San Pedro, CA, October 6, 2000 -- Engineers at General Atomics in San Diego, California are using Intusoft's ICAP/4Windows analog and mixed signal circuit simulation software to design a prototype Electromagnetic Aircraft Launch System (EMALS) Program for the U.S. Navy. The goal is to replace steam catapults with electromagnetic motors to permit faster and heavier aircraft to operate off the Navy's next generation CVNX aircraft carriers.
A linear electric motor is the centerpiece of the EMALS systems design. It must be able to accelerate a next-generation airplane to launch speed. The system employs state-of-the-art power electronics, energy storage and linear motor technologies to produce significant improvements over existing steam powered catapults. The electromagnetic system promises to increase launch performance and eliminate the hazards and maintenance requirements associated with today's high-pressure, high-temperature steam-driven catapult systems.
The EMALS system employs rotational energy storage alternators to supply high-frequency power to the linear motor through a PWM Inverter. The linear motor takes the average power from the Inverter and releases it in a short pulse, which accelerates the aircraft for launch. The Inverter is the pivotal technology enabling EMALS to become a reality aboard ship. It's power electronics enable efficient operation by turning on only the coils that can affect the launch at a particular time rather than the entire motor at once. The inverter is a naturally commutated bridge circuit, which provides a peak current output of several thousand Amps for a launch.
"Within the last year, high powered semiconductors became practical enough to use in building this system," says Terry Smith, Staff Engineer with the Advanced Technology Group of General Atomics. Smith is using Intusoft's SPICE-based circuit simulation program to model motor and inverter connections, to determine cable and motor operational parameters, and to analyze how currents and voltage flow through the system. "ICAP4/Windows allowed us to easily design first cut models, and to test our assumptions and ensure their accuracy," says Smith.
The ICAP/4Windows package combines a schematic entry tool, interactive Spice-based simulator and waveform analyzer with a library of up to 14,000 models. The schematic entry tool allows a user to place objects on different layers to configure the combination he wants to simulate. Circuit performance is measured using ICAP's simulator. Over 100 commands and functions are available to help engineers run simulations, cross probe simulation data and extract important design information.
General Atomics is one of two contractors awarded the design and prototype development phase contract for the EMALS system. Prototype testing will be conducted at the Naval Air Warfare Center Aircraft Division at Lakehurst, New Jersey in 2003 after which the Navy expects to award a single engineering and manufacturing contract.
ICAP/4Windows is produced by Intusoft, a San Pedro, California-based developer of award-winning software tools for analog and mixed-signal circuit design, analysis and test automation. For more information on Intusoft and its products, consult the company's web site at http://www.intusoft.com.