Sensorless Motor Controller With Variable Floating Phase Timing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional motor controllers using Hall sensors are prone to accuracy issues due to environmental interference, increasing system volume and cost, while sensorless methods face noise problems with fixed floating phase times, leading to erroneous phase switching detections, especially when power voltage or load changes.
Innovation Solution
A motor controller with a switch circuit, control unit, and detecting unit that adjusts floating phase time to ensure a stable interval, using transistors and MOSFETs to generate driving and detecting signals, allowing for variable floating phase time to accurately detect phase switching points and reduce noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed floating phase time is used in sensorless driving method, then the phase switching time point detection is simplified, but noise problems occur and erroneous detection happens when power voltage or load changes
Solution Approach 1:
The patent applies dynamics by making the floating phase time variable instead of fixed. The control unit dynamically adjusts the floating phase time based on detection results from the detecting unit, which monitors the current state of the motor coil. This dynamic adjustment allows the system to adapt to changing power voltage and load conditions, preventing erroneous detection while maintaining simplified sensorless operation.
Solution Approach 2:
The patent implements feedback through the detecting unit that continuously monitors the motor coil state and provides information to the control unit. The control unit uses this feedback to adjust the floating phase time accordingly, creating a closed-loop control system that enhances detection reliability without adding Hall sensors or other complex detection devices.
2Reliability
If the floating phase time is increased, then the motor coil current can be released completely, but noise problems occur in the detection
Solution Approach 1:
The system dynamically adjusts the floating phase time duration based on real-time detection feedback. When the detecting unit indicates that the motor coil current has been completely released, the control unit reduces the floating phase time to minimize noise. This dynamic adjustment ensures complete current release while keeping noise levels low.
Solution Approach 2:
The patent changes the parameter of floating phase time from a fixed value to a variable value that is adjusted based on detection results. By modifying this temporal parameter dynamically, the system achieves complete current release only when necessary, thereby reducing overall noise while maintaining reliable operation.
3Object-affected harmful factors
If the floating phase time is decreased, then noise is reduced, but the motor coil current cannot be released completely leading to erroneous detection
Solution Approach 1:
The detecting unit provides continuous feedback on the motor coil current state to the control unit. This feedback ensures that the floating phase time is reduced only after confirming that the current has been completely released, preventing erroneous detection. The system maintains low noise levels by keeping the floating phase time short while ensuring complete current release through feedback-controlled adjustment.
4Measurement precision
If Hall sensor is used for switching phases, then the phase switching detection is accurate, but the system volume and cost increase
Solution Approach 1:
The patent extracts the detection function from external Hall sensors and implements it within the motor controller using the detecting unit. This eliminates the need for separate Hall sensor components, reducing system volume and cost while maintaining accurate phase switching detection through the integrated detecting unit and variable floating phase time mechanism.
Solution Approach 2:
The control unit and detecting unit serve multiple functions: they control the switch circuit for motor driving, detect the motor coil current state, and dynamically adjust the floating phase time for accurate phase switching detection. This multi-functionality replaces the specialized Hall sensor, reducing component count while maintaining detection 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
The motor controller effectively detects phase switching time points in a stable manner, reducing noise and increasing detection success rate by adjusting floating phase time based on current zero points, ensuring optimal efficiency and accuracy even with changing power voltage or load.
Implementation Method 1
The detecting unit may be used for detecting the current of the first coil and a back electromotive force of a floating phase
Data Source
AI summary
A motor controller comprises a switch circuit and a control unit. The motor controller is used for driving a motor, where the motor has a coil. The switch circuit is configured to supply a coil current to the coil. The control unit is configured to generate a plurality of control signals to control the switch circuit. The motor controller enables a floating phase time to be a variable value, where the floating phase time has a stable interval and a detecting interval. The motor controller enables a zero point of the coil current to appear in the stable interval, so as to detect a phase switching time point in a stable way and avoid a noise problem. The motor controller detects a zero crossing point of a back electromotive force in the detecting interval.