AC/DC converter topologies for the Space Station

A new class of AC/DC converter topologies (Type-1 converters) is described, suitable for use in an advanced single-phase sine-wave voltage, high-frequency power distribution system, of the type that was proposed for a 20 kHz Space Station primary electrical power distribution system. The converter comprises a transformer, a resonant network, a current controller, a diode rectifier, and an output filter. The input AC voltage source is converted into a sinusoidal current source using the resonant network. The output of this current source is rectified by the diode rectifier and is controlled by the current controller. The controlled rectified current is then filtered by the output filter to obtain a constant voltage across the load. Three distinct converter topologies, Type-1A, Type-1B, and Type 1-C, are described, and their performance characteristics are presented. All three types have a close-to-unity rated power factor (greater than 0.98), low total harmonic distortion in input current (less than 5%), and high conversion efficiency (greater than 96%)     

Improved Mapham's inverter for HF space power conversion

An improved Mapham's inverter for high-frequency space power conversion is presented. The proposed inverter system uses a starting commutator to facilitate the starting of the conventional inverter under full-load conditions. The load conditions which cause the starting commutation failure of a conventional Mapham inverter are established. An improved inverter system to overcome the starting failure is presented and analyzed. The behavior of the improved inverter has been simulated to verify the predicted performance at start-up. A steady-state analysis of the inverter is presented, and the performance characteristics are derived