17851755. Method and System for Active Detection of Rotor Magnet Temperature simplified abstract (Ford Global Technologies, LLC)
Method and System for Active Detection of Rotor Magnet Temperature
Organization Name
Inventor(s)
Jonathan Hair of Royal Oak MI (US)
Yingfeng Ji of Northville MI (US)
Matthew Penne of Hadar NE (US)
Method and System for Active Detection of Rotor Magnet Temperature - A simplified explanation of the abstract
This abstract first appeared for US patent application 17851755 titled 'Method and System for Active Detection of Rotor Magnet Temperature
Simplified Explanation
The abstract of the patent application describes a controller that can detect the temperature of a rotor magnet in a motor by actively detecting the back electromotive force (BEMF) voltage. The controller achieves this by injecting a known quantity of current into the motor's d-axis while the motor is spinning but not producing any torque. By using a quadrature-axis voltage equation, the controller can solve for the BEMF voltage using the known voltage command, current, and q-axis reactance. The rotor magnet temperature is then determined based on the BEMF voltage.
- The controller detects rotor magnet temperature based on actively detected BEMF voltage.
- It injects a known quantity of current into the motor's d-axis while the motor is spinning but not producing torque.
- The BEMF voltage is determined using a quadrature-axis voltage equation.
- The known voltage command, current, and q-axis reactance are used to solve for the BEMF voltage.
- The rotor magnet temperature is then determined based on the BEMF voltage.
Potential Applications
- Motor temperature monitoring and control in various industries such as automotive, manufacturing, and robotics.
- Improved efficiency and performance of motors by allowing real-time temperature monitoring.
Problems Solved
- Accurate and real-time detection of rotor magnet temperature in motors.
- Elimination of the need for additional temperature sensors or probes.
- Enhanced control and protection of motors by monitoring temperature.
Benefits
- Cost-effective solution for temperature monitoring in motors.
- Improved motor performance and efficiency.
- Early detection of overheating or potential failures.
- Simplified motor control system without the need for additional temperature sensors.
Original Abstract Submitted
A controller detects a rotor magnet temperature based on an actively detected back electromotive force (BEMF) voltage of the motor. The controller detects the BEMF voltage by commanding the injection of a direct-axis (d-axis) current into the motor while the motor is spinning but otherwise commanding no torque. The controller actively detects the BEMF voltage in that the controller purposely injects a known quantity of d-axis current at a chosen time during which the controller detects or is aware that the motor is commanding no torque. Using a quadrature-axis (q-axis) voltage equation, which describes the relationship between a voltage command, the current, the BEMF voltage, and reactance in the q-axis, the controller solves for the BEMF voltage with the voltage command, the current, and the q-axis reactance being known to the controller. The controller detects the rotor magnet temperature based on the BEMF voltage.
