SU1261041A1 - Method of checking current and voltage signals in a.c. networks - Google Patents

Abstract

The invention relates to the field of automation and can be used in relay protection systems and signaling devices of alternating current. The purpose of the invention is to increase speed. First, signals proportional to current and voltages are formed, then, for a certain period of time, starting from the moment of crossing the signal proportional to voltage, the received signals are integrated. At the end of time, the integrators will generate a pulse signal, the amplitude of which is proportional to the sum of the integrated signals. The pulse signal is compared with a predetermined threshold. 2 Il. (L

Description

The invention relates to the field of automation and can be used in relay protection systems and in alternating current signaling devices. The purpose of the invention is to increase the speed of control.

Fig, 1 shows a functional diagram of the deviceJ implementing the proposed method; in fig. Z time diagrams for his work.

The device contains inputs 1 and 2, which receive signals proportional to current and voltage, amplifiers 3 and 4, capacitors 5 and 6, keys 7–9, amplifier 10, threshold element 11, output 12, resistors 13–15.

The device works as follows.

For some time, the beginning of which depends on the moment of transition of the signal, linearly dependent on the primary voltage (Fig. 2a), previously closed switches 7 and 8 are flushed, and integrated signals start to form at the output of amplifiers 3, 4 (Fig. 2b c), which through resistors 13 and 14 enter the input of amplifier 10. At the moment when the input signals are formed, open the switch 9, and the output of amplifier 10 produces a pulse signal (Fig. 2d) equal to the sum of the integrated values signals that enters in d threshold element 11.

If the monitored resistance parameters do not exceed the allowable values, then the polarity of the signal at the output of the amplifier 10 is positive (Fig. 2d). If the monitored resistance parameters exceed the tolerance

limits, the polarity of the pulse signal at the input of the amplifier 10 coincides with the polarity of the threshold signal (Fig. 2e) and at the output 12 of the threshold element 11 there is a pulse signal (Fig. 2e).

Using the proposed method of obtaining signals that are a function of primary currents and voltages in alternating current networks in the rail power supply system, a signal is received about the emergency state of electrical installations by automation devices during the half-time regardless of the excess values . This will reduce the likelihood of damage to electrical installations in an emergency.

when used in railway transport, which will lead to the exclusion of a break in the movement of electric trains.

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Claims (1)

Invention Formula The method of control of current and voltage signals in ac-current networks, based on the comparison of controllers; signals with a given signal and the formation of control signals, comparing the results of the signals, and with the fact that, in order to improve speed, respectively the monitored current signal and voltage signal are pre-integrated over a time interval equal to their half-period, then they are summed up until the zero crossing of the initial voltage signal into which a pulse signal is formed, the amplitude of which corresponds to the sum signal, the generated pulse signal is compared with the specified one. 20 J2 f UZ, 1 Compiled by M. Artamanov. L. Veselovska Editor. Tehred M. Khodanych. Corrector A. Zimokosov Order 5240/54 Circulation 612. Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 FIG. 2