An electrical switching apparatus includes a plurality of poles each comprising separable contacts, an operating mechanism structured to open and close the separable contacts and to trip open the separable contacts in response to a fault condition, and a housing enclosing the separable contacts. The housing includes an interior, an exterior, and a plurality of receptacles extending from the exterior toward the interior. A surge protection assembly includes a plurality of modules, wherein each of the modules is removably disposed in a corresponding one of the receptacles of the housing. Each of the modules provides independent surge protection for a corresponding one of the poles of the electrical switching apparatus.

A transient voltage suppression device includes at least one diode string, a power clamp device, at least one first bypass diode, and at least two second bypass diodes. The diode string is coupled between a power terminal and a common bus and coupled to an input output (I/O) port. The power clamp device is coupled between the power terminal and the common bus. The first bypass diode is coupled between the common bus and a ground terminal. The second bypass diodes are coupled in series, coupled between the common bus and the ground terminal, and coupled to the first bypass diode in reverse parallel. Alternatively, the first bypass diode and the second bypass diodes are replaced with at least one bi-directional electrostatic discharge (ESD) device.

Power delivery may be controlled to help prevent arcing when a data cable supplying power from a power source device to a power sink device is disconnected. The presence of a user in proximity to a connection between a cable plug and a cable receptacle may be detected. The level of a power signal being conveyed from the power source to the power sink may be reduced in response to the detection.

A multi-port solid-state circuit breaker system includes a first electrical power bus, a second electrical power bus, and a plurality of breaker legs conductively coupled with the first electrical power bus and the second electrical power bus in parallel with one another. Each of the plurality of breaker legs includes a first power semiconductor device coupled in series with a second power semiconductor device and an input/output port intermediate the first power semiconductor device and the second power semiconductor device. At least one of the first semiconductor device and the second semiconductor device includes an actively controlled switching device. A surge suppressor is conductively coupled in parallel with the plurality of breaker legs.

A method and a device for supplying energy to a low-voltage load using an electronic power supply device. The method involves: a) setting the power supply device to be able to provide an output current to the low-voltage load up to a specified peak current value upon demand; b) monitoring the output current (I.sub.L) provided to the low-voltage load by the electronic power supply device to detect an increase of I.sub.L over a threshold (I.sub.N) which is lower than the peak current value, c) if an increase of I.sub.L to an increased output current value higher than I.sub.N is detected, detecting the increased I.sub.L value and ascertaining an output current pulse duration (t.sub.Pulse) based on the increased current value; d) providing I.sub.L at the level of the increased current value for the duration of the ascertained t.sub.Pulse; and e) providing the I.sub.L at the level of I.sub.N after t.sub.Pulse has expired.

An apparatus includes a surge protection device, a current sensor configured to sense a current through the surge protection device, and a surge discriminator circuit coupled to the current sensor and configured to discriminate among a plurality of surge levels for the surge protective device responsive to the sensed current. The current sensor may include a current transformer configured to generate a secondary current responsive to the sensed current and the surge discriminator circuit may be configured to discriminate among a plurality of surge levels responsive to the generated secondary current.

An electronic circuit breaker contains a first semiconductor switch which is switched into a current path between a voltage input and a load output and contains a controller which is connected to the control input of the first semiconductor switch. The first semiconductor switch is actuated depending on an actual value of the load current, the actual value is supplied to the controller, and the controller is configured to limit the current of the first semiconductor switch and disconnect same.

The present invention discloses a method for quickly eliminating ferromagnetic resonance of a voltage transformer. The method includes: first sampling a three-phase voltage and an open-delta voltage of a voltage transformer; calculating a flux linkage corresponding to a zero-sequence voltage by means of an integral algorithm; and when detecting that ferromagnetic resonance occurs in the mutual inductor, further checking whether the absolute value of the flux linkage corresponding to the zero-sequence voltage or the absolute value of the open-delta voltage respectively falls within a set range, and if yes, starting a secondary resonance elimination loop for resonance elimination. The present invention also discloses a corresponding device for quickly eliminating ferromagnetic resonance of a voltage transformer. The present method and device accurately analyze and control resonance elimination trigger time based on a conventional secondary resonance elimination principle, and can effectively eliminate the impact of the core saturation of a voltage transformer on a resonance elimination process, thereby greatly improving the success probability of single resonance elimination.

A method of establishing current limits for each of a plurality of device couplers mounted on a trunk of an electrical circuit at distributed physical positions, in which each of said device couplers is capable of servicing one or more spurs connected thereto, and in which said trunk has a total trunk current and a known resistive component, comprising the steps of: a) establishing physical characteristics of the electrical circuit including i) an order in which said device couplers are mounted on said trunk along its length; ii) a load current each device coupler requires to service the one or more spurs connected thereto; and, iii) a voltage drop of each of said sections of trunk caused by the resistive component thereof, which is proportional to a physical length thereof and the combined load currents of each device coupler serviced by that section of trunk; b) calculating a current limit for each device coupler, which current limit is greater than said load current, according to a predetermined tolerance rationale; c) calculating an intermediate trunk current available to each device coupler by deducting from said total trunk current the current limits of each device coupler preceding that device coupler in said order, as well as a consequential reduction in current caused by said voltage drop of each of said sections of trunk preceding that device coupler; and, d) adjusting said current limits so none exceeds the intermediate trunk current available to the corresponding device coupler.

An overvoltage arrester for high voltages having a high-voltage terminal that is connected to an arrester block forming a nonlinear resistor, and a temperature sensor for detecting the temperature of the arrester block. In order to enable a simple and reliable detection of the temperature of the arrester block continually during the operation thereof, the temperature sensor detects a change of the longitudinal extent of the arrester block.