The present invention relates to resistive leakage current in a surge arrester that measures not voltage but leakage current alone in the surge arrester to obtain a resistive leakage current included in the leakage current so as to compensate for shortcomings in conventional metal-oxide surge arresters. The present invention performs a reference point detecting step (S20) to select a reference point by performing pattern analysis based on a characteristic pattern shown in a total leakage current (I.sub.T) when an applied voltage is 0V, a resistive leakage current calculating step (S30) to calculate a resistive leakage current by Fourier series-expanding the total leakage current (I.sub.T) starting at the reference point, and reference point verifying/correcting steps (S40 and S41) to correct the reference point until a characteristic pattern of the resistive leakage current (I.sub.R) according to non-linear resistance characteristics of the surge arrester (1) is shown so that the resistive leakage current (I.sub.R) is recalculated, and the present invention determines that the resistive leakage current (I.sub.R) calculated based on the completely corrected reference point is the resistive leakage current of the surge arrester (1).

The present invention relates to resistive leakage current in a surge arrester that measures not voltage but leakage current alone in the surge arrester to obtain a resistive leakage current included in the leakage current so as to compensate for shortcomings in conventional metal-oxide surge arresters. The present invention performs a reference point detecting step (S20) to select a reference point by performing pattern analysis based on a characteristic pattern shown in a total leakage current (I.sub.T) when an applied voltage is 0V, a resistive leakage current calculating step (S30) to calculate a resistive leakage current by Fourier series-expanding the total leakage current (I.sub.T) starting at the reference point, and reference point verifying/correcting steps (S40 and S41) to correct the reference point until a characteristic pattern of the resistive leakage current (I.sub.R) according to non-linear resistance characteristics of the surge arrester (1) is shown so that the resistive leakage current (I.sub.R) is recalculated, and the present invention determines that the resistive leakage current (I.sub.R) calculated based on the completely corrected reference point is the resistive leakage current of the surge arrester (1).

Provided is a circuit abnormality diagnosis device capable of simply and easily diagnosing a circuit abnormality, a current generating device including the circuit abnormality diagnosis device, a deployed object ejection device for a flight object including the current generating device, an airbag device for a flight object including the current generating device, and a cutting device for a flight object including the current generating device.

A circuit abnormality diagnosis device 110 includes a calculation unit 1, an inspection power supply 2, a rectifier element 3, overcurrent preventing resistors 4 and 5, a voltage amplification unit 6, a voltage reading unit 7, and a light emitting unit 8, and performs a circuit abnormality diagnosis at a preset time (including the time of initial mounting) or every predetermined time. The circuit abnormality diagnosis device 110 diagnoses (determines) that a case where a voltage value is within a range of a first voltage value V.sub.1 or more and a second voltage value V.sub.2 or less, which is set in advance as a range of voltage values indicating that a circuit is normal, is a normal state, a case where the voltage value is less than the voltage value V.sub.1 is a short-circuit state in which the circuit is short-circuited, and a case where the voltage value is higher than the voltage value V.sub.2 is a disconnection state in which the circuit is disconnected.

Provided is a circuit abnormality diagnosis device capable of simply and easily diagnosing a circuit abnormality, a current generating device including the circuit abnormality diagnosis device, a deployed object ejection device for a flight object including the current generating device, an airbag device for a flight object including the current generating device, and a cutting device for a flight object including the current generating device.

A circuit abnormality diagnosis device 110 includes a calculation unit 1, an inspection power supply 2, a rectifier element 3, overcurrent preventing resistors 4 and 5, a voltage amplification unit 6, a voltage reading unit 7, and a light emitting unit 8, and performs a circuit abnormality diagnosis at a preset time (including the time of initial mounting) or every predetermined time. The circuit abnormality diagnosis device 110 diagnoses (determines) that a case where a voltage value is within a range of a first voltage value V.sub.1 or more and a second voltage value V.sub.2 or less, which is set in advance as a range of voltage values indicating that a circuit is normal, is a normal state, a case where the voltage value is less than the voltage value V.sub.1 is a short-circuit state in which the circuit is short-circuited, and a case where the voltage value is higher than the voltage value V.sub.2 is a disconnection state in which the circuit is disconnected.

A ground fault detection device includes: a detection capacitor; a switch group for switching between a first charging path connecting the battery and the detection capacitor, a second charging path connecting the battery, a negative side insulation resistance and the detection capacitor, a third charging path connecting the battery, a positive side insulation resistance and the detection capacitor, and a measurement path for measuring a charging voltage of the detection capacitor; and a controller configured to calculate the insulation resistance based on a charging voltage measured value of the detection capacitor which exists after charging each of the charging paths, wherein after measurement of the charging voltage of the second charging path, the controller is configured to cause the switch group to switch to the third charging path before switching to the first charging path.

A ground fault detection device includes: a detection capacitor; a switch group for switching between a first charging path connecting the battery and the detection capacitor, a second charging path connecting the battery, a negative side insulation resistance and the detection capacitor, a third charging path connecting the battery, a positive side insulation resistance and the detection capacitor, and a measurement path for measuring a charging voltage of the detection capacitor; and a controller configured to calculate the insulation resistance based on a charging voltage measured value of the detection capacitor which exists after charging each of the charging paths, wherein after measurement of the charging voltage of the second charging path, the controller is configured to cause the switch group to switch to the third charging path before switching to the first charging path.

Systems, methods, and computer-readable media are disclosed for high impedance detection in electric distribution systems. An example method may include calculating, by a processor, a relative randomness of a signal, wherein the relative randomness is a derivative of a first scale wavelet transform divided by an energy of the signal. The example method may also include calculating, by the processor, one or more scales of a wavelet transform of the signal. The example method may also include calculating, by the processor, one or more energy ratios between energy of the wavelet transform in the one or more scales. The example method may also include calculating, by the processor, a zero-crossing phase difference between a third harmonic and a fundamental component of the signal. The example method may also include determining, by the processor, that a high impedance fault occurs based on at least one of: the relative randomness, a comparison between the one or more scales of the wavelet transform, and the zero-crossing phase difference.

An arc fault detection system senses current flow in a power source branch and in one or more load branches in an electrical system. Over a frequency range divided into a predetermined number of frequency bins, a controller records and tallies the branch having largest magnitude of power spectral density for each frequency bin. The branch having highest total tally is determined to be the branch in which the arc fault occurred and can then safely be isolated from the electrical system.

An arc fault detection system senses current flow in a power source branch and in one or more load branches in an electrical system. Over a frequency range divided into a predetermined number of frequency bins, a controller records and tallies the branch having largest magnitude of power spectral density for each frequency bin. The branch having highest total tally is determined to be the branch in which the arc fault occurred and can then safely be isolated from the electrical system.

A semiconductor integrated circuit includes: one input terminal; multiple output terminals; multiple first current control elements connected between the input terminal and the respective output terminals; a control circuit that controls the first current control elements; a fault detection circuit that includes multiple voltage comparator circuits each of which compares a voltage proportional to a voltage of one of the output terminals with a predetermined threshold voltage and that detects an open-circuit state or a short-circuit state of the output terminals; an external terminal connected to an external resistor; a voltage convertor circuit that generates the threshold voltage according to a voltage of the external terminal that is generated by flowing a current through the external resistor, the threshold voltage being applied to an input terminal of each of the voltage comparator circuits; and a detection result output terminal for outputting a detection result by the fault detection circuit.