Abb Technology Ag

Abb Schweiz Ag

Hitachi Energy Ltd

Asea Brown Boveri Ab

Abb Technology Ltd

Hitachi Energy Switzerland Ag

Abb Power Grids Switzerland Ag

Jean-Philippe Hasler

Mauro Monge

Falah Hosini

Jan Svensson

Lexuan Meng

Tomas Lars Jonsson

Gunnar Ingeström

Tong Wu

Staffan Norrga

Frans Dijkhuizen

Peter Lundberg

Tomas Larsson

Filippo Chimento

Fredrik Tinglow

Suman Maiti

Theodore Soong

Tomas Jonsson

Thomas Johansson

Lennart Angquist

Hector Zelaya De La Parra

Philippe Maibach

Tomas Tengner

Christopher Townsend

Mohsen Asoodar

Jan Kheir

Aravind Mohanaveeramani

Marcio De Oliveira

Haofeng Bai

Juergen Steinke

Per Karreby

Hongyang Zhang

Richard Rivas

Mikael Tenerz

Rasool Heydari

Pinaki Mitra

Fredrik Tinglöw

Marcio Magalhäes De Oliveira

Åke Petersson

Jan R Svensson

Fredrik Tingloew

The present disclosure provides a method and a control unit for controlling a power unit connected at a connection point to a power grid. The method comprises obtaining a power oscillation damping (POD) signal from a POD controller, based on a power oscillation in the power grid. A gain value may be determined based on a difference between a first voltage measurement at the connection point and a first voltage reference, or an estimated short circuit ratio of the power grid. The POD signal may be added to an input signal of a power unit regulator to obtain an intermediate reference signal. A combined reference signal may be determined based on adding the POD signal, multiplied by the gain value, to the intermediate reference signal. The power unit may be operated using the determined combined reference signal to damp the oscillation in the grid.

Adaptive power oscillation damping controller for a grid-forming converter

There is disclosed herein an energy storage system comprising an energy storage circuit, comprising a string of interconnected energy storage units configured to store electrical energy and provide power to a power grid using said stored electrical energy. The ESS further comprises an auxiliary module configured to provide auxiliary functions for at least one of the plurality of energy storage units, and an auxiliary power supply circuit for providing power to the auxiliary module from a grounded power source. The auxiliary power supply circuit is configured to galvanically isolate the energy storage circuit from the grounded power source, thereby preventing electrical arcing between the ESS, which may be at a high voltage, and ground at the grounded power source.

Auxiliary power supply for energy storage systems

A module () for use in an energy storage system is provided, including a first terminal () and a second terminal (); a supercapacitor branch () including an arrangement () of one or more supercapacitors (), and a resistive bypass branch () including at least a first bypass switch () and a resistance () connected in series. The supercapacitor branch and the resistive bypass branch are connected in parallel between the first terminal and the second terminal. The module may further include a direct bypass branch () having a second bypass switch (), the direct bypass branch being also connected in parallel with the supercapacitor branch () between the first and second terminals. A control method of such a module and an energy storage system including several such modules, are also provided.

Module for large scale energy storage

An arrangement is disclosed, comprising a series connection of a plurality of energy storage units, a plurality of bypass circuits, each bypass circuit being configured to bypass a respective one of the energy storage units in the series connection, and a plurality of control modules, wherein each control module corresponds to a respective one of the bypass circuits. Each control module is configured to control operation of the corresponding bypass circuit and at least one other bypass circuit of the plurality of bypass circuits to selectively bypass the corresponding energy storage units in the series connection in such a way that operation of each bypass circuit of the plurality of bypass circuits to selectively bypass the corresponding energy storage unit in the series connection is controllable by means of at least two of the control modules. A related method is also disclosed.

Arrangement comprising energy storage units and a related method

A power supporting arrangement for a power grid includes a first and a second voltage source converter with an AC side and a DC side. A DC link interconnects the DC sides of the voltage source converters. A first switching arrangement includes a number of settable positions. The AC side of the second voltage source converter is connected to the power grid and the first switching arrangement is connected between a first synchronous machine. The AC side of the first voltage source converter and the power grid and operable to selectively connect the first synchronous machine to the power grid or to the AC side of the first voltage source converter.

Power supporting arrangement for a power grid

A method can be used to control a voltage source converter of a power supporting arrangement to act as a virtual synchronous machine. The method includes obtaining a measured power level of the converter, processing the measured power level using a differential equation of an angular velocity of the virtual synchronous machine in order to obtain a control contribution, providing a phase angle of a physical quantity used to control the converter based on the control contribution, monitoring the ability of the converter to act as a virtual synchronous machine, determining that the ability of the converter to act as a virtual synchronous machine is deemed insufficient, and adjusting the control contribution by increasing the damping term and/or decreasing the moment of inertia term in response to determining that the ability of the converter to act as a virtual synchronous machine is deemed insufficient.

