Abstract: A system and method of dynamically estimating the short circuit current availability (SCCA) at a node in an alternating current electrical distribution system by examining the spectral composition of current drawn by a direct current charging circuit connected to the node. A correlative relationship between the total harmonic current distortion (THDi) in the current drawn by the charging circuit and the SCCA at the node is established for a particular charging circuit. An estimation of the SCCA at the node is accomplished by taking current measurements of current drawn by the charging circuit, analyzing those current measurements to determine the THDi, and estimating a corresponding value of SCCA based on the determined THDi. A method is also provided for calibrating a particular charging circuit to have a reactance and resistance suitable for use in estimating SCCA.

Abstract: Centralized coordination of setting and adjusting trip settings of electronic circuit breakers in an electrical distribution system by monitoring short circuit current availability (SCCA) and adjusting trip settings based on received SCCA estimates from SCCA monitoring devices installed at main, feeder, and branch nodes of the distribution system. The SCCA monitoring devices are capable of automatically estimating the SCCA in the circuit or node at which the SCCA device is installed and transmitting SCCA estimates to a controller, which uses the SCCA estimates to coordinate adjustments to trip settings for the various circuit breakers. Depending on the node position of the circuit breaker and the corresponding SCCA at that node, the controller adjusts in real-time the short-circuit trip settings for the circuit breakers so that they are below the SCCA value. Optional user-inputted settings can affect the trip setting adjustments, such as transient loading conditions that can influence the SCCA estimates.

Abstract: Centralized coordination of setting and adjusting trip settings of electronic circuit breakers in an electrical distribution system by monitoring short circuit current availability (SCCA) and adjusting trip settings based on received SCCA estimates from SCCA monitoring devices installed at main, feeder, and branch nodes of the distribution system. The SCCA monitoring devices are capable of automatically estimating the SCCA in the circuit or node at which the SCCA device is installed and transmitting SCCA estimates to a controller, which uses the SCCA estimates to coordinate adjustments to trip settings for the various circuit breakers. Depending on the node position of the circuit breaker and the corresponding SCCA at that node, the controller adjusts in real-time the short-circuit trip settings for the circuit breakers so that they are below the SCCA value. Optional user-inputted settings can affect the trip setting adjustments, such as transient loading conditions that can influence the SCCA estimates.

Abstract: Embodiments according to the present invention provide an Impedance-based Arc-Fault Determination Device (IADD) and method that, when attached to an electrical node on the power system and through observations on voltage, current and phase shift with a step load change, determine the effective Thevenin equivalent circuit or Norton equivalent circuit at the point of test. The device and method determine the expected bolted fault current at the test location of interest, which enables calculation of incident energy and the assignment of a flash-hazard risk category.

Abstract: A system and method of dynamically estimating the short circuit current availability (SCCA) at a node in an alternating current electrical distribution system by examining the spectral composition of current drawn by a direct current charging circuit connected to the node. A correlative relationship between the total harmonic current distortion (THDi) in the current drawn by the charging circuit and the SCCA at the node is established for a particular charging circuit. An estimation of the SCCA at the node is accomplished by taking current measurements of current drawn by the charging circuit, analyzing those current measurements to determine the THDi, and estimating a corresponding value of SCCA based on the determined THDi. A method is also provided for calibrating a particular charging circuit to have a reactance and resistance suitable for use in estimating SCCA.

Abstract: Embodiments according to the present invention provide an Impedance-based Arc-Fault Determination Device (IADD) and method that, when attached to an electrical node on the power system and through observations on voltage, current and phase shift with a step load change, determine the effective Thevenin equivalent circuit or Norton equivalent circuit at the point of test. The device and method determine the expected bolted fault current at the test location of interest, which enables calculation of incident energy and the assignment of a flash-hazard risk category.

Abstract: Embodiments according to the present invention provide an Impedance-based Arc-Fault Determination Device (IADD) and method that, when attached to an electrical node on the power system and through observations on voltage, current and phase shift with a step load change, determine the effective Thevenin equivalent circuit or Norton equivalent circuit at the point of test. The device and method determine the expected bolted fault current at the test location of interest, which enables calculation of incident energy and the assignment of a flash-hazard risk category.