Integrated EV Relay Assembly for Pre-Charge and Inrush Protection

Solution Overview

Problem

Existing electric vehicles require additional pre-charge relays and complex mechanical and electrical connections, leading to a complicated installation structure and space loss due to the need for multiple components within limited internal spaces.

Innovation Solution

A relay assembly with a switching unit and electromagnet unit that includes multiple contacts rotated by magnetic force, allowing sequential application of pre-charge and main voltages without the need for a separate pre-charge relay, simplifying the installation structure and reducing space requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a pre-charge relay is added to prevent inrush current damage, then the power relay is protected from damage, but the installation structure becomes complicated and installation space increases

Engineering Contradiction:

Improvepower relay protectionVSAvoidinstallation structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the pre-charge relay and power relay functions into a single relay assembly. The relay body contains both a pre-charge contact (with pre-charge resistance) and a main contact (power contact), allowing both functions to be integrated in one device rather than requiring separate relays and their associated mounting hardware.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single relay assembly performs multiple functions: it acts as both a pre-charge relay (limiting inrush current through the pre-charge contact and resistance) and a power relay (conducting full power through the main contact). This multi-functional design eliminates the need for separate dedicated pre-charge and power relay components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a pre-charge relay is added to prevent inrush current damage, then the power relay is protected from damage, but the installation space increases

Engineering Contradiction:

Improvepower relay protectionVSAvoidinstallation space

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The patent combines the pre-charge relay and power relay functions into a single relay assembly. The relay body contains both a pre-charge contact (with pre-charge resistance) and a main contact (power contact), allowing both functions to be integrated in one device rather than requiring separate relays and their associated mounting hardware.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If multiple relays and fastening members are used, then inrush current protection is achieved, but the number of components increases

Engineering Contradiction:

Improveinrush current protectionVSAvoidnumber of components

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent combines the pre-charge relay and power relay functions into a single relay assembly. The relay body contains both a pre-charge contact (with pre-charge resistance) and a main contact (power contact), allowing both functions to be integrated in one device rather than requiring separate relays and their associated mounting hardware.

Inventive Principle:

Principle #5Merging (Combining)

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

The solution simplifies the installation structure and reduces the space needed for the relay assembly by omitting the pre-charge relay and associated components, ensuring stable power supply to the inverter while preventing damage from inrush currents.

Implementation Method 1

a switching unit connecting or disconnecting the battery and the inverter, the switching unit including a plurality of contacts rotated by magnetic force of the electromagnet unit

Methodology Applied

Scientific EffectMagnetic force: Electromagnet

Data Source

PatentUS12479304B2Relay assembly and electric vehicle comprising same

Publication Date: 2025.11.25 LG ENERGY SOLUTION LTD

AI summary

There are disclosed a relay assembly for connecting an inverter of a device driven by a battery as a power source to the battery and an electric vehicle having the relay assembly, the relay assembly including a switching unit connecting or disconnecting the battery and the inverter and an electromagnet unit installed to operate the switching unit, the switching unit including a plurality of contacts rotated by magnetic force of the electromagnet unit and controlled to be connected and disconnected with a degree of rotation. With the relay assembly and the electric vehicle having the same, it is possible to simplify the installation structure and reduce the installation space.