Indirect Winding Temperature Monitoring via Stator Core Sensor
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Solution Overview
Problem
Existing methods for monitoring winding temperature in electric motors are costly, require high installation effort, and often result in delayed switch-off due to thermal insulation and capacitive coupling issues, leading to potential motor damage from overheating.
Innovation Solution
An arrangement for indirect temperature measurement using a temperature sensor placed within the stator core, with a correction element and evaluation electronics to calculate the winding temperature from a local temperature reading, reducing installation costs and improving measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a temperature sensor is installed directly in the winding or in the slots between windings, then the temperature measurement reliability is improved, but the installation effort and cost increase significantly
Solution Approach 1:
The temperature sensor is extracted from the winding interior and placed in the stator core instead. This extraction eliminates the complex installation process of embedding sensors in windings while maintaining measurement capability through indirect measurement of the stator core temperature, which correlates with winding temperature.
Solution Approach 2:
The stator core temperature serves as an intermediary measurement point. Instead of directly measuring winding temperature, the sensor measures stator core temperature, which is then used as a proxy indicator for winding temperature, simplifying the measurement system.
2Reliability
If an insulating layer is placed between the temperature sensor and the winding for electrical insulation, then the electrical safety is improved, but the thermal insulation increases causing delayed temperature detection
Solution Approach 1:
The sensor is extracted from direct proximity to the winding and placed in the stator core, eliminating the need for thick insulating layers between sensor and winding. The measurement point is moved to where electrical insulation is not a constraint.
3Ease of manufacture
If the temperature sensor is placed at a distance from the winding for easier installation, then the installation cost is reduced, but the temperature measurement accuracy deteriorates
Solution Approach 1:
The stator core acts as an intermediary medium that transmits thermal information from the winding to the sensor. The sensor measures stator core temperature, which serves as a reliable indicator of winding temperature, maintaining accuracy without requiring direct contact.
Solution Approach 2:
The system uses the measured stator core temperature as feedback to infer winding temperature conditions. By monitoring stator core temperature changes, the system can detect winding overheating trends and trigger protective actions.
4Measurement precision
If multiple temperature sensors are installed at different winding positions to detect the hottest point, then the temperature monitoring coverage is improved, but the device complexity and cost increase
Solution Approach 1:
Multiple sensors in the winding are extracted and replaced by a single sensor in the stator core. The stator core temperature provides a representative measurement that reflects the thermal state of the entire winding system, eliminating the need for multiple distributed sensors.
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 and timely detection of overheating, reducing the risk of motor damage by allowing for early switch-off and optimizing motor operation with reduced assembly effort and costs.
Implementation Method 1
detecting at least one local temperature TL within the stator core (4), which is different from the winding temperature, by means of a temperature sensor (10)
Implementation Method 2
Calculation of the temperature(s) Tw of the windings from the respective local temperature TL detected by a temperature sensor (10) and a correction value KL
Data Source
AI summary
The invention relates to an arrangement (1) for indirectly detecting the winding temperature of the tooth windings (2) of an electric motor (3) formed with a stator core (4) comprising at least one sensor installation space (5) within the stator core (4), wherein the respective sensor installation space (5) is arranged at a distance from the windings (2) of the motor (3) for the purpose of detecting the respectively local temperature TL using at least one temperature sensor (10) which is arranged in a sensor installation space (5), and also a correction element (20) for ascertaining the winding temperature Tw from the respective local temperature TL, which is detected by a temperature sensor (10), and a correction value KL.