SU993377A1 - Power direction relay - Google Patents

Description

(54) RELAY DIRECTIONS

This invention relates to electro; technology and can be used in directional protection elements of electrical systems.

There is a known electromagnetic relay for power control of the RBM type, which has a rather simple design, high reliability and high speed 1.

However, this relay consumes significant power over current and voltage measuring circuits, has a low return coefficient and is designed to operate with sinusoidal currents and voltages within 10% of current transformer error. If there is an aperiodic component in the current, the angle of maximum sensitivity of the relay changes and a mobile system vibrates. . .

The closest to the present invention is a semiconductor power direction relay containing a pro-intermediate voltage transformer, an intermediate current transformer, a phase-sensitive element and a null indicator and having a high return coefficient and low power consumption C 2.

However, the correct operation of a known relay is also affected by the —peri-dic component of the short-circuit current.

The purpose of the invention is to reduce the effect of the aperiodic component in current on the operation of the power direction relay.

The goal is achieved by the fact that in the relay of the power direction, containing an intermediate voltage transformer, an intermediate current transformer, two diodes and a series-connected phase-sensing element and a zero indicator,

The 15 output of which is the relay output, additionally a trigger, two linearly varying voltage generators, a null organ, a coincidence element, and a one-shot, with this

The output of the intermediate current transformer is connected via oppositely connected diodes to the trigger inputs connected by the outputs to the inputs of the respective generators of linearly varying voltage, the outputs of which are connected to the inputs of the zero-organ connected by the output to the same input of the coincidence element, the output of which is connected to

30 to one input of the phase-sensitive element, to the other input of which the output of the intermediate voltage transformer is connected, and the other input of the coincidence element is connected to one of the outputs of the aforementioned flip-flop.

Fig, 1 shows a functional diagram of the proposed relay; FIG. 2 shows timing diagrams explaining his work.

The relay contains intermediate voltage transformers 1 and current 2, connected by an output through diodes 3 and 4 to the inputs of trigger 5, the output of which includes generators b and 7 of linearly varying voltage, connected by outputs to the inputs of the null organ 8, the output of which is a series element 9 matches, one-shot 10, phase-sensitive element 11 and zero-indicator 12,

The relay works as follows

When a positive voltage appears at the output of the intermediate transformer 2 of the current, the trigger 5 is set to one, while its output has a pulse 11. At the same time, the generator of the linearly increasing voltage is started. With the appearance of the negative voltage, the trigger 5 is set to zero and. running generator 7 linearly decreasing voltage,

At the moment of equality of the voltages at the outputs of the generators 6 and 7, applied to the input of the null organ 8, at its output the pF is a voltage pulse and. To eliminate the failure of the relay, since the moment of equality of the voltages occurs two times per period, the signal from the zero-organ output 8 is fed to the coincidence element 9, which also receives the signal from the single output of the trigger. When the pulses coincide with the zero-organ 8 and the trigger 5 s of the input of the element 9 of the coincidence. The input of the one-vibrator 10 is given a triggering voltage Ug, the duration of the pulse П {, the output of the one-vibrator is equal to half the current period.

If there is an aperiodic component in the current, the duration of the positive half-wave (FIG. 2) increases and the negative decreases, but the pulse period does not change and, therefore, the time of coincidence of the voltages U2 and Uj also does not change and synchronizes with the input phase tension

Thus, the sequence of pulses fed from the output of the one-vibrator to the phase-sensitive element has an oscillation phase that is independent of the presence of an aperiodic component in the current,

Claims (1)

Invention Formula A power direction relay containing an intermediate voltage transformer, an intermediate current transformer, two diodes and a series-connected phase-sensitive element and a zero-indicator, the output of which is the output of a relay, is designed so as to reduce the influence of the aperiodic component a current for the relay operation, a trigger, two generators of linearly varying voltage, a zero-body coincidence element and a one-oscillator are added to it, the output of the intermediate current transformer is connected through Directly connected diodes to the trigger inputs connected by the outputs to the inputs of the respective linearly varying voltage generators, the outputs of which are connected to the inputs of a null organ connected by the output to one input of the coincidence element, the output of which through the single vibrator is connected to one input of the phase-sensitive element, to the other the input of which is connected to the output of the intermediate voltage transformer, and the other input of the coincidence element is connected to one of the outputs of the above-mentioned trigger. Sources of information taken into account in the examination 1, Alekseev V, S, Relay protection, M ,, Energie, 1976. 2, Paperno L, B, Design of relay protection devices on contactless elements, M ,, Higher School 1979, p. 135, rice, 7.7, sha u Uf and. about t t g / 4 eight Uff w 12 It T t rri 1 Fiz.