Electric Machine Partial-Phase Operation Without Neutral Wires
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Solution Overview
Problem
Modern aeronautical gas turbine engines face challenges with the size and weight of electric machine assemblies, which affect efficiency and fuel consumption, and existing designs require shutting down entire sets of windings in case of phase failure, leading to undesirable results.
Innovation Solution
An improved electric machine assembly and method that allows operation in partial phase mode by powering sets of windings to achieve net zero current while maintaining one phase in a non-conducting condition, eliminating the need for neutral or ground wires and incorporating a processing module to determine rotor position without dedicated resolvers or encoders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electric machine designs are used with neutral or ground wires, then reliability is improved, but weight and device complexity increase
Solution Approach 1:
The patent removes the neutral wire and ground wire from the electric machine assembly, extracting these components entirely from the system. The winding sets are configured to provide self-contained phase circuits that operate without requiring external neutral or ground connections, thereby reducing weight while maintaining reliability through the inherent redundancy of the multi-set winding configuration.
Solution Approach 2:
The electric machine is designed to be self-sufficient by configuring winding sets where each phase has an associated winding set that provides its own return path. The system serves its own grounding and neutral functions through the winding configuration itself, eliminating the need for separate neutral or ground wires while maintaining electrical safety and operational reliability.
2Measurement precision
If conventional electric machine designs with dedicated resolvers or encoders are used, then measurement precision is improved, but device complexity and weight increase
Solution Approach 1:
The electric machine uses its own phase windings to determine rotor position. By monitoring the back electromotive force (EMF) generated in the phase windings during normal operation, the system derives rotor position information without requiring separate dedicated sensors. This self-service approach eliminates dedicated resolvers or encoders while maintaining precise rotor position determination.
Solution Approach 2:
The phase windings serve multiple functions: they generate electromagnetic torque and simultaneously provide rotor position information through back EMF monitoring. This multi-functionality eliminates the need for separate position sensing components, reducing device complexity and weight while maintaining measurement precision.
3Reliability
If entire sets of windings are shut down in case of phase failure, then reliability is maintained, but productivity and operational continuity deteriorate
Solution Approach 1:
The electric machine divides its windings into multiple independent sets, where each phase has an associated winding set. This segmentation allows individual phases or winding sets to be isolated and managed independently. When a phase failure occurs, only the affected winding set is disconnected while other winding sets continue to operate, maintaining productivity and operational continuity.
Solution Approach 2:
The system is designed with redundant winding sets that serve as backup capacity. Before a failure occurs, the system is configured with more winding sets than strictly necessary for minimum operation. When a phase failure occurs, the redundant winding sets provide cushioning that allows the system to continue operating at reduced capacity rather than shutting down completely.
4Measurement precision
If additional components like neutral wires and dedicated sensors are added, then measurement precision and reliability are improved, but the size and weight of the electric machine assembly increase
Solution Approach 1:
The phase windings are designed to perform multiple functions simultaneously: generating electromagnetic torque, providing electrical isolation, and enabling rotor position determination through back EMF monitoring. This multi-functionality eliminates the need for separate dedicated components, reducing the overall size and volume of the electric machine assembly while maintaining measurement precision.
Solution Approach 2:
The patent extracts and removes unnecessary components such as neutral wires, ground wires, and dedicated position sensors from the electric machine assembly. By taking out these redundant components and integrating their functions into the essential phase windings, the overall size and weight of the assembly are reduced while maintaining or improving performance.
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 results in a more compact, lighter, and redundant electric machine design with enhanced reliability and efficient operation, allowing torque generation without neutral wires and enabling sophisticated rotor position determination.
Implementation Method 1
The first and second sets of windings can each be configured as a three phase set of windings and the controller is configured to power the first and second sets of windings in a manner to generate a rotating magnetic field
Data Source
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AI summary
A method (500, 600) for operating an electric machine assembly is provided, the electric machine assembly having an electric machine (402) comprising a first set of windings (438) and a second set of windings (440), the method (500, 600) comprising: (502) operating the electric machine (402) in a partial phase mode, wherein operating the electric machine (402) in the partial phase mode comprises: (504) powering a first set of windings (438) to provide a net zero current in the first set of windings (438) while maintaining one phase of the first set of windings (438) in a non-conducting condition; and (506) powering a second set of windings (440) to provide a net zero current in the second set of windings (440) while maintaining one phase of the second set of windings (440) in a non-conducting condition.