A method and associated control device for synchronizing a turbine with an alternating current network having a network frequency, having the following steps: A) accelerating the turbine up to a frequency in the range of the network frequency; B) sensing an angle difference between the turbine and the alternating current network; C) sensing a speed difference between the turbine and the alternating current network; D) accelerating or decelerating the turbine such that the turbine follows a desired trajectory, wherein the desired trajectory is a trajectory calculated in advance that indicates, in dependence on the angle difference, a desired speed difference that should be present such that a target angular position between the turbine and the alternating current network suitable for synchronous feed-in is achieved when the speed of the turbine and the speed of the alternating current network correspond.

An apparatus may determine a parameter related to a voltage value at a midpoint terminal of a system power device, and may adjust a voltage applied to a second terminal of the system power device based on the parameter and a reference value. The second terminal may be different from the midpoint terminal.

A method of controlling reactive power in a power generation system that includes a grid and a cross compound turbine generator system having a first turbine arranged to drive a first generator and a second turbine arranged to drive a second generator includes replacing the first turbine with a motor, the motor coupled to the first generator and operable to drive the first generator. The method also includes decoupling the second turbine and the second generator to allow the second generator to rotate separate from the second turbine, connecting an electrical output of the first generator to the second generator, and powering the motor to drive the first generator and to synchronize the first generator to the grid. The method further includes providing electrical power to the second generator from the first generator to power the second generator and synchronize the second generator to the grid and varying an excitation voltage for one of the first generator and the second generator to vary the reactive power output of the first generator and the second generator.

A method of controlling reactive power in a power generation system that includes a grid and a cross compound turbine generator system having a first turbine arranged to drive a first generator and a second turbine arranged to drive a second generator includes replacing the first turbine with a motor, the motor coupled to the first generator and operable to drive the first generator. The method also includes decoupling the second turbine and the second generator to allow the second generator to rotate separate from the second turbine, connecting an electrical output of the first generator to the second generator, and powering the motor to drive the first generator and to synchronize the first generator to the grid. The method further includes providing electrical power to the second generator from the first generator to power the second generator and synchronize the second generator to the grid and varying an excitation voltage for one of the first generator and the second generator to vary the reactive power output of the first generator and the second generator.

Disclosed are a medium and high voltage grid-connected power generation system, a medium and high voltage grid-connected system, and a control circuitry thereof. The voltage of the medium and high voltage power grid is collected through the control circuitry. A power grid amplitude and a power grid phase synchronization signal are obtained, and then sent to an inverter unit through a communication line.

Provided is a method for exchanging electric power with an electricity supply grid that has a grid frequency using a converter-controlled generation unit that may be a wind power installation or a wind farm, at a grid connection point. The method includes exchanging electric power depending on a control function. The electric power includes active and reactive power and the control function controls the power depending on at least one state variable of the electricity supply grid. It is possible to switch between a normal control function and a support control function, different from the normal control function, as the control function. The normal control function is used when it has been recognized that the electricity supply grid is operating stably and the support control function is used when a grid fault or an end of the grid fault has been recognized.

A power conversion device includes a smoothing capacitor, an input voltage detection unit, a power conversion unit, and a controller. The input voltage detection unit detects a voltage value of the input voltage. The power conversion unit converts a direct-current voltage smoothed by the smoothing capacitor into an alternating-current voltage to output the alternating-current voltage to a power system. The controller has a first operation mode of outputting active power to the power system, has a second operation mode of outputting reactive power to the power system, determines whether or not the voltage value is one of equal to and higher than a determination value, and makes a transition from the first operation mode to the second operation mode within a predetermined time from a time point when it is determined that the voltage value is lower than the determination value.

Examples of power source adjustment can include a device that includes a sensing device to measure a first thermal temperature of a first power source and second thermal temperature of a second power source, a controller to balance power sourced by each of the first and the second power sources based on the first and the second thermal temperatures, and a circuit to adjust the power sourced by each of the first and the second power sources based on the balanced sourced power.

Examples of power source adjustment can include a device that includes a sensing device to measure a first thermal temperature of a first power source and second thermal temperature of a second power source, a controller to balance power sourced by each of the first and the second power sources based on the first and the second thermal temperatures, and a circuit to adjust the power sourced by each of the first and the second power sources based on the balanced sourced power.

The present subject matter is directed to a method for controlling a generator of an electrical power system. The generator includes a generator stator magnetically coupled to a generator rotor. The method includes operating the generator stator of the generator at a first voltage level. Another step includes monitoring, via one or more sensors, at least one of a rotor speed or a rotor voltage of the generator rotor. The method also includes reducing the first voltage level of the generator stator by a predetermined percentage when the rotor speed is within a low speed range or the rotor voltage exceeds a predetermined threshold so as to increase an operating range of the rotor speed. Thus, the increased operating range of the rotor speed increases power production of the electrical power system in the low speed range.