Power electronics and controls for air core compulsator

The Center for Electromechanics at the University of Texas (GEM-UT) has been engaged in a large scale effort to develop the power electronics and control systems required to demonstrate a multi-megawatt, full control, SCR based rectifier/inverter and high power SCR closing switch. The ultimate objective of this development effort is to provide high efficiency switching for self-excitation of air core single phase rotating machines and to control the delivery of energy to the final loads. The self-excitation process is initiated by a seed current capacitor followed by active rectification of the compulsator AC output into the field coil. Upon reaching full open circuit voltage, the main closing switch is used to initiate current into the rail gun load. After termination of the gun current pulse, stored field coil energy is returned to the rotor via source commutated, full wave inversion. This paper presents the theory of operation for the complete rectification and inversion cycle, SCR selection criteria, overall design strategy and all available test data. The test results include the testing of individual devices, multiple series/parallel modules, and full system testing if available.<>