Motor Rotor Angle Detection Using Hall Sensor Harmonic Extraction
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Solution Overview
Problem
Conventional methods using linear hall components for angle detection in permanent-magnet synchronous motors suffer from imperfect sine waveforms, leading to poor precision and torque ripple, which are costly and vulnerable to electromagnetic interference.
Innovation Solution
An angle detecting module and method utilizing three linear hall components spaced by 120 degrees, connected to a processing device that optimizes analog signals by eliminating the third harmonic component, generating an average rotor angle for improved precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If linear hall components are used for angle detection, then cost is reduced and reliability is improved, but measurement precision deteriorates due to imperfect sine waveforms and harmonic components
Solution Approach 1:
The patent extracts and eliminates the harmful third harmonic component from the hall sensor output signals through signal processing. By separating and removing this specific harmonic component, the system achieves cleaner sine waveforms and improved angle detection precision while maintaining the use of cost-effective linear hall components.
Solution Approach 2:
The patent implements a feedback mechanism where the hall sensor signals are continuously processed, the third harmonic components are identified and eliminated, and the corrected signals are used for precise commutation control. This closed-loop approach ensures sustained high precision in rotor angle detection throughout motor operation.
2Device complexity
If linear hall components are used instead of encoders, then device complexity is reduced and cost is lowered, but measurement precision deteriorates due to signal waveform imperfections
Solution Approach 1:
The patent replaces complex mechanical encoder systems with simpler linear hall component-based detection. By using signal processing to eliminate third harmonic components, the system achieves encoder-level precision without the mechanical complexity, fragility, and high cost associated with encoders.
Solution Approach 2:
The patent changes the electrical parameters of the detection system by processing the hall sensor signals to remove third harmonic components. This parameter optimization transforms the imperfect sine waveforms into cleaner signals, achieving high measurement precision with simple linear hall components rather than complex mechanical systems.
3Device complexity
If conventional hall sensor signals are used directly, then device complexity is minimized, but torque ripple increases due to imperfect sine waveforms in commutation control
Solution Approach 1:
The patent extracts and removes the third harmonic components from the hall sensor signals that cause torque ripple. By eliminating these specific frequency components through signal processing, the system generates cleaner sine waveforms for commutation control, significantly reducing torque ripple while maintaining simple control architecture.
4Measurement precision
If high precision encoders are used for rotor angle detection, then measurement precision is improved, but reliability deteriorates due to vulnerability to electromagnetic interference and structural fragility
Solution Approach 1:
The patent uses inexpensive linear hall components instead of expensive, fragile encoders. By applying signal processing to eliminate third harmonic components, the system achieves high measurement precision with robust, cost-effective hall sensors that are resistant to electromagnetic interference and mechanical damage.
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 the precision of rotor angle detection, reduces cost, and improves control accuracy by compensating for phase shifts and harmonic interference, resulting in stable and reliable motor control.
Implementation Method 1
Each hall component outputs an analog signal having third harmonic component due to magnetic saturation
Data Source
AI summary
An angle detecting module for a motor rotor is provided. The angle detecting module includes a permanent-magnet synchronous motor, three linear hall components and a processing device. The permanent-magnet synchronous motor includes a stator and a rotor. The three linear hall components are disposed on the stator; and the linear hall components are spaced by electrical 120 degrees. Each of the linear hall components outputs an analog signal after measuring a magnetic field position of the rotor, and each of the analog signals has magnetically saturated third harmonic component. The processing device is electrically connected to the linear hall components, and the processing device optimizes each of the analog signals and generates an average rotor angle.