Abstract: A method for synchronizing opening of a circuit breaker is presented. The circuit breaker is arranged to interrupt a current to an inductive load. The method is performed in a control device (2) and comprises measuring (S100) a reference signal as a function of time for a circuit breaker (1) connected to an inductive load (5), obtaining (S110) an indication of a power factor of the inductive load through the circuit breaker, determining (S120) an arcing time for opening of the circuit breaker, the arcing time being dependent on the obtained indication of a power factor, predicting (S130) a zero crossing of a current through the circuit breaker based on the measured reference signal, and providing (S140) contact separation of a contact pair of the circuit breaker at a point of time before the predicted zero crossing, the point of time being determined by the determined arcing time and the predicted zero crossing.

Abstract: A method for synchronizing opening of a circuit breaker is presented. The circuit breaker is arranged to interrupt a current to an inductive load. The method is performed in a control device (2) and comprises measuring (S100) a reference signal as a function of time for a circuit breaker (1) connected to an inductive load (5), obtaining (S110) an indication of a power factor of the inductive load through the circuit breaker, determining (S120) an arcing time for opening of the circuit breaker, the arcing time being dependent on the obtained indication of a power factor, predicting (S130) a zero crossing of a current through the circuit breaker based on the measured reference signal, and providing (S140) contact separation of a contact pair of the circuit breaker at a point of time before the predicted zero crossing, the point of time being determined by the determined arcing time and the predicted zero crossing.

Abstract: A switching system for breaking a current, including a contact arrangement having a first and second terminals, a resonance circuit connectable across the contact arrangement, In the closed state the first switch enables current to flow through the resonance circuit in a first flow direction and into the contact arrangement in a direction opposite to a contact arrangement arc current flow direction. A second switch connected to the resonance circuit and to the second terminal. In the closed state the second switch enables current to flow through the resonance circuit in a second flow direction opposite to the first flow direction.

Abstract: A switching system for breaking a current, including a contact arrangement having a first and second terminals, a resonance circuit connectable across the contact arrangement, In the closed state the first switch enables current to flow through the resonance circuit in a first flow direction and into the contact arrangement in a direction opposite to a contact arrangement arc current flow direction. A second switch connected to the resonance circuit and to the second terminal. In the closed state the second switch enables current to flow through the resonance circuit in a second flow direction opposite to the first flow direction.

Abstract: A battery energy storage system including a control unit and a plurality of battery units. The battery units are arranged in series, and each battery unit includes a semiconductor switch and a battery module including a plurality of battery cells. Each battery module is connected in series with a respective semiconductor switch, and the control unit is operatively connected to the semiconductor switch and adapted to control the semiconductor switch of every battery unit.

Abstract: A drive system is disclosed for operating an electric device. The drive system includes an electric motor having a permanent magnet rotor connectable to the electric device for controlling the operation of it by a limited-angle rotation, the electric motor further including a stator winding. The drive system includes a drive circuit connected to the stator winding. The permanent magnet rotor can be arranged to be aligned to a magnetic field created by the stator winding when supplied with current from the drive circuit, so that a maximum torque can be applied to the rotor and thereby to the movable part within an interval of ±25 degrees around a middle position between two end positions of the limited-angle rotation of the rotor.

Abstract: A battery energy storage system including a control unit and a plurality of battery units. The battery units are arranged in series, and each battery unit includes a semiconductor switch and a battery module including a plurality of battery cells. Each battery module is connected in series with a respective semiconductor switch, and the control unit is operatively connected to the semiconductor switch and adapted to control the semiconductor switch of every battery unit.

Abstract: A drive system is disclosed for operating an electric device. The drive system includes an electric motor having a permanent magnet rotor connectable to the electric device for controlling the operation of it by a limited-angle rotation, the electric motor further including a stator winding. The drive system includes a drive circuit connected to the stator winding. The permanent magnet rotor can be arranged to be aligned to a magnetic field created by the stator winding when supplied with current from the drive circuit, so that a maximum torque can be applied to the rotor and thereby to the movable part within an interval of ±25 degrees around a middle position between two end positions of the limited-angle rotation of the rotor.

Abstract: A device for breaking DC currents exceeding 2500 A has a resonance circuit connected in parallel with an interrupter and a surge arrester connected in parallel with the resonance circuit. The resonance circuit has a series connection of a capacitor and an inductance. The relationship of the capacitance in ?F to the inductance in ?H of the resonance circuit is ?1.

