Distributive Photovoltaic Power Conversion on Optical Fiber for Ultrasonic Testing
Abstract
Funds are provide to Dr. Ming Han, from University of Nebraska, Lincoln, in the amount of $100,000.00 for the FY-17 only increment o""f a Grant totaling $200,251.00 for work towards investigating the feasability of a ""Distributive Photovoltaic Power Conversion on Op""tical Fiber for Ultrasonic Testing"". Some of the activities to be performed as part of this effort include: 1-Investigate wavelength"-selective light tapping method for light around 850 nm and use silicon-based photovoltaic cells for power conversion; 2- Investigate wavelength-selective light tapping method for light at 1550 nm and study the use of Indium-Gallium-Arsenide (InGaIn) photodetector arrays for power conversion. 3- Study the feasibility of grating-assisted coupling for wavelength-selective light tapping. 4- Develop circuit for charging a small-size battery and driving piezoelectric transducers with relatively high driving voltage. 5- Evaluate signal transmission through the same fiber and low-power microprocessors for node control. 6- Construct and characterize two-node systems for technology demonstration.ABSTRACTUltrasonic testing is one of the most powerful and well-developed tools for non-des"tructiveevaluation of structures. It uses ultrasonic waves to probe the flaws in a structure, measuredimensions, and characterize" material properties. The ultrasonic waves are typically generatedfrom a piezoelectric transducer that converts the electrical energy to ultrasonic energy. Thetransducer can generate ultrasonic waves in a structure with well-defined frequency componentsand type"s. However, the requirement for electrical power often make them unsuitable forapplications where many transducers are permanently" installed at locations far away from thepower supply. The limitation arise from the large electrical power loss over long electrical wiresand the needs for a pair of electrical wire for each transducer. A vision that can overcome thesechallenges is to fabricat"e many power nodes at various locations in a fiber, each of which is aphotovoltaic power converter that convert light at a particul"ar wavelength to electrical power. Theelectrical power generated from a node will be used to charge a battery to power a nearbypiezoelectric transducer for ultrasonic testing of the structure. The same fiber can also transmitcontrol signals to control the charg"ing and ultrasound generation. In this vision, the power can bedelivered to a distance very far away from the light sources thanks"" to the extremely small opticalloss of optical fibers (0.2 dB/km at 1550 nm). In addition, a single optical fiber can power manyno""des, which, together with the small size and light weight of optical fibers, makes power-overfibermore desirable for ultrasonic tes""ting in aircraft structures.In this program, we will study the feasibility of several wavelength-selective light tapping andpower" conversion schemes for the PPC node. We will also demonstrate simple circuits for batterycharging and signal generation for drivin"g the piezoelectric transducer.If successful, this project will lead to a new concept of ultrasonic testing where multiplepiezoele"ctric transducers are powered at various locations of a single optical fiber. Such schemeaugments the capabilities of current state of the art optical fibers for distributes structuralmonitoring with the capability to actively monitor structures by means of ultrasonic waves withoutthe need of electrical wires for powering or communicating. The proposed scheme combines theadvantages of low-"optic loss, small size, light weight, and corrosion resistance of optical fibersand the capability to generate high-quality ultraso"und of piezoelectric transducers. The powerover-fiber will protect the power supply as well as the transducers from dangerously hig"h voltagessuch as those from lightning and significantly reduces the number, size, and weight of the cablesneeded in the system. T"he concept studied in this program will greatly ex
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 07, 2017
- Source ID
- N000141712654
Entities
People
- Ming Han
Organizations
- Office of Naval Research
- United States Navy
- University of Nebraska system