In one embodiment, a method includes receiving low voltage pulse power from power sourcing equipment at a powered device, synchronizing the powered device with a waveform of the low voltage pulse power received from the power sourcing equipment, and operating the powered device with high voltage pulse power received from the power sourcing equipment.

A method for accurate fault location in a multi-type cable connection system is provided that includes, first normalizing the measurement parameters, then grouping the data, calculating compensation correction, finding the maximum value of the data, and comparing whether the cable has faults or not. By means of a blended data automatic analysis algorithm of the method, in the presence of multiple cables, data obtained through one-time measurement can be accurately identified to determine specific data of each scanning point that belongs to each cable, and after data allocation is completed, each group of data is separately corrected by using cable parameters corresponding to the group of data, thereby obtaining an accurate fault position and a DTF return loss result.

An apparatus and a method for detecting a fault location of an underground cable are proposed. The apparatus includes: an optimal reference signal design unit configured to design a reference signal for detecting the fault location of the underground cable considering propagation characteristics of the underground cable according to a time-frequency domain reflectometry method; a signal application and acquisition unit configured, as the designed reference signal is generated and applied to the underground cable, to acquire the reference signal applied to the underground cable and a reflected signal of the applied reference signal; and a data analysis unit configured to analyze whether a fault location of the underground cable exists according to a decision on similarity between the reference signal and the reflected signal after obtaining a time-frequency domain energy distribution for the acquired reference signal and reflected signal.

A method analyzes the state of an electrical operating resource. The method includes: applying a test voltage to the operating resource; acquiring a measurement signal at a connection point of the operating resource; ascertaining transfer parameters that characterize a signal transmission from a location of a partial discharge in the operating resource to the connection point depending on the measurement signal; and determining at least one characteristic variable of the partial discharge depending on the transfer parameters.

The invention relates to a method and a device for identifying arc faults in an ungrounded power supply system. This object is attained by detecting a displacement voltage to ground at an active conductor or at a neutral point of the ungrounded power supply system; by providing a value of an operating frequency occurring in the power supply system; and by analyzing a frequency spectrum of the detected displacement voltage by calculating and assessing Fourier coefficients at the locations of the operating frequency and its harmonics. Due to the broadband detection of the displacement voltage interacting with the “quick” generation of the basic functions by means of a DDS generator, arc faults can be identified reliably in an ungrounded power supply system.

Techniques for identifying faulty sections in power transmission lines are described. A first positive sequence voltage and first positive sequence current at a first terminal of a power transmission line are computed based on a first voltage and first current at the first terminal. A second positive sequence voltage and second positive sequence current at a second terminal are computed based on a second voltage and second current. Based on the first positive sequence voltage and the first positive sequence current, a first junction voltage and first junction current from the first terminal at a junction are computed. Based on the second positive sequence voltage and the second positive sequence current, a second junction voltage and second junction current from the second terminal are computed. A ratio of a junction voltage parameter to a junction current parameter is computed. Using the ratio, the faulty section is identified.

The invention relates to a magnetic field measuring device and a method for detecting a localization current in a branched AC power supply system. Furthermore, the invention relates to a use of the magnetic field measuring device according to the invention as a device for detecting a test current for an insulation fault localization system. By combining two current sensors having a different magnetic field measuring sensitivity and a different magnetic field measuring range, it can be achieved that a reliable detection of localization currents in insulation fault localization systems is possible by means of a constructionally easy and cost-effective realization, in particular as retrofitting in existing systems.

In general, a monitoring system includes one or more nodes that are capacitively coupled to a cable of a multiphase electric power line. In some examples, a node includes a coupling layer disposed over a jacket layer of the cable and capacitively coupled to a shield layer of the cable. In some examples, a node may include a first coupling layer capacitively coupled to a first cable, and a second coupling layer capacitively coupled to a second cable, such that the node is differentially coupled to the cable pair to generate a differential data signal and to perform at least one of: sensing a native signal within the cable pair; injecting an intentional signal into the cable pair; receiving an intentional signal from within the cable pair; or providing a channel characterization.

A method for locating a fault point (F) in a high-voltage three-phase AC cable (1) with a cross bonding or solid bonded connection system. The method includes determining the conductor (R, S, T) in fault. In the event that the cable (1) includes more than one main section (MP.sub.1, MP.sub.2, MP.sub.3), determining the main section (MP.sub.1, MP.sub.2, MP.sub.3) in fault, and locating the fault point (F) by means of a model of the shields (S.sub.A, S.sub.B, S.sub.C; S.sub.R, S.sub.S, S.sub.T) of the main section (MP.sub.1, MP.sub.2, MP.sub.3) in fault, taking into account that the shields (S.sub.A, S.sub.B, S.sub.C; S.sub.R, S.sub.S, S.sub.T) are attached to one another at the ends of said main part (MP.sub.1, MP.sub.2, MP.sub.3).

Method for locating a fault point (F) on a high-voltage three-phase AC cable with single point connection system. The method includes the following steps: (a) determining the conductor (R, S, T) in fault based on previously measured conductor currents (I.sub.R1, I.sub.1S, I.sub.T1, I.sub.R2, I.sub.S2, I.sub.T2). In the event the cable includes more than one section (P.sub.1, P.sub.2), determining section (P.sub.1, P.sub.2) in fault based on previously measured shield currents (I.sub.SR1, I.sub.SS1, I.sub.ST1, I.sub.SR2, I.sub.SS2, I.sub.ST2). The fault point (F) being located by means of a model of section (P.sub.1, P.sub.2) in fault of the earth continuity conductor (ECC), the only unknown being the distance (x) to the fault point (F) from an end of said section (P.sub.1, P.sub.2) in fault.