Polyphase Inductive Power Transfer Across Gaps With Loose Alignment
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Solution Overview
Problem
Existing inductive power transfer systems for underwater or unmanned autonomous vehicles require precise alignment between the transmitter and receiver, leading to reduced efficiency and output voltage when alignment is not perfect, limiting their effectiveness in transferring power across liquid or air gaps.
Innovation Solution
A polyphase traveling-wave inductive power transfer system utilizing a polyphase dynamoelectric machine with mechanical-inertial energy storage and bidirectional power flow, capable of transferring power across gaps with less precise alignments through a resonant electromagnetic field, allowing for efficient power transfer to underwater vehicles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If single-phase stationary electromagnetic fields are used for power transmission, then the system structure is simple, but alignment precision between transmitter and receiver must be very accurate
Solution Approach 1:
The patent divides the single-phase stationary electromagnetic field into multiple polyphase traveling-wave electromagnetic fields. This segmentation allows the system to tolerate misalignment better, as the distributed nature of multiple phases provides redundancy and smoother power transfer across the gap even when perfect alignment is not achieved.
Solution Approach 2:
The patent transitions from stationary electromagnetic fields to traveling-wave electromagnetic fields. The traveling-wave nature introduces dynamic characteristics that enable the field to adapt to positional variations between transmitter and receiver, reducing the stringent alignment requirements while maintaining power transfer efficiency.
2Power
If single-phase stationary electromagnetic fields are used, then power transmission can be achieved, but electrical transfer efficiency falls off rapidly with misalignment
Solution Approach 1:
By segmenting the power transmission into multiple polyphase components, the system distributes the energy transfer across multiple field interactions. This reduces the sensitivity to misalignment, as the combined effect of multiple phases maintains efficient energy transfer even when individual phase alignments are not optimal.
Solution Approach 2:
The patent changes the fundamental parameters of the electromagnetic field from single-phase stationary to polyphase traveling-wave. This parameter transformation fundamentally alters the efficiency characteristics, creating a system where efficiency remains stable across a range of alignments rather than falling off rapidly.
3Power
If precise alignment is required between transmitter and receiver, then power transfer can be maintained, but the system becomes difficult to operate and position
Solution Approach 1:
The traveling-wave characteristic provides dynamic adaptability that automatically compensates for positional variations. The wave propagation nature allows the field to naturally adjust to misalignment conditions, eliminating the need for precise positioning while maintaining stable power transfer.
Solution Approach 2:
The polyphase traveling-wave system possesses self-aligning characteristics where the electromagnetic fields naturally adjust to maintain effective coupling between transmitter and receiver. This self-service property eliminates the need for external alignment mechanisms or precise positioning systems.
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 system enables efficient power transfer with larger gap separations and reduced alignment requirements, supporting high power transmission to underwater vehicles, including those operating at depths of 10 km and distances of 1 to 50 km, with improved efficiency and reliability.
Implementation Method 1
A power transfer system includes: a polyphase dynamoelectric machine, wherein the dynamoelectric machine includes multiple electrical ports, including primary and secondary electrical ports; a mechanical-inertial energy storage device coupled to the polyphase dynamoelectric machine; polyphase traveling-wave inductive power transmitters coupled to respective of the secondary ports; and polyphase travelling-wave power receivers inductively coupled to the transmitters
Implementation Method 2
A polyphase traveling-wave inductive power transfer system utilizing a polyphase dynamoelectric machine with mechanical-inertial energy storage and bidirectional power flow, capable of transferring power across gaps with less precise alignments through a resonant electromagnetic field
Data Source
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AI summary
An inductive power transfer system is used for transferring electrical power across a gap, such as an air gap or a liquid gap, such as to unmanned autonomous vehicles (UAVs). The power transfer system is a polyphase system that creates a travelling magnetic field in the air or liquid gap, implementing a resonant electro-magnetic (EM) field to allow larger gap separations and less precise alignments. The power transfer system may have a polyphase dynamoelectric machine attached to primary mechanical-inertial storage device with multiple stator and rotor ports connected to a polyphase traveling-wave inductive power transmitter apparatus. The system may be of use in transferring power to underwater vehicles in a subsea salt water environment. Such a power transfer system may part of a larger system for underwater power transfer, for instance at depths of at least 10 km, and/or at distances of 1 to 50 km.