Abstract: Devices, methods and techniques are disclosed to interrupt a fault current in a high-voltage direct-current circuit. In one example aspect, a device includes a mechanical switch including a pair of contacts configured to be positioned apart upon activation of the circuit breaker, and a photoconductive component connected in parallel with the mechanical switch. The photoconductive component is configured to establish a current upon activation of the circuit breaker. The photoconductive component comprises a crystalline material positioned to receive a pulsed light signal from a laser light source, and a pair of electrodes coupled to the crystalline material and configured to allow an electric field to be established across the crystalline material to generate the current.

Abstract: Devices, methods and techniques related to ultrafast latching switches are disclosed. In one example aspect, a device includes a photoconductive switch and a non-mechanical latching switch configured to maintain a state after the state is activated. The non-mechanical latching switch is coupled to the photoconductive switch. The non-mechanical latching switch is configured to be triggered to switch to an opposite state upon an activation of the photoconductive switch.

Abstract: Devices, methods and techniques related to the suppression of electrical transients are disclosed. In one example aspect, an electrical transient protection device includes a sensor configured to monitor power transmission on a transmission line of a power system, a controller configured to generate a control signal in response to a detection of one or more electrical transients by the sensor, and a controller transient suppression unit comprising at least a switch that exhibits a changeable impedance. The controllable transient suppression unit configured to impose a load to the power system. The load has a substantially same impedance as a characteristic impedance associated with a part of the power system.

Abstract: Devices, methods and techniques are disclosed to interrupt a fault current in a high-voltage direct-current circuit. In one example aspect, a device includes a mechanical switch including a pair of contacts configured to be positioned apart upon activation of the circuit breaker, and a photoconductive component connected in parallel with the mechanical switch. The photoconductive component is configured to establish a current upon activation of the circuit breaker. The photoconductive component comprises a crystalline material positioned to receive a pulsed light signal from a laser light source, and a pair of electrodes coupled to the crystalline material and configured to allow an electric field to be established across the crystalline material to generate the current.