987 results about "Protective relay" patented technology

An adapter is provided for a communication device. The adapter includes an elongated hollow shell and a foldable adapting element. The foldable adapting element includes an input half part and an output half part pivotally rotatable with each other between an expansion accommodating position and a fold operation position. The output half part includes an output port for a transmission connector in the communication device. The input half part includes a set of power input ends corresponding to the power output port in the back cover mobile power source of the communication device. When located in the fold operation position, the output port can be plugged into the transmission connector, and the power input ends can be correspondingly connected to the power output port.

A method and system for programming and implementing automated fault isolation and restoration of high-speed fault detection of circuits in power distribution networks using sequential logic and peer-to-peer communication is provided. High-speed fault detection of circuits in power distribution networks uses protective relay devices (14) segmenting a distribution line (11) having Intelligent Electronic Devices (IED) (22) associated with switching devices (20) communicating peer-to-peer via a communication system (30) to provide fast and accurate fault location information in distribution systems with sequential logic.

The invention discloses an electric automobile high-voltage power-on circuit and a control method thereof. The circuit comprises a battery pack, a positive relay, a negative relay, a pre-charge resistor, a pre-charge relay and a pre-charge capacitor, wherein the positive relay, the negative relay, the pre-charge resistor and the pre-charge relay are connected between the battery pack and a load; the pre-charge capacitor is arranged at the two ends of the load; certain ends of the positive relay and the negative relay are connected to a master positive end and a master negative end of the battery pack respectively; the other ends of the positive relay and the negative relay are connected with the load; the pre-charge resistor and the pre-charge relay form a series branch; the series branch is arranged at the two ends of the positive relay and forms a parallel circuit; the pre-charge resistor is connected to the master positive end of the battery pack. The detection of an actual state of the relay is realized, a fault can be timely reported under the condition that a high-voltage loop fails, high-voltage power-on operation is stopped, and the safety of the battery system and the vehicle is guaranteed.

A protective case for a portable digital media device includes a hinged element and an aperture registered with an input element for such device, to provide protection against inadvertent damage to the device, to selectively operate as a stand to maintain the device in an upright position, and enable user access to the input element when the case is closed.

A differential protection system for power transformers using Rogowski coils as current sensors can support an inrush current detection method based on sensing lows in the derivative of the sensed current. Effective detection of power transformer inrush conditions can enable blocking of a protection relay during inrush where the differential current may exceed a differential threshold value indicative of a fault without the presence of an actual fault. The outputs of the Rogowski coils, being proportional to the first time derivative of the sensed current, may be useful in the inrush detection method. Also, with reduced saturation concerns, the Rogowski coil protection system may employ a single slope response with increased sensitivity. A discrete time sampling technique for identifying low di/dt portions within the sensed current also may be useful in detecting power transformer inrush conditions.

A protective relay having an embedded web server to allow communication with a remote device having a standard web browser package. The relay can receive and transmit HTML files according to the HTTP protocol over a communications network. The relay can receive commands from the remote device, and can generate and return requested data to the remote device.

The invention concerns a method of impedance groundfault detection for differential protection of an overhead transmission line in a three-phase high voltage electric power transmission system which comprises many lines (1,12) and many protection relays (2,4), which comprises the following steps: 1) in prefault condition: —measuring the differential current (I); —measuring the phase voltage (II) at the relay location; —measuring the phase current (III) the relay location; —calculating the differential admittance (IV), with the following equation: (formula (V)). With (VI): the positive sequence impedance of the line-protected. 2) In operating condition: —measuring the differential current (VII); —measuring the phase voltage (VIII) at the relay location; —measuring the phase current (IX) at the relay location; calculating the differential admittance (X), with the following equation: (formula (XI)); —detecting a high impedance groundfault detection, if the following formula is verified: (XII) with (XIII); B₀=the total line admittance.

In preferred embodiments, an expandable and modular protective mobile device case apparatus comprises a protective shell configured to receive a mobile device; a circuit board located within the protective shell said circuit board comprising a USB hub and a mode selection switch, wherein the USB hub is in electrical communication with the mode selection switch; and a male plug member in electrical communication with the mode selection switch and configured to transfer electrical signals from the mode selection switch to the mobile device.

