Abstract: A controllable inductor comprises at least a tubular core (13) a main winding (5) surrounding the core, a control winding (13) passing substantially axially through the core, a ground part (15) arranged inside the main winding and an element surrounding the core and adapted to carry the main winding wound outside thereof at a distance to the ground part while creating a voltage taking air gap between the main winding and this part. The main winding has a first end (10) thereof on high potential and the potential falls towards the second opposite end (11). The element carries the main winding at the first end (10) at a larger radial distance to the ground part than at the second end.

Abstract: An apparatus for interconnection in a voltage-stiff converter is provided. The converter has at least one phase leg with at least two current valves. The apparatus connects a current valve with a respective pole conductor. A cable extends between an end of the phase leg and a capacitor which defines a direct voltage. The cables attached to different poles are arranged close beside each other and are made of an insulation layer of polymer base which surrounds a conductor.

Abstract: An industrial robot wrist unit comprising a wrist housing capable of being detachably mounted to the distal end of a robot arm, the housing having two fork arms supporting a pivotally mounted tilt housing which supports a rotatably mounted turntable on which an external implement can be mounted. The tilt housing is positively confined between the fork arms so that reactive forces stemming from the gearings in the housing are prevented from forcing the fork arms apart.

Abstract: A plant for transmitting electric power having an alternating voltage network with at least one phase and at least one VSC converter is provided. The converter has at least one phase leg with two current valves connected in series. Each phase leg is connected at a point between the two current valves to a respective phase of the alternating voltage network. The plant also comprises at least one additional phase leg in the converter more than the number of phases of the alternating voltage network and a means for disconnecting a phase leg from its respective phase and for connecting the additional phase leg at a point between its two current valves to the disconnected phase.

Abstract: A VSC converter has each current valve of a phase leg formed by a plurality of units of semiconductor elements and rectifying members, located on top of each other forming at least one stack. The phase leg is constructed according to the flat cable principle with the phase leg formed by such stacks arranged side by side in pairs at small distances (d) running back and forth. A cooling plate of electrically conducting material is arranged between each unit in the stacks.

Abstract: A system for transmitting electric power between a direct voltage network and alternating voltage networks through VSC-converters. A first station which transmits electric power is in voltage regulating mode. Switching members at a second station are adapted to be alternatingly switched in and out upon occurrence of a sudden change of power so as to alternatingly connect one of the poles of the direct voltage network through an associated resistance to ground. A ground current generated therethrough is detected by a ground current measuring member of the first station, which is thereby informed about the unbalance. The first station then takes corrective measures to reduce or eliminate the unbalance.

Abstract: A connection arrangement between superconducting strands of a winding located in a cryotank with strands located external thereof is disclosed. Current leads inside the cryotank are mutually insulated by spacers and current leads outside the cryotank are grouped and interconnected into corresponding single current leads.

Abstract: The present invention relates to a method and a device for two-shaft force measurement and its application to the determination of tensile force in a continuous web. The device comprises a force-introducing part (4) with two force-measuring parts A and B for determining the forces F.sub.A and F.sub.B, and the force is applied in a torque-free manner around a center of force via a device (3), for example in the form of a deflector roll journalled in bearing brackets (3) placed on the force-introducing part, and wherein the force-measuring parts, due to their built-in design, measure forces F.sub.A and F.sub.B in directions directed through angles .+-..phi.

Abstract: A device for converting direct voltage into a three phase alternating voltage having a two level converter connected to a direct voltage network and to an alternating voltage network. A control apparatus for performing pulse width modulation determines the pulse width modulation pattern for each phase by comparing a triangular wave for each phase with a reference alternating voltage. The triangular wave is inverted an even number of times during a fundamental oscillation of the reference alternating voltage and the time position of the inversions of each triangular wave is always such that two triangular waves are half a period displaced with respect to the third.

