Reconfigurable Stator Coil Paths for Variable Speed Generators
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Generators driven by variable speed sources, such as aircraft engines or flywheel energy storage devices, face challenges in maintaining output voltage within a usable range due to varying rotational speeds, often requiring complex and heavy gear assemblies to compensate, which are undesirable in portable or aircraft systems.
Innovation Solution
A reconfigurable stator system using switches to alter the electrical configuration of coils, allowing the generator to maintain output voltage within a specified range across a wide range of operating speeds by switching between series and parallel configurations, reducing back currents and enabling efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gear assemblies are used to interface between variable speed source and generator, then output voltage can be maintained within usable range, but device complexity and weight increase significantly
Solution Approach 1:
The patent replaces the mechanical gear assembly with an electrical reconfiguration system. Switches connected to the coil ends enable changing the electrical connections between stator coils based on rotor speed, eliminating the need for mechanical transmission components while maintaining voltage stability across variable speed ranges.
Solution Approach 2:
The patent implements dynamic reconfiguration of the stator coil connections through switches that respond to rotor speed changes. The system transitions between different coil connection patterns (series, parallel, or combinations) as operating conditions change, allowing the generator to maintain acceptable output voltage without mechanical speed regulation.
2Reliability
If gear assemblies are used to maintain rotor speed, then generator output voltage remains usable, but system weight increases
Solution Approach 1:
The patent eliminates heavy mechanical gear assemblies by substituting them with lightweight electrical switches and control circuitry. The switches connected to coil ends provide a minimal-weight solution for maintaining voltage stability, dramatically reducing the overall system weight compared to mechanical speed regulation approaches.
3Adaptability or versatility
If stator coils are reconfigured by switching electrical connections, then output voltage remains within specified range over large speed variations, but device complexity increases
Solution Approach 1:
The patent divides the stator winding into multiple independent coil groups with discrete connection points. Switches are connected to these coil ends, allowing individual coils or groups to be reconfigured independently. This segmentation enables flexible combination patterns (series, parallel, or mixed) that can adapt to various speed conditions while keeping the switching logic manageable.
Solution Approach 2:
The patent designs the switching system to perform multiple functions: it can connect coils in series for high voltage at low speeds, in parallel for current management at higher speeds, or in various hybrid configurations. This multi-functional switching architecture allows a single system to handle the entire operating speed range without requiring separate systems for different conditions.
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
The reconfigurable stator system extends the range of usable energy extraction from variable speed sources, improving efficiency and reducing weight and complexity by maintaining output voltage within acceptable limits, allowing for higher energy extraction efficiency from flywheels and other variable speed generators.
Implementation Method 1
a first voltage generated across the first coil path due to relative motion of the rotor and the stator
Data Source
AI summary
A device includes a rotor and a stator with coils arranged to form a phase element. The phase element includes a first coil group including a first coil and a second coil and a second coil group including a third coil and a fourth coil, where the rotor is positioned between the first coil group and the second coil group. The device also includes one or more switches that enable reconfiguration of the phase element by switching an electrical configuration of the coils. In a first mode, the coils are arranged with the first coil in a first coil path and the second coil in a second coil path that is coupled in parallel with the first coil path. The coils are arranged such that a voltage generated across the first coil path is substantially equal to a voltage generated across the second coil path.