Portable power source needs of the future Army-batteries and fuelcells

This paper describes the US Army's future needs for silent portable power in the area of batteries and fuel cells. These needs will continue to increase as a result of the introduction of newer types of equipment, the increasing digitization of the battlefield, and future integrated Soldier Systems. Current battery programs are aimed at improved, low-cost primary batteries, and rechargeable batteries with increased energy densities. The Army fuel cell program aimed at portable systems capable of the order of 150 W is also described     

Soldier Identification System utilizing low probability ofintercept (LPI) techniques

This paper documents the design of a laser/radio frequency (RF) Soldier Identification (ID) System developed by Dynetics, Inc., Harris, Corp., and the US Army Communications and Electronics Command (CECOM). The Soldier ID system includes an Interrogation Unit with a programmable activation code. The Interrogation Unit consists of a directive, eye-safe laser and a spread-spectrum RF transceiver. This allows for a low probability of intercept (LPI) interrogation, which is of interest during covert operations. A Responder Unit is worn, for example, by a soldier and transmits an LPI spread-spectrum RF response, only after receiving the proper interrogation codes. The basic subsystems for the identification system are a Laser Interrogation Unit, an RF Responder Unit, and an electronic Programming Unit. The operating principles for the subsystem are reviewed, and the design issues are discussed. In addition to the preliminary design performed under Phase I of the program, a breadboard system was developed to validate the proof-of-principle concept. Hardware implementation is reviewed and test results are presented. The brassboard development and engineering plans are also presented     

A maintenance-free lead acid battery for inertial navigationsystems aircraft

Historically, aircraft inertial navigation system (INS) batteries have utilized vented nickel-cadmium batteries for emergency DC power. The United States Navy and Air Force developed separate systems during their respective INS developments. The Navy contracted with Litton industries to produce the LTN-72 and Air Force contracted with Delco to produce the Carousel IV INS for the large cargo and specialty aircraft applications, over the years, a total of eight different battery national stock numbers (NSNs) have entered the stock system along with 75 battery spare part NSNs. The standard hardware acquisition and reliability program is working with the Aircraft Battery Group at Naval Surface Warfare Center Crane Division, Naval Air Systems Command (AIR 536), Wright Laboratory, Battelle Memorial Institute, and Concorde Battery Corporation to produce a standard INS battery. This paper discusses the approach taken to determine whether the battery should be replaced and to select the replacement chemistry. The paper also discusses the battery requirements, aircraft that the battery is compatible with, and status of Navy flight evaluation. Projected savings in avoided maintenance in Navy and Air Force INS systems is projected to be $14.7 million per year with a manpower reduction of 153 maintenance personnel. The new INS battery is compatible with commercially sold INS systems which represents 66% of the systems sold     

US Army Research Laboratory power sources R&D programs

The current status and thrust of the US Army Research Laboratory's battery and fuel cell R&D programs that support emerging electronic battlefield equipment applications are reviewed. Major technical barriers are identified along with the approaches proposed to solve these anticipated problems     

US Army small fuel cell development program

This presentation includes results of fuel cell research activities sponsored by the US Army for the last three years, It outlines current efforts and future plans. The soldier's increasing power demands dictate that alternatives to batteries be exploited wherever possible. Fuel cells promise significant advantages in terms of weight, coupled with cost and/or logistics benefits. Considerable progress has been made in reducing size and weight of proton exchange membrane (PEM) fuel cells. The supply of hydrogen to PEM fuel cells has been one of the key barriers to introducing fuel cells to the military. The discussion will focus on several approaches being pursued     

Silent energy source for tactical applications

Power source requirements for the Soldier System, which includes all items/equipment worn, consumed, or carried by the soldier in the field for his or her individual use, are discussed. The use of fuel cells, which offer silence and high efficiency, is considered. It is concluded that the proton exchange membrane (PEM) fuel cell coupled with a good hydrogen source offers a very attractive power source for the Soldier System and for other portable requirements needing power in the range of 50 to 500 W     

Electronic technologies that enables aerospace

This section highlights early electronics milestones that have made significant contributions to aerospace and defense. Today everyone thinks digital, whereas more than 50% of electronic advances since society founding 50 years ago were in the analog or continuous domain. It is too easy to forget that before the 1970s and 1980s analog systems had been the norm. Digital electronics emerged late in WWII, when the US Army contracted with the University of Pennsylvania to compute extensive artillery firing tables. The Cold War substantially accelerated advances in solid state electronics which led to the microelectronics that are so ubiquitous today. Defense and then aerospace programs were symbiotic with electronics in the development and mass production of transistors, integrated circuits, microelectronics, microprocessors, magnetic and then solid state memory. Small, reliable, low power and high performance electronics were the key to aerospace progress. The government backed virtually all these developments out of necessity. The power of computers has increased by over a million since 1972 and is still climbing. The initial enabling technology for advances in military electronics was the almost forgotten vacuum tube. The existence of electrons was first recognized as the “Edison Effect” in 1883. The seminal event in electronics was the audion invented by Lee De Forrest in 1906. The audion appeared just three years after the first Wright brother's flight and four years before the Army purchased their first Wright airplane. Up until the World War I (WWI) radio amateurs were the electronics pioneers, but the war created new demand for radio communications. Electronics expanded from communications into radar, navigation and control systems in World War II (WWII). Both wars brought about dramatic improvements in electronics, which resulted in a surplus of equipment and trained personnel to fuel postwar advances     

