SU655007A1 - Power transmission line hf differential protection device - Google Patents

Description

luvolpi sinusoid current, the other inputs of which are connected to the output of the combined starting organ, and the outputs of all measuring organs are connected for each half-wave of the sinusoid current, respectively, to the primary windings of the transformers of the enable signal and to the tone frequency generator of the inhibitory signal. The secondary windings of the transformer-formers are resolvable, its signal and the receivers of the tone frequency of the permit and prohibitory signals are connected to the comparison organs connected to the tone frequency generators of the resolution signal and the output opiaiam, while the measuring bodies are filled with two transistors, the emitter of the first of which is connected to the circuit collector of the transistor switch at the output of the starting body, the emitter of which is connected to the common connection point of all the secondary windings of the transreactors of the current blocks, the collector of the first transistor is connected through a differentiating circuit to one output of the primary winding of the transformer-former and through a diode to the control circuit of the tone generator of prohibiting signals and to the reference element, and its base through a resistor and diode connected to the base of the second transistor, the base-emitter junction a voltage divider connected in parallel with the capacitor in turn connected in parallel with the secondary windings of the transreactors of the current blocks, and the collector of the second transistor connected to the second the output of the primary winding transformer-rammer. In order to prevent false alarms in case of high-frequency noise in the secondary circuits, the tone frequency generator of the permitting bolt is connected to the comparison unit via a pulse transformer of the tone frequency generator start-up transformer. FIG. 1 shows a block diagram of the device; in fig. 2 is a circuit diagram for a part of a device that reacts to one of the half-waves (positive) of a sinusoidal current, where 1 is the input current unit of the measuring element during asymmetrical short circuits with a three-winding output transreactor; 2 — combined sequence current-sequence reverse sequence with current-braking of the direct sequence and two mutually blocked transistor switches at the output; 3 - input current unit of the measuring organ with symmetrical short circuits with a three-winding output transreactor; 4 - measuring body with asymmetrical short circuits, reacting to the positive half-wave of the sinusoid of the fault current; 5 - measuring body with asymmetrical short circuits, which reacts to a negative half-wave sinusoils of fault current; 6 - symmetrical short circuit organ, pearii to the positive half-wave of the fault current sinusoid; 7 - measuring body with symmetrical short circuits, reacting on the negative half of a sinusoidal current wavelength damaged; 8 - tonal frequency generator of prohibiting signal (), which reacts to io; iozh1 tolpuyu ioluvo, iiu sinusoid of fault current; 9 - 1sneror Toiia.ibnoii of the frequency of the prohibiting signal 1a, which responds to the negative half-wave of the sinusoid of the fault current; 10 is a receiver of the tonal frequency of the inhibiting signal from the other end of the transmission line, which responds to the positive half-wave of the sinusoid of fault current; 11 - tone receiver. the frequency of the inhibit signal from the other end of the electric emission line, which reacts to a negative half-wave of the sinusoid of the fault current; 12 - receiver of the tone frequency of the permitting signal from the other end of the transmission line, which responds to the positive half-wave of the sinusoid of the fault current; 13 - the receiver of the tone frequency of the permitting signal from the other end of the electric transmission, responding to the negative half-wave of the sinusoid of the fault current; 14 is a tone frequency generator of a permitting signal responsive to a positive half-wave of a si-wave fault current; 15 - generator of the tone frequency of the transmitted signal reacting to the negative half-wave of the sinusoid of the fault current; 16 is a comparison organ, reacting at a positive half-time, or a damage current fault; 17 is a reference organ reacting to the limiting half-wave of a sinusoid of fault current; 18 output block, triggered by a negative half-wave of the sinusoid current of internal damage; 19 - output block triggered by an open half-wave of a sinusoidal current of internal damage; 20 - power line switch; 21 - transistor switch at the output of the combined starting body 2, connecting measuring organs 6 and 7 with symmetric short circuits x; 22-transistor switch at the output of the combined starting body 2, connecting the measuring bodies 4 and 5 during asymmetrical short circuits x; 23- output transreactor of the input current unit 3 of the measuring body with symmetrical short circuits x; 24 - output transreactor of the input current unit 1 of the measuring body with asymmetrical short circuits x; 25 - the first transistor of the measuring body 4; 26 - the second transistor measuring oriia 4; 27 - transformer-forming TCJiij enabling signals; 28-pulse transformer start-up of the tone frequency generator; 29 —signing transistor of the reference organ; 30 is the output dynistor of the reference organ; 31 - output pulse transformer of the output unit 18; 32 - resistive voltage divider resistor; 33 - voltage divider resistor; 34 - diode; 35 - capacitor voltage divider; 36, 37 - comparison organs; 38, 39 - transistor innovator; 40 - capacitor.

In the case of an asymmetrical short circuit, the current unit 1 and the triggering organ 2 are triggered in the zone of operation of the device. Depending on the half-period of the short circuit, a half-wave of the voltage sine wave proportional to the current is on one pin of the windings and the other is negative the half-wave of a sinusoid of the same voltage. The winding of the transreactor 24 is connected to the measuring bodies 4 and 5, respectively, for a positive and negative half-wave sinusoids. When triggered body 2 and an asymmetrical short circuit, transistor switch 22 is opened.

