Wound Rotor Synchronous Motor Temperature Estimation
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Solution Overview
Problem
Current methods for controlling wound rotor synchronous motors fail to accurately estimate rotor coil temperature in real-time, leading to reduced control performance, overheating risks, and increased fire hazards due to excessive heat generation and copper loss, which results in performance degradation and additional data storage expenses.
Innovation Solution
A system and method that determine optimum rotor current and voltage using real-time motor operating information, and estimate rotor coil temperature using a correlation equation between rotor voltage and temperature, enabling real-time temperature estimation and protection logic to prevent overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional control method of permanent magnet synchronous motor is used for wound rotor synchronous motor, then control implementation is simplified, but overload of control CPU and massive map data occur due to combination of control variables
Solution Approach 1:
The patent extracts and removes the rotor current If variable from the control variable combination, using only stator currents Id and Iq for control. This extraction eliminates the need for massive map data and reduces CPU overload while maintaining control effectiveness for wound rotor synchronous motors.
2Power
If rotor current is increased to generate sufficient electromotive force, then motor torque is improved, but copper loss increases and rotor coil overheating occurs
Solution Approach 1:
The patent implements feedback control by continuously monitoring rotor temperature and adjusting rotor current accordingly. When rotor temperature exceeds a threshold, the system automatically reduces rotor current to prevent overheating, maintaining a balance between torque generation and thermal safety.
Solution Approach 2:
The patent dynamically changes the rotor current parameter based on operating conditions and temperature feedback. By adjusting rotor current magnitude according to real-time temperature measurements, the system optimizes torque production while preventing copper loss-induced overheating.
3Device complexity
If rotor coil temperature is not monitored and protected, then system complexity is reduced, but copper loss and rotor coil damage occur
Solution Approach 1:
The patent implements self-service temperature monitoring and protection where the control system automatically measures rotor temperature through voltage and current measurements, compares it with threshold values, and adjusts rotor current without external intervention. This self-monitoring mechanism prevents rotor coil damage while maintaining relatively simple system architecture.
4Measurement precision
If database with measured temperature values for each operating condition is stored, then accurate temperature control is achieved, but excessive data storage space and processing time are required
Solution Approach 1:
The patent extracts essential temperature information through real-time calculation using the relationship between rotor voltage, rotor current, and temperature, rather than storing comprehensive measured temperature databases. This approach achieves accurate temperature control while minimizing data storage requirements by calculating temperature on-demand based on operating parameters.
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 approach enhances control performance, reduces overheating risks, and prevents rotor coil loss, improving motor efficiency and safety while minimizing data storage needs and manufacturing costs.
Implementation Method 1
heating and temperature rise frequently occur due to copper loss of a rotor coil
Data Source
AI summary
The present disclosure provides a system for controlling a wound rotor synchronous motor including: a current/voltage determiner configured to determine optimum rotor current using a map from real-time motor operating information and to determine and output a rotor voltage according to the determined optimum rotor current, and a temperature estimator configured to calculate and output a rotor coil temperature from the rotor voltage and the optimum rotor current output from the current/voltage determiner using a rotor coil temperature estimation equation set from a correlation equation between the rotor voltage and the rotor coil temperature for each rotor current.