Abstract: A protection circuit is disclosed. The protection circuit includes a direct current (DC) blocking component electrically connected between a neutral of the transformer and a ground, and an overvoltage protection device electrically connected in parallel with the DC blocking component. The overvoltage protection device is constructed to repeatably and reliably provide overvoltage protection in response to a voltage at the transformer neutral above a threshold. The DC blocking component has an impedance below a predetermined value, thereby effectively grounding the neutral of the transformer. The DC blocking component is persistently maintained in connection to the transformer neutral.

Abstract: 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.

Abstract: The present disclosure relates generally to an overvoltage protection assembly, and an electrode useable in pairs in such an overvoltage protection device. In various aspects, at least one electrode is made from a single piece of conductive source material to ensure its strength, reliability, and ease of manufacture. Still further, the electrode has a specific geometry selected to enhance electromagnetic effects experienced during high voltage, high current overvoltage events in a way that quickly relocates and dissipates an arc formed at a gap between an electrode pair, to ensure repeatable, reliable performance of the overvoltage protection device.

Abstract: Some variations provide a system for extracting a product from biomass, comprising: a process chamber having an internal volume; one or more mechanical elements configured to controllably and reversibly mechanically seal the process chamber and reduce the internal volume to mechanically compress the biomass; a fluid port in flow communication with the process chamber; and a collection sub-system in flow communication with the fluid port. Other variations provide a method of extracting a product from biomass, the method comprising: introducing biomass into a process chamber; mechanically sealing the process chamber; mechanically compressing the biomass to release a first fluid material; mechanically decompressing the biomass; introducing an extraction solvent into the process chamber; maintaining process-chamber pressure from about 1 bar to about 1000 bar, wherein the extraction solvent extracts a second fluid material; and recovering the second fluid material from the process chamber.

Abstract: Electrical protection devices, such as for use with power systems for overvoltage protection, are disclosed. One electrical protection device includes a first electrical connection, a second electrical connection, a first electrical discharge device, and a second electrical discharge device. The first electrical discharge device includes a first conductive bus connected to the first electrical connection and a second conductive bus connected to the second electrical connection. The first electrical discharge device has a first breakdown voltage. The second electrical discharge device includes a third conductive bus connected to the first electrical connection and a fourth conductive bus connected to the second electrical connection. The second electrical discharge device has a second breakdown voltage.

Abstract: A protection circuit is disclosed. The protection circuit includes a direct current (DC) blocking component electrically connected between a neutral of the transformer and a ground, and an overvoltage protection device electrically connected in parallel with the DC blocking component. The overvoltage protection device is constructed to repeatably and reliably provide overvoltage protection in response to a voltage at the transformer neutral above a threshold. The DC blocking component has an impedance below a predetermined value, thereby effectively grounding the neutral of the transformer. The DC blocking component is persistently maintained in connection to the transformer neutral.

Abstract: A circuit includes a detector and controller circuit configured to detect a high field RF (radio frequency) electromagnetic fields indicating a potential of an electromagnetic pulse event capable of damaging electrical equipment connected to a power grid. The circuit also includes controller receiving an input from the detector circuit, the controller being included within a shielded enclosure and configured to initiate an event in response to detection of the high field electromagnetic pulse field to remove the electrical equipment from the power grid.

Abstract: 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.

Abstract: Some variations provide a system for extracting a product from biomass, comprising: a process chamber having an internal volume; one or more mechanical elements configured to controllably and reversibly mechanically seal the process chamber and reduce the internal volume to mechanically compress the biomass; a fluid port in flow communication with the process chamber; and a collection sub-system in flow communication with the fluid port. Other variations provide a method of extracting a product from biomass, the method comprising: introducing biomass into a process chamber; mechanically sealing the process chamber; mechanically compressing the biomass to release a first fluid material; mechanically decompressing the biomass; introducing an extraction solvent into the process chamber; maintaining process-chamber pressure from about 1 bar to about 1000 bar, wherein the extraction solvent extracts a second fluid material; and recovering the second fluid material from the process chamber.

Abstract: Electrical protection devices, such as for use with power systems for overvoltage protection, are disclosed. One electrical protection device includes a first electrical connection, a second electrical connection, a first electrical discharge device, and a second electrical discharge device. The first electrical discharge device includes a first conductive bus connected to the first electrical connection and a second conductive bus connected to the second electrical connection. The first electrical discharge device has a first breakdown voltage. The second electrical discharge device includes a third conductive bus connected to the first electrical connection and a fourth conductive bus connected to the second electrical connection. The second electrical discharge device has a second breakdown voltage.

