Abstract: A method and an arrangement are disclosed for balancing load between parallel connected inverter modules, which inverter modules are arranged to supply a common load. The method can include providing similar switching instructions for parallel connected inverter modules, determining on the basis of phase currents of each parallel inverter module a first time period for each output phase of each inverter module for correcting current imbalance by advancing or delaying turn-on or turn-off time instants of switch components of the inverter modules, and advancing or delaying the turn-on or turn-off time instants of the switching instructions based on the first time period.

Abstract: A method and device are disclosed for synchronizing an inverter with an alternating voltage source. The method includes measuring a current generated by the alternating voltage source and flowing through diodes of the inverter, determining a phase angle and angular velocity relating to the alternating voltage source from the measured current for enabling synchronization between the inverter and the alternating voltage source, and starting modulation of the inverter according to the obtained phase angle and angular velocity.

Abstract: An electric power sea cable including at least one cable core. The cable core includes an electric conductor, an electric insulation surrounding the conductor, and a protective sheath surrounding the electric insulation and acting as a water barrier. At least one outer layer surrounds the at least one cable core. The protective sheath is made of metal and the electrical power sea cable includes at least one friction reducing layer surrounding the at least one cable core and arranged inside of the at least one outer layer.

Abstract: A tool for surface machining of a workpiece includes a drive, a spindle operatively and detachably connected to the drive so as to be acted upon by the drive and a basic body connected to the spindle having at least two working surfaces. The drive is configured to act on the basic body so that the at least two working surfaces simultaneously machine the workpiece.

Abstract: An attachment part for a mechanical connection of a rear wall to a first and a second side wall, a base wall and a ceiling wall of a cabinet includes a plurality of resilient tongues each integrally formed on the attachment part and each having a latching lug, wherein the attachment part can be attached to an inside of the rear wall at each one of four corners of the rear wall at a right angle with the rear wall, and wherein the first and the second side wall, the base wall and the ceiling wall are each firmly latchable to the latching lugs.

Abstract: A method of operating a converter circuit is disclosed, wherein the converter circuit has a converter unit with a multiplicity of controllable power semiconductor switches and the converter unit is connected at the AC voltage end to an electrical AC voltage network. According to the method, the controllable power semiconductor switches are controlled by means of a control signal.

Abstract: A pressure sensor is disclosed wherein pressure induced changes in birefringent properties of an optical sensing element are read out by transmission of at least one light beam. The pressure sensor can include at least one single-material transparent body which is subjected to at least two different pressures (p1, p2) in at least two different regions via at least two pressure chambers. The transparent body can transmit by a parallel or minimally divergent light beam without total reflection in the body such that the pressure-induced birefringence and a corresponding differential phase shift between linear polarisation components of the light beam depends on a difference of the different pressures (p1, p2).

Abstract: A method and apparatus are provided for decelerating an inverter-controlled machine reel in a paper machine. The method includes detecting a break in a paper web from a machine reel, determining the inertia of the machine reel, determining continuously the angular speed of the machine reel, and determining continuously the torque required to decelerate the machine reel, on the basis of the determined inertia and angular speed, for the purpose of stopping the machine reel in a predefined time. The method also includes decelerating the machine reel electrically to stop the machine reel, in accordance with the determined torque, and using a mechanical brake when the rotation speed of the machine reel is lower than a predefined rotation speed and when the torque obtained by electrical deceleration is too small to stop the machine reel in a predefined time.

Abstract: The present disclosure provides a pole part of a low-voltage, medium-voltage and/or high-voltage switching device. The pole part includes a vacuum interrupter chamber having a fixed contact and a movable contact, which includes an electrical contact piece. The vacuum interrupt chamber is cast into an insulating material. The insulating material has opening at the bottom in at least one of a region of the movable contact and a drive rod driving that drives the movable contact. To reduce the heating of the pole part to enable production of a higher rated current carrying capacity, in the region of the movable contact and/or the articulation point of the drive rod, at least one ventilation opening is formed to pass through at least one of an exterior wall of the insulation, a boundary zone between the insulation and the electrical connection piece, and the electrical connection piece.

Abstract: A solar power plant is disclosed for converting solar energy into electric energy, and having a plurality of solar cell units, each solar cell unit containing a first cell pole and a second cell pole. The cell poles can cooperate for feeding electric energy produced by the solar cell unit as direct current out of the solar cell unit. A direct-current converter can include a plurality of direct-current input poles and two direct-current output poles, each direct-current input pole being connected to at least one cell pole. The direct-current converter can convert input direct currents entered via the direct-current input poles, and having input voltages, into an output direct current having an output voltage, and feed the output direct current via the direct-current output poles out of the direct-current converter.

Abstract: A method and an electronic device are disclosed for testing drive parameters of an electropneumatic valve which is inserted into a closed control loop for position regulation of a switching element of a pneumatic actuating drive for a fitting which can be operated thereby. The electropneumatic valve can be driven by an alternating signal of a specific amplitude, such that the control loop will oscillate about a nominal position value to be regulated by alternate ventilation and venting of the valve, such that hysteresis present in the pneumatic actuating drive can be overcome. The trajectory of the position oscillation that is produced can, at the same time, be detected at the switching element using sensors, from which a characteristic of the control loop for the selected amplitude can be determined to confirm whether an opening point which is suitable for the control loop has been found.

