Abstract:
A drive unit has a control power supply, a power source (1) producing direct current to one or more inverters (2), an energy storage (C) arranged at the power source (1) output, and a discharge circuit (8,10) for discharging the energy stored in the energy storage (C) and including a power resistor (8). Switches (5, 6) are arranged between the power source (1) and energy storage (C) and in default position when there is no control power in the drive unit. The power source (1) is disconnected and the energy storage (C) discharged through the power resistor (8) when the switches (5, 6) are in default position.
Abstract:
A design of a protection relay, and interface with an operator of a protection relay, are disclosed. The protection relay can include a base relay for measurement of line current and for generation of a trip signal, a base Human Machine Interface (HMI) for user specifying of a base setting of an operating parameter of the protection relay, and an optionally active Human Machine Interface (HMI) unit having a processing unit to manage plural activities with controlled power consumption.
Abstract:
A wind power converter comprises a multiple of phase power converters, each of which being adapted to convert power output from a corresponding phase of a wind generator to a corresponding phase of a grid; each of the phase power converters comprising: a full-wave rectifier, being adapted to rectify the power input through a first terminal and a second terminal from the corresponding phase of the wind generator; a capacitor being adapted to be charged by the power rectified by the full-wave rectifier; and a full-wave active inverter, being adapted to invert the power stored in the capacitor and output the inverted power to the corresponding phase of the grid through a third terminal and a fourth terminal; wherein: the first terminal or the second terminal is connected to a first virtual neutral; and the third terminal or the fourth terminal is connected to a second virtual neutral.
Abstract:
An industrial robot system has at least one robot (1) having a robot coordinate system (xr1, yr1, zr1) and a positioner (2) having a positioner coordinate system (xp, yp, zp) and adapted to hold and change orientation of a workpiece by rotating about a rotational axis. Target points for the robot are programmed with respect to an object coordinate system (xo1, yo1, zo1). A robot controller (3), at least three calibration objects (24a-c) arranged on the positioner, and a calibration tool (26) held by the robot are provided. The positions of the calibration objects are determined for at least three different angles of the rotational axis of the positioner, to determine the direction of the rotational axis of the positioner and relation between the object coordinate system and the positioner coordinate system by performing a best fit between known and determined positions of the calibration objects.
Abstract:
An HVDC network including a first station including a first converter, a second station including a second converter, each converter including non-extinguishable semiconducting elements. A first transmission conductor and a second transmission conductor. The first station includes a first switching arrangement.
Abstract:
A converter for converting alternating voltage into direct voltage and vice versa in a converter station of a high voltage transmission system. A series connection of converter valves includes power semiconductor devices connected in series and arranged in superimposed layers. The valves are arranged on top of each other in a column. Coolant liquid conducting tubes are in an extension over at least one part of the circumference of the column having no connections to cooling blocks for cooling the devices made of metal. Such metal tubes are arranged in the part for over this part of the column circumference forming an electric field shielding screen. The coolant liquid conducting tubes are when extending over parts of a circumference of the column where connections are made to cooling blocks made of an electrically insulating material. An electric field shield is arranged outside the column over these parts.
Abstract:
A retrofit diverter switch which has a mechanical and electrical interface that is compatible with the existing designs is provided. The diverter switch may include a vacuum switch. The feature where the mechanical and electrical interface is compatible enables a retrofit from traditional On Load Tap Changers to a vacuum based on Load Tap Changers. The diverter switch may be retrofitted into existing tap changer housings. Retrofitting from traditional to vacuum based, traditional to vacuum based and up rating, and vacuum up rating may be possible. Also, the diverter switch may include modular components that allow for easy customization of the diverter switch for different applications.
Abstract:
The invention is a condition monitor for a switchgear device in an electrical power distribution system. The switchgear device is arranged with an electrically powered actuator for operating a moveable part of the switchgear device, for example, operating the opening and/or closing of a circuit breaker. The switchgear device has a control unit with means to receive state information from the actuator, and panel means to present information via an HMI. The HMI may be accessed remotely. In other aspects of the invention a method, a human-machine interface and a computer program for carrying out the method are described.
Abstract:
An electric power transmission system includes at each end of a high voltage direct current transmission line including three conductors, a converter station for conversion of an alternating voltage into a direct voltage for transmitting direct current between the stations in all three conductors. Each station has a voltage source converter and an extra phase leg connected between the two pole conductors of the direct voltage side of the converter. A third of the conductors is connected to a midpoint between current valves of the extra phase leg. An arrangement is adapted to control the current valves of the extra phase leg to switch for connecting the third conductor either to the first pole conductor or the second pole conductor for utilizing the third conductor for conducting current between the stations.
Abstract:
A retrofit assembly and method of retrofitting a circuit breaker in a switchgear are described. The retrofit assembly can includes one or more adjustable elements for fitting a circuit breaker into a switchgear panel of the switchgear. The adjustable elements can include a plurality of adjustable modular female tulip contacts to receive a corresponding plurality of male contacts in a panel of the switchgear, each female tulip contact being flexible for a plurality of diameters, a plurality of modular phase adjustment contact arms to provide phase alignment between the poles of the circuit breaker, and/or an adjustable truck for placing the circuit breaker in contact with a rack for the circuit breaker in the switchgear.