Future trends in space power technology

The status of the US Air Force Space Power Research and Development Program is summarized. Generic issues and requirements affecting the strategic planning of space power advances for the 1990s and beyond are described. The major thrusts of the Air Fore part of the Strategic Defense Initiative Office Space Power Program are highlighted, with emphasis on the ongoing advanced component technology development program. The status of these component technologies in the areas of power sources, energy storage, power management and distribution, and thermal management is described. Technology projections for the full range of envisioned technology options for the foregoing are used as the basis for a series of point designs for deriving the subsystem- and system-level benefits of the technologies. The primary focus is on baseload (CW) power systems operating in the range from 100 W for small satellites to 50 kW for potential large surveillance satellites. The secondary focus is on large, multimegawatt pulsed power systems and related components for potential applications such as directed energy. Potential `trump card' technologies related to energy conversion, storage, power electronics, and thermal management are identified     

Aerospace and military battery applications

This paper gives a review of the papers presented at the IEEE 17th Annual Battery Conference on Applications and Advances, Long Beach, CA, USA, 2002. The topics covered are: Li batteries for satellites, capacity fade of Li-ion cells cycled at different temperatures, Ni-H/sub 2/ battery lifetime, batteries for Mars-exploring vehicles, Li-ion cell performance enhancement at low temperatures, navy service batteries, and US Army man portable applications and mobile power challenges.     

Nuclear Power Systems for Spacecraft

A review and comparison of the weights, sizes, and costs of nuclear and non-nuclear spacecraft power systems is presented and discussed. Nuclear power systems include the range below 10 kW, with an electrical output to weight ratio of 0.5 to 1.0 pounds per watt. Comparisons show that primary batteries are lighter for short-duration missions of a few hours; fuel cells are lighter for durations of one to two months; and solar-cell/secondary battery combinations are to be preferred when sunlight is adequate.     

Fuel cells for tactical battlefield power

Basic fuel cell concepts are presented. The various types of fuel cells used by the US Army are described. The technological problems encountered are discussed     

First Mars outpost power systems

Research into potential power systems for the First Mars Outpost (FMO) was performed. The author examined a representative mission architecture which was developed by NASA to determine power system requirements. Power system options including nuclear, isotope, photovoltaic (PV), chemical heat engine, and regenerative fuel cell (RFC) concepts were identified for potential Mars surface applications. A top-level characterization study was conducted to determine power system mass and area for each application. It is seen that PV systems are generally not suited for Mars surface applications due to the large surface area required and higher mass than a closed Brayton cycle SP100 reactor system. A reactor is currently being considered by NASA Lewis Research Center to provide power for base architectures including an ISRU (in situ resource utilization). An oxygen/methane powered heat engine would provide 40 kWe of emergency power for the habitat. A dynamic isotope power system (DIPS) is the current choice for a long-duration pressurized rover due to the excessive size of a PV/RFC system and higher mass of a heat engine system. DIPS has advantages for other low power systems due to its neatly immediate availability and flexibility (night or day power; no recharging required)     

Safety testing of lithium ion batteries for navy devices

Lithium ion battery technology is being introduced into power supplies used by our armed forces for a variety of applications. In many cases, the same cells and design parameters that support commercial battery packs are being used in military battery packs. This approach is expected to result in a major decrease in the total life cycle cost of the equipment these batteries support. On June 13, 1991, NAVSEA issued INST9310.1B1, which states that all lithium battery powered equipment must undergo safety evaluation and approval prior to fleet use. This safety program governs a process whereby approvals are issued for lithium batteries to be used in specific equipment on ground facilities, surface combatants, air combatants, and/or submarines. The Naval Ordnance Safety and Security Activity (NOSSA) manages the program. The chief technical advisors are Code 644 at NSWC Carderock Division and Code 609A at NSWC Crane Division. This paper describes three battery designs that incorporate lithium ion technology, and the results of battery safety tests conducted in accordance with navy requirements.     

