Physical Scale Model Alternators as a Pulsed-Power Source Simulator

Pulsed alternators configured as counter-rotating pairs are being considered as a potential pulsed-power source for electromagnetic launchers. The Institute for Advanced Technology is interested in studying the electrical and mechanical characteristics of such a pair of counter-rotating pulsed alternators; however, implementation and experimentation have only been attempted on a single subscale alternator machine that requires extensive laboratory support for operation. As a first step toward testing the electromechanical effects of counter-rotating alternators, two iron-core wound field alternators driven by dc motor prime movers were obtained and implemented as a scale model pulsed-power source simulator. These alternators were originally designed and fabricated at the Massachusetts Institute of Technology as physical scale models of 900-MVA utility alternators, which exhibit the same per-unit reactance and time constants as the full-scale machines. A digital signal processor was integrated into a real-time control system designed to maintain the two generators as an electrically coupled, counter-rotating generator pair. This paper documents the control system design, the incorporated control algorithm, and the automated test setup implemented for experimental data collection