A method and circuit for determining and extinguishing electrical faults includes a power supply, and electrical load, a controller module, and electrical sensors, and when the controller module does not extinguish the electrical fault, another switch blows a fuse.

An arc detection apparatus is provided. The arc detection apparatus detects an arc using an electrical energy, eliminates the possibility of a false arc detection caused by noise due to a power environment, increases accuracy of arc detection, and prevents fires that may occur in a home or an industrial site due to an arc occurrence.

A method and circuit for determining and extinguishing electrical faults includes a power supply, and electrical load, a controller module, and electrical sensors, and when the controller module does not extinguish the electrical fault, another switch blows a fuse.

The present invention are a system and a method for controlling solar photovoltaic power generation on the basis of machine learning, the system comprising: solar photovoltaic modules; node control units for switching off a connected solar photovoltaic module when measured current, voltage and power data do not satisfy control data; a gateway unit for storing measured data; a real-time control module for classifying, comparing and analyzing data and storing same, and transmitting a control command to the gateway unit; and machine learning for monitoring a device and data, learning on the basis of machine learning, and extracting functional data required for controlling solar photovoltaic power generation so as to provide control service data according to the result of performed modeling.

Systems and methods are provided for detecting and compensating for loss of a phase of a three-phase power source, elements of the system including: a sensing unit, which measures current and voltage levels of each phase of the three-phase power source; a switching unit having three primary relays and three backup relays; and a microcontroller, configured to receive measurements from the sensing unit, to determine from the measurements a lost phase and a less-loaded phase of the two remaining phases, and responsively to activate the switching unit to disconnect the lost phase and to connect the less loaded phase to provide backup power in place of the lost phase.

In the disclosure, the occurrence of an arc is rapidly detected while the frequency of erroneous detection is suppressed. An arc detecting apparatus includes an arc presence/absence determining part determining presence or absence of an arc based on an AC current from a solar cell, and a repeat number setting part setting, based on the DC current from the solar cell, a repeat number of processing that the arc presence/absence determining part repeatedly performs to determine the presence or absence of the arc.

A method for detecting fault direction of a transmission line of an AC power system and a control system using the same. The method includes sampling current values and voltage values at one end of the transmission line for a series of time points; computing instantaneous voltage values at compensated point on the transmission line from the current value samples and the voltage value samples based on a time domain lumped parameter differential equation for the transmission line for the series of time points; recording the current value samples and the computed instantaneous voltage values at the compensated point; computing at least one voltage fault component each using the recorded computed instantaneous voltage values for at least the at least two of the series of time points; identifying the fault direction in consideration of the at least one computed voltage fault component and the at least one computed current fault component; and generating a fault direction signal indicating the identified fault direction. Where a fault directional element is designed using the voltage fault components at the compensated point, it will work well for the AC power system with strong power source.

The invention relates to a method for ascertaining an earth fault and the earth-fault direction in a three-phase network which is operated in a compensated manner or in an insulated manner. Value pairs of a zero voltage and a zero current are measured, the active or reactive energy is calculated, and a voltage flag and a current flag are combined by a Boolean link, wherein the presence of a earth fault is ascertained depending on the result, and a decision is made as to whether the earth-fault direction is signalled as forward or reverse at least on the basis of the sign of the active or reactive energy.

Methods and apparatus are provided for fault detection and direction determination with a phase overcurrent relay using individual phase torques and the negative sequence torque, and with a ground overcurrent relay using the zero sequence torque. A directional element includes a ground element logic circuit, a negative element logic circuit and a phase element logic circuit to evaluate the operation state of the system, detect a fault condition and determine the direction of the fault condition in an electrical power distribution system having multiple sources on a power grid.

A method, control system and protective relay are provided for detecting faulted phases of transmission lines in an AC power system. The method includes sampling electric signals at one end of the transmission lines at a series of time points; computing instantaneous voltage values of electric signals at compensated points on the transmission lines from the values of the sampled electric signals based on a time domain lumped parameter differential equation for the transmission lines for the series of time points; recording the computed instantaneous voltage values of the electric signals; computing fault component or sudden-change of the instantaneous voltage values of the electrical signals; detecting the faulted phases or fault types by comparing the calculated fault component of the instantaneous voltage values at the preset compensated points; and generating signals indicating the faulted phases of fault types.