A system and method for maintaining electrical stability of a high-voltage transmission power system in response to a fault. The method includes detecting the fault, opening a switch to clear the fault, performing a first pulse test for a predetermined duration of time to determine if the fault is still present, preventing a reclosing operation from occurring if the pulse test indicates that the fault is still present, and allowing the reclosing operation to occur if the first pulse test indicates that the fault is not present. One or more subsequent pulse tests can be performed if the first pulse test is inclusive about the persistence of the fault, where the reclosing operation is prevented from occurring if the pulse tests indicate that the fault is still present and the reclosing operation is allowed if the pulse tests indicate that the fault is no longer present.

A shoot-through protection circuit includes a current sensor providing a sensor signal connected to a comparator input via at least a burden resistor. A switch protection circuit including a protection input connected to an output of the comparator and a plurality of outputs. Each of the outputs is connected to a corresponding switch in a plurality of stacked switches. Wherein the switch protection circuit is configured to drive each switch of the plurality of stacked switches open in response to a positive output signal from the comparator.

In a multi-terminal DC power transmission system, a common control device is connected to a plurality of individual protective devices via a first communication network. Each of the individual protective devices is configured, when detecting change in current or voltage in a corresponding protection zone, to output a fault signal to the common control device via the first communication network and open the corresponding DC circuit breaker such that the corresponding protection zone is disconnected from the multi-terminal DC power grid and deenergized. The common control device estimates a fault occurrence zone where a fault occurs among a plurality of protection zones, based on a plurality of received fault signals. The common control device requests an individual protective device corresponding to a deenergized protection zone of the protection zones excluding the fault occurrence zone to reclose the DC circuit breaker such that the deenergized protection zone is restored.

A system is provided that includes a power transmitter configured to provide power to a current loop, a power receiver configured to receive the power from the current loop. The power receiver is configured to, on a periodic basis, disconnect from the current loop to stop pulling power from the current loop for a period of time to enable a safety check to be performed by the power transmitter. The power transmitter is configured to: monitor current on the current loop; determine whether a current level on the current loop passes the safety check within a predetermined time interval since a determination that the current level was not within a safe range; and control connectivity of the power to the current loop depending on whether the safety check has or has not passed within the predetermined time interval.

A method of clearing a fault in a high voltage DC electrical network, including power converters interconnected by a DC power transmission, comprising: detecting a fault in the DC power transmission and reconfiguring each power converter to a fault blocking mode drinving the DC fault current towards zero; locating the fault and isolating a faulty portion from a healthy remaining portion; reconfiguring one of the power converters designated as a re-energising power converter from the fault blocking to re-energise the healthy remaining portion; and detecting a rise in the voltage level in the healthy remaining portion above a threshold level and reconfiguring the remaining power converter connected with the healthy remaining portion from the fault blocking to the normal power transmission.

Embodiments of the present invention include a test-boost electric power recloser that limits the duration of the test current imposed on the power line to less than two electric power cycles, and preferably less than one electric power cycle, when attempting to reclose into a fault. The test-boost recloser sends a test pulse causing a non-latching close followed by a boost pulse causing a latching close if waveform analysis based on the test close indicates that the fault has likely cleared. The test-boost approach can typically be implemented through a software and calibration upgrade to a conventional single-coil recloser, accomplishing results comparable to a dual-actuator recloser at a much lower cost. The recloser may perform iterative and feedback learning feedback processes to automatically improve its operation over time in response to measured fault and non-fault conditions and its success in predicting whether faults have cleared.

A method for reactivation of an electrical system of a vehicle comprising a first electrical system operating at a first lower voltage and a second electrical system operating at a second higher voltage, comprising: detecting a fault or a crash situation in the second electrical system; disconnecting a power source of the second electrical system; determining the fault of the second electrical system is no longer present or that the crash situation is resolved; reconnecting the power source to the second electrical system and increasing the voltage of the second electrical system from zero to an intermediate voltage lower than the second voltage; and if a detected current in the second electrical system is higher than a current threshold value; or if a detected voltage of the first electrical system is higher than a voltage threshold value; reducing the voltage of the second electrical system to zero.

A power supply comprises voltage regulation circuitry, a load-share controller, and overcurrent protection circuitry. The voltage regulation circuitry is configured to output a regulated voltage. The load-share controller is configured to control the voltage regulation circuitry to adjust the regulated voltage responsive to a load-share voltage signal (LSV) that indicates an amount of load current being delivered to a load. The overcurrent protection circuitry is configured to selectively couple the regulated voltage to the load. When the load current exceeds a threshold current, the overcurrent protection circuitry is configured to decouple the regulated voltage from the load. While the regulated voltage is decoupled from the load, and when the LSV signal indicates that load current is being delivered to the load by a different power supply, the overcurrent protection circuitry is configured to recouple the regulated voltage to the load.

An auto recovery circuit breaker (ARCB) device is disclosed that may include a step-down transformer which may provide a low voltage AC test signal to detect a fault in a phase line or neutral of an electric circuit. A first current transformer (CT) is positioned on the first line, and a second CT is positioned on the second line. Each of the first CT and the second CT may sense a current flowing through the electric circuit, and detect an earth leakage through the electric circuit. A microcontroller is configured to: monitor the analog signal in the circuit, detect earth leakage before powering ON the circuit, detect output short before power ON, and upon detection of a fault removal in the electrical circuit, turn ON a relay. Once turned ON, the ARCB device may continue test by sensing the CT’s provided in the phase and neutral lines.

A system and method for determining the optimal time to perform a pulse test to determine the presence of a fault after a switch opens to clear the fault to prevent generator instability. The method includes detecting the fault, opening a switch to clear the fault, determining an optimal time for performing the pulse test for determining the continued presence of the fault based on predetermined system data and parameters after the switch is opened so as to prevent the pulse test from occurring too early that could cause generator instability, and performing the pulse test at the optimal time to determine if the fault is still present. Determining the optimal time can use available system data and information, such as a priori knowledge or real-time behaviour. If the fault is not present, then the method determines a desired time to perform a reclose operation.