SU473969A1 - The method of determining the location of damage - Google Patents

Description

the voltage at the other end of the line from which the damage site is located, and two resistances proportional to the current readings. In this case, it is understood that the readings of the voltage clamps are converted into currents by dividing them by the resistance of the line. By readings / А „- / v„ by voltage clamps for through damages, it is possible to determine the currents in the line regardless of the readings of current clamps (for example, in their absence).

To facilitate the transfer of the results of the fixation of currents and voltages to the model, one of the EMF and one of the resistances, proportional to each other, are introduced into the model in one step.

FIG. 1 shows a diagram of a mathematical model; in fig. 2 - conventional circuit of the electric line in emergency mode.

The mathematical model contains regulated sources EMF 1 and 2 and counter EMF 3, connected in series. The emf is proportional to the voltage and current readings at the end of the L line AB, respectively. The counter-emf is proportional to the voltage readout at the end B of the AB line, from which the damage is located. In this case, it is understood that the readings of the voltage clamps are converted to currents by dividing them by the resistance of the line. Variable resistors 4 and 5 proportional to the current readings at the ends of the AB line are connected in series with the sources of EMF 1, 2 and counter EMF 3. In order to facilitate the transfer of the results of the fixation of currents and voltages to the model, the EMF 2 and variable resistance 4, proportional to each other, are introduced into the model in one step with the help of a single regulator. Ammeter 6, included in the control circuit cd, the scale of which is calibrated in relative units of the length of the line AB, measures the current proportional to the distance of the line from the end B to the point of damage.

In the event of an accident on the AB line with fixing devices installed at its ends, currents (ammeters 7 and 8) and voltages (voltmeters 9 and 10) are counted, converted to zero-sequence currents, which are communicated to the computing personnel, where they are located above describe the model. The model establishes the values of EMF 1 and counter EMF 3, proportional to the readings of the voltage clamps at the ends L and S of the line AB, EMF 2, proportional to the counting of the current clamp at the end B of the line AB, from which the damage site is located,

resistances are proportional to the readings of current delays at the ends A and B of the AB line. Having established the design parameters on the model, from the scale of the device 6, calibrated in relative units of the length of the AB line, they take indications of the location of the damage.

Subject invention

The method of determining the location of damage on the transmission line of software kV and higher by counting currents and zero-sequence voltages recorded during a short circuit at the ends of the line, characterized in that, in order to simplify and improve accuracy by eliminating calculations and graphical constructions, the location of the damage is determined using a mathematical model, for which the models consistently establish the values of two emfs, proportional to the voltage and current readings at one end of the line, respectively, versus the emf, tional count voltage at the other end,

from which the damage site is found, the resistances proportional to the current readings at both ends of the line, and a current proportional to the distance to the damage site is determined from the instrument in the control circuit with a scale scaled in relative units of the length of the LINE.