Abstract: A precision printed circuit board based Rogowski coil is formed including a printed circuit board including a first layer and second layer. The printed circuit board further defines an aperture for receiving an electrical path therethough. A first return path is defined about the aperture on the first layer of the printed circuit board, and a second return path—parallel to the first return path—is defined about the aperture on the second layer of the printed circuit board. A plurality of radial paths defined on the first layer of printed circuit board extend between the aperture and the first return path. A plurality of radial paths defined on the second layer of the printed circuit board extend between the aperture and the second return path. Each first layer radial path is connected with an adjacent second layer radial path to form a generally toroidally-shaped winding.

Abstract: An improved Rogowski coil is formed on a toroidal core made of a thermoplastic or other moldable material, the core having a preferably continuous groove or grooves extending around the core. The grooves correspond in size to magnet wire which registers within the grooves, thus controlling the specific location of the wires. The grooving may be helical. A return loop can be provided for return path cancellation, or a reverse winding can be added in a direction opposite to the direction of advancement of the main coil. In using the return loop, a resistive network can be added to improve the cancellation of the return path due to the effect of geometries. In addition, it can compensate for thermal and other variations.

Abstract: A system for remotely controlling and monitoring an electrical system includes an electrical system controlling device connected to the electrical system for monitoring and controlling the electrical system and electronic controls for monitoring and controlling the electrical system controlling device. A wireless communications interface enables remote wireless access to the electronic controls.

Abstract: Protection systems for electrical systems such as substation power dividers are described. The protection systems may be designed and used to detect and clear faults that may occur within the substation power dividers. For example, a first Rogowski coil may be used to detect current along a primary conductor, and output a corresponding current signal to a multi-function, differential relay having multiple voltage and current inputs. Similarly, additional Rogowski coils may be used at each of a plurality of secondary feeders, where power from the primary feeder may be distributed to the secondary feeders using a connection bus. By comparing the signals from the first Rogowski coil and the additional Rogowski coils, the differential relay may determine whether a fault exists at some point along the conductor(s) and between the first Rogowski coils and the additional Rogowski coils, including whether a fault is associated with the connection bus.

Abstract: In one general aspect, a system to control and monitor an electrical system includes a switchgear housing unit connected to the electrical system that includes a switchgear mechanism for controlling a connection within the electrical system and electronic controls for monitoring and controlling the switchgear mechanism, where the electronic controls are embedded within the switchgear housing unit to form a single, self-contained unit.

Abstract: Methods and system for making and using vacuum switching devices are disclosed. A vacuum switching device has an operating rod for actuating a movable electrical contact within the device. The operating rod may be a hollow epoxy glass tube with an electrical sensor disposed within it, and there may be an elastomeric polymer filling compound disposed within the tube and encasing the sensor. The operating rod may be attached to the movable electrical contact on one end by a steel end-fitting that has been press-fit into the tube and secured with at least one cross pin. In this way, a very secure electromechanical connection may be made between the operating rod and the rest of the vacuum switching device, and the sensor is protected from shock associated with the operation of the device. Moreover, the vacuum switching device is compact and easy to construct.

Abstract: Memory sharing techniques include providing a first device and one or more additional devices. Each device has a memory and is configured to be connected to a network. A portion of the first device memory is allocated, and may be divided into two or more first device memory segments. Each first device memory segment corresponds to a device, and at least one of the first device memory segments corresponds to an additional device. A portion of the additional device memory is allocated, and may be divided into two or more additional device memory segments. Each additional device memory segment corresponds to a device, and at least one additional device memory segment corresponds to the first device. A first device data segment is provided to the additional device, and a first device data validity indication is derived at the additional device.

Abstract: A method and apparatus for simultaneously measuring voltage and current in a primary high voltage conductor. A current and a voltage from the primary conductor is monitored. The current and voltage information present on the current transformer secondary winding is separated. The voltage information present on the current transformer secondary winding is used to provide a voltage measurement output proportional to the voltage present on the primary conductor. The current information present on the current transformer secondary winding is used to provide a current measurement output proportional to the current flowing on the high voltage conductor.

Abstract: Protection systems for electrical systems such as substation power dividers are described. The protection systems may be designed and used to detect and clear faults that may occur within the substation power dividers. For example, a first Rogowski coil may be used to detect current along a primary conductor, and output a corresponding current signal to a multi-function, differential relay having multiple voltage and current inputs. Similarly, additional Rogowski coils may be used at each of a plurality of secondary feeders, where power from the primary feeder may be distributed to the secondary feeders using a connection bus. By comparing the signals from the first Rogowski coil and the additional Rogowski coils, the differential relay may determine whether a fault exists at some point along the conductor(s) and between the first Rogowski coils and the additional Rogowski coils, including whether a fault is associated with the connection bus.

Abstract: Memory sharing techniques include providing a first device and one or more additional devices. Each device has a memory and is configured to be connected to a network. A portion of the first device memory is allocated, and may be divided into two or more first device memory segments. Each first device memory segment corresponds to a device, and at least one of the first device memory segments corresponds to an additional device. A portion of the additional device memory is allocated, and may be divided into two or more additional device memory segments. Each additional device memory segment corresponds to a device, and at least one additional device memory segment corresponds to the first device. A first device data segment is provided to the additional device, and a first device data validity indication is derived at the additional device.

Abstract: Active crosstalk cancellation in a multi-phase system is achieved using a capacitive voltage divider for each phase in the multi-phase system. A voltage measurement is obtained for the desired phase and each additional phase of the multi-phase system. A product is generated for each additional phase by multiplying each additional phase voltage measurement by a corresponding predetermined constant. The product for each additional phase is subtracted from the voltage measurement of the desired phase.

Abstract: A method and apparatus for simultaneously measuring voltage and current in a primary high voltage conductor. A current and a voltage from the primary conductor is monitored. The current and voltage information present on the current transformer secondary winding is separated. The voltage information present on the current transformer secondary winding is used to provide a voltage measurement output proportional to the voltage present on the primary conductor. The current information present on the current transformer secondary winding is used to provide a current measurement output proportional to the current flowing on the high voltage conductor.

Abstract: Active crosstalk cancellation in a multi-phase system is achieved using a capacitive voltage divider for each phase in the multi-phase system. A voltage measurement is obtained for the desired phase and each additional phase of the multi-phase system. A product is generated for each additional phase by multiplying each additional phase voltage measurement by a corresponding predetermined constant. The product for each additional phase is subtracted from the voltage measurement of the desired phase.

Abstract: A Rogowski coil measures a current in a conductor and includes first and second loops electrically connected in series with each other. The first loop is wound with a substantially constant winding density in a first direction around a first core that has a substantially constant cross section. The second loop is wound with a substantially constant winding density in a second direction around a second core that has a substantially constant cross section. A direction of the first loop is substantially perpendicular to the normal of the first core cross section. Moreover, a direction of the second loop is substantially perpendicular to the normal of the second core cross section.

Abstract: A system for controlling and monitoring operation of an electrical system is described. The system includes a fault protection device, for example, a circuit breaker, that is connected to the electrical system to provide fault isolation. The system also includes a protection system that includes an interface and a logic system connected to the electrical system. The logic system is connected to the interface and controlled by a processor to receive input from the electrical system and input from a user through the interface. The logic system operates the fault protection device when the received input from the electrical system indicates a fault event. Additionally, the logic system indicates information relating to operation of the electrical system through the interface.