SU687521A1 - Starting member for relay protection - Google Patents

Description

one

The invention relates to the relay protection of energy objects and can be used, for example, to perform high-speed relay protection and automation devices.

Triggering bodies for relay protection are known, containing instrument transformers, splitters, rectifiers and actuators. And

In these devices, single-phase voltage to three-phase voltage splitters are inertial, i.e. the use of inductive elements causes a response delay of the reacting organ.

Closest to the proposed invention, the device contains a transreactor on the internal side; In this device, a single-phase voltage to three-phase splitter is made using

capacitors, which also causes a delay in the response of the reacting organ.

In some cases, for example, when executing relay protection devices with a time of the order of 10 ms, the delay introduced by the splitter may be unacceptably long.

The purpose of the invention is to increase the speed of triggering organs for relay protection devices,

This is achieved by the fact that in a known device containing a transreactor, to the output of which a successive organ is connected through a successively connected double splitter and a three-phase rectifier, the splitter is designed as a phase shifter on the first operational amplifier.

Claims (2)

0 and an inverting adder on the second operational amplifier, with the phase rotation input connected simultaneously to the first input of the inverting summer adder and to the first input of the three-phase rectifier, and the output of the phase rotation input is simultaneously connected to the second input of the three-phase rectifier and to the second input of the inverting summer adder which is connected to the third input of the three-phase rectifier. The drawing is a diagram of the proposed device. The device contains a transreactor 1, to the secondary winding of which a single-phase voltage splitter 2 is connected to a three-phase, three-phase rectifier 3 and a reacting organ 4. The phase splitter consists of phasops% 6th element 5 and adder b The device operates as follows. When a sinusoidal current JB passes through the primary winding of the transreactor 1, the voltage from its output, proportional to the first derivative of the input current, is fed to the input of the splitter 2 of the single-phase voltage to the three-phase voltage, the last is rectified by the three-phase rectifier 3 and fed to the input of the reacting organ 4, Voltage from the output of the transreactor 1 is fed to the input of the phase-turning element 5, in which the inertia-free is performed (if the resistor Cc and the capacitor Cd have a zero value) or with a given inertia degree (at the end the value of the resistor R4 and the capacitance of the capacitor Co) phase shift by 120 in the direction of lag. The transmission coefficient of the phase-shifting element 5 with a sinusoidal input signal is equal to j (oii-da тг cos о 2, Т, (1-ш ot -or-c-tg-) ai (c-iRi-Col o) d., - arctg : {g; 725 ;;; s The parameters of circuit elements 5 are chosen so that the following conditions are met; T 0 ° ScC2 Tl (, The output voltage psd to one of the two inputs (R) inverts 1 of the totalizer b, the second input (R) which receives the voltage from the output of the transreactor. The transmission coefficient for each of the inputs is equal and amounts to - --I 02- -R. As a result, the output voltage of the sucmator 6 forms a voltage that is ahead of the input ( at the output of the transreactor) at 120. All three voltages, equal in magnitude and shifted relative to each other by 120 °, are fed to a three-phase full-wave rectifier 3. From the output of the rectifier 3, the voltage goes to the reacting organ 4, which If the input voltage exceeds a given level, it issues a signal to the logic circuit of the protection or automation device with which this trigger is used. In a transient short circuit process, when the current at the input of the transreactor of the starting organ contains an aperiodic component in the voltage on the secondary winding of the transreactor, the aperiodic component is almost completely absent. Regardless of the initial voltage phase at the input of the phase rotation element 5 at the output of the rectifier 3, it is practically inertia-free Tili with a given degree of inertia. A voltage equal to the amplitude of the input voltage is formed. The device allows you to perform high-speed relay protection devices, which leads to an increase in the quality of transmitted electricity and an increase in the stability of power systems by reducing the off time for "damage to power facilities." The invention Starting organ for relay protection containing a transreacor, to the output of which, via a serially connected splitter and a three-phase rectifier, is connected a reacting organ, characterized in that, in order to improve speed, the splitter is made in the form of a phase-turning element on the first operational amplifier and an inverting adder on the second operational amplifier, the input of the phase-turning element being simultaneously connected to the nepBcwy input of the inverting adder and to the first input of the three-phase ypr DC converter, and the phase rotation output element connected both to the second input of the three-phase rectifier and to an inverting second input of the adder whose output is connected to the third input of the three-phase rectifier. Sources of information taken into account in the examination 1. USSR author's certificate 493848, cl. H 02 H 3/08, 1975. - 2. USSR author's certificate 316149, class, H 02 H 3/38, 1971, 3, Bochev A, S ,, Figurnov, E.P. SchemeNbi cleavage for relay protection. Electric 1967, 4, p. 13-17. 4. USSR author's certificate 306526, class, H 02 H 3/40, 1971.