Position-Controlled Motor-Generator Without Permanent Magnets
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Solution Overview
Problem
There is a need for an electric motor-generator that does not require permanent magnets.
Innovation Solution
An electric motor-generator design that includes a stator, coils wrapped around the stator, a rotor with segments extending radially, electrical conductors along the stator, a rotary position sensor, and a controller to determine rotational positions and drive currents through the conductors based on sensor data, eliminating the need for permanent magnets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If permanent magnets are used in the electric motor-generator, then the motor-generator can achieve efficient operation and reliable magnetic field generation, but the device complexity and manufacturing cost increase due to the requirement of permanent magnets
Solution Approach 1:
The patent removes permanent magnets from the motor-generator system entirely. Instead of using permanent magnets to generate the magnetic field, the invention uses electromagnets (coils wrapped around the stator) that can be controlled electrically. This extraction of the permanent magnet component simplifies the device structure while maintaining the essential function of magnetic field generation through alternative means.
Solution Approach 2:
The patent changes the method of magnetic field generation from passive permanent magnets to active electromagnets. By controlling the current parameters (magnitude, direction, timing) through a controller based on rotor position feedback, the system dynamically adjusts the magnetic field characteristics. This parameter-based control replaces the fixed magnetic properties of permanent magnets, enabling flexible operation without the complexity of permanent magnet integration.
2Volume of moving object
If permanent magnets are used in the electric motor-generator, then the motor-generator achieves compact design with integrated magnetic fields, but the manufacturing cost and material requirements increase
Solution Approach 1:
The invention extracts the permanent magnet material requirement from the design. By replacing permanent magnets with electromagnets consisting of coils and magnetic cores, the system achieves similar or better compactness while using more readily available and easier-to-manufacture components. The coils can be wound around standard magnetic cores, simplifying the manufacturing process compared to integrating permanent magnets.
Solution Approach 2:
The patent substitutes the magnetic material-based system (permanent magnets) with an electrically-controlled system (electromagnets). This substitution replaces the need for specialized magnetic materials and their precise positioning with electrical components that are easier to manufacture and assemble. The electromagnetic system allows for standard manufacturing techniques to be used for the coils and magnetic cores.
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 efficient operation of the motor-generator without permanent magnets, allowing for effective rotational control and energy conversion.
Implementation Method 1
electrical conductors extending along inner surfaces of the stator in a direction parallel to a longitudinal axis of the stator
Implementation Method 2
drive currents through the electrical conductors based on the rotational positions of the shaft
Data Source
AI summary
An electric motor-generator can include a stator; at least two coils, wherein each coil is wrapped around a respective portion of the stator; a rotor mounted on a shaft and positioned in the stator, the rotor including: a plurality of rotor segments, wherein for each rotor segment: a first portion is mounted on the shaft, the second and third portions are connected to the first portion and extend in an outward radial direction toward the stator; electrical conductors extending along inner surfaces of the stator in a direction parallel to a longitudinal axis of the stator; a rotary position sensor operably coupled to the shaft; and a controller in communication with the rotary position sensor and configured at least to: determine rotational positions of the shaft based on sensor data from the rotary position sensor; drive currents through the electrical conductors based on the rotational positions of the shaft.