An arrangement contains a polyphase transformer which has primary windings and secondary windings. The secondary windings are connected to form a star circuit, the star point of which is connected to earth potential by means of an overvoltage-limiting device. The overvoltage-limiting device has a first overvoltage-limiting component. A switch, which electrically bridges the first overvoltage-limiting component in its closed state, is assigned to the first overvoltage-limiting component.

An example transformer includes a controller that determines the currents on a power grid side of the transformer, as well as an inverter/load side of the transformer. The transformer may be of a delta-wye configuration. The controller compares the currents on the delta side of the transformer to the currents on the wye side of the transformer to determine whether the currents on either side are imbalanced. If the currents on the delta side are balanced, while the currents on the wye side are imbalanced, then the controller may determine that an open phase condition exists on the wye side of the transformer. Alternatively, if the currents on the delta side are imbalanced or if the currents on the delta side are balanced and the currents on the wye side are also balanced, then the controller determines that no open phase condition exists.

An example transformer includes a controller that determines the currents on a power grid side of the transformer, as well as an inverter/load side of the transformer. The transformer may be of a delta-wye configuration. The controller compares the currents on the delta side of the transformer to the currents on the wye side of the transformer to determine whether the currents on either side are imbalanced. If the currents on the delta side are balanced, while the currents on the wye side are imbalanced, then the controller may determine that an open phase condition exists on the wye side of the transformer. Alternatively, if the currents on the delta side are imbalanced or if the currents on the delta side are balanced and the currents on the wye side are also balanced, then the controller determines that no open phase condition exists.

The present disclosure relates to systems and methods for protecting against and mitigating the effects of over-excitation of elements in electric power systems. In one embodiment, a system consistent with the present disclosure may comprise a point pair subsystem to receive a plurality of point pairs that define an over-excitation curve for a piece of monitored equipment. The system may receive a plurality of measurements corresponding to electrical conditions associated with the piece of monitored equipment. A logarithmic interpolation subsystem may determine a logarithmic interpolation corresponding to one of the plurality of measurements based on the plurality of point pairs. An over-excitation detection subsystem may detect an over-excitation condition based on the logarithmic interpolation, and a protective action subsystem may implement a protective action based on the over-excitation condition.

The present disclosure relates to systems and methods for protecting against and mitigating the effects of over-excitation of elements in electric power systems. In one embodiment, a system consistent with the present disclosure may comprise a point pair subsystem to receive a plurality of point pairs that define an over-excitation curve for a piece of monitored equipment. The system may receive a plurality of measurements corresponding to electrical conditions associated with the piece of monitored equipment. A logarithmic interpolation subsystem may determine a logarithmic interpolation corresponding to one of the plurality of measurements based on the plurality of point pairs. An over-excitation detection subsystem may detect an over-excitation condition based on the logarithmic interpolation, and a protective action subsystem may implement a protective action based on the over-excitation condition.

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.

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.

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.

The present disclosure provides exemplary embodiments of voltage harvesting devices used in power distribution systems, and provides power distribution system architectures utilizing the voltage harvesting devices. Generally, the voltage harvesting devices transform distribution line AC voltages to produce a low wattage output for distribution system communication and control type devices. The voltage harvesting device can operate whether irrespective of the presence of load current.

The present disclosure provides exemplary embodiments of voltage harvesting devices used in power distribution systems, and provides power distribution system architectures utilizing the voltage harvesting devices. Generally, the voltage harvesting devices transform distribution line AC voltages to produce a low wattage output for distribution system communication and control type devices. The voltage harvesting device can operate whether irrespective of the presence of load current.