Abb Research Ltd.

Hitachi Energy Switzerland Ag

Abb Schweiz Ag

Hitachi Energy Ltd

Abb Technology Ltd

Alexandre Oudalov

Mats Larsson

Petr Korba

Adrian Vasile Timbus

Thomas Von Hoff

James Stoupis

Bertil Berggren

Peter Karl Steimer

Zhenyuan Wang

Tord Bengtsson

Yannick Maret

Jens Rocks

Dmitry Ishchenko

Stefan G Thorburn

Yvonne-Anne Pignolet

Xavier Kornmann

Nikolaus Zant

Fang Yang

James Ottewill

Sami Pettersson

Antonio Coccia

Daniel Chartouni

Gerardo Escobar

Antonio Fidigatti

Xianyong Feng

Mehmet Mercangoez

Ngai-Man Ho

Christian Frei

Jan Poland

Srinivas Ponnaluri

Enrico Ragaini

Martin Naedele

Salman Mohagheghi

Leonardo-Augusto Serpa

Lennart Balgard

Andrew D Paice

Lorenz Herrmann

Rudolf Wieser

Zhao Li

Cherry Yuen

Bertil Nygren

Johan Lindberg

Chau-Hon Ho

Jose Taborda

Erald Pjetri

Luca Milani

Robin Gremaud

Patrik Kaufmann

Laurent Fabre

Ira Nagel

Rachid Cherkaoui

Maher Kayal

Konstantinos Papastergiou

Marco Schneider

Emmanuel Logakis

Thomas Koch

Otmar Goerlitz

Yan Zhang

Thomas Locher

Sebastian Obermeier

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.

Method of performing a state of health estimation for a rechargeable battery energy storage system

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.

Adaptive protection for distribution grid based on area concept

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.

Microgrid energy management system and method for controlling operation of a microgrid

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.

Energy storage systems

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. The second stage, for at least one electrical quantity of the grid, determines a value of the electrical quantity, forms a positive feedback term using at the determined value adding a positive feedback term to the control reference, determines a change in an electrical quantity induced by the feedback term, and determines islanding condition on the basis of the change in the quantity induced by the feedback term.

Method and apparatus for detecting islanding conditions of a distributed grid

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.

Detecting islanding conditions in power networks

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.

Method for operating an energy storage system

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. The latter may be on-line adapted to continuously reflect an updated aspect of the power system behavior, and thus enable an improved, fast and reliable power flow control in power systems comprising a meshed power network with two parallel flow paths or corridors connecting two areas or sub-systems.

Determination and use of power system sensitivities

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 (y) and a control parameter (cp) of a FACTS controller is derived therefrom. The control parameter and a first system signal (y) 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.

Damping electromechanical oscillations in power systems

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.

Converter control unit

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Fislisbach, Switzerland

Alexandre Oudalov