National Aeronautics and Space Administration

Glenn Research Center

Linear Alternator Research

Linear Alternator Test Rig

Linear Alternator Test Rig

GRC is conducting an in-house technology project to support the Department of Energy (DOE), Lockheed-Martin (LM), and Sunpower in developing an Advanced Stirling Radioisotope Generator (ASRG) for possible use on future NASA space missions.

As a part of this in-house effort, GRC is conducting research on linear alternators to assist in developing the Stirling power convertor for space qualification and mission implementation.  An Alternator Test Rig (ATR) was assembled to facilitate this research.  The ATR can be used to test 100W class linear alternators, and is a variable stroke (up to 13mm) and variable frequency (up to 120 Hz) linear dynamometer.  The performance of the alternator being tested is typically mapped at steady-state conditions over a range of temperatures, mover amplitudes, and linear alternator loads.  Performance measurements that are typically made include the linear alternator terminal voltage, current, and power.  A load cell positioned between the drive motor of the ATR and the test alternator is used to measure the alternator mechanical input power.  The alternator efficiency and power factor are calculated from these measurements.