To improve functional security in electric power systems, a fault detector is provided in the electric power system that is connected to the data communication bus and that evaluates streamed values of at least one process parameter. In order to detect an electric fault in the electric power system, the fault detector is arranged to send a fault present indication to the switching element when an electric fault is detected. The fault present indication is sent to and received by the switching element, before the tripping operation of the switching element is triggered upon receipt of the switching command from the automation system, and the switching element triggers the tripping operation of the switching element only when a fault present indication has been received.

The present disclosure relates to a recloser control that provides autosynchronization of a microgrid to an area electric power system (EPS). For example, a recloser control may include an output connector that is communicatively coupled to a recloser at a point of common coupling (PCC) between the area EPS and the microgrid. The recloser control may include a processor that acquires a first set of measurements indicating electrical characteristics of the area EPS and acquires a second set of measurements indicating electrical characteristics of the microgrid. The recloser control may send synchronization signals to one or more distributed energy resource (DER) controllers to synchronize one or more DERs to the area EPS based on the first set of measurements and the second set of measurements.

A time alignment method for a differential protection device, the differential protection device and a differential protection system are disclosed. The time alignment method includes obtaining a plurality of current sampled values and a count value of each current sampled values; resampling the plurality of current sampled values with sampling frequency of J points/cycle to obtain a plurality of current resampled values; and performing Fourier transform on the plurality of current resampled values to obtain a plurality of temporally arranged current Fourier values, the plurality of current Fourier values includes a reference current Fourier value corresponding to the sampling moment of the current sampled value whose count value is the first value in the plurality of current sampled values, and the reference current Fourier value is determined based on the reference current resampled value and the J−1 current resampled values that temporally arranged before the reference current resampled value.

Provided is a determination method of differential protection suitable for an electricity transmission line with multi-terminal T-connection. The determination method includes: sampling and calculating all phase currents, and calculating a maximum fault component current Δİ.sub.max in phase current amplitudes of each phase current, a differential current I.sub.cd in the each phase current, a resistive current I.sub.res in the each phase current and a vector sum Δİ.sub.Σ of fault component currents except Δİ.sub.max in the phase current amplitudes of the each phase current; and comparing the maximum fault component current Δİ.sub.max in phase current amplitudes of each phase current and a threshold setting value I.sub.max0, determining a value of a resistive coefficient K corresponding to the phase current amplitudes of the each phase current according to a comparison result, and performing differential determination on the differential current I.sub.cd and the resistive current I.sub.res in phase current amplitudes of the each phase current according to a differential determination formula: if the differential current I.sub.cd of the target phase satisfies the above differential determination formula, it is determined that a fault occurs in an area of the target phase.

Described herein are improvements for a power system by operating the power system using updated performance characteristics for a protection device. In one example, a method includes operating the power system based on a first operational curve for a first protection device of the one or more protection devices. The first operational curve indicates conditions upon which the first protection device will trip. The method also provides obtaining trip information describing conditions that cause the first protection device to trip at each of one or more trip occurrences during operation of the power system. The method further provides adjusting the first operational curve to generate an adjusted first operational curve that reflects the trip information and operating the power system based on the adjusted first operational curve.

Wireless communication enabled circuit breakers are described. Methods associated with such wireless communication enabled circuit breakers are also described. The wireless communication enabled circuit breakers may controlled by a remote entity. The remote entity may wirelessly case the wireless communication enabled circuit breakers to trip.

Safety power disconnection for remote power distribution in power distribution systems is disclosed. The power distribution system includes one or more power distribution circuits each configured to remotely distribute power from a power source over current carrying power conductors to remote units to provide power for remote unit operations. A remote unit is configured to decouple power from the power conductors thereby disconnecting the load of the remote unit from the power distribution system. A current measurement circuit in the power distribution system measures current flowing on the power conductors and provides a current measurement to the controller circuit. The controller circuit is configured to disconnect the power source from the power conductors for safety reasons in response to detecting a current from the power source in excess of a threshold current level indicating a load.

Techniques for identifying faulty sections in power transmission lines are described. A first positive sequence voltage and first positive sequence current at a first terminal of a power transmission line are computed based on a first voltage and first current at the first terminal. A second positive sequence voltage and second positive sequence current at a second terminal are computed based on a second voltage and second current. Based on the first positive sequence voltage and the first positive sequence current, a first junction voltage and first junction current from the first terminal at a junction are computed. Based on the second positive sequence voltage and the second positive sequence current, a second junction voltage and second junction current from the second terminal are computed. A ratio of a junction voltage parameter to a junction current parameter is computed. Using the ratio, the faulty section is identified.

Provided is a determination method of differential protection suitable for an electricity transmission line with multi-terminal T-connection. The determination method includes: sampling and calculating all phase currents, and calculating a maximum fault component current Δİ.sub.max in phase current amplitudes of each phase current, a differential current I.sub.cd in the each phase current, a resistive current I.sub.res in the each phase current and a vector sum Δİ.sub.Σ of fault component currents except Δİ.sub.max in the phase current amplitudes of the each phase current; and comparing the maximum fault component current Δİ.sub.max in phase current amplitudes of each phase current and a threshold setting value I.sub.max0, determining a value of a resistive coefficient K corresponding to the phase current amplitudes of the each phase current according to a comparison result, and performing differential determination on the differential current I.sub.cd and the resistive current I.sub.res in phase current amplitudes of the each phase current according to a differential determination formula: if the differential current I.sub.cd of the target phase satisfies the above differential determination formula, it is determined that a fault occurs in an area of the target phase.

A method and device for timing in time-varying distance protection based on multiple lines of a tower. The method includes: collecting an instantaneous current value at a time-varying distance protection installation location in the multiple lines of the tower, and acquiring preset parameters; calculating, according to the preset parameters and a multi-line ranging model, a multi-line ranging result; calculating, according to the preset parameters, the multi-line ranging result, and an adaptive calculation model, time of a section-II distance protection action and final time of a section-III distance protection action; and determining, according to the instantaneous current value, the preset parameters, and a cross-line failure auxiliary criterion model, final time of the section-II distance protection action.