Abstract: In a method for control of an installation for transmission of high-voltage direct current in dependence on at least one stress parameter for a valve in a converter included in the installation and controlled by control equipment (CE1, CE2), a value (PDR, PDI, UMAX, TRC, TTC) of the stress parameter is continuously calculated, based on predetermined relationships (f1, f2, g1R, g2R, g1I, g2I, h1, h2) and in dependence on measured values (UN, .alpha., .gamma., ID, TO, TI, RECT/INV) of the operating parameters of the installation. At least one influencing signal (HTH, HCC, HCR) is generated in dependence on a comparison between the calculated value and at least one comparison value for the parameter, and the influencing signal is supplied to the control equipment to influence this in a direction which limits the value of the stress parameter.The member (HAS) comprises a monitoring device (PD, UA, TR, TT) for calculating the value of the stress parameter.

Abstract: A trigger control system for a thyristor-controlled series capacitor (TCSC) is disclosed. In one application, a power system 10 is coupled to a load 12 by a series capacitor 14 connected in parallel to a thyristor unit 16 and inductor 17. The thyristors are triggered by the control system 18, which includes a first circuit 20 that generates signals proportional to the peak of the line currents, a stabilizer circuit 22, an adder 24, a look-up table 26, a conversion circuit 28, a pulse generator 30, a phase-locked loop (PLL) 32, a ramp generator 34, a trigger window circuit 36, and a three input AND gate 38 the output of which is a grid pulse signal 40 that triggers the thyristor unit 16. The control system diminishes power swing oscillations and subsynchronous resonance oscillations.

Abstract: Control equipment (CE) for a series capacitor (1) connected into an electric power line (2) has a semiconductor valve (3), which is controllable in both directions, for connection in parallel with the capacitor. An inductor (4) is adapted to form, together with the capacitor, an oscillation circuit in which the semiconductor valve is included. The equipment has control members (PLL, TC) for firing the semiconductor valve for reversal of the capacitor charge and for control of the times (t.sub.p) for the zero crossings of the capacitor voltage (u.sub.C) such that these become substantially equidistant also in the presence of subsynchronous components in the power line current.

Abstract: A method and device for tilting a car body of a vehicle in a trackbound train when the train passes through a track curve. The respective vehicles in the train comprise bogies supporting a car body resting thereon, includes devices for tilting the car body in relation to the bogies, for indicating a track curve, and a control system for controlling the tilting of the car body in dependence on the geometry of the track curve. The position of the train along a route is determined point-by-point by the train being equipped with devices for detecting its position and by registering the curve geometry of the track when the train runs over a track section from the determined position, and storing it in real time as a sequence of measured values describing the curve geometry of the track section in an electronic memory. The curve-geometry data about the track section, previously stored in the memory is used for controlling the tilting of the car body during the next passage through curves within the track section.

Abstract: A driving unit comprising an electric motor and a reduction gear unit preferably intended for an industrial robot. A gear case (11) supports a motor (10) with a shaft (12) extending into the gear case and provided with a bevel pinion (13). An intermediate shaft (15) is rotatably journalled with two bearings (16). On the intermediate shaft are fixed a larger bevel gear (14) and between the bearings a smaller cylindrical gear (17). An output shaft (20) provided with a larger cylindrical gear (18) is rotatably journalled and parallel with the intermediate shaft (15). The gears are arranged such that the bevel pinion (13) is in engagement with the larger bevel gear (14) and the smaller cylindrical gear (17) is in engagement with the larger cylindrical gear (18). The motor shaft (12) is oriented approximately perpendicular to the output shaft (20).

