A system and method for determining when an electronic interrupting device will open in response to detecting overcurrent, where the interrupting device protects a transformer in a power distribution network. The method includes obtaining a time/current through fault protection curve that is defined by a plurality of time/current points for the transformer that identifies when the transformer may experience thermal or mechanical damage in response to a certain current flow over a certain time in the transformer windings, selecting a time multiplier, and determining an operating curve for the interrupting device by multiplying the multiplier and a time portion of each of the plurality of time/current points on the through fault protection curve, where the operating curve identifies when the interrupting device will open in response to a certain current flow over a certain time.

A photovoltaic array of photovoltaic solar cells; a smart dynamic programmable circuit breaker for electrically providing a pulsed 100 microseconds duration short circuit to the photovoltaic array electrical outputs, wherein a response time for the smart dynamic programmable circuit breaker is more than 1 millisecond when responding to a short circuit; a computer program comprising instructions that when executed by the processor perform functions that control the smart dynamic programmable circuit breaker, the computer program comprising: instructions to command the smart dynamic programmable circuit breaker to initiate the 100 microsecond pulsed short circuit; instructions to measure a current magnitude and current rise time of the smart photovoltaic system outputs during the 100 microsecond pulsed short circuit; and instructions to select a behavior curve from a plurality of smart dynamic programmable circuit breaker behavior curves 10% above the current magnitude and current rise time during the pulsed short circuit.

A method and switch module are for operating a load zone on a power grid. In an embodiment of the method, at least one load profile is captured and stored during setup operation of the load zone, documenting a temporal progression of a load zone current or voltage in a time window after closing of the current path. Based on the at least one load profile, a tolerance range for the temporal progression of at least one operating parameter of the load zone in the time window is defined. During normal operation of the load zone, the temporal progression of the at least one operating parameter in the time window after closing the current path is monitored and the load zone is disconnected from the power grid upon the temporal progression of an operating parameter in the time window, after closing the current path, being outside the tolerance range.

A method operates an electrical network, in particular a power supply network or power distribution network, in which protective apparatuses are connected to a multiplicity of measurement positions. The protective apparatuses monitor an assigned network section of the electrical network and are respectively parameterized with at least one apparatus-side parameter value which influences the mode of operation of the respective protective apparatus. Accordingly, the protective apparatuses are remotely readable and are connected to a superordinate central device, and the central device reads out the apparatus-side parameter values from the protective apparatuses.

A solid state circuit breaker apparatus includes a solid state switch, a current sensor, and a control circuit. The control circuit is programmed to operate the solid state switch by, in response to receipt of a signal from the current sensor indicating that an overcurrent condition exists: (i) using pulse width modulation to generate a set of control pulses; and (ii) using the control pulses to trigger the solid state switch to open and close in a pattern that corresponds to the control pulses, and thus limit an amount of let-through current that the solid state switch may pass to a load. The amount of let-through current that the solid state switch may pass to the load may be, for example, a threshold level above which the overcurrent condition will exist.

The present invention relates to estimating source impedances across one or more transmission lines connecting at least two substations. Each substation is associated with an equivalent source having a respective source impedance. Voltage and current measurements and status signals are obtained. The voltage and current measurements provide terminal or bus voltages and line currents at each terminal, and the status signals are associated with switching events at the one or more transmission lines or at the substations. An event associated with a disturbance or current injection is detected from one or more of the obtained measurements and the obtained status signals. The source impedance of each equivalent source is estimated based on the event, using line parameters and the voltage and current measurements associated with the event.

Systems, methods, techniques and apparatuses of high current protection are disclosed. One exemplary embodiment is a power system comprising a solid-state circuit breaker including a solid-state switching device, an energy dissipation branch, an assistive branch, and a controller. The energy dissipation branch is coupled in parallel with the solid-state switching device and includes an energy dissipation device. The assistive branch is coupled in parallel with the solid-state switching device and includes a resistor, an inductor, and a galvanic isolation switching device coupled together in series. The controller is configured to determine the solid-state circuit breaker is conducting a high magnitude current, select a continuous current limiting mode or an intermittent current limiting mode, and operate the solid-state switching device based on the selected current limiting mode.

A method for characterizing power quality events in an electrical system includes deriving electrical measurement data for at least one first virtual meter in an electrical system from (a) electrical measurement data from or derived from energy-related signals captured by at least one first IED in the electrical system, and (b) electrical measurement data from or derived from energy-related signals captured by at least one second IED in the electrical system. In embodiments, the at least one first IED is installed at a first metering point in the electrical system, the at least one second IED is installed at a second metering point in the electrical system, and the at least one first virtual meter is derived or located at a third metering point in the electrical system. The derived electrical measurement data may be used to generate or update a dynamic tolerance curve associated with the third metering point.

A circuit interrupter including a current sensor having a normal sensor output and an over current detection output, a solid state switch module structured to have a closed state to allow current to flow through the circuit interrupter and an open state to interrupt current flowing through the circuit interrupter, a gate driver structured to control the solid state switch module including a desaturation function output, wherein the gate driver is structured to cause the solid state switch module to interrupt current flowing through the circuit interrupter when the DESAT function output changes to the on state, and an electronic trip circuit structured to output a trip signal to the gate driver when the normal sensor output reaches a first threshold level or the overcurrent detection output changes to the on state.

A field programmable circuit breaker receives a measurement of a displacement of a terminal spring element, from a detector associated with the terminal spring element, when a field wire is inserted into the terminal spring element. The terminal spring element provides a wire clamp force in a terminal configured to receive the inserted field wire. A trip current value is determined based on the wire size and a time interval is measured during which the current in the field wire is continuously greater than the trip current value. A trip curve is accessed corresponding to the trip current value to determine whether the measured time interval exceeds a maximum interval indicated by the trip curve. A tripping signal provided to a current monitoring unit interrupts the current when the measured interval exceeds the maximum interval for the measured current to be continuously greater than the trip current value.