Drive Motor Rotor Alignment for Zero Locked-Rotor Torque
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Solution Overview
Problem
The locked-rotor torque produced during boost charging and power battery heating in electric vehicles affects brake performance and driving experience due to the random position of the rotor relative to the stator magnetic vector, especially in two-parallel and one-series boost charging solutions.
Innovation Solution
A control method and system that adjusts the position of the rotor to align the stator magnetic vector with the direct axis of the drive motor, using a static or rotating magnetic field to eliminate locked-rotor torque by controlling the magnetic field generated by the stator and coordinating with the vehicle's brake system to ensure the rotor is positioned correctly before initiating boost charging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the drive motor is used for boost charging or power battery heating, then system integration is improved and costs are reduced, but locked-rotor torque is generated which affects brake performance and driving experience
Solution Approach 1:
The control method detects the rotor position before boost charging or heating operations and pre-adjusts the rotor to a target position where the locked-rotor torque is minimized or eliminated. This preliminary positioning action prevents the generation of harmful locked-rotor torque while maintaining the benefits of using the drive motor for boost charging or heating, thus resolving the technical contradiction between system integration and brake performance
Solution Approach 2:
The invention changes the rotor position parameter to a specific target position before initiating boost charging or heating modes. By adjusting the rotor position parameter, the locked-rotor torque is reduced to minimal levels, allowing the drive motor to perform boost charging or heating functions without adversely affecting brake performance and driving experience
2Productivity
If the rotor position is not adjusted, then the boost charging and heating functions can be immediately performed, but impact torques occur affecting brake performance
Solution Approach 1:
The control method performs preliminary detection of rotor position and pre-adjustment to target position before initiating boost charging or heating. This preliminary action ensures that the rotor is properly positioned to minimize locked-rotor torque, thereby maintaining brake performance reliability while enabling subsequent high-efficiency charging operations
Solution Approach 2:
The control method continuously detects the rotor position and provides feedback to the control system. Based on this feedback, the system adjusts the rotor position to the optimal target position before and during boost charging or heating operations, ensuring that brake performance is maintained while achieving efficient charging
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 eliminates locked-rotor torque, ensuring stable brake performance and improved driving experience by accurately aligning the rotor with the stator magnetic vector, thereby preventing impact torques and maintaining system reliability.
Implementation Method 1
supply first current to the drive motor, so that a magnetic field generated by a stator adjusts a position of a rotor
Data Source
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AI summary
This application provides a control method and a related device for a drive motor of an automobile, and a transmission gearbox of an automobile. A stator of the drive motor includes a first phase winding, a second phase winding, and a third phase winding. The method includes: obtaining a position of a rotor of the drive motor, where the first phase winding is connected in parallel to the second phase winding, the first phase winding is connected in series to the third phase winding, and the second phase winding is connected in series to the third phase winding; and the drive motor is in a boost charging mode, and is configured to charge a power battery of the automobile after boosting a charging voltage; and if the position of the rotor is not a first target position, supplying a first current to the drive motor, so that a magnetic field generated by the stator adjusts the position of the rotor to the first target position, to make a locked-rotor torque of the drive motor be zero. In this embodiment of this application, the locked-rotor torque of the drive motor can be released.