A method for monitoring a starting sequence of a turbomachine including a compressor provided with a rotor, a starter capable of rotating the rotor and a combustion chamber, the method including determining a bracketing of a time zone during which the ignition instant takes place, the bracketing being defined by, on the one hand, a lower limit corresponding to an event necessarily taking place before the ignition instant and an upper limit corresponding to an event necessarily taking place after the ignition instant; and determining between the lower limit and the upper limit, a break point in the variation with time of the measurement signal, this break point corresponding to an ignition instant of the air-fuel mixture in the combustion chamber.

A method for monitoring a starting sequence of a turbomachine including a compressor provided with a rotor, a starter capable of rotating the rotor and a combustion chamber, the method including determining a bracketing of a time zone during which the ignition instant takes place, the bracketing being defined by, on the one hand, a lower limit corresponding to an event necessarily taking place before the ignition instant and an upper limit corresponding to an event necessarily taking place after the ignition instant; and determining between the lower limit and the upper limit, a break point in the variation with time of the measurement signal, this break point corresponding to an ignition instant of the air-fuel mixture in the combustion chamber.

Methods and systems for starting an aircraft gas turbine engine are described. The method comprises, in a first phase of a startup upon receipt of a start request, modifying a first set of engine control parameters to cause light-up; in a second phase of the startup, modifying a second set of engine control parameters to set conditions for light-around; and in a third phase of the startup, modifying a third set of engine control parameters to propagate a flame around a combustor of the gas turbine engine.

Methods and systems for starting an aircraft gas turbine engine are described. The method comprises, in a first phase of a startup upon receipt of a start request, modifying a first set of engine control parameters to cause light-up; in a second phase of the startup, modifying a second set of engine control parameters to set conditions for light-around; and in a third phase of the startup, modifying a third set of engine control parameters to propagate a flame around a combustor of the gas turbine engine.

A hybrid electric propulsion system includes a gas turbine engine having a low speed spool and a high speed spool. The low speed spool includes a low pressure compressor and a low pressure turbine, and the high speed spool includes a high pressure compressor and a high pressure turbine. The hybrid electric propulsion system also includes an energy storage system, an electric motor configured to augment rotational power of the high speed spool, and a controller. The controller is operable to detect a start condition of the gas turbine engine, control power delivery from the energy storage system to the electric motor based on detecting the start condition, and provide a compressor stall margin using a power-assist provided by the electric motor to the high speed spool over a targeted speed range during starting of the gas turbine engine.

According to an aspect, a bowed rotor sensor system for a gas turbine engine is provided. The bowed rotor sensor system includes a bowed rotor sensor operable to transmit a sensing field in an observation region and receive a signal indicative of a gap between an air seal and a blade tip within the gas turbine engine. The bowed rotor sensor system also includes a controller operable to monitor a plurality of gap data from the bowed rotor sensor indicative of the gap between the air seal and the blade tip of a plurality of blades passing through the observation region and determine a bowed rotor status of the gas turbine engine based on the gap data.

According to an aspect, a bowed rotor sensor system for a gas turbine engine is provided. The bowed rotor sensor system includes a bowed rotor sensor operable to transmit a sensing field in an observation region and receive a signal indicative of a gap between an air seal and a blade tip within the gas turbine engine. The bowed rotor sensor system also includes a controller operable to monitor a plurality of gap data from the bowed rotor sensor indicative of the gap between the air seal and the blade tip of a plurality of blades passing through the observation region and determine a bowed rotor status of the gas turbine engine based on the gap data.

Methods and systems for detecting an abnormal start of a gas turbine engine are described. Speed data points are sampled from a sensor associated with the engine in accordance with a sampling rate, the speed data points being indicative of a rotational speed of a gas generator of the engine during engine start. The speed data points are continuously stored during the engine start. Previously-obtained speed data points which are older than an abnormal start delay are discarded. An abnormal engine start event is detected by comparing a first one of the stored speed data points with a second one of the stored speed data points, the second one of the stored speed data points obtained before the first one.

Methods and systems for detecting an abnormal start of a gas turbine engine are described. Speed data points are sampled from a sensor associated with the engine in accordance with a sampling rate, the speed data points being indicative of a rotational speed of a gas generator of the engine during engine start. The speed data points are continuously stored during the engine start. Previously-obtained speed data points which are older than an abnormal start delay are discarded. An abnormal engine start event is detected by comparing a first one of the stored speed data points with a second one of the stored speed data points, the second one of the stored speed data points obtained before the first one.

This disclosure generally relates to power generation methods and systems based on gas turbine engines, and particularly to mobile and adaptive power generation systems and methods based on gas turbine engine for supplying mechanical and/or electrical power for fracturing operations at an oil wellsite. Various systems, platforms, components, devices, and methods are provided for flexibly and adaptively configure one of more gas turbines, hydraulic pumps, and electric generators to support both fracturing and electric demands at a well site. The disclosed implementations enable and facilitate a mobile, adaptive, and reconfigurable power system to provide both mechanical and electric power for hydraulic fracturing operation.