A device, preferably a plug-in module, for communication between a controller and a field device. The device includes contacts, wherein a first subset of the contacts is electrically conductively connected or connectable to the controller and a second subset of the contacts is electrically conductively connected or connectable to the field device. The apparatus further includes a circuit having an input electrically conductively connected to the first subset of the contacts and an output electrically conductively connected to the second subset of the contacts. The circuit includes a voltage-limiting unit adapted to limit a voltage at the output, and a current-limiting unit adapted to limit a current between the input and the output and to interrupt the current when the voltage-limiting unit responds.

An electrical system forming part of a solar power plant is described. The electrical system includes a plurality of photovoltaic (PV) panels, a power converter, and a controller. In response to a detected electric arc on the DC side of the power converter, the controller is configured to enable a short circuit state of the power converter by controlling semiconductor switches of the power converter (e.g., turning on some or all of the semiconductor switches) to create a short circuit between DC input terminals of the power converter. The short circuit path though the power converter will extinguish the detected electric arc in the connected DC circuit.

An electronic device includes a voltage transformation circuit, a back-end circuit, a feedback circuit and a protection circuit. The voltage transformation circuit is configured for outputting a conversion voltage. The feedback circuit is electrically coupled to the back-end circuit and the voltage transformation circuit and is configured for outputting a feedback voltage of the conversion voltage. The protection circuit is electrically coupled to the voltage transformation circuit and the back-end circuit and is configured for detecting the feedback voltage, and outputting a control signal to the voltage transformation circuit according to the feedback voltage.

An electronic system for a surgical instrument is disclosed. The electronic system comprises a main power supply circuit configured to supply electrical power to a primary circuit. A supplementary power supply circuit configured to supply electrical power to a secondary circuit. A short circuit protection circuit coupled between the main power supply circuit and the supplementary power supply circuit. The supplementary power supply circuit is configured to isolate itself from the main power supply circuit when the supplementary power supply circuit detects a short circuit condition at the secondary circuit. The supplementary power supply circuit is configured to rejoin the main power supply circuit and supply power to the secondary circuit, when the short circuit condition is remedied.

A device, preferably a plug-in module, for communication between a controller and a field device. The device includes contacts, wherein a first subset of the contacts is electrically conductively connected or connectable to the controller and a second subset of the contacts is electrically conductively connected or connectable to the field device. The apparatus further includes a circuit having an input electrically conductively connected to the first subset of the contacts and an output electrically conductively connected to the second subset of the contacts. The circuit includes a voltage-limiting unit adapted to limit a voltage at the output, and a current-limiting unit adapted to limit a current between the input and the output and to interrupt the current when the voltage-limiting unit responds.

An apparatus includes a first terminal configured to be coupled to a substation around mat for a substation and a second terminal configured to be coupled to a safety around mat for a piece of electrical equipment powered by the substation. The system further includes at least one voltage-dependent resistance device, such as at least one metal oxide varistor (MOV) configured to be coupled between the first and second terminals. At least one circuit interruption device, such as a fuse and/or a disconnect switch may be coupled in series with the at least one voltage-dependent resistance device.

A powered surgical instrument including an end effector, which includes jaws that are configured to transition between various closure states. The surgical instrument includes a sensor configured to measure the closure state of the jaws and a display configured to display information indicative to the detected closure state. The surgical instrument further includes a firing member movable between a first position and a second position to transition the end effector between the plurality of closure states and a motor configured to drive the firing member between the first position and the second position.

This application relates to methods and apparatus for handling a fault associated with a voltage source converter (VSC) for exchanging electrical power between an AC system (101, 102) and a DC system (106-1, 106-2). The VSC (104) is connected to the AC system via an interface apparatus, comprising a transformer (107) with a set of primary windings (202) for coupling to a plurality of AC phases (A, B, C) of the AC system. In embodiments of the disclosure the set of primary windings having a neutral point (N) and the interface apparatus includes a fault module (301) having an energy storage element (302) connected in parallel with a resistive element (303) between the neutral point of the set of primary windings and a reference voltage, such as ground. The fault module does not interfere with normal operation but in the event of a phase-to-ground fault on the secondary side of the transformer, can induce earlier zero-crossing in the AC phases than otherwise would be the case, thus allowing AC breaker (108) to open with a reduced arcing time.

A system for preventing ground fault in a three-phase electric transmission line system caused by a line break, includes: the transmission lines, a programmable relay protection system, including a plurality of relay devices on each line, programmed to include: preset parameter ranges of at least two electric operating conditions, at least one high sensitivity instantaneous undercurrent and at least one high sensitivity condition selected from line differential overcurrent and negative sequence overcurrent (and combinations thereof), the preset ranges being acceptable operating parameter ranges; monitoring; permitting closed circuit operation when all of the lines show that the two operating conditions are within the preset acceptable operating parameter ranges; tripping a circuit breaker on a broken line when that line shows that the two operating conditions are outside the preset parameter ranges; and shutting down power to the broken line before it otherwise causes a ground fault or other short circuit.

Disclosed is a fault current controller for a direct current power grid, which includes a primary circuit and a controller. The primary circuit includes an inductor, a filter capacitor, a resistor, an IGBT switch, a diode, a contactor and a Hall current sensor. The inductor, a first resistor and a second contactor are connected in series and are connected to a first contactor in parallel. A first branch including a second resistor and a first diode, a second branch including a third resistor and a second diode, and the inductor are connected in parallel; the filter capacitor, the IGBT switch and the first resistor are connected in parallel. The Hall current sensor is arranged in the series circuit. The controller controls the IGBT switch and the two contactors in the primary circuit to form different on-off combinations.