC converter for key-off loads. This segmentation allows the key-off converter to operate independently with optimized efficiency for low-power applications, preventing the main converter from running continuously and wasting energy.

Inventive Principle:

Principle #1Segmentation

2Device complexity

If the main DCDC converter is used for all power conversion needs, then system complexity is reduced, but overhead energy consumption increases and efficiency decreases

Engineering Contradiction:

Improvesystem complexityVSAvoidoverhead energy consumption

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The patent segments the power conversion architecture into specialized converters: the main DCDC converter handles high-power propulsion battery operations, while a dedicated key-off DCDC converter handles low-power key-off loads. Each converter is optimized for its specific operating range, minimizing overhead energy consumption in both high and low power scenarios.

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 solution decreases battery drain, increases vehicle range, reduces weight and cost by eliminating the 12V battery, and minimizes energy wastage associated with running the main DCDC converter continuously.

Implementation Method 1

the one or more dedicated key-off conversion units down convert current from the battery to a lower voltage, such as 12V

Methodology Applied

Scientific EffectDCDC conversion:

Data Source

PatentUS12051970B2Dedicated DCDC conversion unit for supplying key-off electrical loads from the propulsion battery in a vehicle

Publication Date: 2024.07.30 VOLVO CAR CORP

AI summary

A device enabling dedicated DCDC conversion for key-off electrical loads is described. According to one or more embodiments, a device is provided comprising a battery, one or more main conversion units coupled to the battery, and one or more dedicated key-off conversion units coupled to the battery and to one or more key-off electrical modules.