Motor Driving Circuit Adaptive Commutation Control
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Solution Overview
Problem
Existing motor driving circuits face challenges in accurately achieving phase commutation of magnetic poles due to limitations in miniature Hall sensors and the inability of sensor-less controllers to adapt at low speeds or when starting, especially without additional mechanisms.
Innovation Solution
A motor driving circuit that selects between a Hall sensor and a sensor-less controller based on the output signals from a hall control device's positive and negative terminals, allowing for adaptive phase commutation according to motor characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a miniature Hall sensor is used for phase commutation, then the volume of the sensor is reduced, but the accuracy and reliability of commutation control deteriorates due to temperature, noise, and other factors
Solution Approach 1:
The motor driving circuit is designed with multi-functionality to support both Hall sensor-based control and sensor-less control modes. The control circuit can automatically select the appropriate control mode based on motor operating conditions, making the system universally applicable to different scenarios and eliminating the reliability issues of miniature Hall sensors in specific conditions.
Solution Approach 2:
The system changes the control parameter by switching between Hall sensor signals and sensor-less control algorithms based on operating conditions. When motor speed exceeds the threshold, the system transitions from Hall sensor control to sensor-less control, effectively adapting to different operational parameters and maintaining reliability across varying conditions.
2Device complexity
If a sensor-less controller is used for phase commutation, then cost and complexity are reduced, but the ability to achieve accurate phase commutation at low speeds or during starting deteriorates
Solution Approach 1:
The control system dynamically adapts its operation mode based on real-time motor speed feedback. The control circuit continuously monitors motor speed and automatically switches between Hall sensor control mode (for starting and low speeds) and sensor-less control mode (for medium-high speeds), making the system dynamically responsive to operational conditions.
Solution Approach 2:
The system performs preliminary action by using Hall sensor control during the starting phase and low-speed operation to establish reliable phase commutation. Once the motor reaches a sufficient speed threshold, the system transitions to sensor-less control, ensuring that the motor has already been properly started and is operating in a regime where sensor-less control is effective.
3Measurement precision
If Hall sensor control is used for phase commutation, then accurate position sensing is achieved, but the system cannot adapt to motor characteristics at medium-high speeds where sensor-less control is sufficient
Solution Approach 1:
The control system dynamically adjusts its sensing methodology based on motor speed. At low speeds and during starting, the system uses Hall sensors for precise position sensing. At medium-high speeds, the system transitions to sensor-less control, adapting to the operating regime where back-EMF measurement becomes more reliable and precise position sensing is less critical for commutation accuracy.
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
Enables reliable phase commutation of magnetic poles by selecting the appropriate sensing device, improving accuracy and adaptability across varying motor conditions.
Implementation Method 1
The Hall sensor senses the positions of the magnetic poles of the motor (or the magnetic field change) so as to determine the position of the rotor
Implementation Method 2
The Sensor-less controller adopts a digital signal processor (DSP) with a complex algorithm (e.g., field oriented control (FOC) and direct torque control (DTC)), and peripheral circuit to achieve the optimization control
Data Source
AI summary
A motor driving circuit is provided, which selects a Hall sensor or a Sensor-less controller to achieve the phase commutation of a magnetic pole of a motor through a hall positive terminal and a hall negative terminal of a hall control device. When the hall positive terminal and the hall negative terminal receive a first hall signal and a second hall signal generated by the Hall sensor, the motor driving circuit selects the Hall sensor and then accordingly drives the motor. When the hall positive terminal and the hall negative terminal are floating, or one of them receives a high-voltage, the motor driving circuit selects the sensor-less controller and then accordingly drives the motor. Accordingly, the motor driving circuit can select different sensing devices to achieve the phase commutation of the magnetic pole of the motor according to the motor characteristics.