CTACTS Charleston Tactical Aircrew Combat Training System

This paper presents an overview of the Ocean Engineering and Construction Project Office (FPO-1) of the Chesapeake Division, Naval Facilities Engineering Command design and construction of eight ocean towers. These towers are for the Charleston Tactical Aircrew Combat Training System (CTACTS). The offshore portion of the CTACTS provides the necessary facilities to accurately monitor and control the training of Navy, Marine Corps, and Air Force pilots, during aerial warfare training exercises. These offshore facilities are located 30 to 72 nautical miles east of northern Georgia in water depths ranging from 81 to 143 feet. In June, 1984, FPO-1 awarded the ocean tower design contract to Brown & Root Development, Inc. The final design was completed in August, 1985 and in January, 1986, FPO-1 awarded a contract to McDermott Marine Construction to fabricate and install the platforms. The installation is scheduled to be completed by mid-September, 1986.     

Spiral evolution applied to legacy avionics systems

The US Department of Defense (DoD), through the Office of the Secretary of Defense (OSD), has determined that evolutionary acquisition is their strategy of choice for future software-intensive systems, and that the spiral development model (SDM) is the preferred method/process for software-intensive development life cycles. Electronic Systems Command (ESC) at Hanscom AFB, Massachusetts, has written a draft handbook on the use of Spiral Development for all future Command and Control (C2) systems, including reference to the DoD 5000 series and Air Force Program Directive 63-1, Acquisition System, which deploys this OSD mandate for future C2 systems. Barry Boehm's continued work on SDM which he conceived in the 1980s, is heavily biased toward development of new systems that are software-intensive, as noted in a workshop he gave at the Software Engineering Institute (SEI) in 2000.     

Industrial battery technologies and markets

Industrial battery market segments generally fall into two major categories--traction batteries, also called motive power batteries; and stationary batteries, also referred to as standby power batteries. The major industrial battery subcategories are discussed. Industrial trucks and rail and mine vehicles represent two major subcategories of motive power batteries. Industrial trucks include forklifts, automated guided vehicles (AGVs), various types of towing vehicles, floor cleaning equipment and so forth. Battery-powered rail and mine vehicles are used in mines where gas is present that could be ignited by spark ignition engines. Locomotive starting batteries and railcar emergency power batteries are also included in the second subcategory. The distinction is beginning to blur between valve-regulated industrial batteries and golf cart or marine batteries. Both industrial and SLI(starting/lighting/ignition)-derivative batteries are competing for markets in the future. The future trends in industrial battery production in Japan, USA and Europe are discussed     

Space colonization

A series of workshops were sponsored by the Physical Science Division of NASA's Office of Biological and Physical Research to address operational gravity-compliant in-situ resource utilization and life support techologies. Workshop participants explored a Mars simulation study on Devon Island, Canada; the processing of carbon dioxide in regenerative life support systems; space tourism; rocket technology; plant growth research for closed ecological systems; and propellant extraction of planetary regoliths.     

燃料电池无人机混合电源动态平衡能量管理策略

飞机电推进的动力系统趋于混合能源形式的发展方向，不同类型的源具有不同的特性，混合能源协调工作的方式可以提高动力系统的性能。本文所研究的飞机电推进系统的能源形式为燃料电池和锂电池所做成的混合能源。针对无人机动力系统工况的特殊性，本文在基于规则的能量管理策略研究基础上，提出了一种基于燃料电池氢气消耗的动态平衡能量管理策略，使燃料电池和辅助电源的能量消耗处于相对平衡的状态，避免了其中一种电源能量先耗尽的情况，可以满足多种工况的变化，提高了混合电源的能量利用率和稳定性，保证了无人机动力系统的可靠性。通过仿真分析结果证明了可行性，最后设计了能量管理系统的硬件并进行了实验验证，通过对实验结果计算分析验证了该能量管理策略的可行性。     

A power and thermal management system for long endurance hypersonic vehicle

Due to the pneumatic heating and combustion effect, the scramjet engine of hypersonic vehicle faces high temperature challenge. It is necessary to comprehensively consider its thermal management and power generation together. A new Power and Thermal Management System (PTMS) combined with Supercritical Carbon Dioxide (SCO₂) closed Brayton cycle and fuel vapor turbine is proposed and discussed in this paper. The new PTMS can meet the cooling requirement of hypersonic vehicle at Mach number 6–7, and avoid the coking and scrapping in the scramjet cooling channels. Compared with the PTMS only based on fuel vapor turbine, the new PTMS utilizes the waste heat of scramjet to generate more electricity. In addition, it can reduce the use of fuel sink for cooling, and the additional weight penalty can be compensated for long endurance hypersonic flight.     

APU飞机级控制系统设计研究

为充分发挥APU（辅助动力装置）在民用飞机上的作用,设计一个好的APU控制系统显得尤为重要。对APU飞机级控制系统的设计进行了相关研究,论述了APU控制板、APU控制器供电、燃油控制、应急停车、APU引气、起动／发电、风门控制和指示告警等控制子系统在设计时所要考虑的因素,并给出了相应的设计样例,然后从功能实现和电气原理的角度进行了详细地分析,可为APU飞机级控制系统的方案设计提供参考。