Abstract: A load commutated converter interconnects an AC power grid with an AC load and comprises a grid-side converter, a DC link and a load-side converter. A method for controlling the load commutated converter comprises: determining a gridside firing angle for the grid-side converter; determining a load-side firing angle for the load-side converter; determining a grid voltage of the AC power grid; modifying the grid-side firing angle and/or the load-side firing angle based on the grid voltage, such that when an undervoltage condition in the AC power grid occurs, the operation of the load commutated converter is adapted to a change in the grid voltage; and applying the grid-side firing angle to the grid-side converter and the load-side firing angle to the load-side converter.

Abstract: A method for estimating a motor parameter in a load commutated inverter arrangement, including the steps of: measuring a motor side ac-voltage; detecting commutation interval information of the measured motor side ac-voltage; estimating a motor parameter based on the detected commutation interval information; and indicating when the estimated motor parameter deviates from a monitoring parameter thereof.

Abstract: A subsea unit includes a housing containing a dielectric liquid, a first heat generating component and a second heat generating component. The first heat generating component is arranged in thermal connection with the housing and the second heat generating component is arranged at a distance from the housing. A method of cooling heat generating components contained in a housing of a subsea unit is also presented.

Abstract: A load commutated converter interconnects an AC power grid with an AC load and comprises a grid-side converter, a DC link and a load-side converter. A method for controlling the load commutated converter comprises: determining a gridside firing angle for the grid-side converter; determining a load-side firing angle for the load-side converter; determining a grid voltage of the AC power grid; modifying the grid-side firing angle and/or the load-side firing angle based on the grid voltage, such that when an undervoltage condition in the AC power grid occurs, the operation of the load commutated converter is adapted to a change in the grid voltage; and applying the grid-side firing angle to the grid-side converter and the load-side firing angle to the load-side converter.

Abstract: A switching device is provided for disconnecting or connecting an electric machine, a converter or a plurality of electrical loads supplied with AC power from a power supply and controlled by a control unit. The switching device includes a current sink and at least one mechanical switch in the switching device are arranged in a circuit. The current sink is arranged, upon receipt of a signal, to close and sink the current, and the at least one mechanical switch is arranged to open and break the current on receipt of a signal to open supplied to the electric machine when the current load is at or close to zero. A method and a computer program for carrying out the method are described.

Abstract: A subsea unit includes a housing containing a dielectric liquid, a first heat generating component and a second heat generating component. The first heat generating component is arranged in thermal connection with the housing and the second heat generating component is arranged at a distance from the housing. A method of cooling heat generating components contained in a housing of a subsea unit is also presented.

Abstract: A method for monitoring at least one subsea electric machine supplied by a system for electric power transmission. The system has a power supply, a controller and an AC power line connecting the at least one machine with the power supply. The method includes the steps of: receiving at the controller, high speed data from at least one subsea sensor arranged between the subsea side of the AC power line and the at least one subsea electric machine, wherein the high speed data includes measurements of an electrical parameter for the at least one machine; and comparing the one or more measurements to a predetermined value. A system for electric power transmission arranged for operating at least one subsea load or electric machine is also described.

Abstract: A switching device is provided for disconnecting or connecting an electric machine, a converter or a plurality of electrical loads supplied with AC power from a power supply and controlled by a control unit. The switching device includes a current sink and at least one mechanical switch in the switching device are arranged in a circuit. The current sink is arranged, upon receipt of a signal, to close and sink the current, and the at least one mechanical switch is arranged to open and break the current on receipt of a signal to open supplied to the electric machine when the current load is at or close to zero. A method and a computer program for carrying out the method are described.

Abstract: A method for estimating a motor parameter in a load commutated inverter arrangement, including the steps of: measuring a motor side ac-voltage; detecting commutation interval information of the measured motor side ac-voltage; estimating a motor parameter based on the detected commutation interval information; and indicating when the estimated motor parameter deviates from a monitoring parameter thereof.

Abstract: A method for monitoring at least one subsea electric machine supplied by a system for electric power transmission. The system has a power supply, a controller and an AC power line connecting the at least one machine with the power supply. The method includes the steps of: receiving at the controller, high speed data from at least one subsea sensor arranged between the subsea side of the AC power line and the at least one subsea electric machine, wherein the high speed data includes measurements of an electrical parameter for the at least one machine; and comparing the one or more measurements to a predetermined value. A system for electric power transmission arranged for operating at least one subsea load or electric machine is also described.

Abstract: A method and a system for organizing and retrieving energy related information for a plurality of real world objects, wherein a number of information types are defined, each information type representing different kind of energy related information. The method includes providing one or more predefined interfaces adapted for retrieval of information of the information types, providing software objects, representing the real world objects, having at least one interface for retrieval of information of at least one of the types, based on the one or more predefined interfaces, arranging the software objects in a hierarchal structure including more than one level, so that the software objects obtain a parent-child relation, receiving and storing information about where to find the source of the information to be retrieved via the interfaces of the software objects.

Abstract: A method and a system for organizing and retrieving energy related information for a plurality of real world objects, wherein a number of information types are defined, each information type representing different kind of energy related information. The method includes providing one or more predefined interfaces adapted for retrieval of information of the information types, providing software objects, representing the real world objects, having at least one interface for retrieval of information of at least one of the types, based on the one or more predefined interfaces, arranging the software objects in a hierarchal structure including more than one level, so that the software objects obtain a parent-child relation, receiving and storing information about where to find the source of the information to be retrieved via the interfaces of the software objects.