Abstract: Methods and systems for ensuring operation of one or more circuit breakers electrically connected on a phase of a multi-phase power line on a transformer electrically connected within a power grid at a substation are disclosed. The method includes detecting, at the transformer, a direct current component of a multi-phase power signal received at the transformer, the direct current component comprising a direct current received at a transformer neutral, the transformer neutral being electrically connected to a ground. The method further includes determining whether the direct current is above a predetermined threshold, the predetermined threshold being based on a determination that, above the predetermined threshold, at least one of the one or more circuit breakers is incapable of reliable operation. The method includes, in response to a determination that the direct current component is above the predetermined threshold, blocking the direct current between the transformer neutral and a ground.

Abstract: A control device for an electrical protection circuit for use in an alternating current system including a transformer is disclosed. An example system includes a first measurement probe, a second measurement probe configured to measure an electrical property within the electrical protection circuit, and a control module, including a processing device. The control module is configured to monitor a measurement from the first measurement probe and transmit a protection activation control signal to the switch assembly based on the measurement from the first measurement probe exceeding a first predetermined threshold. The control module is also configured to monitor a measurement from the second measurement probe and transmit a protection deactivation control signal to the switch assembly based on the measurement from the second measurement probe satisfying a second predetermined threshold.

Abstract: A control device for an electrical protection circuit for use in an alternating current system including a transformer is disclosed. An example system includes a first measurement probe, a second measurement probe configured to measure an electrical property within the electrical protection circuit, and a control module, including a processing device. The control module is configured to monitor a measurement from the first measurement probe and transmit a protection activation control signal to the switch assembly based on the measurement from the first measurement probe exceeding a first predetermined threshold. The control module is also configured to monitor a measurement from the second measurement probe and transmit a protection deactivation control signal to the switch assembly based on the measurement from the second measurement probe satisfying a second predetermined threshold.

Abstract: Methods and devices for shielding electronic equipment within an enclosure are disclosed. One method includes positioning electronic equipment within an interior volume of a shielding enclosure having an opening providing access to the interior volume, the opening surrounded by an enclosure frame. The method further includes closing a door to the shielding enclosure, thereby closing off the opening, and engaging one or more latches to affix the door in a closed position, the door including a shielding curtain positioned across the opening. The method also includes inflating an inflatable member positioned along a perimeter of the door frame, thereby applying a uniform pressure to the shielding curtain toward the enclosure frame to form a seal therebetween.

Abstract: Electrical protection devices, such as for use with power systems for overvoltage protection, are disclosed. One electrical protection device includes a first electrical connection, a second electrical connection, a first electrical discharge device, and a second electrical discharge device. The first electrical discharge device includes a first conductive bus connected to the first electrical connection and a second conductive bus connected to the second electrical connection. The first electrical discharge device has a first breakdown voltage. The second electrical discharge device includes a third conductive bus connected to the first electrical connection and a fourth conductive bus connected to the second electrical connection. The second electrical discharge device has a second breakdown voltage.

Abstract: Methods and devices for shielding electronic equipment within an enclosure are disclosed. One method includes positioning electronic equipment within an interior volume of a shielding enclosure having an opening providing access to the interior volume, the opening surrounded by an enclosure frame. The method further includes closing a door to the shielding enclosure, thereby closing off the opening, and engaging one or more latches to affix the door in a closed position, the door including a shielding curtain positioned across the opening. The method also includes inflating an inflatable member positioned along a perimeter of the door frame, thereby applying a uniform pressure to the shielding curtain toward the enclosure frame to form a seal therebetween.

Abstract: Systems and methods for protecting an electrical component in an alternating current system that includes a transformer are disclosed. In one aspect, a circuit includes a switch assembly connected between a transformer neutral of a transformer and a ground and having an open position and a closed position. In normal operation, the switch remains in a closed position.

Abstract: The present invention relates systems and methods of electromagnetic protection for integrated video and electromagnetic detector security system equipment. A security system configured to be protected from electromagnetic events or attacks includes a quantity of video cameras and a quantity of electromagnetic event detectors disposed at a facility. The system also includes an electromagnetically-shielded cabinet containing computing equipment and a storage media. The electromagnetically-shielded cabinet is configured to receive data from each of the quantity of video cameras and electromagnetic detectors and store the data on the storage media, whereby, in the event of an electromagnetic event, information at the time of the event can be preserved on the storage media.

Abstract: Methods and systems are disclosed for wireless communication, and in particular using a coaxial antenna for distributed wireless transmission. In one example, a wireless transmitter is disclosed that includes a radio frequency signal source and a coaxial cable including a near end and a far end. The near end is electrically connected to the radio frequency signal source and configured to receive signals from the radio frequency signal source. The coaxial cable has an inner conductor and an outer conductor. The wireless transmitter includes a shorting connection at the far end of the coaxial cable, the shorting connection electrically connecting the inner conductor and the outer conductor, and a plurality of openings along the coaxial cable spaced at predetermined locations to output signals generated by the radio frequency signal source. The invention can be used for RF attenuation monitoring and/or testing applications.

Abstract: 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.