An ESD protection device of the present disclosure includes a ceramic multilayer structure inside which a cavity portion is formed, at least one pair of discharge electrodes arranged inside the ceramic multilayer structure, and outer electrodes formed on the surface of the ceramic multilayer structure and connected to the discharge electrodes, wherein the pair of discharge electrodes are arranged in such a way that one end-face of one discharge electrode and one end-face of the other discharge electrode are opposed to each other through the cavity portion, and the cavity portion is formed as a single cavity occupying a region between the opposed end-faces, regions along other end-faces connected to the opposed end-faces via corner portions, and, on first principal surfaces, regions along the opposed end-faces and regions along the other end-faces.

Provided is a gas switch triggered by an optical pulse introduced by an optical fiber, which solves the problem of the existing electrically-triggered gas switch and laser-triggered gas having a complicated trigger system, being insufficiently reliable and having a higher cost due to the pulse amplitude/laser beam energy having higher requirements. The gas switch triggered by an optical pulse introduced by an optical fiber includes at least one trigger gap and one self-breakdown gap; each trigger gap is connected in parallel to a photoconductive switch, and an optical fiber is correspondingly provided for introducing an optical pulse for triggering. In the present disclosure, the advantages of a low trigger requirement of a photoconductive switch and a high voltage and large conduction current of a gas switch are fully utilized, and an optical pulse introduced by an optical fiber is used to trigger the photoconductive switch, so that the gas switch can be controlled and triggered under the action of a low-energy optical pulse (which can be less than 200 μJ) transmitted by optical fiber, thereby greatly simplifying the scale and complexity of the trigger system and promoting the development and application of the pulse power supply technology.

Provided is a gas switch triggered by an optical pulse introduced by an optical fiber, which solves the problem of the existing electrically-triggered gas switch and laser-triggered gas having a complicated trigger system, being insufficiently reliable and having a higher cost due to the pulse amplitude/laser beam energy having higher requirements. The gas switch triggered by an optical pulse introduced by an optical fiber includes at least one trigger gap and one self-breakdown gap; each trigger gap is connected in parallel to a photoconductive switch, and an optical fiber is correspondingly provided for introducing an optical pulse for triggering. In the present disclosure, the advantages of a low trigger requirement of a photoconductive switch and a high voltage and large conduction current of a gas switch are fully utilized, and an optical pulse introduced by an optical fiber is used to trigger the photoconductive switch, so that the gas switch can be controlled and triggered under the action of a low-energy optical pulse (which can be less than 200 μJ) transmitted by optical fiber, thereby greatly simplifying the scale and complexity of the trigger system and promoting the development and application of the pulse power supply technology.

A short-circuit device and a protection method for a submodule for a power converter are disclosed. The submodule includes a bridge circuit having at least one power semiconductor branch extending between a first and a second DC voltage node and at least one controllable power semiconductor switch disposed therein to which a freewheeling diode is connected in anti-parallel, and a capacitor connected in parallel to the bridge circuit. The short-circuit device has at least one selected of the freewheeling diodes anti-parallel to the power semiconductor switches of the bridge circuit, wherein the at least one selected freewheeling diode is manufactured in press pack design and rated such that, when a fault occurs in the submodule, the at least one selected freewheeling diode breaks down due to the fault conditions and provides a durable, stable, low-impedance short circuit path between a first and a second AC voltage connection of the submodule.

A short-circuit device and a protection method for a submodule for a power converter are disclosed. The submodule includes a bridge circuit having at least one power semiconductor branch extending between a first and a second DC voltage node and at least one controllable power semiconductor switch disposed therein to which a freewheeling diode is connected in anti-parallel, and a capacitor connected in parallel to the bridge circuit. The short-circuit device has at least one selected of the freewheeling diodes anti-parallel to the power semiconductor switches of the bridge circuit, wherein the at least one selected freewheeling diode is manufactured in press pack design and rated such that, when a fault occurs in the submodule, the at least one selected freewheeling diode breaks down due to the fault conditions and provides a durable, stable, low-impedance short circuit path between a first and a second AC voltage connection of the submodule.

A gas discharge tube includes a housing defining a chamber, first and second terminal electrodes mounted on the housing, a plurality of inner electrodes located in the chamber, and a gas contained in the chamber. The inner electrodes are serially disposed in the chamber in spaced apart relation to define a series of spark gaps from the first terminal electrode to the second terminal electrode. The chamber is hermetically sealed.

Systems, methods, and devices, for forming and using an arc flash mitigation switch are provided. In one exemplary embodiment, an arc flash mitigation switch includes a cylindrical shell having a first end cap and a second end cap located at either end of the cylindrical shell. A first and second conductive feed through extend through the first and second end cap, respectively, at one end, and at the other connect to a first and second electrode separated by a gap. The exemplary arc flash mitigation switch further includes a trigger feed through that receives a trigger current that commutates the external arc flash event into the arc flash mitigation switch, quenching the external hazard.

Systems, methods, and devices, for forming and using an arc flash mitigation switch are provided. In one exemplary embodiment, an arc flash mitigation switch includes a cylindrical shell having a first end cap and a second end cap located at either end of the cylindrical shell. A first and second conductive feed through extend through the first and second end cap, respectively, at one end, and at the other connect to a first and second electrode separated by a gap. The exemplary arc flash mitigation switch further includes a trigger feed through that receives a trigger current that commutates the external arc flash event into the arc flash mitigation switch, quenching the external hazard.

An ESD protection device 1 includes a ceramic insulating material 10, first and second discharge electrodes 21 and 22, and a discharge auxiliary section 51. The discharge auxiliary section 51 is an electrode configured to reduce a discharge starting voltage between the first discharge electrode 21 and the second discharge electrode 22. The discharge auxiliary section 51 comprises a sintered body including conductive particles and at least one of semiconductor particles and insulating particles. At least the discharge auxiliary section 51 comprises at least one of an alkaline metal component and a boron component. The content of at least one of the alkaline metal component and the boron component in the discharge auxiliary section 51 is larger than the content of at least one of the alkaline metal component and the boron component in the ceramic insulating material 10.

An ESD protection device 1 includes a ceramic insulating material 10, first and second discharge electrodes 21 and 22, and a discharge auxiliary section 51. The discharge auxiliary section 51 is an electrode configured to reduce a discharge starting voltage between the first discharge electrode 21 and the second discharge electrode 22. The discharge auxiliary section 51 comprises a sintered body including conductive particles and at least one of semiconductor particles and insulating particles. At least the discharge auxiliary section 51 comprises at least one of an alkaline metal component and a boron component. The content of at least one of the alkaline metal component and the boron component in the discharge auxiliary section 51 is larger than the content of at least one of the alkaline metal component and the boron component in the ceramic insulating material 10.