SU1356095A1 - Method of automatic repeated connection of electric transmission line - Google Patents

Abstract

The invention relates to automation of electric power systems and can be used to improve the automation of the re-activation of AC power lines. The purpose of the invention is to extend the scope of application of the method to unreacted lines. After the discovery of the fact of a two-phase without land turn off the switches of these phases. After the estimated time, the deiosh-gtsatsy include one of the disabled phases, preferably from the side of the system. The difference in voltage between the one-sided on and off phase is measured, from which the fact of extinction of the charging arc is determined. After the fact of the suppression of the charging arc is established, a signal is generated to re-turn on the switch 2 of the one-way-on phase and turn on the switches 3 and 4, and, if necessary, to limit overvoltages, the switch should be turned on first from the opposite side of the line to the control of the voltage difference control. 1 silt o (L S SO e o o o h e j j

Description

The invention relates to the automation of electric power systems and can be used to improve the automation of the re-activation of AC power lines.

The purpose of the invention is to extend the scope of application of the method to unreacted lines.

The drawing is a diagram of the transmission line with a short without earth ground phases A and B,

The method is implemented as follows.

After detecting the fact of a two-phase ground-free short circuit, for example, on phases A and B of the power line, switches 1-4 of these phases are turned off. After the estimated deionization time of the arc gap, the phase 1 switch A is turned on. The choice of the side from which the switch is made is predetermined. One way included

One of the emergency phases is preferable from the side of the system that provides less than switching overvoltages at the open end of the switched on phase. The voltage difference ijU is measured from the open end of phase A and the disconnected phase B. Upon reaching the measured voltage difference 4U | values exceeding a predetermined setting are judged to suppress the feed arc.

The voltage difference between the one-sided and disconnected phases in the presence of a closure, measured with

the open-end side of the switched on 40 depends on the degree of phase-phase compensation, is close to zero regardless of the location of damage, the degree of compensation of the phase and phase-to-phase capacitance of the line and the angle between the equivalent EMF vectors (transmission angle) of the systems adjacent to the emergency phase and is determined only by asymmetry parameters of emergency phases and voltage drop in the charging arc. When the arc goes out, the difference between the voltages of 50 emergency phases at the measuring point depends on the angle of transmission and the degree of compensation of the phase and phase-to-phase capacitance of the line, while the minimum values of the considered difference in the 55 possible range of angles are commensurate with the operating voltage on the line, which makes it possible to judge the extinction of the feed arc by exceeding the measured

0

five

five

about 5

the difference of some given value. .

After establishing the fact that the recharge arc is extinguished, a signal is generated to re-turn on switch 2 of one-sidedly switched on phase A and to turn on switches 3 and 4, and if necessary to limit overvoltages, the switch should be first turned off from the device controlling the difference in phase voltage .

If the problem of limiting overvoltages is not acute, after determining the fact that the interphase arc has been extinguished, the switches 2 and 4 of the disconnected phases turn on, and the remaining non-switched on switch 3 on the side of the line opposite from the point of control of the voltage difference can be switched on, for example, via a communication channel or on counter voltage.

When the requirements for maintaining the stability of the systems connected by the emergency line are high, the efficiency of the application of the method increases when the one of the damaged phases is turned on. The signal about the extinction of the arc of an interphase closure is formed when the excess values of the corresponding values of the settings at both ends of the transmission line are detected by the monitored voltage.

The measured voltage difference after extinguishing the arc is comparable with the phase voltage of the line. This difference is not

interfacial capacitance, from the place of short circuit and little depends on the angle of shift between the emf of adjacent systems. For the charging arc mode, the voltage difference between the on and off emergency phases depends on the location of the accident on the line. With short circuits x remote from the observation point x, the voltage difference increases with increasing power angle. At high transmission angles, the voltage difference can reach values close to dual phase voltage. In order to avoid generating a false signal on the clearing of the arc of make-up

The method of two-way control is carried out as follows.

After detecting a two-phase groundless short circuit, for example, at phases A and B, the power lines (FIG. 1) turn off the switches 1–4 of these phases and then turn on either of the disabled phases on both sides, for example phase A switches 1 and 2 .

At each end of the electrical transmission line, the difference in voltage dU of the damaged phases is measured, and the measured values are compared in magnitude with the setpoints. The signal that the monitored value exceeds the setpoint is transmitted via communication channels to the opposite end of the line. If there is a line of a similar signal on each korg, the switches of the remaining disconnected phase are switched on (for example, switches 3 and 4 of phase B).

The control-5-fye range of the first angles of power transmission 0-90 is quite sufficient, since at angles greater than 90 ° there is an acute problem of maintaining power transmission (90), at which control of the state of the inter- face arc by the proposed method is still possible, then AR may be prohibited,

5 According to the proposed method, reliable control over the extinction of the arc of make-up on power lines is ensured and the conditions for maintaining the stability of power transmission are simplified, since, if necessary, there are two phases of the line, which can transfer power up to 60% of the pre-emergency power. It brings

) 5 this method according to the effectiveness of the method of the elimination of single-phase damage.

Claims (1)

Invention Formula 20 The reclosing signal is formed after the control voltage exceeds a predetermined value. About the method of automatic reclosing of the power line, in which, when fixing two-phase faults, disconnected faults are disconnected even if the lines are successfully repeated at both ends, they are controlled. In addition, the inclusion of voltage on the affected phases and at high angles causes increased post-accident oscillations of the rotors of the system generators, which can lead to to the loss of stability of the system by ate-30 l and h a m m, and with the fact that, with the help of communication, or on subsequent cycles to expand the range of use on the oscillations. The unreacted lines, one of the Max. The connected phases of the line are included in the extreme transmission in case of an accident can be, on the one hand, with a minimum divided by the preliminary 1 ava-35 calculations by the possible time delay, as well. in the karya regimes or by recalculation, as a controlled voltage, for example, by the current of zero sequence, the difference of voltages between the transmission power, where IF "" TH, P, one on and one off the damaged phases of the line. Editor M. Andrushenko Order 5803/48 Compiled by K. Khoetsian Tehred L.Serdyukova Proofreader V.Kut ha Circulation 618 Subscription VPIII USSR State Committee for inventions and discoveries 113035, Moscow,) K-35, Raushsk nab., d, 4/5 Production and printing company, Uzhgorod, st. Project, 4 power transmission (90), at which it is still possible to monitor the state of the interfacial arc by the proposed method, the automatic reclosure should be prohibited, According to the proposed method, reliable control over the extinction of the arc of charging on power lines is ensured and the conditions for maintaining the stability of power transmission are facilitated, since, if necessary, there can be two phases of the line, through which power can be transferred up to 60% of the power of the pre-emergency mode. It brings this method according to the efficiency of the method of eliminating single-phase damage Invention Formula The signal for reclosing is formed after the control voltage exceeds a predetermined value. About the method of automatic reclosing of the power line, in which when fixing two-phase faults, the damaged phases of the line are disconnected at both ends, the voltage is monitored on the affected phases and The connected phases of the line include at least one side with the shortest possible time delay, a. as a controlled voltage, the voltage difference between one on and one off the damaged phases of the line.