Abstract: The invention relates to the determination of short-circuit power (SCC1, SCC2) in an electric power network (N1, N2) for alternating current, which at a connection point (J1, J2) is connected to a converter installation (PL) for transmission of high-voltage direct current. A converter (SR1, SR2) comprised in the converter installation operates with a control angle (.alpha.1, .alpha.2). Power values (MQ(t'.sub.0)), (MQ(t'.sub.k), MQ(t'.sub.n)) of reactive power (Q1, Q2) consumed by the converter and voltage values (MU(t'.sub.0)), (MU(t'.sub.k), MU(t'.sub.n)) of the voltage (U1, U2) of the power network, sensed at the connection point, are formed and stored at a first calculating time (t'.sub.0) and at least one second calculating time (t'.sub.k, t'.sub.n). During a measurement interval (t1-t2) which at least partly coincides with the calculating interval (t'.sub.0 -t'.sub.n), the control angle (.alpha.1, .alpha.2) of the converter is given a control-angle addition (.DELTA..alpha.1, .DELTA..alpha.2).

Abstract: A high-pressure and a method for high-pressure treatment of substances. The high-pressure press comprises a high-pressure cylinder consisting of a number of concentrically arranged cylinder elements (1, 2, 3). The cylinder elements (1, 2, 3) are radially prestressed to a predetermined prestress and surround a high-pressure chamber (6) for accommodating a pressurized medium. A thin safety liner (3), which is intended to be placed in the high-pressure cylinder until a fracture arises on the safety liner (3), is arranged in the interior of the high-pressure cylinder. Further, means (14, 15) are provided to conduct at least part of the pressurized medium from the high-pressure chamber (6) when a fracture arises on the safety liner (3). The means (14, 15) comprise at least one channel (14) running essentially along the outer envelope surface of the safety liner (3). The method comprises using the high-pressure press without liner replacement until a fracture has occurred on the thin safety liner.

Abstract: A hollow industrial robot, especially suitable for process work such as spot and arc welding, sealing, painting, glueing, laser machining, etc., has a tubular lower robot arm, the lower end of which is pivotably journalled in a robot stand about a preferably horizontal first axis and is rotatably journalled about a second axis coinciding with the longitudinal axis of the arm. A tubular upper robot arm is articulately connected to the upper end of the lower robot arm via an articulated joint member in the form of a tubular sleeve obliquely cut off at both ends. The articulated joint member is journalled in the lower robot arm and is rotatable about a third axis, which intersects the second axis. The upper robot arm is journalled on the articulated joint member and is rotatable about a fourth axis, which intersects the third axis. The upper end of the lower robot arm is secured to a first conical toothed wheel, which engages with a second conical toothed wheel secured to the rear end of the upper robot arm.

Abstract: A method and a device for identifying, when a fault has been detected in a power network, single-phase to ground faults by determining for each phase an auxiliary current based on the present phase current, ground fault current and ground current. If the difference between two consecutive, calculated values of the auxiliary current in some phase is smaller than a predetermined limit value, this means that there is a single ground fault in this phase.

Abstract: An HVDC transmission including at least two converters. Each converter is adapted for connection between a three-phase alternating-voltage network. At least a first converter has ac leads for connection of the first converter to the alternating-voltage network without the use of a separate winding transformer. A dc link is common to the converters. A zero-sequence inductor connection is arranged in the ac leads of the first converter and designed such that the zero-sequence inductor connection exhibits a high impedance to zero-sequence currents and a low impedance to positive-sequence currents.

Abstract: A device for slowing down the non-solidified portions of a cast strand during continuous casting of billets or blooms. The device comprises a group of at least three separate molds (1-4) which are open in the direction of casting and which are arranged such that each one is supplied with a flow of melt. The device also comprises a number of magnetic core parts (5-8), and at least one magnetic-field generating member (9-13), adapted to generate and transfer, together with the magnetic core parts, a static magnetic field or a periodic low-frequency magnetic field to the inflowing melt in such a way that the movement of the melt is slowed down. The magnetic core parts and the magnetic-field generating members are arranged such that, together with all the molds in the group, they form a common closed magnetic circuit. All the molds included in the group are arranged in series with each other in the closed magnetic circuit.