The invention relates to a turbine generator set comprising a turbine and a generator coupled to each other without a step-down gear box, and a static frequency converter connected in series between said generator and an AC electricity grid having a given operating frequency, said static frequency converter operating while the turbine generator set is generating electricity to convert the frequency of the voltage and of the current delivered by the generator into the given operating frequency of the AC electricity grid. According to the invention, while the turbine generator set is being started, said static frequency converter powers the generator which operates as a motor so as to ignite the combustion chambers of the turbine, by taking power from the AC electricity grid.
A power plant includes a gas turbine coupled to an electric generator. The electric generator can be connected to a high-voltage network through a generator switch and can be operated as a motor for the start-up of the gas turbine. The electric generator can also be connected to a static starting device for the run-up of the gas turbine. The static starting device is connected to a medium-voltage network which is provided for the auxiliary service of the power plant. The auxiliary voltage, provided in another way, of the medium-voltage network, produces a variable supply voltage for the generator operated as a motor. In such a plant, reduced circuit complexity is achieved by the fact that the static starting device is designed in such a way or can be activated in such a way that, after the run-up of the gas turbine, the static starting device itself produces the auxiliary voltage of the medium-voltage network from the voltage delivered by the generator.
A method for controlling a power plant which delivers electrical power to an electrical grid. The grid has a grid frequency which fluctuates around a nominal frequency. A power output of the power plant is controlled as a function of a control frequency, in such a manner that the power output is increased when the control frequency decreases below the nominal frequency. On the other hand the power output is decreased when the control frequency rises above the nominal frequency. The grid frequency is continuously measured. The measured grid frequency is averaged to give, as a moving average, a slowly varying averaged trend frequency which is characteristic of the long term behavior of the grid frequency. The averaged grid frequency is used as the control frequency, if the measured grid frequency lies within a predetermined band around the averaged grid frequency. The measured grid frequency is used as the control frequency, if the measured grid frequency lies outside the predetermined band.
An electrical system for a turbine/alternator comprising a gas driven turbine and permanent magnet alternator rotor rotating on a common shaft and comprising an inverter circuit connected either to an AC output circuit or the stator windings of the alternator. A control circuit during start-up mode connects the inverter circuit to the stator windings of the alternator and during the power generation mode it switches and connects the inverter circuit to the AC output circuit. Thus, during the start-up mode, the alternator functions as a motor to raise the speed of the turbine to a safe ignition speed and in the power generation mode the system provides power through the AC output circuit, electrical power having a frequency and voltage unrelated to the rotational speed of the turbine/alternator.
A system and method for generating power includes a motor assembly, an inertia-assisted, torque-enhanced gearbox, including a flywheel assembly and a clutch assembly, and a generator assembly. The motor assembly is used to drive the flywheel assembly up to the generator's designed operating speed. When the flywheel assembly reaches the generator operating speed, the clutch assembly engages and connects the flywheel assembly to the generator assembly. When the flywheel assembly is connected to the generator assembly, it supplies the generator with the starting torque required to start the generator. The motor assembly then supplies the torque necessary to operate the flywheel assembly and the generator assembly at the generator's designed operating speed. When the generator encounters peak loads, the flywheel assembly also supplies peak load torques to the generator assembly. The generator assembly is operable to supply power to a load connected to the generator assembly.
A power generating apparatus has a power generator 4 for generating AC power, a gas turbine engine 2 for driving the power generator 4, and an inverter device 5 for converting the AC power into commercial AC power. The power generating apparatus includes an interconnection switch S.sub.1 for connecting an output of the inverter device 5 with a commercial AC power supply system, a first voltage detector 46 for detecting a DC power supply voltage Vdc-in of the inverter device 5, and a second voltage detector 33, 45 for detecting a full-wave rectification voltage of the commercial AC power supply system. The power generating apparatus also includes an interconnection control part 18 for closing the interconnection switch S.sub.1 when the DC power supply voltage of the inverter device 5 exceeds the full-wave rectification voltage of the commercial AC power supply system.
