An electrical power network employing fault location, isolation and system restoration. The system includes a plurality of switching devices electrically coupled along a power line downstream of a fault interrupting device. The switching devices each have current and voltage sensing capability and the capability to provide pulse tests for detecting fault presence. The fault interrupting device performs reclosing operations, and when the plurality of switching devices detect fault presence a predetermined number of times in coordination with reclosing operations performed by the fault interrupting device and detect loss of voltage, each switching device opens. The fault interrupting device closes when the switching devices open, and the switching devices sequentially pulse test and close from a furthest upstream switching device when detecting return of voltage and no fault presence until a switching device closest to the fault pulse tests and detects fault presence and locks open.

A system includes a dry contact with a first pair of switchable electrodes, a wet contact with a second pair of switchable electrodes, an arc suppressor, and a controller circuit operatively coupled to the arc suppressor and the first and second pairs of switchable electrodes. The controller circuit is configured to detect a failure of the wet contact and determine a stick duration associated with the first pair of switchable electrodes. The stick duration is based on a duration between an instance when a coil of the dry contact is deactivated and an instance of separation of the first pair of switchable electrodes during deactivation of the coil. The controller circuit generates, in-situ and in real-time, health assessment for the first pair of switchable electrodes based on a comparison of the determined stick duration with an average stick duration associated with a window of observation.

The present disclosure relates to a recloser control that monitors compliance of a standard for distributed energy resources (DERs). For example, a method includes obtaining power system measurements between a microgrid and an area electronic power system (EPS). The method includes determining a rate of change of power (RoCoP) based on the power system measurements. The method includes determining that a DER exceeded a threshold of the area EPS based at least in part on the RoCoP. The method includes sending a signal indicating that the DER has violated the threshold.

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.

In aspects, the present invention provides a method for controlled energizing of a transformer (150) being connected to a first electrical subsystem (110) through a first circuit breaker (140). The method comprises acquiring electrical current waveform in a first phase of the transformer during a closing operation of the first circuit breaker at an instance for switching determined by a controller (130), determining a first peak (310) in the current in the first phase within a first predetermined time window (Tpw), calculating a first correction factor for adjusting the instance for switching in the first phase, and adjusting the instance for switching based on the calculated first correction factor for performing a next controlled energization at the adjusted instance of switching in the first phase.

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.

The disclosure provides an Internet of things device and a battery power supply circuit thereof. A voltage of a battery is compared with a predetermined over-discharge voltage to generate a comparison signal. A battery protection circuit serves as a power supply path from the battery to a load and determines whether to cut off the power supply path according to the comparison signal. The battery protection circuit cuts off the power supply path when the voltage of the battery decreases from a value greater than the predetermined over-discharge voltage to a value less than the predetermined over-discharge voltage, but does not turn on the power supply path when the voltage of the battery increases from a value less than the predetermined over-discharge voltage to a value greater than the predetermined over-discharge voltage.

The disclosure provides an Internet of things device and a battery power supply circuit thereof. A voltage of a battery is compared with a predetermined over-discharge voltage to generate a comparison signal. A battery protection circuit serves as a power supply path from the battery to a load and determines whether to cut off the power supply path according to the comparison signal. The battery protection circuit cuts off the power supply path when the voltage of the battery decreases from a value greater than the predetermined over-discharge voltage to a value less than the predetermined over-discharge voltage, but does not turn on the power supply path when the voltage of the battery increases from a value less than the predetermined over-discharge voltage to a value greater than the predetermined over-discharge voltage.

A method and apparatus for tertiary control with over-current protection. In one embodiment, the method comprises calculating at least one unconstrained optimal net intertie target for an area of a power network; calculating, for each resource within the area, optimal scheduled current to achieve the at least one unconstrained optimal net intertie target; calculating, using the optimal scheduled currents and a plurality of stress coefficients, net scheduled current for each power line segment within the area; comparing the net scheduled currents to corresponding stress thresholds to identify any stress violations; reducing, when the comparing step identifies one or more stress violations, the optimal scheduled current for one or more resources contributing to the one or more stress violations; and calculating, when the comparing step identifies the one or more stress violations, updated optimal scheduled current for one or more resources not contributing to the one or more stress violations.

A method and apparatus for tertiary control with over-current protection. In one embodiment, the method comprises calculating at least one unconstrained optimal net intertie target for an area of a power network; calculating, for each resource within the area, optimal scheduled current to achieve the at least one unconstrained optimal net intertie target; calculating, using the optimal scheduled currents and a plurality of stress coefficients, net scheduled current for each power line segment within the area; comparing the net scheduled currents to corresponding stress thresholds to identify any stress violations; reducing, when the comparing step identifies one or more stress violations, the optimal scheduled current for one or more resources contributing to the one or more stress violations; and calculating, when the comparing step identifies the one or more stress violations, updated optimal scheduled current for one or more resources not contributing to the one or more stress violations.