ABB Ltd

About: ABB Ltd is a company organization based out in Zurich, Switzerland. It is known for research contribution in the topics: Voltage & Signal. The organization has 6222 authors who have published 6852 publications receiving 83994 citations.

Ground fault detection

Abstract: The present invention relates to a ground fault detection arrangement for a synchronous three-phase electrical machine, and an electrical system comprising a ground fault detection arrangement and a synchronous three-phase electrical machine. The ground fault detection arrangement injects an off-nominal frequency voltage between a neutral point of the synchronous three-phase electrical machine and ground and measure resultant currents to detect a ground fault.

Damping electromagnetic oscillations in power systems

Abstract: Exemplary embodiments of the present disclosure provide a method and controller for damping multimode electromagnetic oscillations in electric power systems which interconnect a plurality of generators and consumers. The controller for damping such oscillations includes a phasor measurement unit (PMU) and a power oscillation damper (POD) controller. Each oscillating mode signal is damped and then superposed to derive a control signal. A feedback controller is used to feedback the control signal to a power flow control device in the power system.

Method and apparatus for engine piston installation by use of industrial robots

Abstract: A method and apparatus for engine piston installation in which robots are used for the entire engine piston installation process. A first robot equipped with a stuffing gripper and force control picks up a piston with a connection rod, detects the piston ring presence, squeeze the rings, find the engine cylinder bore, and stuffs the piston into the cylinder bore. A second robot can be used to load and unload the engine block, hold the block and position it to the location, and indexes the crankshaft into the proper orientation for each cylinder bore. A set of tools either fixed on a stationary station or on a third robot is used to guide the piston connecting rod, transport and place on the connecting rod cap, and fasten the cap onto the connecting rod. The piston connecting rod guiding process may be omitted in piston stuffing for some types of engines.

Modular multilevel converter with cell-connected battery storages

Abstract: The invention concerns a method, voltage source converter and computer program product for supporting an associated AC system and comprising: a number of cells (CA1, CA2, CA3, CA4, CA5, CA6, CB1, CB2, CB3, CB4, CB5, CB6, CC1, CC2, CC3, CC4, CC5, CC6), each cell comprising a string of switching elements in parallel with a cell capacitor, at least some cells further including a battery module group comprising at least one battery module connectable in parallel with the cell capacitor and a control unit (20) configured to selectively connect the battery module groups of a number of cells in parallel with corresponding cell capacitors for exchanging power with the associated AC system.

Current-limiting resistor having PTC behavior

Abstract: The current-limiting resistor has two connection electrodes (1, 2) which are arranged parallel to one another as well as a resistance body (3) which has PTC behavior and with which large-area contact is made by the connection electrodes (1, 2). A varistor (40) is in electrically conductive contact with the resistance body (3). The resistance body (3) contains two contact areas (50, 51) as well as a response point (60) which is connected in parallel with the varistor (40) via the two contact areas (50, 51) and implements a PTC transition above a threshold value of a current flowing through the resistor. Since the resistance body effects the electrical contact with the varistor (40) in the case of this resistor, no metal connection electrodes are required for the varistor. At the same time, due to the outward displacement of the response point (60) away from the varistor (40), the operational reliability of the resistor is considerably improved. Effective current limiting in load circuits which are operated at high voltage can be achieved by a series circuit formed by a plurality of varistors (40, 41, . . . ) provided in a resistance body (3) which is designed in the form of a meander or is of some other continuous design.