Abstract: An exemplary breaker is disclosed with a gas drive for low-voltage, medium-voltage and high-voltage switching devices, in which disconnection can be generated via detonation capsules. To ensure that a low number of connection and disconnection operations in relation to the total operating duration of the circuit breaker is taken into consideration in design terms, without in the process reducing safety, exemplary embodiments include a piston/cylinder arrangement with a plurality of detonation capsules for generating a limited number of connection and disconnection operations in the cylinder in each of the two cylinder subareas which are separated by the piston.

Abstract: The present disclosure is concerned with a secure and trustable way of accessing devices in an embedded device environment with no network connectivity to outside service. This type of access to access-critical embedded devices by a user or service technician is controlled by way of a mobile memory or access-ticket storage i.e., such as a physical token. The token can, for example, be a smartcard or USB stick with appropriate memory for storing a user credential(s) or user identification such as a password or fingerprint. In an exemplary embodiment, a user can acquire an electronic access ticket with a suitable expiration period from a centralized ticket or access authorization server before travelling to the access-critical device, or to a location communicatively connected to the latter. The access ticket can contain access rights of the user with respect to one or several access-critical devices, and can be stored on the mobile memory.

Abstract: A robot tool for machining workpieces, includes a connecting element for connection to a robot. A cutting blade is maintained in a predetermined position by a retaining element, the retaining element being connectible to the robot by a connecting element.

Abstract: A method and an electronic device are disclosed, for finding an opening point for an electropneumatic valve, which method or electronic device can be used in a closed control loop for position regulation of a switching element of a pneumatic actuating drive for a fitting which can be operated thereby. An exemplary method can include: a) energizing the electropneumatic valve by a drive signal which corresponds to an estimated opening point; b) measuring control-loop characteristics for this drive signal by using sensors to detect movement of the switching element; c) if determined control-loop characteristics for a present opening point do not correspond to nominal presets, then varying the drive signal based on an evaluation result to produce a better-matched opening point, and the finding process then starts again with step a).

Abstract: A method for sensorless estimation of rotor speed and position of a permanent magnet synchronous machine, when the permanent magnet synchronous machine is fed with a frequency converter, the method comprising the steps of forming a stator voltage reference for the permanent magnet synchronous machine, injecting a high frequency signal (uc) into the stator voltage reference, measuring a DC-link current (idc) of the frequency converter when the permanent magnet synchronous machine (4) is fed with a voltage (us,ref) corresponding to a sum of the stator voltage reference and the injected signal, calculating a stator current estimate (îs), calculating a current error (?s) as a difference between the stator current estimate and the measured DC-link current, and estimating a rotor speed ({circumflex over (?)}m) and position ({circumflex over (?)}m) of the permanent synchronous machine based on the current error.

Abstract: A high voltage AC transmission cable system for transmitting power between two points, each connected to one or more power networks, and a method to operate the system. At least one transformer is arranged at each end of the AC transmission cable, wherein at least one of the transformers is arranged to operate the transformer at a voltage whereby losses due to reactive power transport and dielectric losses are minimized. The AC cable is run at a variable voltage regulated such that the voltage is a function of the load for the transmission cable. This operating voltage is not necessarily the same as the nominal voltages in the connection points. A control and communication system and a graphical user interface for carrying out the method are also provided.

Abstract: Hydraulic valve having a valve body and housing, which has a first, second and third cutout. A hydraulic medium is fed via the first cutout. The hydraulic medium is fed to a pressure consumer via the second cutout and to a pressure sink via the third cutout. The valve body moves to and fro between two end positions. From a second end position, the hydraulic medium passes from the first to the second cutout. In a first end position, the hydraulic medium passes from the second to the third cutout. Owing to the valve body, a constant flow cross section for the hydraulic medium, released by the first cutout, arises during a switching operation from the first into the second end position in a fixed time span, resulting in a maximum flow cross section being achieved when the valve body is in the second end position.

Abstract: A method for producing an arc-erosion resistant coating provides a substrate material with an arc-erosion resistant layer by a cold-gas spraying method. The method can be used for producing an arc-erosion resistant coating in inner regions of vacuum interrupter chambers that are exposed to electric arcs. An exemplary vacuum interrupter chamber with a shield coated inside is disclosed for medium-voltage switchgear.

Abstract: A sheet metal housing is disclosed for housing measurement and control devices. The sheet metal housing comprises a cover plate, a baseplate, two lateral walls and a back wall, to accommodate rail-mounted, plug-in modules, the front panels of which are embodied to together form a closed front. The housing can be made up of two identical, essentially C-shaped housing shells and the back wall. The cover plate and the baseplate are both of double-wall construction and can form an inner and an outer plate, separated from each other, whereby the inner plates comprise means for accommodating guide rails. Each inner plate and each outer plate of opposing walls can be components of the same housing shell.