Abstract: A power transmission system can include a transformer and compensator circuit(s), each coupled between a node of the transformer and a ground connection. The compensator circuit(s) can each be configured to counteract a DC signal component of an AC signal at the transformer. The compensator circuit(s) can include a converter circuit having an AC side and a DC side and configured to convert a DC voltage on the DC side to an AC signal at the AC side. The compensator circuit(s) can include a DC link coupled to the DC side of the converter circuit. The compensator circuit(s) can include a controller configured to measure a DC signal component between the load and the ground; to determine, based at least in part on the DC signal component, a compensating signal configured to counteract the DC signal component; and to inject, by the converter circuit, the compensating signal to counteract the DC signal component.

Abstract: A system for detecting water trees in branching underground electrical cables includes a pulse generator configured to inject a pulse into a first underground cable that branches into a second underground cable and a third underground cable. The system includes a first sensor associated with the first cable, a second sensor associated with the second cable, and a third sensor associated with the third cable. The system includes a control device configured to obtain a first, second, and third signal associated with the first, second and third sensors, respectively. The control device determines a lead-lag relationship between the second and third signals and determines presence of a water tree within at least one of the second and third cable based on the lead-lag relationship. When presence of a water tree is determined, the control device generates a control action associated with repairing or replacing the second and/or third cable.

Abstract: A power transmission system can include a transformer and compensator circuit(s), each coupled between a node of the transformer and a ground connection. The compensator circuit(s) can each be configured to counteract a DC signal component of an AC signal at the transformer. The compensator circuit(s) can include a converter circuit having an AC side and a DC side and configured to convert a DC voltage on the DC side to an AC signal at the AC side. The compensator circuit(s) can include a DC link coupled to the DC side of the converter circuit. The compensator circuit(s) can include a controller configured to measure a DC signal component between the load and the ground; to determine, based at least in part on the DC signal component, a compensating signal configured to counteract the DC signal component; and to inject, by the converter circuit, the compensating signal to counteract the DC signal component.

Abstract: Devices, systems and methods for use of an autonomously powered inductive time domain reflectometer sensor device are provided. A sensor device for a power line can include a first induction coil and a second induction coil coupled to the power line and a control device. The first induction coil can be configured to inject a first signal on a power line by inducing a first current on the power line. The second induction coil can be configured to inject a second signal on the power line by inducing a second current on the power line. The control device can be configured to control the second induction coil to inject the second signal to cancel a portion of the first signal. As a result of the second signal cancelling a portion of the first signal, the first signal can be configured to propagate in a single direction on the power line.

Abstract: A system for detecting water trees in branching underground electrical cables includes a pulse generator configured to inject a pulse into a first underground cable that branches into a second underground cable and a third underground cable. The system includes a first sensor associated with the first cable, a second sensor associated with the second cable, and a third sensor associated with the third cable. The system includes a control device configured to obtain a first, second, and third signal associated with the first, second and third sensors, respectively. The control device determines a lead-lag relationship between the second and third signals and determines presence of a water tree within at least one of the second and third cable based on the lead-lag relationship. When presence of a water tree is determined, the control device generates a control action associated with repairing or replacing the second and/or third cable.

Abstract: Devices, systems and methods for use of an autonomously powered inductive time domain reflectometer sensor device are provided. A sensor device for a power line can include a first induction coil and a second induction coil coupled to the power line and a control device. The first induction coil can be configured to inject a first signal on a power line by inducing a first current on the power line. The second induction coil can be configured to inject a second signal on the power line by inducing a second current on the power line. The control device can be configured to control the second induction coil to inject the second signal to cancel a portion of the first signal. As a result of the second signal cancelling a portion of the first signal, the first signal can be configured to propagate in a single direction on the power line.