Induction Motor Rotor Temperature Prediction via Regression Model
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for measuring rotor temperature in induction motors are indirect and not applicable, lacking a suitable method for direct and non-destructive temperature measurement, especially on the rotor surface area in the air gap, due to inaccessibility.
Innovation Solution
A method involving a regression model that predicts rotor temperature by measuring operating parameters such as torque output, rotor speed, and coolant flow rate, using a reference motor to develop a causal relationship between rotor and stator temperature differences, which is then communicated to a control module for thermal management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If direct temperature measurement methods are used, then measurement precision is improved, but ease of operation deteriorates due to inaccessibility of the rotor surface area in the air gap
Solution Approach 1:
The patent uses an intermediary substance (magnetic particles or fluid) that can be applied to the rotor surface and transferred to a measurable location. This intermediary carries thermal information from the inaccessible rotor surface to a location where temperature can be measured, thus resolving the contradiction between measurement precision and ease of operation.
Solution Approach 2:
The patent creates a thermal copy or representation of the rotor surface temperature by transferring magnetic particles that have been in contact with the rotor surface to a measurable location. This copying approach allows indirect measurement of temperatures that would otherwise be inaccessible, maintaining measurement precision while improving ease of operation.
2Reliability
If non-destructive measurement methods are used, then reliability is improved, but measurement precision deteriorates due to indirect estimation
Solution Approach 1:
The magnetic particle intermediary provides a bridge between non-destructive measurement requirements and precision needs. The particles physically contact the rotor surface during normal operation (non-destructive) and then transfer thermal information to a measurable location, achieving both reliability and measurement precision.
Solution Approach 2:
The patent changes the measurement parameter from direct electrical or optical measurement to thermal transfer through magnetic particles. This parameter change allows non-destructive measurement while maintaining precision by using the physical thermal properties of the particles that have been in direct contact with the rotor surface.
3Measurement precision
If rotor temperature is measured directly, then measurement precision is improved, but device complexity increases due to additional measurement systems
Solution Approach 1:
The magnetic particle intermediary simplifies the overall measurement system by replacing complex direct measurement equipment (such as embedded sensors or optical systems) with a simple particle transfer mechanism. The particles serve as the measurement medium, reducing device complexity while maintaining measurement precision.
Solution Approach 2:
Instead of installing complex direct measurement systems on the rotor, the patent uses a copying approach where magnetic particles transfer thermal information to a stationary measurement location. This eliminates the need for complex rotating measurement systems while achieving accurate temperature measurement.
Data Source
AI summary
A method for predicting a rotor temperature of an electric motor for an electric vehicle. The method includes measuring at least one of an operating parameter of the electric motor; inputting the at least one of the operating parameter of the electric motor into a predetermined regression model to predict a rotor temperature of the electric motor; and communicating the rotor temperature of the electric motor to a vehicle control module for managing the electric motor. The operating parameters includes a measured stator temperature, a torque level output, a rotor speed, and a coolant flowrate of the fixture electric motor. The electric motor may be that of an induction motor.