Honeywell International Inc.

Alliedsignal Inc.

Edward L Johnson

Evgeni Ganev

William Warr

Cuong Nguyen

Brian T Branecky

William H Warr

A power conversion system having a DC power distribution bus includes multiple power converters connected to the DC power distribution bus with modulation frequencies synchronized so that providing phase shifts between the different modulations has the effect of compensating voltage and current ripples, e.g., reducing voltage fluctuations, across the DC bus. Power conversion may be controlled using space vector modulation implemented, for example, by any of a variety of pulse width modulation schemes. Phase shifts in which nulls of the modulation cycles of different converters do not overlap (in the time domain) may be particularly effective for DC bus voltage ripple compensation. The novel method for DC bus voltage ripple compensation may be implemented by programming a digital signal processor to control the power converters.

Intelligent method for DC bus voltage ripple compensation for power conversion units

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%.

Overspeed protection for sensorless electric drives

A motor controller for brushless motors operates an inverter in a current-controlled mode for low motor speeds and in a voltage-controlled mode for high motor speeds. By switching from the current-controlled mode to the voltage-controlled mode at higher speeds, the motor can be designed at maximum efficiency, and minimum weight, cost and volume.

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Torrance, CA, United States of America

Edward L Johnson