The invention discloses a safety chain system of a wind generating set and a fault rapid identification method thereof. According to different safety chain trigger objects, a non-intelligent safety relay and a conventional relay are adopted to construct a safety chain loop by a hard-wired series mode so as to form a unit safety system; the state of the safety system is effectively monitored; for the same protected object, the safety chain loop adopts a redundancy design mode; and at least two independent safety chain protection connection points can simultaneously operate, so that the state of effectiveness loss of the safety chain, which is caused by output adhesion of a certain equipment object protection relay connection point, can be more effectively prevented. The safety chain system of the wind generating set and the fault rapid identification method thereof, which are disclosed by the invention, are simple to implement, effective to monitor and low in cost; and meanwhile, the safety and reliability of the safety chain system of the wind generating set are protected by adopting a multilevel protection mode.

An arc suppression circuit in a protection relay having trip contacts is used to turn off a battery-powered solenoid and trip an AC power circuit breaker. The arc suppression circuit uses a switch-control circuit to control the turning off of a semi-conductor switch so that the semi-conductor switch provides a current path around the trip contacts, and is carrying all, or substantially all, of the load current, before the trip contacts are opened. When the trip contacts begin to open, the switch-control circuit holds the semi-conductor switch on for a sufficient time to prevent an arc from becoming established before turning the semi-conductor switch off. In a second embodiment, the arc suppression circuit provides a second switch-control circuit. This second switch-control circuit is configured to accept control signals from a microprocessor within a protection relay. The microprocessor turns the semi-conductor switch on before the contacts begin to open, thereby providing a current path around the contacts before the contacts begin to open. The microprocessor turns the semi-conductor switch off after a time sufficient to prevent an arc from becoming established.

Disclosed herein is an apparatus for connection to the secondary terminals of a CT to prevent CT damage and electric shock when the secondary terminals are opened, by providing an input signal and operating a relay circuit to short the CT secondary terminals. The apparatus monitors opening of the CT secondary terminals, and to prevent accidental opening, determines opening and provides an over voltage breaking upon opening. To prevent false operation of the protecting relay connected to the secondary terminals caused by the over voltage generated by accident other than opening of the CT secondary terminals, a secondary delay time of operation of the protecting relay is provided that can be variously set by DIP switch or otherwise, allowing the user to choose a desired setting. Further, expected over voltage values can be set according to load characteristics, allowing the apparatus to operate during voltage above the set value.

A method and an adaptive distance protection relay for compensating for a remote line end infeed effect during determination of a distance to a resistive fault on a three-phase power transmission line. It is assumed that a fault current flows through the fault resistance. A fault loop impedance is first calculated by a known algorithm from phase voltages and phase currents. A shift of the fault loop impedance is determined from the fault loop impedance, the impedance of the transmission line for the positive current sequence and the phase angle of a complex fault current distribution factor, where the fault current distribution factor is the ratio of the fault loop current to the fault current. The distance to fault is calculated by subtracting the impedance shift from the fault loop impedance and dividing the result by the impedance of the transmission line for the positive current sequence.

A system for collecting data and monitoring the operation of electrical circuits, such as branch circuits at a substation is provided. The system collects data from a plurality of sensors coupled to a plurality of electrical equipment associated with a circuit. The data from the sensors is collected and used to determine the activation of the electrical equipment, such as a protective relay for example. The data is further transformed to allow assessment of the circuit's performance against desired parameters.

A method and apparatus for high-speed fault detection of circuits in power distribution networks utilizing protective relay devices (14) segmenting a distribution line (11) having Intelligent Electronic Devices (IED) (22) associated with switching devices (20) communicating peer-to-peer via a communication system (30) to provide fast and accurate fault location information in distribution systems.

The invention relates to an intelligent monitoring system for a flexible passive protective net. The intelligent monitoring system of the flexible passive protective net includes a dangerous source capture system, a signal processing system and an alarm system. Under a condition that the signal processing system determines that dangers happen in the protective net and/or the protective net reaches a dangerous degree, alarm signals and/or intelligence information are/is sent in one or more methods. Fiber bragg grating sensors are preinstalled on lower support ropes of the flexible passive protective net. Through monitoring the tension of the lower support ropes of the protective net, signals related with rock fall and breakage of the protective net are monitored in a real-time manner and then the signals are returned to a fiber bragg grating demodulator.

A multichip module comprises a flexible circuit having conductive patterns on its surface(s) to which microelectronic device(s) are attached. The flexible circuit is enclosed and supported by two rigid frames, which may further be provided with protective heat spreading covers. Contact pads on the rigid frame(s) may be configured to engage a mating socket or they may be solderable to a printed circuit board.