A system and method for persistent monitoring, detecting, and mitigating detecting and isolating a high-altitude electromagnetic pulse (“HEMP”) along electrical lines electrically connected to a monitored infrastructure so as to protect the monitored infrastructure, the method including a phase unit receiving sensor signals from a plurality of analog sensor circuits electrically connected to each of the electrical lines, respectively, upstream of and associated with the monitored infrastructure. The method includes determining, limiting, shunting, and limiting the impinged transient surges and instantaneously indicates locally the status of the monitored parameters using visual and audio sound via a cybersecure optical communication channel supporting a plurality of wavelengths, from which one wavelength is utilized for a one-directional communication and a different wavelength optical signal establishing a controlled temporary two-directional communication for surge protection system maintenance and update.

A system and method for suppressing EMP-induced voltage surges due to detonation of a nuclear weapon at high altitude generating an EMP (HEMP) comprising E1, E2, and E3 component pulses. A plurality of shunting assemblies, each including transient voltage suppressors (TVSs), metal oxide varistors (MOVs), gas discharge tubes (GDTs), other mechanical, electrical and ionization discharge devices (IDDs) and combinations thereof of surge limiting technologies, are positioned intermediate a signal stream and a plurality of electronic device ports associated with a plurality of communication channels for sensing upstream of the communication channels an overvoltage associated with each of the E1, E2, and E3 components of the EMP and shunting the over-voltages to predetermined allowable levels within the predetermined time.

A system and method for suppressing EMP-induced voltage surges due to detonation of a nuclear weapon at high altitude generating an EMP (HEMP) comprising E1, E2, and E3 component pulses. A plurality of shunting assemblies, each including transient voltage suppressors (TVSs), metal oxide varistors (MOVs), gas discharge tubes (GDTs), other mechanical, electrical and ionization discharge devices (IDDs) and combinations thereof of surge limiting technologies, are positioned intermediate a signal stream and a plurality of electronic device ports associated with a plurality of communication channels for sensing upstream of the communication channels an overvoltage associated with each of the E1, E2, and E3 components of the EMP and shunting the over-voltages to predetermined allowable levels within the predetermined time.

Methods and systems for controlling a circuit designed to protect electrical equipment, in particular sensitive power grid equipment such as transformers, are disclosed. In particular, methods of local and remote control of operation of protection circuits are provided that allow for remote access to change an operational mode of such protection circuits, while ensuring that power grid equipment is protected locally regardless of any configuration instructions received from a remote or centralized facility. Override levels may be set to ensure power grid transformer protection, regardless of operational mode or remote instruction.

Systems and method for automated self-testing of a protective device for a transformer are disclosed. One system includes a protection circuit electrically connected to a transformer neutral, the transformer electrically connected to a power grid, the protection circuit may include a DC blocking component, a switch assembly, and a spark gap assembly each positioned in parallel between the transformer neutral and ground, a switch assembly. The system may further include various testing circuits configured within the protection circuit and switches which when actuated inject a signal to test various components in the protective device.

A method for protecting an electronic system against a voltage surge, which electronic system is connected to a telecommunication network and includes a control integrated circuit, the method including successively connecting the electronic system to a remote server containing meteorological data; recovering meteorological data originating from the remote server; analyzing by the control circuit the recovered meteorological data to assign thereto a danger level of the current or imminent meteorological event; and, when the assigned danger level exceeds a main warning threshold: sending by the control circuit a warning signal to a display terminal connected to the electronic system; displaying a first warning message on the display terminal from information contained in the warning signal, the first warning message warning a user of the display terminal of a risk of voltage surge due to the current or imminent meteorological event; and electrical isolating a port of the electronic system.

An electric power substation includes a circuit breaker, an electromagnetic pulse mitigation module coupled to the circuit breaker and comprising a continuous conductive enclosure that is impervious to radiated or coupled electromagnetic energy, an input/output device housed within the electromagnetic pulse mitigation module, and a control house communicably coupled to the circuit breaker via a primary communication line and housing one or more primary relay panels.

A drive for a mobile compressor includes EMI and transient protection circuits, second chokes, converters and an inverter. The EMI and transient protection circuits include respectively common mode chokes and at least one component. Each of the common mode chokes is configured to receive a first direct current voltage and is connected to first and second grounds. The at least one component is connected to a third ground. The first, second and third grounds are at different voltage potentials. The second chokes are connected downstream from the common mode chokes. The converters are connected to outputs of the second chokes and are configured to collectively provide a second direct current voltage to a direct current bus. The inverter is connected to the direct current bus and configured to convert the second direct current voltage to an alternating current voltage to power the mobile compressor downstream from the inverter.

A three-stage surge protection device protects against complex, time-variant voltage transients, including those resulting from a high-altitude nuclear electromagnetic pulse or a solar coronal mass ejection. The device relies on interaction between a snubbing low-pass filter, a transient voltage suppressor, and an electronic crowbar circuit. The low-pass filter significantly lowers the let-through voltage of the device for short-duration pulses, and helps to spread the energy to more effectively utilize the transient voltage suppressor. The transient voltage suppressor limits the let-through voltage to a clamping level and provides indication to the crowbar circuit when it is no longer able to do so. Once the clamping level is no longer able to be maintained, the crowbar circuit draws enough current to trip an upstream protective device, such as a breaker or fuse.

Systems and method for detecting potentially harmful harmonic and direct current signals at a transformer are disclosed. One system includes a protection circuit electrically connected to a transformer neutral, the transformer electrically connected to a power grid, the protection circuit including a DC blocking component positioned between the transformer neutral and ground and one or more switches selectively actuated to form a path between the transformer neutral and ground in the event of unwanted DC current at the transformer neutral. The system also includes a control circuit electrically connected to the protection circuit and positioned to selectively actuate the switches based on observed conditions within the protection circuit. The system further includes a plurality of test connections disposed within the protection circuit and useable to test electrical properties of the protection circuit.