If the positive half-wave sinusoid voltage is on the transreactor winding connected to the measuring unit 4, a circuit is formed for the current through the transistor switch 22, the emitter-base junction of the transistor 25 of the measuring organ 4, the resistor 33, the diode 34 and the capacitor 35 connected to the terminals of the secondary winding of the transreactor 24. At the same time opening the transistors 22 and 25, the transistor opens, stopping the tone frequency generator 8, thereby creating an opening condition prohibiting second transistor 29 in comparator 16. The transistor body 29 is opened at the time when the receiver 10 the signal tones frequencies zapreschayuodego fixes stopping tone generator prohibiting signal on the other end of the transmission line. Transistor 26 opens in 4-5 ms, i.e. approximately at the moment when the voltage at the output of the trans-reactor 24a reaches the schlitd value. To set the required opening moment of the transistor 26, a variable resistor 32 of the voltage divider is used.

At the moment of opening of the transistor 26, a circuit is created for the current through the primary winding of the transformer-former 27. The secondary voltage of the transformer 27 turns on distor 36, thereby creating a current circuit through the emitter-collector junction of transistor 29, distor 36 and the primary winding of the transformer 28,

as a result, a generator of 14 tonal frequencies of a permitting signal transmitted to the other end of the transmission line is started up. In addition, the transistor repeater 38 of the state of the mentioned dynistor 36 enters another state.

At about the same time, the receiver of the tone frequencies of the permissive signal 12 records the start of the tone generator 10 times the permissive signal at the other end of the transmission line. The appearance of the signal at the output of the receiver 12 leads to the inclusion of the second dynistor 37 of the comparator 16 and the transition to another state of the transistor repeater 39. This leads to an increase in the voltage on the capacitor 40 connected between the emitters and collectors of the transistor repeaters 38, 39 nor any dynistor, before switching switching of the dynstor 30, the activation of which leads to the start-up of the output unit 18 through the pulse transformer 31, acting on the opening of the switch 20.

5 When the positive half-wave of the sinusoid current disappears, transistor 25 closes, thereby triggering the tone generator of the inhibit signal 8, and regardless of the presence or absence of the inhibit signal from the other end of the transmission line, transistor 39 closes. This leads to a reset transistor repeaters 38, 39 of the state of the dynistor 36, 37 5 and the output block 18. However, the return of the output block 18 occurs only if after 20-25 ms the device did not respond again -keeping.

Before switching off the power switch, after a period of industrial frequency, i.e. after about 20 ms, the transistors 25 and 29 are reopened with the preparation of the switch for switching on the dynistor 30.

5 Similarly, during the negative half-wave of a sinusoidal current, the measuring body 5. of the comparison body 17 and the output unit 19 is triggered with the launch of the corresponding tonal frequency generators 9 and 15 and the receivers 11, 13.

As for the rest, the device operates in the same way as for asymmetrical short circuits.

In case of a short circuit outside the zone of action of the device, the transistor 29 is closed for the entire duration of the closure, thus preventing the switch of both dynistors 36, 37 in the comparison organ.

In normal mode, both transistor 0 key 21 and 22 are closed.

With a symmetrical short circuit

in the area of the device opens on

time 0.3-0.4 s transistor switch 21 and

The secondary windings of the output transreactor 23 of the input current unit 3 are connected to the used in this case, the measuring bodies 6 and 7.

The described device for high-frequency differential-phase separation provides high speed and self-redundancy — failure in one half-period is reserved by operation in the other. In addition, the block design and the principle of operation of the device ensure high operational reliability.

Claims (3)

1. Device for high-frequency differential protection of a power line, containing an ultrashort wave communication channel, tone generators and devices of enabling and prohibiting signals, a combined reverse sequence current triggering device with current-mode braking, to which the measuring elements are connected from symmetrical and asymmetrical 1x short-circuits of one half-wave of a sinusoid current, the other inputs :. which are connected to current blocks with output directional reactors, transformer-forming permitting sigpal, comparing organ and output organ, differing from the fact that, in order to increase speed and reliability of operation, it spabzheig measuring bodies from symmetric and asymmetrical short circuits, generators and the receivers of the tonal frequencies of the other half-wave of the sinusoid current and the second transformer-former, the comparator and the output unit, while the transreactors at the output of the current units are equipped with main secondary winding to which the measuring bodies from symmetrical and iesymmetric short circuits of the other half-wave sinusoid current, other inputs of which are connected to the output of the combined starting organ, and the outputs of all measuring organs are connected respectively for each half-wave of the SYNUSOID current to the primary winding of the transformer-former of the resolving signals and to the prohibitive tone generator, and the secondary windings transforming transformers of the permitting signal and receivers of the tone frequency of the permitting and prohibiting signals are connected to the comparison units connected to the tone-frequency generators of the permitting signal and output organs. 2. Device n. 1, characterized in that the measuring bodies are made in the form of two transistors, the emitter of the first of which is connected to the collector circuit of the transistor switch at the output of the starting body, the emitter of which is connected to the common connection point of all secondary windings of current-supply transreactors, the chip of the first transistor is connected through a differential circuit to the single output of the primary transformer of the transformer formative and through a diode to the circuit control of the tone pickup frequency of the transducer signals, and its base is connected to the base of the second transistor through a resistor and diode, the base-emitter junction of which is switched on) on the capacitor of the voltage divider: connected in parallel to the secondary windings of the transconteractor current blocks, and the collector of the second transistor is connected to the second terminal of the primary winding of the transformer-transformer. 3. Device by n. 1, characterized in that, in order to prevent false alarms in case of high-frequency interference in the secondary circuits, the tone frequency generator of the enabling signal is connected to the comparator through a pulse starting transformer of the tone generator of the resolution signal. Sources of information taken into account in the examination 1. USSR author's certificate No. 307456, cl. H 02 H 3/30, 1970. 2. USSR author's certificate No. 263721, cl. H 02 H 3/30, 1968. f ff "p