Electromechanical Actuation for Thrust Vector Control Applications
Abstract
At present, actuation systems for the Thrust Vector Control (TVC) for launch vehicles are hydraulic systems. The Advanced Launch System (ALS), a joint initiative between NASA and the Air Force, is a launch vehicle that is designed to be cost effective, highly reliable and operationally efficient with a goal of reducing the cost per pound to orbit. As part of this Initiative, an electromechanical actuation system is being developed as an attractive alternative to the hydrau ic systems used today. The NASA Lewis Research Center is developing and demonstrating an Induction Motor Controller Actuation System wlth a 40 hp peak rating. The controller will Integrate 20kHz resonant link Power Management and Distribution (PMAD) technology and Pulse Population Modulation (PPM) techniques to implement Field Oriented Vector Control (FOVC) of a new advanced induction motor. Through PPM, multiphase variable frequency, variable voltage waveforms can be synthesized from the 20kHz source. FOVC shows that varying both the voltage and frequency and their ratio (VIF), permits Independent control of both torque and speed while operating at maximum efficiency at any point on the torque-speed curve. The driver and the FOVC will be microprocessor controlled. For Increased system rellablllty, a Built-in Test (BITE) capability will be Included. This involves Introducing testability Into the design of a system such that testing Is calibrated and exercised during the design, manufacturing, maintenance and pre-launch activities. An actuator will be Integrated with the motor controller for performance testing of the EMA TVC system. The design and fabrication of the motor controller is being done by General Dynamics Space Systems Division. The University of Wisconsin-Madison will assist In the design of the advanced induction motor and In the implementation of the FOVC theory. A 75 hp electronically controlled dynamometer will be used to test the motor controller in all four quadrants of operation
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1990
- Accession Number
- ADA578286
Entities
People
- Mary E. Roth
Organizations
- National Aeronautics and Space Administration