RESEARCH
Small Business Innovation Research (SBIR)
The highly competitive SBIR program was established by Congress in 1982 for the purpose to encourage domestic small businesses to engage in Federal research and development. DTI won its first Phase I award in 1988 and continues to grow our SBIR portfolio to currently include over 90 Phase I awards and 55 Phase II awards. The stability and success of our technological innovation within the SBIR research program has positioned DTI as a reliable and recognized resource to the Federal research community.
NAVY
N161-026 Fault Current Limiting Liquid Nitrogen Cooled Circuit Breaker
DTI built a high speed circuit breaker using liquid nitrogen as a dielectric / coolant. The small volume of liquid nitrogen contained in this unit (approximately 8 liters) minimizes the asphyxiation hazard associated with a liquid nitrogen release. Liquid nitrogen allows for a high speed breaker due to its superior dielectric properties compared to conventional dielectrics; as well as reduction or even elimination of resistive losses in the breaker due to operating at cryogenic temperatures. This reduces the size and mass of the moving contacts thus allowing for faster operating speed with a given actuation force.
N181-069 Compact, Flexible Integrated Power Node Center for Direct Current Distribution
DTI built an air-cooled galvanically-isolated, high power density integrated power node center for DC distribution. The inputs are 440 VAC, 60 Hz and/or 1000 VDC and the outputs are 440 VAC, 60 Hz, 440 VAC, 400 Hz, or 650 VDC, among others. The output seamlessly transfer among inputs or outputs. The high power density of 2 MW/m3 can only be achieved by high frequency switched mode power supplies. DTI developed and demonstrated a high power isolation inverter capable of full power while meeting the galvanic isolation and insulation goals. The unit is air-cooled, and interfaces to sources and loads, as appropriate. A 3-phase active power-factor input module with controls was also demonstrated. DTI worked with the Navy to perfect the mechanical and electrical interfaces required for mission-critical ship-born electrical subsystems, ultimately leading to a full form-fit-function prototype for evaluation in the field by Navy sponsors.
N201-039 Power Dense Single Core Three-Phase Transformer
DTI developed a compact, lightweight 112.5 kVA militarized isolation transformer for suitable Navy shipboard vital loads. DTI and our subcontractor Neeltran, Inc. designed a complete 60 Hz, 440 VAC, 112.5 kVA isolation transformer as specified, including the protective cabinetry weight, and worked with the Navy on a new 150 kVA transformer specification and design. The design ruggedized for military usage and optimized for increased power density on weight and volume bases and reduced losses. In addition, the transformer improved fault-current performance with reduced stray magnetic fields. DTI and Neeltran fabricated, demonstrated, and tested two full-scale 112.5 kVA transformers of the optimized design. The main technical objective was to reduce the size and weight of single-core three-phase transformers for use within shipboard power distribution systems. The Phase II project is currently underway.
N123-161 Dynamic Tuner for Narrow-Band VLF Submarine Communication Transmitting System
DTI investigated several potential approaches to dynamic tuning to down-select to an optimal solution, based on cost, technical robustness, and serviceability, from which to build and test a dynamic tuning system for use at one or more U.S. Navy VLF station(s). DTI explored each of these options, using advanced materials, techniques, and simulation tools to create a cost-effective solution for VLF dynamic tuning. DTI utilized significant internal experience and specific familiarity with VLF systems, and is highly cognizant of the importance of controlling carrier frequency harmonics and modulation sidebands. This was sub sequentially demonstrated in a RIF program for the U.S. Navy in 2019.
