Abstract: A for ensuring grid stability by using a distributed ledger, the method comprising the steps: measuring metrics from a plurality of distributed energy resource, DER, wherein said metrics are related to grid stability; storing (a) said metrics/measurements in the distributed ledger; transferring said metrics from the distributed ledger into a smart contract (2); computing any deviations between said metrics and predetermined values stored in advance in the smart contract (2) by executing the smart contract; transferring and storing results from the computing step in the distributed ledger; and transferring said results from the distributed ledger to the respective DER of the plurality of DERs, wherein said DER receives positive or negative values which regulates the amount of contribution to the grid.

Abstract: An aspect of the present disclosure relates to a method for providing a data structure comprising a refined energy schedule, the method comprising receiving a plurality of energy demand requests, energy storage offers, and/or energy supply offers from a plurality of participants of a power network; determining by a plurality of distributed computational units the refined energy schedule, using an optimization function, under consideration of the plurality of energy demand requests, energy storage offers, and/or energy supply offers, wherein the refined energy schedule is an at least substantially optimal energy schedule; and appending the refined energy schedule to the data structure. A further aspect of the disclosure relates to a data structure, in particular to the data structure provided in the method.

Abstract: A method can be used to perform a state of health (SoH) estimation for a rechargeable battery energy storage system during operation of the rechargeable battery energy storage system. The rechargeable battery energy storage system includes a plurality of parallel strings that are individually controllable. The method includes selecting at least one string from the plurality of parallel strings, placing the selected at least one string into a SoH calibration mode for performing a SoH calibration while concurrently maintaining at least one other string of the plurality of parallel strings in operative mode, and causing the selected at least one string to return to the operative mode after the SoH calibration has been completed for the selected at least one string.

Abstract: A method can be used to perform a state of health (SoH) estimation for a rechargeable battery energy storage system during operation of the rechargeable battery energy storage system. The rechargeable battery energy storage system includes a plurality of parallel strings that are individually controllable. The method includes selecting at least one string from the plurality of parallel strings, placing the selected at least one string into a SoH calibration mode for performing a SoH calibration while concurrently maintaining at least one other string of the plurality of parallel strings in operative mode, and causing the selected at least one string to return to the operative mode after the SoH calibration has been completed for the selected at least one string.

Abstract: Method of protecting a distribution network with a line interconnecting busbars, each busbar being connectable, by means of switching devices adjacent to the busbar, to the line and to loads and/or generators. The method divides the distribution network in multiple protection areas, each comprises a busbar, a protection device and an area controller. Upon a change in connect status of a distribution feeder line, load or generator connectable to one of the busbar, the logic controller in this protection area re-calculates the short circuit level of the areas. Based on the recalculated short circuit levels, the protection settings of the areas may be adapted. The embodiment also provides a system and computer program product adapted to perform the method.

Abstract: A microgrid includes a plurality of distributed energy resources such as controllable distributed electric generators and electrical energy storage devices. A method of controlling operation of the microgrid includes periodically updating a distributed energy resource schedule for the microgrid that includes on/off status of the controllable distributed electric generators and charging/discharging status and rate of the electrical energy storage devices and which satisfies a first control objective for a defined time window, based at least in part on a renewable energy generation and load forecast for the microgrid. The method further includes periodically determining power set points for the controllable distributed energy resources which satisfy a second control objective for a present time interval within the defined time window, the second control objective being a function of at least the distributed energy resource schedule for the microgrid.

Abstract: A method for controlling an energy storage system for connection to a power system, and such an energy storage system are provided. The method makes use of a model based predictive controller to optimize the charging/discharging rates of energy storage elements in a hybrid energy storage system. The method includes determining respective desired charging/discharging rates for the energy storage elements in dependence upon state of charge predictions from respective models of the storage elements, using model predictive control, and adjusting respective charging/discharging rates of the storage elements in accordance with the determined rates. The energy system includes a controller configured to control respective charging/discharging rates of the energy storage elements in accordance with the method.

Abstract: Method of protecting a distribution network with a line interconnecting busbars, each busbar being connectable, by means of switching devices adjacent to the busbar, to the line and to loads and/or generators. The method divides the distribution network in multiple protection areas, each comprises a busbar, a protection device and an area controller. Upon a change in connect status of a distribution feeder line, load or generator connectable to one of the busbar, the logic controller in this protection area re-calculates the short circuit level of the areas. Based on the recalculated short circuit levels, the protection settings of the areas may be adapted. The embodiment also provides a system and computer program product adapted to perform the method.

Abstract: An exemplary method and apparatus for detecting islanding conditions of a distributed grid are disclosed, wherein transfer of power through a power electrical unit is controlled on the basis of a control reference. The apparatus includes a first stage and a second stage performing a respective portion of the method. The first stage injects a reactive component to the control reference, and, for at least one electrical quantity of the grid, determines a change in the quantity induced by the injected component, and determines, on the basis of the change in the electrical quantity, whether to move to the second stage of the method.

Abstract: A tubular electrical insulation device for a cable is arranged for receiving a plurality of electrical conductors segments by insertion. The insulation device is flexible and includes an inner circumferential electrically conductive layer for establishing an electric contact to the electrical conductors once inserted into the tubular electrical insulation device. A high voltage power cable arrangement includes a plurality of elongated electrical conductor segments arranged to be placed alongside one another and in electrical contact to one another to form an inner electrical conductor of a high voltage power cable, and an elongated tubular electrical insulation device arranged to house and surround the inner electrical conductor. A method for providing a flexible insulated high voltage power cable includes the step of assembling a plurality of elongated electrical conductor segments and an electrical insulation device on site to form the cable.

