Hamilton Sundstrand Corporation

Alex Seguritan

Michael E Mehrer

Peter J Suttie

Ravishankar Piramanayagam

Gilles E Marion

Embodiments are directed to modulating a pulse width modulation (PWM) signal, by initializing at least one phase index to an initial value, establishing a set of values in a lookup table that correspond to data points for PWM comparator values that correspond to a given number of samples of a single periodic waveform during a predetermined sampling rate that establishes a table resolution, repeatedly executing the following operations at the predetermined sampling rate: determining a value of a command signal frequency, setting a value to a jump factor equal to the quotient of the value of the command signal frequency divided by the table resolution, progressing the value of the phase index by the value of the jump factor, selecting a value of a commutation vector from the lookup table that corresponds to the phase index, and loading the value of the commutation vector into a corresponding PWM comparator.

Lookup table assisted pulse width modulation

An event-driven starter controller regulates the speed of a gas turbine engine based on detected events. The event-driven starter controller is used to supply motive force to the gas turbine engine prior such that the gas turbine engine is able to ignite (i.e., achieve light-off). In particular, in response to engine speed reaching a defined threshold, the event-driven starter controller causes the speed of the starter motor to ramp or increase through a defined range of speeds suitable for engine light-off (i.e, light-off window). Upon reaching an upper threshold of the light-off window, the event-driven starter controller causes the speed of the starter motor to decrease through the range of speeds suitable for engine light-off. If at any time during the light-off window the event-driven starter controller detects a successful light-off condition, the event-driven starter controller causes the speed of the gas turbine engine to increase toward a second threshold.

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San Diego, CA, United States of America

Alex Seguritan