N152-098 Undersea Power Converter
DTI has developed and fielded a significant advance in remote (undersea) power network technology using high-voltage, solid state DC-to-DC power conversion. These units have been undersea for over ten years as part of the National Science Foundation Ocean Observatories Initiative Region Scale Nodes. On-shore power supplies provide medium-voltage (MV) DC power to an undersea power cable hundreds of kilometers-long operating at 10 kV and up to 100 kW. At each undersea node, electrical power is shared in a parallel architecture with a high-frequency DC-to-DC down-converter at 375 VDC at up to 10 kW. Power delivered at this low voltage is available to support a wide range of sensors, electronics, repeaters, motors, or remotely operated vehicles. Since, in a parallel architecture, direct connections to the 10 kVDC power cable can be made at any point, and in any potential configuration, down-conversion nodes can be arbitrarily located. This is a significant advance over alternative serial systems, where each node imposes a fixed voltage drop on the cable, limiting the number and configuration of potential nodes.
N162-109 Heavy Payload and High Velocity Electromagnetic Launcher
Use of electromagnetic energy to accelerate payloads has significant advantages over conventional methods such as chemical propellant, steam, or compressed air. Systems can be safer, lower wear, lower maintenance and can potentially achieve higher velocities than conventional methods. Tailoring of launch velocities and launch velocity profiles over a wide range is also readily done. The key to effective electromagnetic launchers is the creation, conversion, and delivery of extremely high peak powers (in the multi-megawatt to multi-gigawatt range) to the payload in a safe, reliable, long lived, and efficient manner. The coil gun approach being developed by DTI under this SBIR met these goals; there is none of the high current sliding contact associated with railgun power delivery; therefore, the launcher (barrel and coils) can be built to have minimal (theoretically near-zero) wear. Solid state electronics and modern energy storage capacitors have the potential for long lives as well. DTI is advancing this technology in two categories, heavy payloads accelerated to modest velocities and light payloads to high (supersonic / hypersonic) velocities.
N162-119 Megawatt Power Converter
DTI developed a compact 6.5 kV, 1.2 Megawatt average power capacitor charging SiC Power Converter, utilizing the benefits of SiC devices to achieve a power density greater than 4.8 MW/m3 (Figure 2). This design provided almost twice the power density of the 300 kW converters delivered to NSWCDD and over ten times that of commercially available units. The 1.2 MW converter continuously charges eighteen 325 kJ capacitor loads (5.8 MJ total) in five seconds, at up to ten rounds per minute. Ten of these converters, with a combined volume of less than three cubic meters, will charge a 50 MJ bank at continuous repetition rate. DTI is building prototype Power Converters for future evaluation and qualification.
U.S Air Force
AF171-089 High Voltage (HV) Fireset Systems and Subsystem Component Level Designs
Fireset systems are used to safely and efficiently conduct detonation research in order to characterize and optimize the performance of explosive trains for future weapon systems. DTI designed and built the power system and the performance will be proven at Battelle's facilities with energetic materials. The fundamental innovations proposed were: (1) a multichannel rail gas spark gap switch, (2) an extremely low inductance stripline interconnect, and (3) high current, low inductance capacitors. This research significantly contributes to the improved performance and safety with respect to the handling and reliability of energetic materials, which benefits military personnel in the field as well as civilians who come into close proximity to unexploded ordnance. DTI is a leader in the high voltage, pulsed power field. Battelle has extensive laboratory facilities for testing all facets of ordnance and energetic materials.
AF151-013 Materials and Designs for Compact High-Voltage Vacuum Insulator Interfaces
DTI proposed to develop a compact short-pulse high voltage insulator through management of the electric field gradients over the insulation distance and selection of materials that are resistant to surface breakdown initiation. Electric field gradient management is accomplished by placing conductors at regular intervals along the insulation path of the insulator. DTI proposed the voltage grading be performed by a continuous conductor spiral as opposed to the more conventional few concentric rings. This structure has the potential to be simpler to construct and also provides a DC short circuit across the output between pulses, thus bleeding off residual charge automatically. For short pulses the inductance of this spiral insures ensures that the current through it is small compared to the load current .
