Method and apparatus for determining the direction of a fault on a power transmission line
AssigneeEnertec
InventorMichel Souillard
Life of this patent
Estimating the term…
Abstract
Directional relay and method for monitoring at least one A.C. power transmission line to determine the position of a fault on the line with respect to a measurement location thereon. According to a representative embodiment characteristic parameters, typically the respective phases, of a first signal representing the difference of complex voltages after and before the occurrence of the fault and of a second signal representing the line current after the occurrence of the fault, are compared, the result of the comparison providing the desired indication.
Claims40
A method for determining the direction of a fault on an A.C. electrical power transmission line with respect to a measurement point located on said line, comprising the steps of:
- producing a first signal which is a function of a value of the complex voltage U at the measurement point after the appearance of the fault;
- producing a second signal which is a function of a value of the complex voltage U.sub.m at the measurement point before the appearance of the fault;
- combining the first signal with the second signal to obtain a third signal which is a function of U and U.sub.m ;
- and obtaining an indication of the direction of the fault with respect to the measurement point as a function of said third signal.
A directional relay for monitoring at least one A.C. electrical power transmission line to determine whether a fault affecting the line is upstream or downstream of a measurement point located on said line, comprising:
- first means for producing a first signal which is a function of both a value of the complex line voltage U at the measurement point after the appearance of the fault and a value of the complex line voltage U at the measurement point before the appearance of the fault, second means for producing a second signal which is a function of a characteristic parameter measured on the line, and third means for combining the first and second signals to produce an indication of the direction of the fault with respect to the measurement point.
A directional relay for monitoring an A.C. electrical power transmission line to determine, when said line is affected by a fault, whether said fault is upstream or downstream of a measurement point positioned on said line, comprising:
- first means for producing a first complex signal which is a function of the difference between a value representative of the complex voltage U of said line after the appearance of said fault and a value representative of the complex voltage U.sub.m of the line before the appearance of the fault, second means for producing a second complex signal substantially representative of the complex current I of the line after the appearance of said fault and third means for comparing at least one of the characteristic parameters of said first complex signal with one of the corresponding parameters of the second complex signal to provide a signal indicating the direction of the fault with respect to the measurement point.
A method for determining the direction of a fault on an oriented alternating power transmission line with respect to a measurement location comprising the steps of:
- deriving a first signal representative of a complex voltage value U at the measurement location after the occurrence of a fault;
- deriving a second signal representative of a complex voltage value U.sub.m at the measurement location before the occurrence of said fault;
- deriving a third signal representative of a complex current value I in the line at the measurement location after the occurrence of said fault;
- and combining said first, second and third signals to produce a fourth signal which provides an indication of the direction of said fault with respect to the measurement location on the oriented power line.
A power transmission line monitoring apparatus for determining the direction of a fault on an oriented alternating power transmission line with respect to a measurement location comprising:
- first means for producing a first signal functionally related to the difference between values U and Um of complex voltage at the measurement location after and before the occurrence of a fault, respectively;
- second means for producing a second signal functionally related to a value of complex current in the line at the measurement location;
- and third means responsive to said first and second signals for producing a third signal which provides an indication of the direction of the fault with respect to the measurement location on the oriented line.
A power transmission line monitoring apparatus for determining the direction of a fault on an oriented alternating power transmission line with respect to a measurement location thereon, comprising:
- means for producing a first signal functionally related to values U and Um of complex voltage at the measurement location respectively after and before the occurrence of a fault;
- means for producing a second signal functionally related to a value I of complex current in the line at the measurement location after the occurrence of said fault;
- and
- means for combining characteristic parameters of said first and second signals to produce a third signal which provides an indication of the direction of the fault with respect to the measurement location on the oriented line.
A power transmission line monitoring apparatus for determining the direction of a fault on an oriented alternating power transmission line with respect to a measurement location thereon, comprising:
- first means for deriving a first signal functionally related to a value U of complex voltage at the measurement location after the occurrence of a fault;
- second means for deriving a second signal functionally related to a value Um of complex voltage at the measurement location before the occurrence of said fault;
- third means for deriving a third signal functionally related to a value I of complex current in the line at the measurement location after the occurrence of said fault and;
- fourth means for combining said first, second and third signals to provide an indication of the direction of said fault with respect to the measurement location on the oriented power line.
A power transmission line monitoring apparatus for determining the direction of a fault on an oriented alternating power transmission line with respect to a measurement location thereon, comprising:
- first means for deriving a first signal related to the amplitude relationship of values U and Um of voltage at the measurement location after and before the occurrence of a fault respectively;
- second means for deriving a second signal functionally related to the phase of U with respect to a reference;
- third means for deriving a third signal functionally related the phase of Um with respect to the reference, and
- fourth means for combining said first, second and third signals to provide an indication of the direction of the fault with respect to the measurement location.
Dependencies are inferred from the claim text.