Electric Motor System Independent Coil Bridge Circuit Reliability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electric motor systems with three or six coils are prone to failure if one coil malfunctions, leading to operational issues and reduced reliability, especially in critical applications like motor vehicles.

Innovation Solution

An electric motor system with at least four coils, each independently supplied via power electronics and bridge circuits, allowing continued operation even if one or two coils fail, with the option to use a 'sling-shot' method to maintain motor shaft acceleration and employing full bridges for enhanced reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If three coils are connected in a star or delta connection in a stator module, then the electric motor can operate with a compact design, but the failure of one coil leads to the failure of the remaining coils and significant malfunction

Engineering Contradiction:
Improvecoil configurationVSAvoidoperational reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent divides the motor into multiple independent stator modules, each with its own bridge circuit. This segmentation allows one module to fail without affecting the others, as each module operates independently. The control device can deactivate failed modules and continue operating with the remaining functional modules, thereby maintaining system reliability while preserving the compact three-coil design within each module.

Inventive Principle:
Principle #1Segmentation

2Reliability

If six coils are provided with separate bridge circuits for each coil, then operational reliability is improved, but the device complexity and space requirements increase

Engineering Contradiction:
Improveoperational availabilityVSAvoidbridge circuit configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple bridge circuits into a single integrated bridge circuit that can serve multiple stator modules. Instead of providing separate bridge circuits for each coil as in the prior art, the invention uses one bridge circuit to control multiple modules sequentially or in parallel, thereby reducing overall device complexity while maintaining the reliability benefits of having multiple independent modules.

Inventive Principle:
Principle #5Merging (Combining)

3Strength

If one coil fails in a three-coil stator module, then the motor must be shut down to prevent damage, but this reduces productivity and increases loss of time

Engineering Contradiction:
Improveprotection against damageVSAvoidcontinuous operation capability
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The control device is equipped with monitoring capabilities that detect coil failures in advance. When a failure is detected, the control device immediately deactivates the affected stator module and redistributes the operational load to the remaining functional modules. This preliminary action prevents the failed coil from causing damage to other coils while maintaining continuous motor operation, thereby protecting the system without sacrificing productivity.

Inventive Principle:
Principle #10Preliminary action

4Reliability

If the electric motor is designed with redundant coils and modules, then the probability of failure is reduced, but the manufacturing cost and device complexity increase

Engineering Contradiction:
Improvefailure probabilityVSAvoidmanufacturing simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent designs the stator modules to be universal and interchangeable, with each module capable of performing the complete function of the motor independently. The bridge circuit is designed to control multiple modules using the same control logic and hardware. This universality allows for simplified manufacturing processes, as identical modules can be produced using the same tooling and assembly procedures, while still providing redundancy and reduced failure probability.

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 configuration enhances operational safety and availability, reduces the probability of failure, and allows for more flexible and space-saving designs, enabling continued operation with fewer coils while providing early warning signals for maintenance.

Implementation Method 1

Electric motors typically have three coils that drive a motor shaft, usually made of permanent magnets, during operation

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3582392B1Electric motor system
Publication Date: 2021.09.08 MAHLE INT GMBH
  • EP3582392B1 patent drawingFigure 1~2
  • EP3582392B1 patent drawingFigure 3

AI summary

The present invention relates to an electric motor system (5) with an electric motor (2) having at least four coils (14) for driving a motor shaft (4) of the electric motor (2). Increased operational reliability and/or more flexible operation of the electric motor system (5) is/are achieved by providing a power electronics unit (11) of the electric motor system (5) with an associated bridge circuit (18) for each of at least four of the coils (14) of the electric motor (2). The invention further relates to a motor vehicle (1) with such an electric motor system (5).