Embodiments of the present disclosure provide an over-voltage protection method, an over-voltage protection device and a display device. When the voltage value of the output signal is greater than the first preset voltage threshold, it is determined whether the voltage value of the output signal meets the preset over-voltage protection condition. If the voltage value of the output signal is detected to meet the preset over-voltage protection condition, the first control signal is output to stop output of the output signal or lower the voltage value of the output signal.

A protective device includes a first fuse circuit, an overvoltage protection circuit, and a second fuse circuit. The first fuse circuit prevents a flow of a line current from a voltage terminal to the electrical load when the line current reaches a first nominal current. The overvoltage protection circuit is connected downstream of the first fuse circuit and upstream of the electrical load, and is adapted to electrically connect two poles of the voltage terminal when a voltage at the voltage terminal reaches a first voltage limit to force the line current to the first nominal current such that the first fuse circuit is triggered. The second fuse circuit is connected downstream of the overvoltage protection circuit and upstream of the electrical load, and prevents flow of the line current when the line current reaches a second nominal current, wherein the second nominal current is based on the electrical load.

A protective device includes a first fuse circuit, an overvoltage protection circuit, and a second fuse circuit. The first fuse circuit interrupts a flow of a line current from a voltage terminal to the electrical load when an intensity of the line current reaches a first current intensity limit value. The overvoltage protection circuit electrically connects poles of the voltage terminal when a first voltage limit value of a voltage is reached on the first fuse circuit to force the line current to reach the first current intensity limit value. The second fuse circuit activates the overvoltage protection circuit when a second voltage limit value of a voltage on the second fuse circuit is reached to electrically connect the poles of the voltage terminal. The second voltage limit value is based at least in part on a nominal voltage of the electrical load.

An apparatus and a method for operating an electric power network are disclosed. The electric power network is a compensated network arranged to be compensated by an arc suppression coil. An indication for an occurrence of an earth fault in the electric power network is received and the arc suppression coil is tuned away from resonance with respect to a resonance point of the electric power network, while the earth fault is present in the electric power network, to increase fault current in the electric power network for tripping one or more relays in the electric power network.

Provided is a nano grid protection device for a nano grid including a distributed power supply, a large power grid including the nano grid protection device, and a method for controlling the nano grid protection device. In an embodiment, the nano grid is connected with a bus through the nano grid protection device and a main grid is connected with the bus through a main grid protection device. In an embodiment, the nano grid protection device includes: a signal unit, configured to detect and send current information passing through the nano grid protection device, the current information including the magnitude and direction of the current; a controller, configured to determine, based upon the received current information, whether to send a trip signal or not; and an execution mechanism, configured to execute a trip operation of the nano grid protection device upon receiving the trip signal.

A solid-state circuit breaker (SSCB) with galvanic isolation capability includes an electrical bus with line-side and load-side terminals and a solid-state device connected in series with a closeable air gap between the line-side and load-side terminals. During normal operating conditions, the solid-state device is switched ON and the SSCB forces movable contacts inside the SSCB to close the air gap, so that an electrical current path is maintained between the line-side and load-side terminals and electrical current is allowed to flow through the SSCB and an attached load. Upon a short circuit or overload of unacceptably long duration occurring in the load circuit, the SSCB switches the solid-state device OFF to prevent current from flowing through the load, and releases the movable contacts to open the air gap and thereby establish galvanic isolation between the line-side and load side terminals.

An electrical distribution panel for controlling the distribution of electrical power to a plurality of loads includes a plurality of solid-state circuit breakers (SSCBs), each including a thermally conductive heatspreader and one or more power semiconductor devices that control whether electrical current is able to flow to an attached load; a distribution panel heatsink configured in thermal contact with the SSCB heatspreaders; one or more cooling fans that blow air onto the distribution panel heatsink; a stacked bus bar with quick-fit pin-mount receptacles for receiving mating/matching press-fit connection pins located on line-side terminals of the SSCBs; a communications and control (comm/control) bus communicatively coupled to the plurality of SSCBs; and a head-end interface and gateway to which an external computer can connect, to, among other things, set and alter trip settings of the plurality of SSCBs via the comm/control bus.

A fault isolating device for use in a microgrid disconnected from a main power grid includes a voltage meter for detecting a voltage anomaly indicative of an electrical fault, a timer for establishing a time window that begins and ends a predetermined time after a voltage anomaly is detected, a switch that is opened at the start of the time window, and a microcontroller that determines whether to leave the switch open to isolate a faulted portion of the microgrid or to close the switch. A plurality of fault isolating devices can be distributed throughout a microgrid to isolate a faulted branch or faulted branches of an islanded microgrid without interfering with normal fuse operation when the microgrid is connected to the main power grid.

Solid state and hybrid circuit protection devices include improved arc-less switching capability and overcurrent protection, improved terminal assemblies and improved thermal management features that reduce or eliminate ignition sources for hazardous environments. The solid state and hybrid circuit protection devices are ignition protected and avoid possible explosions and therefore obviate a need for conventional explosion-proof enclosures to ensure safe operation of an electrical power system in hazardous locations.

A protective device includes a first fuse circuit, an overvoltage protection circuit, and a second fuse circuit. The first fuse circuit prevents a flow of a line current from a voltage terminal to the electrical load when the line current reaches a first nominal current. The overvoltage protection circuit is connected downstream of the first fuse circuit and upstream of the electrical load, and is adapted to electrically connect two poles of the voltage terminal when a voltage at the voltage terminal reaches a first voltage limit to force the line current to the first nominal current such that the first fuse circuit is triggered. The second fuse circuit is connected downstream of the overvoltage protection circuit and upstream of the electrical load, and prevents flow of the line current when the line current reaches a second nominal current, wherein the second nominal current is based on the electrical load.