AF162-009 Electric Propulsion for Dual Launch
DTI developed a low-cost, small size, high performance Magnetic Induction Plasma (MIP) engine enabled by advanced solid state switching technology. We proposed to design, fabricate, and test a prototype system. We designed and tested an electrodeless plasma source; model electromagnetic and plasma behavior to inform design of the thruster; designed high power solid state power electronics to power and control the thruster; fabricated and tested at our facility; as well as, tested the engine at more sophisticated facilities operated by the Air Force.
AF171-113 Solid State Amplifier / Transmitter Replacement for Travelling Wave Tube (TWT) Technology
DTI successfully designed and demonstrated a unique, integrated, L-band, 32.5 kW, solid state power amplifier with GaN transistors. This advanced concept radically simplifies solid state transmitters, delivers long term reliability, graceful degradation, and, by combining multiple units, can be easily scaled to very high power levels (200 kW). This solid state amplifier consisted of three power modules in an assembly that can accept up to 16 modules, with both power and bandwidth increasing proportionally to the number of modules. The amplifier achieved an efficiency of 62%, approximately double the efficiency of present day VEDs used for high power RF amplifiers, and a 90 MHz bandwidth. Since both power and bandwidth scale with the number of modules, a fully populated assembly can produce power in excess of 40 kW with a bandwidth up to 200 MHz. This high efficiency solid state amplifier, with its high efficiency, long-lived components, graceful degradation, scalability, absence of high voltage and cumbersome support circuitry has the potential to dramatically decrease the operating cost and increase the up-time of radar systems.
AF18B-T014 X-ray Cinematography for Explosive Events
In the Phase I effort, DTI developed an affordable scalable, single anode, multiple pulse flash X-ray source that can be used to make high resolution X-ray movies of explosive and high-speed tests. The new source eliminates parallax, creates images of closely-timed x-ray pulses, and capitalizes on recent advances in very high speed cameras to provide many frames of high resolution images. The unique combination of advanced source generation and imaging capabilities in the prototype system provides an x-ray cinematography solution to increase the information quality and quantity of explosive events and high-speed dynamic processes and reduces the overall cost of explosives system development. DTI is currently working on the Phase II effort.
Army
A16-015 Innovative, Shock-load Resistant Pulsed Power Supply
Electro-thermal-ignition (ETI) technology increases accuracy and muzzle energy of present and future tank, artillery, and close-in weapon system guns by improving the predictability and repeatability of the ignition, and rate of expansion, of propellants inside the barrel. A compact, barrel-mounted pulsed power system poses survivability challenges for subassembly components. Electrical components must be designed to meet high-shock performance requirements. DTI developed a shock-rated system capable of supplying ETI pulsed power to the gun breech, and delivered it to Picatinny Arsenal.
DARPA
SB171-010 Ultra-Compact Power Conditioning System for High Power RF Transmitters
Vacuum Electronic Devices (VEDs) represent the most compact and efficient means of generating high power RF available today. Unfortunately, the legacy electronics required to operate these VEDs remain large, heavy, and often unreliable. The transition to solid state, high voltage electronics, spearheaded by DTI over the last 20 years, has improved VED transmitter reliability by more than an order of magnitude. The overall size and weight of these transmitters has only marginally improved over the legacy designs, however. Continued use of high power VEDs in military systems demands more compact, lightweight transmitters. DTI has prototyped a highly compact 30 kW, 20 kV Ultra-Compact VED Transmitter (UCT) at over 90% efficiency, and demonstrated the key switching and transformer / multiplier subsystems. This positions us to qualify the design for production and fielding of these systems in Phase III.
DEPARTMENT OF ENERGY
Topic 25d (Section 2.4 AF RF Cavity Topic) High Power Solid State Resonant Cavity Amplifier
High performance solid state transmitters are needed to power RF cavities at superconducting ion linear accelerators and electron beam light source facilities. Existing solid state transmitters are very complex and too expensive. DTI designed a solid state amplifier to compete with microwave vacuum tubes at increased power levels up to 100 kilowatts. A single cavity system reached 15 kW at 66% efficiency. This innovation brings favorable cost scaling with increased power and improved reliability and maintainability.