Proposed is an earth leakage breaker having a built-in trip module type circuit breaker, which is installed at a line between a power supply and a load and has a trip module configured to cut the line off, the earth leakage breaker including: a CT installed on the line and configured to monitor an instantaneous current; and a control circuit unit comprising: an operation module configured to receive an instantaneous current sensed by the CT, to measure an instantaneous current value per unit time, and to calculate a slope of the instantaneous current per unit time; a determination module configured to determine a case as an overload state, the case having the slope exceeding an overcurrent determination value A, and to cause an overload state determination signal to be output; and an output module configured to output a trip module actuation signal according to the overload state determination signal of the determination module and to cut off the line, and accordingly, the earth leakage breaker causes the trip module to be actuated according to an instantaneous current slope.

An overcurrent detector with an electric line and a sensor for monitoring an electric current in the line and outputting a measurement signal, and an integral-unit adapted to integrate an interval of consecutive values of the measurement signal and outputting an integrator-signal, the detector comprises a comparator unit for comparing a value of the integrator-signal with a threshold level and outputting a trigger signal, with the detector further comprises a threshold level determination unit, an input being connected to the sensor for receiving an actual measurement signal, and with an output being connected to the comparator unit, proving the comparator unit with the threshold level, and that the threshold level determination unit is adapted to determine the threshold level in dependence on the value of the actual measurement signal.

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.

Systems and methods for providing detailed information about high load events in a circuit interrupter are disclosed. The systems and methods provide a user with information such as the maximum high load current reached during a high load event and the average high load current calculated for the duration of the event. In addition, detailed waveform and metered data captures are generated in order to provide a comprehensive cycle-level and/or sub-cycle level overview of the event.

An electric switch includes a thermal tripping unit which, when a thermal budget acting on it is exceeded, trips and switches off the electric switch. In an embodiment, the tripping unit includes an adjustment module which, as a function of an accessory connected to the electric switch, uses an actuating element to set a tripping element of the thermal tripping unit such that the heat effect of the accessory is compensated for in the event of tripping.

A disclosed under-voltage lockout (UVLO) circuit includes an automatic UVLO threshold configuration. The UVLO circuit may include an over-voltage protection circuit that receives power from a power source, a peak detector that detects a peak voltage output for the power source, a voltage threshold generator that sets a UVLO threshold based on the peak voltage output, and a comparator that compares an instantaneous voltage with the UVLO threshold and configures an operating mode of a device based on the comparison.

The embodiments of the present invention disclose a line protection method and a related apparatus for a flexible grounding system of a power distribution network. The method comprises outputting a first compensation voltage by a voltage source of a flexible grounding device of each line of a target power distribution network in the case where a ground fault occurs in the target power distribution network; starting to calculate the zero-sequence impedance of each line in real time by the zero-sequence impedance protection device; after the first compensation voltage is output for a first output duration, outputting a second compensation voltage; calculating the zero-sequence impedance of each line in real time by the line zero-sequence impedance protection device; determining a fault line by the zero-sequence impedance protection device, and cutting off the fault line to isolate the ground fault after a trip for a preset time delay.

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.

Systems and methods are described herein to accommodate different settings associated with a converter-based electric power generator and an inverter-based electric power generator for electric power generation within an electric power delivery system. The electric power delivery system may provide electric power generated by a bulk electric system to the loads via distributed substations using a first operating frequency. Moreover, the distributed substations may include inverter-based electric power generators to supply the electric power demand of downstream loads in an islanded configuration. That said, the inverter-based electric power generators may supply the electric power using a second frequency that is higher than the first frequency. Protective systems, positioned downstream from the distributed substations, may use different settings associated with the bulk electric system or the inverter-based electric power generators based on detecting the frequency of the supplied electric power.

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.