Abstract: An apparatus for reactive power compensation in an ac medium voltage power network. The apparatus includes a common connection; a first branch including a first switch, and a first capacitor; and a second branch including a second switch and a second capacitor.

Abstract: A device for reduction of the voltage derivative for an electrical component connected to an electric conductor via an electric bushing. The device protects an electrical component in an electrical apparatus against high voltage derivatives.

Abstract: An apparatus for reactive power compensation in an ac medium voltage power network. The apparatus includes a common connection; a first branch including a first switch, and a first capacitor; and a second branch including a second switch and a second capacitor.

Abstract: An apparatus for controlling an electric switching device (1) for alternating current arranged in a current path for opening the switching device and for breaking the current in the current path after occurrence of a fault current comprises members (15) adapted to detect the current in the current path and a unit (20) adapted to control the electric switching device to break the current in the current path directly after a half wave of the alternating current having a peak value below a predetermined current limit value, so that the breaking is completed through a zero-crossing of the alternating current terminating a said half wave.

Abstract: A method for evaluating a condition of a switching device. The switching device includes contact parts, an electric motor and a mechanical coupling device for transforming motion from the electric motor to at least one of the contact parts. A self-diagnostic test is performed on a component of the switching device. The test includes making at least one small movement with the electric motor. A switching device includes contact parts, an electric motor, a mechanical coupling device for transforming motion from the electric motor to at least one of the contact parts, and tester for making self-diagnostic tests, wherein the tester makes small motor movements that are a fraction of a full breaking movement, thereby producing data for evaluating a condition of the switching device.

Abstract: An apparatus (14) for detecting a zero-crossing of an alternating current after occurrence of a fault in a current path (2) for determining a suitable time for opening an electric switching device (2) arranged in the current path for breaking the current in the current path comprises members (15) adapted to detect the current in the current path. An arrangement (19) is adapted to calculate the dc-level of the current and the decay of the dc-level with time on the basis of values of the alternating current detected and also predict the time for a future zero-crossing of the alternating current on the basis of at least current values obtained through said current detection, the dc-level calculated, the dc-decay calculated and information about the period time of the alternating current.

Abstract: An electric switching device for alternating current comprises two branches (2, 3) connected in parallel in a current path and having each at least two contact members (4–7) connected in series. A semiconductor device (8) is adapted to interconnect the midpoints between the two contact members of each branch. When opening the current path a first contact member (5) of one, first branch located before said midpoint as seen in the current direction existing is controlled to open and a second contact member (6) of the second branch located after the midpoint as seen in the current direction is controlled to open for transferring the current to a temporary current path through the semiconductor device. The current path through the switching device is then broken when the semiconductor device is in a blocking state by opening a contact member (4, 7) of the switching device arranged in the temporary current path.

Abstract: The present invention relates to a method for testing, controlling and regulating a switching device with contact parts, to a switching device and to a computer program therefore. The switching device comprises an electric motor (6) and a mechanical coupling device (41) for transforming motion from the electric motor to one of the contact parts (4, 5). Position, speed and/or acceleration of the contact part during operation are controlled during operation. By means of a control unit (43), the operation of the switching device is adaptively controlled in real-time. Storage means (70) are provided and contain information on measurements, events and failures in the switching device and include operation parameters. In the logs, information regarding self-diagnostic tests of the switching device can be stored as well.

Abstract: An apparatus (14) for detecting a zero crossing of an alternating current after occurrence of a fault in a current path (2) for determining a suitable time for opening an electric switching device (2) arranged in the current path for breaking the current in the current path comprises members (15) adapted to detect the current in the current path. An arrangement (19) is adapted to calculate the dc-level of the current and the decay of the dc-level with time on the basis of values of the alternating current detected and also predict the time for a future zero-crossing of the alternating current on the basis of at least current values obtained through said current detection, the dc-level calculated, the dc-decay calculated and information about the period time of the alternating current.

Abstract: An apparatus for a controlling an electric switching device (1) for alternating current arranged in a current path for opening the switching device and for breaking the current in the current path after occurrence of a fault current comprises members (15) adapted to detect the current in the current path and a unit (20) adapted to control the electric switching device to break the current in the current path directly after a half wave of the alternating current having a peak value below a predetermined current limit value, so that the breaking is completed through a zero-crossing of the alternating current terminating a said half wave.