Systems and methods to isolate faults and restore power are described herein. For example, an intelligent electronic device (IED) may receive a blocking signal indicating a fault is detected on a power line. The IED may obtain one or more current measurements of the power line. The IED may determine that a fault is not present on the power line at the IED based on the one or more current measurements. The IED may trip a first current interruption device of the IED The IED may send a close permissive signal to another IED indicating that the other IED is permitted to permitted to close an open current interruption device of the other IED to restore power to one or more loads.

In order to ensure safe operation of a multi-phase system, even a system including a plurality of phases, a number of phase groups is provided, which comprises some of the phases, wherein phase currents of the number of phase groups are merged in a group node to form a group sum current and a group sum current measurement value of the group sum current is captured. The current measurement values belonging to the number of phase groups are summed up to form a group sum and the group sum is compared with the group sum current measurement value to validate the phase currents of the phases in order to ensure safe operation.

A cooking apparatus and a controlling method, where the cooking apparatus includes a plurality of power input terminals, a plurality of heaters, a detection circuit connected to the power input terminals for detecting the phase of power input into the power input terminals, and a processor. The processor configured to identify a phase difference of input power based on an electronic signal of the power output from the detection circuit, and, based on the phase difference being within one of a plurality of threshold ranges, identify the voltage between live terminals among the plurality of power input terminals based on the phase difference of the power and control at least one heater among the plurality of heaters according to the identified voltage between the live terminals, and, based on the phase difference being outside the plurality of threshold ranges, stop the operation of the cooking apparatus.

The invention provides a method and device for fault section identification in a multi-terminal mixed line. The method comprises obtaining positive sequence voltage and current phasors from measurements of voltages and currents at each terminal of the mixed line. The method further comprises calculating a voltage phasor for each terminal, wherein the calculation of the voltage phasor for a first terminal is performed using at least the voltage and current phasors obtained for one of a second terminal and a third terminal, and the current phasor obtained for the first terminal. Thereafter, the method comprises determining a section of the mixed line having the fault, based on comparison of the calculated and obtained voltage phasors for each terminal. In addition, the method comprises controlling a switching device with a re-trip signal generated based on the determination of the section with the fault.

An electrical apparatus configured to electrically connect to a multi-phase alternating current (AC) electrical power distribution network includes: an input electrical network including: a plurality of input nodes, each configured to electrically connect to one phase of the multi-phase AC electrical power distribution network; at least one non-linear electronic component electrically connected to the input electrical network; an impedance network electrically connected between the input electrical network and ground; and a control system configured to: access a voltage signal that represents a voltage over time at the input electrical network; determine a frequency content of the voltage signal; determine a property of the frequency content; and determine whether an input current performance condition exists in the electrical apparatus based the property of the frequency content.

In the field of multi-terminal electrical power network protection, a protection apparatus comprises a measurement apparatus to measure the respective terminal current (I.sub.L, I.sub.R1, I.sub.R2, I.sub.R3, I.sub.R4, I.sub.R5) flowing at each terminal (L, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5) in a multi-terminal network that includes a plurality of electrically interconnected terminals (L, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5). The protection apparatus also includes a control unit that is programmed to process the measured terminal currents (I.sub.L, I.sub.R1, I.sub.R2, I.sub.R3, I.sub.R4, I.sub.R5) to obtain first and second summed values (I.sub.POS(n), I.sub.NEG(n)). The first summed value (I.sub.POS(n)) is the sum at a given time (n) of the or each terminal current (I.sub.L, I.sub.R1, I.sub.R2, I.sub.R3, I.sub.R4, I.sub.R5) flowing in a first direction (Di) relative to a corresponding terminal (L, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5) and the second summed value (I.sub.NEG(n)) is the sum at the same given time (n) of the or each terminal current (I.sub.L, I.sub.R1, I.sub.R2, I.sub.R3, I.sub.R4, I.sub.R5) flowing in a second direction (D.sub.2) opposite the first direction (D.sub.1) relative to the corresponding terminal (L, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5). The control unit is further programmed to compare the phase of the first summed value (I.sub.POS(n)) with the phase of the second summed value (I.sub.NEG(n)) to determine whether a fault in the multi-terminal network is internal or external to the multi-terminal network and thereafter to produce an internal fault output signal upon the determination of an internal fault.

A system level electrostatic discharge (ESD) detection device includes a phase detection unit including at least one phase detector suitable for detecting a phase difference between a plurality of supply voltages or between a plurality of input signals; a storage unit suitable for shifting between a first and a second state, the second state indicating a phase difference detected by the phase detection unit; and an output unit suitable for outputting a system level electrostatic discharge (ESD) detection signal according to the first or second state of the storage unit.

A circuit interrupter including a first electrical conductor, a second electrical conductor, separable contacts, an operating mechanism configured to open and close said separable contacts, a trip circuit configured to trip open said separable contacts, a ground fault detection circuit configured to sense a difference between a current through the first electrical conductor and a current through the second electrical conductor and to output an output signal based on said sensed difference, a power supply, a confirmation circuit structured to input a confirmation signal to the power supply, and a processor configured to receive said direct current power and said output signal. The processor is configured to determine whether a characteristic of said confirmation signal is present in said output signal and to control the trip circuit based on said determination.

In a method and a corresponding device for detecting phase failures in a converter, current regulators of a positive phase sequence system and current regulators of a negative phase sequence system are provided for the current control of the converter, wherein the current regulators of the positive phase sequence system and the current regulators of the negative phase sequence system each have an integrator, resulting, in the case of a network fault, in coupling of the integrators. At least one measured or calculated value is checked by a monitoring unit for a course that is typical of the coupling of the integrators, wherein the monitoring unit generates a fault signal if such a typical course is detected.

A cooking apparatus and a controlling method, where the cooking apparatus includes a plurality of power input terminals, a plurality of heaters, a detection circuit connected to the power input terminals for detecting the phase of power input into the power input terminals, and a processor. The processor configured to identify a phase difference of input power based on an electronic signal of the power output from the detection circuit, and, based on the phase difference being within one of a plurality of threshold ranges, identify the voltage between live terminals among the plurality of power input terminals based on the phase difference of the power and control at least one heater among the plurality of heaters according to the identified voltage between the live terminals, and, based on the phase difference being outside the plurality of threshold ranges, stop the operation of the cooking apparatus.