An electric power delivery system may be protected upon occurrence of a fault condition by the systems and methods disclosed herein by detecting the fault condition and signaling a protective action before the overcurrent condition reaches the protective equipment. The protective action may be an opening of a circuit breaker or engagement of a fault current limiter. The overcurrent condition may be a non-steady-state condition. The fault may be detected using traveling wave or incremental quantity techniques.

The present disclosure pertains to systems and methods for detecting traveling waves in electric power delivery systems. In one embodiment, a system comprises a capacitance-coupled voltage transformer (CCVT) in electrical communication with the electric power delivery system, the CCVT comprising a stack of capacitors and an electrical contact to a first ground connection. Electrical signals from accessible portions of the CCVT are used to detect traveling waves. Current and/or voltage signals may be used. In various embodiments, a single current may be used. The traveling waves may be used to detect a fault on the electric power delivery system.

A method can be used to determine a fault location in a power transmission line that connects a first terminal with a second terminal. Parameters associated with travelling waves are detected from measurements carried out at the first and second terminals. The parameters include arrival times of first and second peaks of the travelling waves at the first and second terminals respectively, and rise times of the first peaks of corresponding travelling waves. A first half, a second half, or a mid-point of the power transmission line is identified as having a fault based on the parameters. The fault location can be estimated based on the arrival times of the first and second peaks of the travelling waves detected from measurements carried out at the first and second terminals, a velocity of propagation of the travelling wave in the power transmission line, and/or a length of the power transmission line.

A method can be used for fault location in a power transmission line connecting a first terminal with a second terminal. Arrival times of a first peak and a second peak of travelling waves are detected from measurements carried out at the first and second terminals. a rough location of a fault is identified based on a comparison of the arrival times obtained for the travelling waves detected from the measurements carried out at the first terminal, and the arrival times obtained for the travelling waves detected from the measurements carried out at the second terminal. The fault location is estimated based the rough location, the arrival times of the first and second peaks of the travelling waves detected from measurements carried out at the first and second terminals, and a length of the power transmission line.

The present disclosure pertains to systems and methods for detecting faults in an electric power delivery system. In one embodiment, system may include a data acquisition subsystem configured to receive a plurality of representations of electrical conditions. The system may also include an incremental quantities subsystem configured to calculate an incremental current quantity and an incremental voltage quantity based on the plurality of representations. A fault detection subsystem may be configured to determine a fault type based on the incremental current quantity and the incremental voltage quantity, to select an applicable loop quantity, and to declare a fault based on the applicable loop quantity, the incremental voltage quantity, and the incremental current quantity. A protective action subsystem may implement a protective action based on the declaration of the fault.

The present disclosure pertains to systems and methods for detecting traveling waves in electric power delivery systems. In one embodiment, a system comprises a capacitance-coupled voltage transformer (CCVT) in electrical communication with the electric power delivery system, the CCVT comprising a stack of capacitors and an electrical contact to a first ground connection. A current transformer is disposed between the stack of capacitors and the first ground connection. The current transformer provides an electrical signal corresponding to a current associated with the CCVT. An intelligent electronic device (IED) in electrical communication with the first current measurement device generates a voltage signal based on the electrical signal from the current transformer. The IED detects a traveling wave based on the first voltage signal; and analyzes the traveling wave to detect a fault on the electric power delivery system.

A method of free wave energy protection for a half-wavelength line based on a one-sided current includes: performing sampling and calculation on a current at protection measuring points to obtain variations in current sampling values; and activating a protective element to determine an occurrence time of a fault in a half-wavelength line. A free wave energy protection section includes a quick-action section, a basic section and a sensitive section, wherein the quick-action section, the basic section and the sensitive section serve as action criteria for performing protection with respect to the free wave energy of the half-wavelength line.

The technology described herein is generally directed towards a system for power transmission system protection and fault location, such as implemented in a deployable device at one or more junction points of a power transmission system. Aspects of the described technology can be directed to analyzing a traveling wave corresponding to a fault on a power transmission system. Example aspects can comprise receiving data representing current and voltage components of a traveling wave, maintaining the data in storage for fault location determination of the fault, transforming the data via a wavelet transform, into wavelet transform results and using the wavelet transform results for protection of the power transmission system.

The present application is directed to a three phase power transmission system including a first conductor line, a second conductor line and a third conductor line. One or more sensors are configured to detect traveling waves in each of the first second and third conductors. A controller is configured to receive data transmitted by the one or more sensors and determine which of the traveling modal waves is a first metallic mode wave (MM1), a second metallic mode (MM2) wave and/or a ground mode (GM0) wave. The controller is operable to determine which of the conductor lines are faulted based on detection of one or more of MM1 waves, MM2 waves and/or GM0 waves.

There is provided mechanisms for travelling wave protection of a transmission line. A method includes performing high-pass filtering of a current and/or voltage measurement of a transmission line so as to detect fault-caused high-frequency components of the current and/or voltage measurement. The method includes providing a result of the high-pass filtering as input to a trip decision maker performing travelling wave detection.