Motor Start-Up Resistance Estimation for Low-Complexity Speed Control
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Solution Overview
Problem
Existing motor control systems face challenges in achieving high efficiency and low vibration and acoustic noise, particularly in consumer and industrial applications, due to the complexity and computational intensity of Field-Oriented Control (FOC) techniques, which can overwhelm microcontrollers and reduce system functionality.
Innovation Solution
A motor control method and system that estimates phase resistance during a start-up mode using a reference torque generating current parameter, determines feedback torque generating current parameters, and controls the motor in a speed control mode based on phase resistance measurements, reducing computational complexity and enhancing system functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Field-Oriented Control (FOC) techniques are used to achieve high efficiency and low vibration, then motor performance is improved, but computational complexity increases and microcontroller resources are overwhelmed
Solution Approach 1:
The patent applies preliminary action by measuring and storing motor parameters (resistance, inductance, back-EMF constants) during a start-up phase before normal operation begins. This pre-characterization allows the controller to use simplified control algorithms during runtime, reducing computational complexity while maintaining FOC performance benefits.
Solution Approach 2:
The patent implements partial action by applying FOC techniques selectively - using full FOC during start-up for precise control, then transitioning to a simplified model-based control using pre-measured parameters during steady-state operation. This partial application of FOC maintains motor performance while reducing computational burden during normal operation.
2Measurement precision
If FOC techniques are implemented for precise motor control, then control precision is improved, but microcontroller functionality is reduced due to resource constraints
Solution Approach 1:
The system performs preliminary parameter measurement and storage during start-up, enabling the microcontroller to operate with simplified algorithms during normal function. This preserves microcontroller resources for other system functions while maintaining control precision through the use of pre-characterized motor parameters.
Solution Approach 2:
The patent creates a computational model (copy) of the motor's electrical characteristics by measuring and storing parameters such as resistance, inductance, and back-EMF constants. This mathematical model allows the controller to predict motor behavior and implement precise control without requiring complex real-time calculations, thus preserving microcontroller functionality.
3Measurement precision
If phase resistance measurement is performed during start-up in stationary state, then measurement accuracy is improved, but start-up time is extended
Solution Approach 1:
The patent implements periodic action by performing parameter measurements during the start-up sequence at specific intervals - measuring resistance during the stationary phase, then measuring inductance and back-EMF constants as the motor accelerates. This structured periodic measurement approach ensures accuracy while minimizing the time added to start-up through efficient sequencing.
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 allows for improved motor control with reduced computational demands, enabling increased functionality and efficiency in motor systems while maintaining high performance and reducing noise and vibration.
Implementation Method 1
Permanent Magnet Synchronous Motors (PMSMs) are employed in consumer and industrial motor applications
Implementation Method 2
determining a phase resistance measurement of the motor based on the demand torque generating voltage parameter and the feedback torque generating current parameter
Data Source
AI summary
According to some embodiments, a method for controlling a motor includes applying a first reference torque generating current parameter during a start-up mode to a motor in a stationary state, generating a demand torque generating voltage parameter based on the first reference torque generating current parameter, determining a feedback torque generating current parameter based on measured motor current in the stationary state, determining a phase resistance measurement of the motor based on the demand torque generating voltage parameter and the feedback torque generating current parameter, and controlling the motor in a speed control mode based on the phase resistance measurement.