Improved Thermal Sensing of Distributed Electrical Generation Sources
Abstract
Improved Thermal Sensing of Distributed Electrical Generation SourcesAbstractThis proposal requests funds to procure two Luna Innovations Inc. Optical Distributed Sensor Interrogators (ODiSIs). The ODiSIs will be used to significantly improve the thermal and strain measurement capability of ongoing ONR supported experiments being performed in the University of Texas at Arlington~s (UTA~s) Pulsed Power and Energy Laboratory (PPEL). The US Navy~snext generation electrical power systems will rely on the integration of several interconnected power sources that will include, but are certainly not limited to, diesel and gas turbine driven generators, flywheels, and electrochemical batteries. Advanced distributed generation electrical power system architectures are required in order to meet the high power demands of the Navy~sfuture directed energy loads. At high power, significant ohmic losses occur that cause many components of the power system to heat up quickly. The thermal properties of many components are well known and therefore their thermal state can be predicted. On the flip side, the properties of many other components, such as the lithium-ion batteries, are not well known and significant research is still needed to be able to improve our understanding. The thermal state of a power system must be known and controlled at all times to ensure safety. In some instances, as in the case with lithium-ion batteries, improper thermal management can result in catastrophic damage. This is also the case with rotating machines in which not only can elevated temperature be a potential safety issue but so is elevated stress and strain on the rotating components. Historically, thermal measurements have relied on the placement of many thermocouples, each at a single location within the component being studied. Thermocouples are bulky, have slow thermal time constants, and rely on having a dedicated data acquisition channel available for each measurement. This severely limits the number of measurements that can be made, reducing ourability to thoroughly characterize the components properties and performance while also compromising safety. Similarly, strain measurements have relied on strain gauges which have similar limitations. To overcome these limitations, Luna Innovations has developed a single channel OFDR that is able to simultaneously measure the temperature and strain at discrete points,1 mm to 5 mm, down the length of a thin, < 80 microns, fiber optic cable. Using a system loaned to the PPEL in support of an ONR SBIR effort, we have been able to show the OFDR~s ability to simultaneously measure the temperature of over 140 lithium-ion cells installed within a 1000 V battery being studied for ONR. Previously, 140 thermocouples would have been required, which places a large overhead the battery. It is proposed here the UTA procure two Luna OFDR~s to be used simultaneously within a 150 kW distributed generation testbed that we are funded to develop with ONR support. It is proposed that one system be used to monitor the 150 kW high voltage battery and the other be used to monitor the 150 kW rotating machine. When deployed together we will be able to accurately monitor all thermal and strain aspects of the power system to ensure its safety, obtain thorough data that can be used in the development of thermal and strain modeling tools, develop algorithms for integrating the measurements into existing control systems, and validate the systems viability for use as an advanced diagnostic in future Navy shipboard power applications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 10, 2018
- Source ID
- N000141812286
Entities
People
- David A. Wetz
Organizations
- Office of Naval Research
- United States Navy
- University of Texas at Arlington