EV Charging System Relay Control Without Bypass Resistor

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Solution Overview

Problem

Existing battery charging systems for electric vehicles require a bypass resistor to control high-voltage relays, increasing power losses, manufacturing costs, and safety concerns due to potential resistor breakdowns.

Innovation Solution

A charging system that uses an insulation monitoring module and controller to form a current path without a bypass resistor, employing power and battery access switches, and pre-charging switches to control the charging circuit, thereby eliminating the need for a bypass resistor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a bypass resistor is connected in parallel across the traction battery to control the high-voltage relay, then the charging circuit can be formed, but power losses increase and manufacturing costs increase

Engineering Contradiction:
Improvecharging circuit formationVSAvoidpower losses
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent removes the bypass resistor from the charging system by using the insulation monitoring module to directly control the battery relay. The insulation monitoring module detects insulation resistance and controls the relay closing based on detected current, eliminating the need for the bypass resistor that caused power losses.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The insulation monitoring module serves multiple functions: it monitors insulation resistance, detects current in the charging circuit, and controls the battery relay closing. This multi-functional approach replaces the separate bypass resistor component, reducing both power losses and manufacturing costs while maintaining charging circuit formation capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If a bypass resistor is connected in parallel across the traction battery, then the charging circuit can be formed, but manufacturing costs increase

Engineering Contradiction:
Improvecharging circuit formationVSAvoidmanufacturing costs
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent removes the bypass resistor from the charging system by using the insulation monitoring module to directly control the battery relay. The insulation monitoring module detects insulation resistance and controls the relay closing based on detected current, eliminating the need for the bypass resistor that increased manufacturing costs.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The insulation monitoring module serves multiple functions: it monitors insulation resistance, detects current in the charging circuit, and controls the battery relay closing. This multi-functional approach replaces the separate bypass resistor component, reducing both power losses and manufacturing costs while maintaining charging circuit formation capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If a bypass resistor is connected in parallel across the traction battery, then the charging circuit can be formed, but safety concerns increase when the bypass resistor breaks down

Engineering Contradiction:
Improvecharging circuit formationVSAvoidsafety concerns
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent removes the bypass resistor from the charging system by using the insulation monitoring module to directly control the battery relay. The insulation monitoring module detects insulation resistance and controls the relay closing based on detected current, eliminating the bypass resistor that posed safety concerns when it broke down.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The insulation monitoring module acts as an intermediary between the charging circuit and the battery relay. It detects current and insulation resistance, then controls the relay closing accordingly, providing safe and controlled charging circuit formation without the safety risks associated with bypass resistor breakdown.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Loss of energy

If the insulation monitoring module is used to control the battery relay without a bypass resistor, then power losses are reduced and manufacturing costs are reduced, but the system complexity increases

Engineering Contradiction:
Improvepower lossesVSAvoidsystem complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The insulation monitoring module serves multiple functions: it monitors insulation resistance, detects current in the charging circuit, and controls the battery relay closing. By consolidating these functions into a single existing component, the patent reduces power losses and manufacturing costs without significantly increasing system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The insulation monitoring module uses its existing current detection capability to control the battery relay, making the system self-sufficient. The module leverages its own detection functions to perform relay control, eliminating the need for separate bypass resistor components and reducing overall system complexity despite the enhanced control functionality.

Inventive Principle:
Principle #25Self-service

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 reduces manufacturing costs, minimizes power losses, and enhances electrical safety by controlling the charging circuit without a bypass resistor, ensuring reliable and safe battery charging.

Implementation Method 1

the controller is configured to control, when starting charging, the insulation monitoring module, power supply access switches, a pre-charging switch, a battery, and a first battery access switch to form a current path, so as to close the other of the battery access switches after current is detected in the current path

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3713038B1Charging station and charging system, method and apparatus
Publication Date: 2023.03.15 NIO ANHUI HLDG CO LTD
  • EP3713038B1 patent drawingFigure 1
  • EP3713038B1 patent drawingFigure 2
  • EP3713038B1 patent drawingFigure 3~4

AI summary

Disclosed are a charging station, a charging system and method, and apparatuses, which solve the technical problem of how to control a high-voltage relay in a traction battery to be closed so as to form a charging circuit, without adding a bypass resistor. The charging system may control, by means of a controller (17) when starting charging, an insulation monitoring module (16), power supply access switches (13), a pre-charging switch (15), a battery, and one of battery access switches (14) to form a current path, so as to close the other battery access switch (14) after current is detected in the current path, i.e., controlling conventional devices in the charging circuit to form a current path without the need to provide a bypass resistor, thereby decreasing the manufacturing cost of the charging system and avoiding safety concerns caused by the bypass resistor. In addition, in the invention, the charging station comprises the charging system, the charging method can be used to control the charging system to charge a battery, and the apparatuses can be used to carry out and implement the above method.