Universal Motor Electronic Commutation via Rotor Position Control
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Solution Overview
Problem
Universal motors face inefficiencies due to the use of noisy and inefficient commutators or complex slip rings for coupling rotor windings to an external power source, limiting their performance and manufacturing simplicity.
Innovation Solution
An electric motor apparatus with a rotor winding control unit that generates a rotor waveform based on rotational position information, synchronized with a stator waveform, eliminating the need for commutators and multiple slip rings by decoupling the rotor waveform frequency from the rotational frequency, allowing for flexible waveform selection and reduced mechanical complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a commutator is used to couple external power to rotor coils, then the rotor windings can be powered, but the motor becomes noisy and inefficient
Solution Approach 1:
The patent replaces the mechanical commutator system with an electronic control system. A rotor winding control unit generates the rotor waveform electronically based on rotational position information from a sensor, eliminating the need for physical commutator contacts. This substitution removes the source of noise and inefficiency while maintaining the essential function of coupling power to the rotor windings.
Solution Approach 2:
The patent introduces a rotor winding control unit as an intermediary between the power source and the rotor windings. This control unit receives rotational position information and generates appropriate rotor waveforms, acting as a mediator that eliminates the need for direct mechanical contact while still achieving the required power coupling function.
2Adaptability or versatility
If numerous slip rings are used to provide electrical connections to the rotor, then multiple rotor windings can be powered, but manufacturing complexity increases significantly
Solution Approach 1:
The patent replaces the complex mechanical slip ring system with an electronic control system. The rotor winding control unit generates all necessary rotor waveforms electronically, eliminating the need for multiple slip rings and concentric power channels. This substitution dramatically reduces manufacturing complexity while maintaining the capability to power multiple rotor windings.
Solution Approach 2:
The rotor winding control unit serves multiple functions: it generates rotor waveforms for multiple windings, processes rotational position information, and controls the timing of waveform application. This single multi-functional electronic component replaces what would otherwise require numerous separate mechanical components.
3Productivity
If the rotor waveform frequency is coupled to the rotational frequency, then the motor operates at a fixed design speed, but efficiency is lost when operated at different speeds
Solution Approach 1:
The patent makes the rotor waveform frequency dynamic rather than fixed. The rotor winding control unit adjusts the frequency of generated rotor waveforms based on the actual rotational speed and operational requirements, allowing the motor to maintain efficiency across a wide range of speeds rather than being locked to a single design speed.
Solution Approach 2:
The patent changes the parameter of waveform frequency from a fixed value coupled to rotational frequency to a variable parameter controlled independently by the rotor winding control unit. This allows the frequency to be optimized for different operating conditions and speeds, improving overall efficiency and adaptability.
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 solution enhances efficiency and flexibility by synchronizing rotor and stator interactions, reducing noise and manufacturing complexity, and enabling the motor to operate effectively across varying speeds without the need for mechanical transmissions.
Implementation Method 1
a rotational position indicator configured to generate rotational position information indicative of a relative orientation of the rotor component and the stator component
Implementation Method 2
said rotor winding control unit configured to perform a rotor waveform generation operation to generate a rotor waveform from said rotor supply voltage in dependence on said rotational position information and to apply said rotor waveform to said rotor winding arrangement
Implementation Method 3
a stator winding waveform generator configured to receive a stator supply voltage, to generate therefrom a stator waveform in dependence on said rotational position information and to apply said stator waveform to said stator winding arrangement
Implementation Method 4
wherein the rotor waveform and the stator waveform are generated in synchronization with the relative orientation of the rotor component and the stator component in order to synchronize mutual interactions of the rotor winding arrangement and the stator winding arrangement with the relative orientation
Data Source
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AI summary
An electric motor apparatus configured as a universal motor and method of operating the same are provided. The electric motor apparatus comprises a rotor component arranged to rotate with respect to a stator component. A rotor winding arrangement is mounted on the rotor component and a stator winding arrangement is mounted on the stator component. A rotational position indicator generates rotational position information indicative of a relative orientation of the rotor component and the stator component. A rotor winding control unit is fixedly mounted on the rotor component and is coupled to a rotor supply voltage supplied to the rotor component. The rotor control unit is configured to perform a rotor waveform generation operation to generate a rotor waveform from the rotor supply voltage in dependence on the rotational position information and to apply the rotor waveform to the rotor winding arrangement. A stator winding waveform generator is configured to receive a stator supply voltage, to generate therefrom a stator waveform in dependence on the rotational position information and to apply the stator waveform to the stator winding arrangement. The rotor waveform and the stator waveform are generated in synchronization with the relative orientation of the rotor component and the stator component in order to synchronize mutual interactions of the rotor winding arrangement and the stator winding arrangement with the relative orientation.