Abstract: In high-efficiency power source applications, AC power is converted to DC power, which is isolated from the source and regulated. A level of performance is achieved that exceeds the power quality requirements of MIL-STD-704 over the extended frequency range, typically from about 360 Hz to 800 Hz. While high-efficiency and low-weight of the invention, among other benefits, are advantageous primarily in airborne systems, its use can be extended to terrestrial applications as well. The isolation, regulation and the main power processing are achieved by low-weight, high-frequency conversion stages arranged in 2 channels that produce the line harmonic content typical of the 12-pulse rectification. Control of the conversion stages provides effective rejection of line transients, while output ripple voltage is typically an order of magnitude lower than in conventional transformer rectifier units.

Abstract: In high-efficiency power source applications, AC power is converted to DC power, which is isolated from the source and regulated. A level of performance is achieved that exceeds the power quality requirements of MIL-STD-704 over the extended frequency range, typically from about 360 Hz to 800 Hz. While high-efficiency and low-weight of the invention, among other benefits, are advantageous primarily in airborne systems, its use can be extended to terrestrial applications as well. The isolation, regulation and the main power processing are achieved by low-weight, high-frequency conversion stages arranged in 2 channels that produce the line harmonic content typical of the 12-pulse rectification. Control of the conversion stages provides effective rejection of line transients, while output ripple voltage is typically an order of magnitude lower than in conventional transformer rectifier units.

Abstract: An electrical AC-DC power conversion system featuring 18-pulse rectification and utilizing a low weight wye-connected phase shifting autotransformer (500) supplied from a 3-phase AC source (40) through a 3-phase line reactor (41). The current harmonic distortion is less that 5% and can be further reduced to 3% level by the use of additional suppression devices (eg., chokes) which are often required in aerospace applications. The transformer (500) includes three sections (501) each spaced 120° electrically apart, wherein each section (501) includes a main winding (510) and a pair of phase shift windings (540). The main winding (510) has a neutral end connected to a floating neutral point (502) and a source end (514) is connected to one phase (1, 2, 3) of the three-phase power source (40). The pair of phase shift windings (540) each include a second winding (520) and a third winding (530) connected in series and arranged to generate phase outputs (4-9) of the autotransformer (500).

Abstract: An electrical AC-DC power conversion system featuring 18-pulse rectification and utilizing a low weight wye-connected phase shifting autotransformer (500) supplied from a 3-phase AC source (40) through a 3-phase line reactor (41). The current harmonic distortion is less that 5% and can be further reduced to 3% level by the use of additional suppression devices (eg., chokes) which are often required in aerospace applications. The transformer (500) includes three sections (501) each spaced 120° electrically apart, wherein each section (501) includes a main winding (510) and a pair of phase shift windings (540). The main winding (510) has a neutral end connected to a floating neutral point (502) and a source end (514) is connected to one phase (1, 2, 3) of the three-phase power source (40). The pair of phase shift windings (540) each include a second winding (520) and a third winding (530) connected in series and arranged to generate phase outputs (4-9) of the autotransformer (500).

Abstract: A system of multiparalleling a set of voltage source power converters is provided in which any one of the converters may assume the role of a master or a slave. The system can survive the failure of either the master or any of the slaves. A main controller issues PWM command signals to control the current generated in the power converters. The PWM command signal is modified for each power converter such that all of the converters produce the substantially the same current, the current generated in the master unit being used as a reference. A current feedback signal is used to provide the main controller with an accurate estimate of the total current generated by the system.

Abstract: A high-frequency converter of the bridge circuit type includes a snubber circuit connected across the output terminals of the bridge for connecting pairs of charged switching capacitors with an inductor upon the switching of the transistors of the bridge to their OFF conditions. The snubber circuit includes parallel-connected oppositely-poled additional switching devices with reverse blocking characteristic connected in series with the inductor, whereby the energy of the discharging switching capacitors is temporarily stored in the inductor in a substantially loss-free manner, and is pumped in the same direction to assist in the charging of the other capacitors.