Abstract: A method is provided for detecting islanding conditions in an electric power network which includes a plurality of sub-networks. The sub-networks include at least one power electrical unit and are separable from each other and a main grid supplying the network by switching devices. The method includes determining topological information of at least one sub-network of interest, detecting islanding conditions in at least one sub-network of interest on the basis of the topological information by using separate detecting devices for each sub-network of interest, and sending, on the basis of the islanding conditions detected by using the detecting devices, a disconnect signal to at least one power electrical unit in at least one sub-network of interest.

Abstract: A microgrid includes a plurality of distributed energy resources such as controllable distributed electric generators and electrical energy storage devices. A method of controlling operation of the microgrid includes periodically updating a distributed energy resource schedule for the microgrid that includes on/off status of the controllable distributed electric generators and charging/discharging status and rate of the electrical energy storage devices and which satisfies a first control objective for a defined time window, based at least in part on a renewable energy generation and load forecast for the microgrid. The method further includes periodically determining power set points for the controllable distributed energy resources which satisfy a second control objective for a present time interval within the defined time window, the second control objective being a function of at least the distributed energy resource schedule for the microgrid.

Abstract: The present disclosure is concerned with operation of an energy storage system (ESS) connectable to an electric power system. The charging-discharging schedule of the ESS can be determined through application of a time-dependent forecast of ESS and power system states based on historical data. Exemplary embodiments can include ESSs which have been historically activated with a certain periodicity, for example, for power system load leveling, frequency regulation, arbitrage, peak load shaving and/or integration of renewable power generation.

Abstract: A method for controlling an energy storage system for connection to a power system, and such an energy storage system are provided. The method makes use of a model based predictive controller to optimize the charging/discharging rates of energy storage elements in a hybrid energy storage system. The method includes determining respective desired charging/discharging rates for the energy storage elements in dependence upon state of charge predictions from respective models of the storage elements, using model predictive control, and adjusting respective charging/discharging rates of the storage elements in accordance with the determined rates. The energy system includes a controller configured to control respective charging/discharging rates of the energy storage elements in accordance with the method.

Abstract: A method and apparatus are provided for detecting islanding conditions for distributed generators connected to a grid. The method includes estimating a grid impedance, and inducing, on the basis of the estimated grid impedance, a variation on a value of a first electrical quantity of the grid. The method also includes monitoring a grid response to the variations, and determining islanding conditions on the basis of the monitored response.

Abstract: The present disclosure relates to power system sensitivities as computed from power flow parameters and control parameters of a Power Flow Control Device (PFC). To this end, control parameter variations are applied to or generated by a PFC, and comprise variations in a control input u, a control effort e (injected series voltage, inserted series reactance), or a control effect q (power flow, active power transfer, phase-shift, current). A power flow response measuring unit measures a variation of a power flow response such as current, active or apparent power, in a way sufficiently synchronized with the control parameter variation to allow establishing an unambiguous causal relationship or correspondence in the form of a power system sensitivity.

Abstract: The disclosure concerns a method and an apparatus for adapting at least one set of parameters to at least one Intelligent Electronic Device (IED) of an electrical power network having a plurality of switching devices (CB). The method includes: a) reading the current network status of the electrical power network, wherein the network status includes the status of the plurality of switching devices; b) simulating at least one network fault in the electrical power network; c) deducing at least one new set of parameters for the at least one IED using a simulated fault current induced by the at least one simulated network fault under consideration of the present network status and the network topology of the electrical power network; and d) setting the at least one set of parameters in at least one of the at least one IED.

Abstract: The present disclosure is concerned with the combined voltage or power flow control and damping of electromechanical oscillations in an electric power system by Flexible AC Transmission System (FACTS) devices or High Voltage DC (HVDC) transmission devices. To this end, information about a state or operating point of the power system is generated from suitable second system signals (y2) and a control parameter (cp) of a FACTS controller is derived therefrom. The control parameter and a first system signal (y1) are used in the calculation of a control command (u) defining the settings of the FACTS device. Following a change in the state of the power system such as a change in the topology of a transmission network, poorly damped or even unstable oscillations are avoided by appropriate re-tuning of the control parameter of the damping or stabilizing equipment.

Abstract: The disclosure relates to a converter control unit or power system stabilizing unit for counteracting oscillations in electric power systems that is equipped and employed to provide and processes information for system-wide monitoring, protection, control and metering. It comprises means for synchronized (e.g. via GPS or another absolute/global time reference) sampling of voltages and/or currents, means for down-sampling in order to decrease the number of samples, and means for calculating phasors, i.e. time stamped amplitude and phase angle of the voltages and/or currents.

Abstract: An apparatus is provided for emulation of a power system. The apparatus includes a plurality of programmable elements which are selectively connectable to one another. Each programmable element includes at least two elements selected from the group consisting of a generator element, a line element and a load element. A programmable switch element is operable to selectively connect the at least two elements of each programmable element to one another, and to selectively connect the programmable element to one or more other programmable elements. A system, which incorporates the apparatus, is also provided for emulating a power system incorporating such apparatus.