Power supporting arrangement for a power grid operated as a virtual synchronous machine

A method of providing power support to an electrical power grid is provided. The power support is provided by an arrangement including a synchronous machine connected to a converter, the converter in turn being connected to the electrical power grid. The method is performed in a control device controlling the arrangement and includes: receiving feedback from one or both of the electrical power grid and the synchronous machine, and controlling the converter such that power support is provided to or absorbed from the electrical power grid by means of the synchronous machine based on the received feedback. A control device, arrangement, computer program and computer program products are also provided.

Method of providing power support to an electrical power grid

A method for voltage control of a static synchronous compensator, STATCOM, or a static var compensator, SVC, is presented. The method is performed in a control device. The method includes obtaining a synchronous condenser, SC, error, obtaining a STATCOM or SVC voltage setpoint, adjusting the obtained STATCOM or SVC voltage setpoint with the obtained SC error to a total STATCOM or SVC voltage reference, and providing the total STATCOM or SVC voltage reference for voltage control of the STATCOM or SVC. A control device and a computer program for voltage control of a STATCOM or an SVC are also presented.

Voltage control of a facts shunt compensator

An electrical chain-link converter system includes a converter phase leg for converting a plurality of DC electrical currents from a plurality of DC power sources to an AC current of an electrical power distribution network. The phase leg includes a plurality of serially connected converter cells each of which is connected to a respective power source of the plurality of DC power sources. The system also includes a control unit associated with the phase leg, the control unit including a processor; and a storage unit storing instructions that, when executed by the processor, cause the control unit to, for each of the converter cells: obtain a dedicated voltage reference for the converter cell; and transmit the voltage reference to the converter cell.

Chain-link converter system with different DC-sources and method for operation

A method for controlling a modular multilevel converter to reduce the lower order harmonics generated by the converter is provided. The method may also reduce the overall switching loss of the converter by switching the switches close to fundamental switching frequencies while still reducing the lower order harmonics that are generated.

Method and device for damping voltage harmonics in a multilevel power converter

A method for reducing lower order harmonics of a power converter includes, for each phase leg of the converter: obtaining a voltage reference for the phase leg; for a present sample, obtaining a flux error of the output voltage of the leg; dividing the first sample flux error by a time period to obtain an average voltage error over said time period; subtracting an obtained processed average voltage error, based on the average voltage error, from the voltage reference to obtain a modified voltage reference for the phase leg; and providing the modified voltage reference to a modulation unit of the converter for controlling the phase leg.

A method is performed in a control device for controlling a power compensation arrangement including a voltage source converter and one or more power compensation branches, each power compensation branch including a thyristor controlled reactor, a thyristor switched reactor or a thyristor controlled capacitor. The voltage source converter and the one or more power compensation branches are connected to a same busbar. The method includes: detecting a request in an electrical power system to which the power compensation arrangement is connected; determining, based on the request, a need for reactive power supply to the electrical power system; providing reactive power by means of the voltage source converter and/or by one or more of the power compensation branches; and compensating, by means of the voltage source converter, any disturbances caused by the power compensation branches when providing the reactive power to the electrical power system. Corresponding devices are also disclosed.

Methods and devices for power compensation

A method for controlling a chain-link power converter including three phase legs, each of which phase legs includes a plurality of series-connected converter cells, each of the cells including a DC capacitor, the phase legs being connected in a delta configuration. The method includes detecting an unsymmetrical voltage condition at a terminal of the converter; determining a ratio between a zero sequence and a negative sequence component of a compound current to be injected into the converter, based on the detected unsymmetrical voltage condition; calculating the compound current comprising the zero sequence component and the negative sequence component in accordance with the determined ratio; and injecting the compound current into the converter to control the converter in view of the detected unsymmetrical voltage condition.

Method for balancing a chain-link converter in delta configuration

An apparatus and a method for filtering harmonics in a power transmission contact line of a railway system includes a multilevel converter multilevel converter having one single phase leg, which phase leg comprises switching cells, each switching cell comprises semi-conductor switches arranged to selectively provide a connection to a corresponding energy storage element. The multilevel converter also includes a controller provided to control the switching of each switching cell, and wherein the phase leg is configured in two parallel branches of cascaded switching cells, which branches is interconnected in a closed circuit. The controller is provided to monitor the content of harmonics in the contact line, and is adapted to filter the monitored harmonics by means of adapting the switching of the switching cells to absorb the harmonics.

Apparatus for filtering harmonics in railway contact lines and method

A method in a controller for protection of a voltage source converter including one or more phases, each phase including one or more series-connected converter cells. Each converter cell has a by-pass switch for enabling by-pass thereof. The method includes the steps of detecting an over-voltage condition, and controlling simultaneously the by-pass switches of each converter cell, so as to bypass the converter cells upon detection of such over-voltage condition. The invention also encompasses a controller, computer programs and computer program products.

Method and controller for protecting a voltage source converter

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Vasteras, Sweden

Jean-Philippe Hasler