Abstract: A multiple-winding induction machine may be used to obtain a reduced-speed-variation electric drive when using a variable-frequency power distribution system. Each winding may have a different number of poles. The winding with the smallest number of poles may operate the machine at the lowest bus frequency, while the winding with the largest number of poles may operate the machine at the highest bus frequency. In one embodiment, a third winding, with a middle number of poles, may operate the machine at the middle frequency ranges. The speed of the induction machine is a function of the electrical frequency and the number of the winding poles. Therefore, the operating speed range can be reduced by switching from one winding to another. According to the present invention, windings with different numbers of poles can be designed to achieve different reductions in speed variation.

Abstract: Overspeed protection of sensorless electric drives is needed in the aerospace industry. Methods for overspeed protection may include software implementations, hardware implementations or combinations thereof. Typical high-speed rotating machinery is designed to sustain overspeed operation of up to 50% beyond maximum normal operation. This requirement leads to substantial penalties in weight and volume. The methods of the present invention may allow for an opportunity to reduce this overspeed design to about 5 to 15%, typically about 7%.

Abstract: A multiple-winding induction machine may be used to obtain a reduced-speed-variation electric drive when using a variable-frequency power distribution system. Each winding may have a different number of poles. The winding with the smallest number of poles may operate the machine at the lowest bus frequency, while the winding with the largest number of poles may operate the machine at the highest bus frequency. In one embodiment, a third winding, with a middle number of poles, may operate the machine at the middle frequency ranges. The speed of the induction machine is a function of the electrical frequency and the number of the winding poles. Therefore, the operating speed range can be reduced by switching from one winding to another. According to the present invention, windings with different numbers of poles can be designed to achieve different reductions in speed variation.

Abstract: Overspeed protection of sensorless electric drives is needed in the aerospace industry. Methods for overspeed protection may include software implementations, hardware implementations or combinations thereof. Typical high-speed rotating machinery is designed to sustain overspeed operation of up to 50% beyond maximum normal operation. This requirement leads to substantial penalties in weight and volume. The methods of the present invention may allow for an opportunity to reduce this overspeed design to about 5 to 15%, typically about 7%.

Abstract: The present invention provides systems and methods that allow for individual power sources to be disconnected and reconnected without interrupting the power supply from the other power sources and that allow for these power sources to provide power at substantially the same electrical parameters such as frequency, phase, and voltage.

Abstract: A bathtub shower accessory comprising a number of shield units, each securable to the tub and shower stall sidewalls in a manner to prevent water from exiting the shower area past the end edges of the shower curtain. The shield units are stackable one on top of the other for the desired height attainment and can include tray compartments on the interior facing side for holding soap, shampoo, toothbrushes, etc., or a towel rack holder.

Abstract: A fast boot computer which has three user-selectable modes of performing POST operations. The user can select full POST or quick POST be performed, as in conventional computers. However, he can also select an intermediate mode, wherein the full POST is performed if and only if a given number of days (as programmed by the user) have elapsed since the last full POST operation. This permits users to set their own trade-off between fast boot operation and maximum reliability.