Joint Tactical Electric Vehicle
The hybrid Joint Tactical Electric Vehicle (JTEV), designed and built for the Marine Corps, demonstrates AeroVironment’s ability to rapidly develop an advanced, fully integrated system. This stealthy, high mobility vehicle was a ground- up design requiring the development of traction motor inverters, drive train, an actively cooled battery package equipped with an advanced battery management system, an engine-driven primary propulsion generator with converter, and a system controller containing hybrid electric control algorithms, vehicle control and instrumentation. The JTEV was designed and fabricated in 12 months. The success of this project enabled the Marine Corps/DARPA to begin the Reconnaissance Surveillance Targeting-Vehicle (RST-V) program, for which AeroVironment was contracted to develop a preliminary design.
GM Impact Electric Car
AeroVironment provided systems engineering, powertrain, mechanical design, thermal control and fabrication for the world’s first practical electric car, the GM Impact. With an urban driving range of more than 100 miles and a top speed of 80 mph, the Impact accelerated from 0 to 60 mph in just 8.0 seconds with a total output of 110 hp. Its drag coefficient of 0.19 is roughly half that of current production automobiles. The EV1’s design drew heavily off of the Impact and was developed, produced and sold by GM.
AeroVironment also designed and constructed the two AC induction motors for the Impact; one for each front wheel. The motors, which feature an integral single speed planetary gear reduction, operate at efficiencies of 90 to 95 percent over most operating speeds and torques encountered in an automobile. At the Impact’s governor-limited top speed of 80 mph, the motor turns at 11,900 rpm. The motor and electronics system of the Impact also provide regenerative braking to improve urban driving cycle range.
Unmanned Sea Surface Vehicle Sensor Power Source
AeroVironment, under contract to Naval Surface Warfare Center, Carderock Division (NSWCCD), investigated the feasibility of using a dedicated diesel engine in a hybrid configuration with an ultracapacitor or battery pack to provide payload power for ten-day missions for Unmanned Sea Surface Vehicles (USSVs). USSVs require a low signature power source for on-station operation of sensor payloads. The power source must have a high energy density, be reliable, require low maintenance, and be able to withstand salt spray and heavy seas for ten-day missions. In addition, the payload duty cycle can require 25 kW peak loads for ten seconds out of every minute, with constant loads of one kilowatt. AV also looked at using a low temperature PEM fuel cell operating on pure hydrogen and air to provide the continuous base power in a fuel cell hybrid configuration for missions requiring low signatures.
AeroVironment, working with General Motors and GM’s Hughes Electronics, conceived, designed and built the breakthrough solar powered Sunraycer to compete in the inaugural 1,950 mile World Solar Challenge road race across Australia in November 1987. Starting from scratch, the team developed a vehicle that incorporated innovative materials and technologies to enable it to generate 1,500 watts of electricity at full sunlight, and travel at up to 65 miles per hour. The Sunraycer’s average speed during the race was over 40 miles per hour, allowing it to complete the course in 5.2 days, a full 2 days ahead of the second place finisher. In 1988 the Sunraycer set a new speed record for solar powered land vehicles by exceeding 75 miles per hour. The success of the Sunraycer led to AeroVironment’s subsequent development of the GM Impact electric car, the prototype for GM’s EV-1. This program, in turn, resulted in the development of AeroVironment’s Power Processing Products, as well as its PosiCharge fast charge systems.
Direct Lamination Cooling for Transformers, Inductors, & Motors
AeroVironment developed innovative cooling technologies to increase motor efficiency and decrease motor mass, volume, and cost. A major limiting factor in the design and performance of electric motors and other devices, such as inductors and transformers, is the ability to transfer heat from the device. The steel lamination incorporated into motors generate heat caused by magnetic losses and by conduction from the copper current-carrying windings embedded in the magnetic device. Conventional technology requires that these magnetic elements transfer their heat through conduction to a heat sink or a special coldplate, resulting in added material and cost. AV developed an alternative cooling approach where cooling fluid passes directly through the lamination assembly, thereby eliminating the heat sink or coldplate.
Ironless Core Motor
AeroVironment developed its Ironless Motor technology to support Lockheed Martin’s High Altitude Airship program, which required highly efficient and light electric motors to move and keep the airship on station at high altitudes. Employing innovative new winding strategies and tools, AeroVironment designed the Ironless Motor to take full advantage of new and stronger magnetic materials, such as high temperature Neodymium Iron Boron (NdFeBr), as they come into existence. Since iron or amorphous-based machines will suffer from higher losses and more core saturation at these high flux levels, only an ironless machine can take full advantage of such strong magnets. The other major advantage of the ironless machine is its superb part load efficiency of up to 98%. AeroVironment’s Ironless Motor technology may offer a unique value proposition to numerous applications and industries including environmental management, marine propulsion and micro motors.