Wind Turbine Generator Rotor Temperature Monitoring Without Slip Rings

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Solution Overview

Problem

Existing temperature monitoring methods for electrical generators in wind turbines are prone to failure due to reliance on slip rings, which are susceptible to wear and require frequent replacement.

Innovation Solution

A temperature monitoring system using a passive control element on the rotor and a receiving unit on the stator that detects mechanical or optical changes in response to temperature variations, allowing for slip ring-free communication between the rotor and stator, utilizing mechanisms such as movable pins, magnetic elements, and optical sensors to transmit temperature data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a slip ring is used to transmit temperature signals from the rotor to the stator, then temperature monitoring is enabled, but the system reliability deteriorates due to wear and frequent replacement needs

Engineering Contradiction:
Improvesystem reliabilityVSAvoidmaintenance needs
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts the problematic slip ring component from the temperature monitoring system and replaces it with a contactless detection approach. The receiving unit on the stator detects temperature-related changes (magnetic field variations, optical changes, or mechanical displacements) from the rotor without physical contact, thereby eliminating wear and maintenance requirements while maintaining system reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical slip ring system with non-contact detection methods. Instead of mechanical electrical contact through slip rings, the system uses magnetic sensors, optical sensors, or capacitive sensors to detect rotor temperature changes, substituting mechanical transmission with field-based detection to eliminate wear.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a passive control element is used on the rotor to detect temperature changes, then the system becomes slip ring-free, but the device complexity increases due to additional components

Engineering Contradiction:
Improvesystem reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by placing a simple passive control element (such as a temperature-sensitive magnetic element, thermal expansion element, or color-changing material) at the specific location on the rotor where temperature monitoring is needed. This localized approach keeps the added complexity minimal while achieving reliable temperature detection.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The passive control element acts as an intermediary that converts rotor temperature changes into detectable signals (magnetic field changes, optical changes, or mechanical displacements) that can be detected by the receiving unit on the stator, enabling indirect but reliable temperature measurement without direct electrical contact.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables reliable temperature monitoring without slip rings, reducing maintenance needs and ensuring timely detection of excessive heating, thereby preventing generator damage.

Implementation Method 1

a temperature change on the rotor causes a mechanical or optical change in the control element

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

the movable pin comprises a magnetic element and the receiving unit comprises a magnetic sensor which detects an approach of the magnetic element of the control element

Methodology Applied
Scientific EffectMagnetic field detection: Magnetic Field

Implementation Method 3

the passive control element comprises a temperature measuring strip that changes color depending on the detected temperature

Methodology Applied
Scientific EffectThermochromism: Thermochromism

Data Source

PatentEP4597804A1Method for monitoring the temperature of a generator of a wind turbine
Publication Date: 2025.08.06 WOBBEN PROPERTIES GMBH
  • EP4597804A1 patent drawingFigure 1
  • EP4597804A1 patent drawingFigure 2~3A
  • EP4597804A1 patent drawingFigure 3B~3C

AI summary

A method is provided for monitoring the temperature of an electrical generator (200) of a wind turbine (100), wherein the generator (200) has a stator (220), a rotor (210), and a temperature monitoring unit (300). The temperature monitoring unit has a passive control element (310) on the rotor (210) and a receiving unit (320) on the stator (220). A temperature change on the rotor (210) leads to a mechanical or optical change in the passive control element (310). The mechanical or optical change in the passive control element (310) is detected by the receiving unit (320) on the stator (220).