Abstract: A method for operating an inverter for coupling an electric machine designed for operation on AC voltage, to an AC voltage network, includes the steps of determining a torque-related machine current component composed of electrical machine currents of the electrical machine, detecting an actual value for a magnetic flux, determining an actual value of a machine torque of the electric machine by linking the detected magnetic flux to the torque-related machine current component, determining a torque difference between the actual value of the machine torque and a setpoint value of the machine torque of the electric machine, filtering the torque difference by a bandpass filter which is tuned to a machine-side natural frequency, determining a compensation signal by processing a filter output signal of the bandpass filter, and superimposing the compensation signal on the network control signal and/or the machine control signal.

Abstract: A method for operating an inverter for coupling an electric machine designed for operation on AC voltage, to an AC voltage network, includes the steps of determining a torque-related machine current component composed of electrical machine currents of the electrical machine, detecting an actual value for a magnetic flux, determining an actual value of a machine torque of the electric machine by linking the detected magnetic flux to the torque-related machine current component, determining a torque difference between the actual value of the machine torque and a setpoint value of the machine torque of the electric machine, filtering the torque difference by a bandpass filter which is tuned to a machine-side natural frequency, determining a compensation signal by processing a filter output signal of the bandpass filter, and superimposing the compensation signal on the network control signal and/or the machine control signal.

Abstract: A self-commutated converter is connected to further self-commutated converters by its AC voltage connection via an inductive component using a coupling point, which is common to all the converters, in an AC voltage network. An active power P and a frequency fN are determined from a network voltage at the coupling point and a converter current flowing via the inductive component. An active power difference value ?P is supplied to an orthogonal controller and to a parallel controller. The output value from the parallel controller is used to minimize the reactive power exchanged between converter and coupling point. The frequency difference value ?f is supplied to a frequency controller and the output value from the frequency controller is logically combined with the output value from the orthogonal controller and the output value from the parallel controller, the frequency difference value ?f being simultaneously minimized.

Abstract: A power generation facility includes at least one generator which has a converter on the generator side and a converter on the network side and which is connected by the converters to an alternating voltage network on the power plant side. A rectifier connects the alternating voltage network on the power plant side to a DC transmission line. An inverter on the energy network side connects the DC transmission line to an energy network operating on the basis of alternating voltage. A control unit is configured to control the converter on the generator side and the converter on the network side of the at least one generator, at least on the basis of DC current and/or DC voltage measurement values measured on the DC transmission line. A method for operating a power generation facility is also provided.

Abstract: A method is provided for controlling the operation of a wind turbine includes (a) receiving an active power reference signal; (b) determining, based on the active power reference signal and an active power feedback signal, a first voltage control signal and a power controller frequency signal; (c) receiving a power reference signal; (d) determining, based on the power reference signal and the power feedback signal, a power offset frequency signal; (e) determining, based on the power controller frequency signal, a second voltage control signal; (f) determining, based on the power offset frequency signal, an angle signal indicative for an actual angle of a rotating dq reference frame; and (g) controlling the operation of a power converter based on the first voltage control signal, the second voltage control signal, and the angle signal.

Abstract: A method for controlling the operation of a wind turbine is provided. The method includes receiving, by means of a power controller, an active power reference signal and an active power feedback signal; determining, by means of the power controller and based on the active power reference signal and the active power feedback signal, a first voltage control signal and a power controller frequency signal; determining, by means of a frequency droop gain unit and based on the power controller frequency signal, a second voltage control signal; determining, by means of a theta integrator unit and based on the power controller frequency signal, an actual angle signal being indicative for an actual angle between a rotating dq reference frame and a stationary abc reference frame; and controlling operation of a network bridge based on the first voltage control signal, the second voltage control signal, and the actual angle signal.

Abstract: A method is provided for controlling the operation of a wind turbine includes (a) receiving an active power reference signal; (b) determining, based on the active power reference signal and an active power feedback signal, a first voltage control signal and a power controller frequency signal; (c) receiving a power reference signal; (d) determining, based on the power reference signal and the power feedback signal, a power offset frequency signal; (e) determining, based on the power controller frequency signal, a second voltage control signal; (f) determining, based on the power offset frequency signal, an angle signal indicative for an actual angle of a rotating dq reference frame; and (g) controlling the operation of a power converter based on the first voltage control signal, the second voltage control signal, and the angle signal.

Abstract: A method for controlling the operation of a wind turbine is provided. The method includes receiving, by means of a power controller, an active power reference signal and an active power feedback signal; determining, by means of the power controller and based on the active power reference signal and the active power feedback signal, a first voltage control signal and a power controller frequency signal; determining, by means of a frequency droop gain unit and based on the power controller frequency signal, a second voltage control signal; determining, by means of a theta integrator unit and based on the power controller frequency signal, an actual angle signal being indicative for an actual angle between a rotating dq reference frame and a stationary abc reference frame; and controlling operation of a network bridge based on the first voltage control signal, the second voltage control signal, and the actual angle signal.

Abstract: A self-commutated converter is connected to further self-commutated converters by its AC voltage connection via an inductive component using a coupling point, which is common to all the converters, in an AC voltage network. An active power P and a frequency fN are determined from a network voltage at the coupling point and a converter current flowing via the inductive component. A active power difference value ?P is supplied to an orthogonal controller and to a parallel controller. The output value from the parallel controller is used to minimize the reactive power exchanged between converter and coupling point. The frequency difference value ?f is supplied to a frequency controller and the output value from the frequency controller is logically combined with the output value from the orthogonal controller and the output value from the parallel controller, the frequency difference value ?f being simultaneously minimized.

Abstract: A method for controlling a static converter connected to a direct-current source. The converter has power conductor switches that can be deactivated and is configured to supply a distribution network with three-phase voltage. The currents flowing through the respective power semiconductor switches are measured, current values respectively assigned to the power semiconductor switches are obtained, the current values are sampled and digitized to obtain digital current values. The latter are checked by a logic in a control unit for the presence of an excess current condition. If no excess current condition is detected, the power semiconductor switches are activated and deactivated with the aid of a nominal operation controller and if an excess current condition is detected, at least the power semiconductor switches with assigned digital current values that fulfill the excess current condition are deactivated after a pulse block has expired.

Abstract: A method and an apparatus for improving the voltage quality of a secondary power supply unit uses a compensation device with a pulse-controlled power converter which is connected serially to a transmission line through the use of a coupling transformer. Positive and negative phase-sequence system deviations are determined and a basic transmission ratio space-vector is generated from them. Control signals for a pulse-controlled power converter are generated from the basic transmission ratio space-vector through the use of the link voltage of the pulse-controlled power converter. As a result, a compensator voltage is connected serially into the transmission line. A power system voltage of an ideal power supply system is thus generated for a secondary power supply unit from a distorted power system voltage.

Abstract: A method and an apparatus for power factor correction for a non-ideal load, which is supplied from a mains power supply, by a compensation device which is electrically connected in parallel with the load and has a pulse converter with at least one capacitive store. A transfer function space vector is calculated as a function of a determined mains power supply voltage space vector, a mains power supply current space vector, a compensator current space vector and of an intermediate circuit voltage which is present on the capacitive store. As a result of which the pulse converter generates a compensator voltage space vector on the mains power supply side as a function of the intermediate circuit voltage. A compensator current space vector, that keeps the undesirable reactive current elements away from the mains power supply, is thus obtained via a coupling filter that is represented as a compensator inductance.