The present application discloses a fuel system for a gas turbine engine. The engine includes a main alternating current electrical generator driven by an engine shaft such that the electrical output frequency of the electrical generator varies in dependence on shaft rotational speed. The fuel system includes a variable flow fuel pump for providing a fuel flow to the engine, a frequency and/or voltage controller configured to provide electrical power having at least one of a predetermined output frequency and a predetermined voltage, and a variable speed electric motor configured to drive the fuel pump. The electric motor includes an induction motor having a stator and at least a first rotor, the stator having first and second sets of stator windings. Each set of stator windings is configured to impart a torque on the rotor in use.

The gas turbine power generation system of the present invention repeats either the supply or absorption of power, in addition to generating power. A frequency converter for converting a frequency of power is connected between the rotating electrical machine and a power system via a power line, and a controller obtains a request for an output from the gas turbine power generation system and controls the combustor on the basis of the request. With respect to the frequency converter, the controller performs frequency converter control for changing the rotational speed of the rotating electrical machine on the basis of the request. The rotating electrical machine supplies or absorbs power in accordance with the change in the rotational speed. With respect to the speed adjustment mechanism, the controller performs speed adjustment mechanism control for setting the rotational speed to a reference value.

The disclosure relates to optimization of gas turbine power plant response during power system transients. In certain embodiments, systems, methods, and apparatus can control a power generating system by using the reactive components of the current and the reactive components of the voltage and the magnitude of the voltage at the generator terminals of a gas turbine generator system. In one embodiment, a system can identify a power system fault based on at least three conditions occurring for a specified duration and at substantially the same time: (1) an increase in the reactive current, (2) a decrease in the magnitude of the voltage, and (3) an increase in the reactive power. In one embodiment, a power system can further detect a remote breaker open (RBO) condition, and distinguish a RBO condition from a power system fault condition.

A method for synchronising a turbine with an AC network having a network frequency, having the following steps: A) accelerating the turbine up to a stated rotational speed, without taking into consideration a difference angle between the turbine and the AC network; B) detecting a difference angle between the turbine and the AC network; C) accelerating or decelerating the turbine in such a way that the differential speed follows a target trajectory, wherein the target trajectory is a trajectory that indicates a target rotational speed depending on the detected difference angle, such that a target angular position that is suitable for a synchronous supply is achieved between the turbine and AC network.

A trim ring gear for use in an integrated drive generator has a ring gear body extending between a first end and a second end. Outer gear teeth are formed on an outer surface, and inner gear teeth are formed on an inner surface. The outer tooth roll angle at A is between 16.0 and 17.5, at B is between 17.5 and 190, at C is between 22.0 and 23.5, and at D is between 23.0 and 24.5. The inner tooth roll angle at A is between 31.5 and 33.0, at B is between 30.0 and 31.5, at C is between 25.5 and 27.0, and at D is between 24.0 and 25.5. An integrated drive generator, and a method of replacing the trim ring gear are also disclosed and claimed.

A power-on/off command is output to a breaker for switching when a frequency difference between a plurality of electric power supply sources is within a predetermined range and a phase difference between the plurality of electric power supply sources is within a predetermined range, in switching of electric power supply between the plurality of electric power supply sources. A generator drive rotation speed of a transmission device is feedback controlled so that the frequency difference is maintained at a value within the predetermined range and the phase difference is maintained at a value within the predetermined range when the detected frequency difference is within the predetermined range and the detected phase difference is within the predetermined range. A generator rotation speed command is calculated by adding to the rotation speed command of the transmission device an output value obtained by subjecting the detected phase difference to a proportional-integral-control.

There are described methods and systems for synchronizing at least two generators for an engine. A first generator is mechanically coupled to the engine. A power source is connected in parallel to the first generator and to a second generator, the second generator mechanically uncoupled from the engine, the power source connected across a same respective phase of a stator in the first generator and the second generator. Power from the power source is applied to the first generator and the second generator to align a respective rotor to the respective phase in each generator and cause the first generator and the second generator to be in-phase. The second generator is then mechanically coupled to the engine.

Herein provided are methods and systems for controlling an engine having a variable geometry mechanism. A power level difference between a requested engine power level and a current engine power level is determined at a computing device. The power level difference is compared to a predetermined power threshold at the computing device. When the power level difference exceeds the predetermined power threshold, a position control signal for changing a position of the variable geometry mechanism is generated and output at the computing device, the position control signal generated based on a requisite bias level, the requisite bias level being based on the power level difference.

A propulsion and electric power generation system includes a dual-spool turbofan gas turbine engine and an electrical generator. The dual-spool turbofan gas turbine engine includes at least a low-pressure turbine coupled to a fan via a low-pressure spool. The low-pressure turbine is configured to generate mechanical power. The electrical generator is directly connected to the low-pressure spool and is disposed downstream of the low-pressure turbine. A first fraction of the mechanical power generated by the low-pressure turbine is controllably supplied to the fan for propulsive power generation (P.sub.t). A second fraction of the mechanical power generated by the low-pressure turbine is controllably supplied to the electrical generator for electrical power generation (P.sub.e). A ratio of P.sub.e to P.sub.t (P.sub.e/P.sub.t), during operation of the dual-spool turbofan gas turbine engine, controllably spans a range from less than about 0.06 to at least 0.18.

A gas turbine system includes a combustor configured to combust an oxidant and a fuel in the presence of an exhaust gas diluent to produce combustion products, an oxidant supply path fluidly coupled to the combustor and configured to flow the oxidant to the combustor at an oxidant flow rate, and a turbine configured to extract work from the combustion products to produce an exhaust gas used to generate the exhaust gas diluent. The turbine causes a shaft of the gas turbine system to rotate when the work is extracted from the combustion products. The system also includes an electrical generator that generates electrical power in response to rotation by the shaft, and a controller that performs load control in response to a target load by adjusting the oxidant flow rate along the oxidant flow path as a primary load control parameter.