A power restoration system for restoring power to feeder segments in response to a fault. The system includes a reclosing device having a switch and one or more sensors for measuring current and/or voltage on the feeder, where the reclosing device performs a pulse testing process to determine circuit fault conditions. The system also includes a plurality of switching devices electrically coupled along the feeder, where each switching device includes a section switch and one or more sensors for measuring current and/or voltage on the at least one feeder. In one embodiment, each switching device recognizes predetermined pulse codes having a sequence of pulses, where the reclosing device uses the pulse testing process to generate and selectively transmit defined pulse codes on the feeder that selectively cause the section switches to change states between an open state and a closed state depending on the code.

A method for preventing ground fault in a three-phase electric transmission line system caused by a line break, includes: providing a programmable relay protection system, including a plurality of relay devices on each line, programmed to include: preset parameter ranges of at least two electric operating conditions, at least one high sensitivity instantaneous undercurrent and at least one high sensitivity condition selected from line differential overcurrent and negative sequence overcurrent (and combinations thereof), the preset ranges being acceptable operating parameter ranges; monitoring; permitting closed circuit operation when all of the lines show that the two operating conditions are within the preset acceptable operating parameter ranges; tripping a circuit breaker on a broken line when that line shows that the two operating conditions are outside the preset parameter ranges; and shutting down power to the broken line before it otherwise causes a ground fault or other short circuit.

A short circuit test device includes: a first line test conductor couplable to a first load line conductor of an electric load network and a neutral test conductor couplable to a neutral conductor of the electric load network; a voltage source switchable to the first line test conductor and the neutral test conductor to output a predefinable test signal; a measurement unit for measuring an electric voltage and/or current, the measurement unit including measurement inputs which are connectable to the first line test conductor and the neutral test conductor, the measurement unit including an output for providing a measurement signal; and a control unit connected to the voltage source and the measurement unit, the control unit: causing the voltage source to apply a test voltage to the first line test conductor and the neutral test conductor and comparing the measurement signal provided by the measurement unit.

A circuit breaker distribution system is configured to provide selective coordination. The system comprises a solid-state switch disposed as a main or upstream breaker and a switch with an over current protection disposed as a branch or downstream breaker. The solid-state switch comprises a microcontroller including a processor and a memory, and computer-readable logic code stored in the memory which, when executed by the processor, causes the microcontroller to: allow repeated pulses of current through to the branch or downstream breaker in an event of an overload or short circuit, and choose a maximum current limit for the solid-state switch as a “chop level” such that the chop level is chosen higher than a rated current of the solid-state circuit breaker but low enough that the solid-state switch is not damaged from repeated pulses over a period of time needed to switch OFF the branch or downstream breaker.

A circuit breaker distribution system is configured to provide selective coordination. The system comprises a solid-state switch disposed as a main or upstream breaker and a switch with an over current protection disposed as a branch or downstream breaker. The microcontroller to: allow repeated pulses of current through to the branch or downstream breaker in an event of an overload or short circuit, choose a maximum current limit for the solid-state switch as a “chop level” such that the chop level is chosen higher than a rated current of the solid-state circuit breaker but low enough that the solid-state switch is not damaged from repeated pulses over a period of time needed to switch OFF the branch or downstream breaker and add a pulse interval after the current chops to zero but before the solid-state circuit breaker returns to an ON state for a next pulse to begin.

An electronic device for series connection on a power supply line includes a plurality of switches and a control unit configured to perform the following steps: operating error detection means during operation of the device in a first mode; operating the device in a second mode in response to an erroneous power state being detected by the error detection means during operation of the device in the first mode; operating the error detection means during operation of the device in the second mode in order to determine an error location associated with the erroneous power state detected by the error detection means during operation of the device in the first mode.

A detection scheme for temporary overvoltages and/or ground fault overvoltages in electric power systems is described. Current passing through a surge arrestor component of the power system is monitored. An algorithm for identifying one or more frequency components of the measured current signal is performed to screen out unwanted harmonics. In some embodiments, this is a frequency domain analysis. The frequency component(s) of the current signal is then compared to a calculated pickup current or pickup voltage of the system to determine if system protection steps should be undertaken.

A system includes a first circuit breaker comprising a first solid state switch, first mechanical contacts, and a current sensor structured to sense current flowing through the first circuit breaker, and a second circuit breaker electrically coupled to the first circuit breaker and being structured to interrupt current flowing to the first circuit breaker, wherein the first circuit breaker is structured to transmit, to the second circuit breaker, a request upon detecting a failure mode, and wherein the second circuit breaker is structured to interrupt current flowing to the first circuit breaker in response to receiving the request, and the first circuit breaker is further structured to open the first mechanical contacts when the current flowing through the first circuit breaker drops to a predetermined level.

An electrical system for a motor vehicle includes a current distributor; a plurality of first lines which are designed to connect a corresponding plurality of electric components to the current distributor; a plurality of semiconductor-based first switch elements, wherein a specified first switch element of a specified first line is designed to interrupt said specified first line; a second line which is designed to connect the current distributor to the electrical system; a limiting unit which is designed to limit or prevent a second current on the second line; and a control unit which is designed to determine that the specified first switch element does not open although a first current running through the specified first switch element exceeds a first current threshold and, in response to said determination, to trigger the limiting unit to limit or prevent the second current on the second line.

A transformer assembly includes: a first switching apparatus configured to be electrically connected to a first segment of a transformer loop; a second switching apparatus configured to be electrically connected to a second segment of the transformer loop; and a transformer including: a first coil electrically connected to the first switching apparatus and the second switching apparatus; and a second coil electrically connected to an output configured to electrically connect to a load.