Ripple Current Sensing Motor Control Eliminates Hall Sensors
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Solution Overview
Problem
Existing motor control technologies require the installation of hall sensors, encoders, or resolvers near motors, leading to complex wiring and increased costs due to the need for connecting these sensors to a motor controller, complicating the sensing of motor rotation and direction.
Innovation Solution
A sensorless ripple current sensing motor control system using shunt resistors, amplifying circuits, and a detector to sense motor rotation by analyzing changes in voltage signals generated during motor operation, eliminating the need for physical sensors and simplifying the connection structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If hall sensors, encoders, or resolvers are installed near the motor to detect rotation, then rotation detection accuracy is improved, but wiring complexity and device complexity increase
Solution Approach 1:
The patent extracts the rotation detection function from external sensors (hall sensors, encoders, resolvers) and implements it within the motor controller itself by analyzing ripple current signals. This eliminates the need for separate sensing components and their associated wiring, thereby reducing device complexity while maintaining rotation detection capability
Solution Approach 2:
The motor controller is designed to perform multiple functions: it not only controls the motor but also detects rotation direction and speed by analyzing the ripple current signals generated during motor operation. This multi-functionality eliminates the need for dedicated sensing devices, reducing overall system complexity
2Measurement precision
If hall sensors, encoders, or resolvers are installed near the motor to detect rotation, then rotation detection accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The patent merges the rotation detection function with the motor controller by utilizing the existing current sensing circuitry to extract rotation information from ripple current signals. This integration eliminates the need for separate sensing components, reducing the total number of parts while maintaining detection accuracy
Solution Approach 2:
The motor controller is designed to perform multiple functions: it not only controls the motor but also detects rotation direction and speed by analyzing the ripple current signals. This multi-functionality eliminates the need for dedicated sensing devices, reducing overall system complexity
3Reliability
If external sensors are used for motor control, then rotation sensing capability is improved, but ease of manufacture deteriorates due to complex wiring
Solution Approach 1:
The patent extracts the rotation detection function from external sensors and implements it within the motor controller itself by analyzing ripple current signals. This eliminates the need for separate sensing components and their associated wiring, thereby reducing device complexity while maintaining rotation detection capability
Solution Approach 2:
The motor itself serves as the source of rotation detection information by generating ripple current signals during operation. The controller analyzes these self-generated signals to determine rotation direction and speed, eliminating the need for external sensing services and simplifying installation
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 accurate detection of motor rotation and direction without additional wiring, reducing implementation costs and simplifying the motor sensing module, while maintaining accurate RPM measurement with low error rates.
Implementation Method 1
a first shunt resistor having one end connected to one end of a motor and the other end of the first shunt resistor connected to a ground; a second shunt resistor having one end connected to the other end of the motor and the other end of the second shunt resistor connected to the ground
Implementation Method 2
a first amplifying circuit configured to amplify a first signal from one end of the motor; a second amplifying circuit configured to amplify a second signal from the other end of the motor
Data Source
AI summary
Provided are an apparatus and method for controlling a ripple current sensing motor. An apparatus for controlling a ripple current sensing motor may include a first shunt resistor having one end connected to one end of a motor and the other end of the first shunt resistor connected to a ground, a second shunt resistor having one end connected to the other end of the motor and the other end of the second shunt resistor connected to the ground, a first amplifying circuit amplifying a first signal from one end of the motor, a second amplifying circuit amplifying a second signal from the other end of the motor, and a detector detecting a rotation amount and a rotation direction of the motor using a change in voltages of a first detection signal from the first amplifying circuit and a second detection signal from the second amplifying circuit.