Abstract: A method for estimating grid properties of a power grid coupled to a generator at a point of common coupling is provided. First, a voltage VPCC at the point of common coupling is measured. Second, a current IPCC at the point of common coupling is measured. Third, the grid properties are estimated by a grid model using as input parameters the measured voltage VPCC at the point of common coupling, the measured current IPCC at the point of common coupling and the determined phase angle. Advantageously, the absolute phases of the voltage and the current at the point of common coupling are not necessary, which makes the present method less prone to errors due to measurement noise. Further, a device and a computer program product are provided.

Abstract: A system and method for time synchronization in a communication network. The communication network includes a plurality of network nodes each having a respective internal clock, and a reference node having a reference clock and each configured transmits synchronization messages within the communication network. At least one network node is configured to determine an estimated reference clock time discretely upon arrival of a synchronization message at the at least one network node. To that end, the at least one network node includes a controller for determining a controlled time comprising a time-continuous estimate of the discreetly estimated reference clock time. The controller is configured to determine the controlled time based on an input that is extrapolated to an execution time instant of the controller, where the execution time instant is separated from the time instant of arrival of the synchronization message by a delay (?tdelay).

Abstract: Method, device and system for detecting a disturbance, e.g., at least one short mechanical impact (shock or vibration) on a clock of a slave device by detecting a non-typical variation of a tracking error, i.e., a tracking error having a deviation that exceeds a predetermined threshold, wherein such a non-typical variation can be determined by the deviation from a statistical measure, e.g., a variance or a standard deviation, such that the determination of the quality of a clock signal is advantageously allowed and thus suitable counter-measures are provided. The method, device and system are applicable for all kinds of technical systems comprising slave devices that have a clock, e.g., devices in industrial and automation systems. The method, device and system are also applicable in communication systems that use a protocol to synchronize the clocks of its devices, e.g., Profinet.

Abstract: A method for time synchronization in a communication network comprising a multiplicity of network nodes, wherein synchronization messages are transmitted in the communication network and the synchronization message received in a slave node contains synchronization information for synchronizing the slave time of the slave node with the master time, i.e., synchronization messages are transmitted in a closed ring or line topology and the slave node receives first and second synchronization messages from different transmission directions, and wherein the slave node synchronizes a first time with the synchronization message from one transmission direction and a second time with the synchronization message from the other transmission direction.

Abstract: A method for synchronizing clocks in a communication network includes a first clock of a first network element which is a master element is used for synchronizing second clocks of one or more second network dements which are slave elements. A first sequence of first messages transmitted from the first network element to the second network element and/or a second sequence of second messages transmitted from the second network element to the first network element is recorded. First messages and/or second messages out of those sequences are identified by using an appropriate threshold function with respect to the transmission delays of those messages. Those identified messages have the same constant minimum delay, and based on those messages clock synchronization between the first clock and the second clock is performed.

Abstract: The invention refers to a method for synchronizing clocks in a communication network, wherein a first clock of a first network element (MA) which is a master element is used for synchronizing second clocks of one or more second network elements which are slave elements. According to the method of the invention, a first sequence of first messages transmitted from the first network element to the second network element and/or a second sequence of second messages transmitted from the second network element to the first network element is recorded. First messages and/or second messages out of those sequences are identified by using an appropriate threshold function with respect to the transmission delays of those messages. Those identified messages have the same constant minimum delay, and based on those messages clock synchronization between the first clock and the second clock is performed.

Abstract: A method for transmitting synchronization messages in a communications network including a plurality of nodes having a first node and at least one second node, wherein in order to take into account differences in a reference clock frequency of a reference clock and an internal clock frequency of an internal clock of the at least one second node, a compensation interval, with which the second clock count state is adjusted on measurement of a delay time, is subdivided into smaller compensation timespans, and the smaller compensation timespans are used to determine a compensated time value for the delay time with a high degree of accuracy, where the compensated time value is then used to update the time information in the synchronization message.

Abstract: A device and method for time synchronization in a communication network, wherein a virtual clock is produced by a controller in each network node based on the PROFINET-Standard and/or the Precision Transparent Clock Protocol. In contrast to known methods for estimating the time, the time of the virtual clock does not undergo sudden changes. The virtual clock includes a controlled, continuous path. As a result, the virtual clock is particularly suitable for time-critical applications. Here, the estimation of the time of a reference clock is improved by 18-35%. Accordingly, a markedly greater number of network nodes may be synchronized with a predetermined level of accuracy for the time synchronization.

Abstract: The disclosure relates to a method for controlling a wind farm, the wind farm includes at least two wind turbines, the method includes determining the required power, determining fatigue load versus power curves for each wind turbine, and based on the determined fatigue load versus power curves attributing different power settings to the wind turbines such that sum of the power settings of all wind turbines is equal to the required power. Furthermore, the invention concerns a park controller for controlling a wind farm and a program element for controlling a wind farm.

Abstract: A method for transmitting synchronization messages in a communications network including a plurality of nodes having a first node and at least one second node, wherein in order to take into account differences in a reference clock frequency of a reference clock and an internal clock frequency of an internal clock of the at least one second node, a compensation interval, with which the second clock count state is adjusted on measurement of a delay time, is subdivided into smaller compensation timespans, and the smaller compensation timespans are used to determine a compensated time value for the delay time with a high degree of accuracy, where the compensated time value is then used to update the time information in the synchronization message.

Abstract: Method, device and system for detecting a disturbance, e.g., at least one short mechanical impact (shock or vibration) on a clock of a slave device by detecting a non-typical variation of a tracking error, i.e., a tracking error having a deviation that exceeds a predetermined threshold, wherein such a non-typical variation can be determined by the deviation from a statistical measure, e.g., a variance or a standard deviation, such that the determination of the quality of a clock signal is advantageously allowed and thus suitable counter-measures are provided. The method, device and system are applicable for all kinds of technical systems comprising slave devices that have a clock, e.g., devices in industrial and automation systems. The method, device and system are also applicable in communication systems that use a protocol to synchronize the clocks of its devices, e.g., Profinet.

Abstract: A method for time synchronization in a communications network having multiple nodes, wherein the nodes comprise a first node and at least one second node, where the first node generates first cycle counter states according to a reference clock frequency and the second node or nodes each generate second cycle counter states according to an internal clock frequency, where a time synchronization is carried out in sequential synchronization cycles, in which synchronization messages originating from the first node are sequentially transmitted from one node to another node, and a synchronization message transmitted by a node contains information used for time synchronization in the at least one second node receiving the synchronization message such that a time synchronization is performed in a given second node based on an estimation of a first cycle counter state and a compensation factor in combination with a linear quadratic regulator.

Abstract: The disclosure relates to a method for controlling a wind farm, the wind farm includes at least two wind turbines, the method includes determining the required power, determining fatigue load versus power curves for each wind turbine, and based on the determined fatigue load versus power curves attributing different power settings to the wind turbines such that sum of the power settings of all wind turbines is equal to the required power. Furthermore, the invention concerns a park controller for controlling a wind farm and a program element for controlling a wind farm.

Abstract: A method for time synchronization in a communication network having a plurality of nodes each comprising a first node and at least one second node, wherein the first node generates first cycle counting states according to a reference cycle frequency and the second node generates second cycle counting states according to an internal cycle frequency, wherein time synchronization is performed in consecutive synchronization cycles in which, starting from the first node, synchronization messages are consecutively transferred from one node to a further node and a synchronization message transmitted by the node includes a segment of information that is used for time synchronization in the node receiving the synchronization message, wherein time synchronization is performed in the second node based on an estimate of a first cycle counting state in combination with a linear-quadratic regulator to obtain a synchronized time comprising a controlled first cycle counting state.

Abstract: A system and method for time synchronization in a communication network. The communication network includes a plurality of network nodes each having a respective internal clock, and a reference node having a reference clock and each configured transmits synchronization messages within the communication network. At least one network node is configured to determine an estimated reference clock time discretely upon arrival of a synchronization message at the at least one network node. To that end, the at least one network node includes a controller for determining a controlled time comprising a time-continuous estimate of the discreetly estimated reference clock time. The controller is configured to determine the controlled time based on an input that is extrapolated to an execution time instant of the controller, where the execution time instant is separated from the time instant of arrival of the synchronization message by a delay (?tdelay).

Abstract: A method for controlling a power production entity is provided. The method includes generating a plurality of electric power signals by a plurality of power production entities, measuring a plurality of power levels of the plurality of power signals, modifying the plurality of power signals, supplying the plurality of modified power signals at a common node, and adjusting an operation voltage of at least one power production entity of the plurality of power production entities based on the plurality of measured power levels such that a power loss of the power signals caused by the modifying and/or supplying is minimized. Also a system for controlling a power production entity is described.

Abstract: The invention refers to a method for synchronizing clocks in a communication network, wherein a first clock of a first network element (MA) which is a master element is used for synchronizing second clocks of one or more second network dements which are slave elements. According to the method of the invention, a first sequence of first messages transmitted from the first network element to the second network element and/or a second sequence of second messages transmitted from the second network element to the first network element is recorded. First messages and/or second messages out of those sequences are identified by using an appropriate threshold function with respect to the transmission delays of those messages. Those identified messages have the same constant minimum delay, and based on those messages clock synchronization between the first clock and the second clock is performed.

Abstract: A device and method for time synchronization in a communication network, wherein a virtual clock is produced by a controller in each network node based on the PROFINET-Standard and/or the Precision Transparent Clock Protocol. In contrast to known methods for estimating the time, the time of the virtual clock does not undergo sudden changes. The virtual clock includes a controlled, continuous path. As a result, the virtual clock is particularly suitable for time-critical applications. Here, the estimation of the time of a reference clock is improved by 18-35%. Accordingly, a markedly greater number of network nodes may be synchronized with a predetermined level of accuracy for the time synchronization.

Abstract: There is described a method for transmitting synchronization messages in a communication network, the communication network comprising a plurality of network nodes communicating with one another, each containing an internal clock, which is timed with a node clock frequency assigned to the respective network node. The synchronization messages transmitted in the communication network serve to synchronize the times of the internal clocks of the network nodes and contain the pulse counter status of a synchronization clock operating at a predefined synchronization clock frequency. The pulse counter status is estimated by each network node and updated in the synchronization message. Changes in the synchronization clock frequency are taken into account when estimating the pulse counter status.

Abstract: There is described a method for transmitting synchronization messages in a communication network, the communication network comprising a plurality of network nodes communicating with one another, each containing an internal clock, which is timed with a node clock frequency assigned to the respective network node. The synchronization messages transmitted in the communication network serve to synchronize the times of the internal clocks of the network nodes and contain the pulse counter status of a synchronization clock operating at a predefined synchronization clock frequency. The pulse counter status is estimated by each network node and updated in the synchronization message. Changes in the synchronization clock frequency are taken into account when estimating the pulse counter status.