SU966806A1 - Method of phasewise automatic reconnection of generator-transformer-line block - Google Patents

Description

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The invention relates to electrical engineering, in particular, to relay protection and linear automation of electrical networks and systems, and specifically to automatic reclosing devices of the circuit breaker.

There is a method of single-phase automatic reclosing (OAPV) of a high-voltage power line switch, which, at single-phase short circuit (short-circuit), automatically detects the damaged line phase, turns it off at both ends using a switch and then re-enables Cl.

The disadvantage of this method is that it cannot be used for a power line operating in a unit with a transformer with a star-delta winding circuit and a generator if the switch is not installed on the high voltage side of the transformer.

The closest to the present invention is the single-phase automatic reclosing method, implemented using a special PADS device, which consists in detecting and disconnecting the damaged phase of the transmission line at single-phase, K. 3. on it

10 re-enabling phase 2.

The disadvantage of this method is the inability to use it with single-phase short-circuit. on the power line and operation of the line in the block, with a generator having a switch and a transformer with a star-delta winding circuit without a switch on the higher voltage side, since there is a device for selecting a damaged phase to be installed on the generator-transformer side , can ensure the selection and deactivation of only one phase of the generator switching off of the bodies, and switching off in addition to the damaged phase of the linear switching off of the bodies of one, any phase of the generator switch does not ensure termination of the arc makeup in place KZ, to side of the unit transformer winding connected in a star. The purpose of the invention is to increase the reliability of operation of the unit with the wiring diagram of the transformer windings. The goal is achieved according to the method of phase-by-phase automatic reclosing of the block | Generator-transformer-line, with: holding the generator and linear switches, the connection circuit of the star-delta transformer windings and the Line with a length of no more than 100-150 km, comprising choosing the damaged phase in single-phase shorting, disconnecting this phase from the power system with a linear switch and re-enabling the same phase after a dead time, is additionally determined by the same intact phase l and a generator. This switch disconnects these phases simultaneously with the damaged one, and after a dead time, reenable all three G disconnected phases of the linear switching switches. Figure 1 shows the functional scheme of the device that implements the proposed method for phase AR; in fig. 2 - distribution of currents in the circuit after switching off the switches in the proposed sequence. Protected power lines 1, we are longer than 100-150 km, and transformer 2 with a star-delta connection circuit are connected via a line switch 3 to the power system and through a generator switch 5 to generator 6. Current transformers 7 and voltage transformer 8 each phase switches 3, connected to the phase and neutral wires of the secondary windings to eight inputs of the block of electoral authorities AR 9, the first output of which is through the delay unit 10 and the reclosing unit 11 phases of the switch 3 connected to this switch the breaker. The second, third and fourth outputs of block 9 through block 1.2. Disconnecting individual phases of the power line are connected to each phase of switch 3, and the fifth output through block 13 of detecting the additionally disconnected backward phase of the power line is connected to the inputs of block 12. Current transformers k and transformer The voltages 15 installed on the side of the high winding of the transformer 2 in each phase of power line 1 are connected to the phase and neutral wires of the secondary windings to the eight inputs of the selective-off unit 16 damaged phase, the first output of which is through the delay unit 17 and the recloser 18 phases of the switch 5 is connected to this switch, and the second, third and fourth outputs are connected to each of the switchable phases of the switch 5. The short circuit on the power line is indicated with position 19. Operation of the device - in networks of 110 kV and above, is performed as follows. At occurrence of the most frequent in the specified networks single-phase short-circuit. 19 it is advisable to use the device of phase-wise AR, since experimental studies in existing networks indicate the reality, the elimination of short-circuits. during a pause-free phase-by-phase reclosing, thus, on the high efficiency of the single-phase reclosing, which increases the reliability of the power system as a whole. Blocks 16 and 9 reveal the damaged phase of the power line 1, turn it off: block 16 — directly, and block 9 — through block 12 to shut off the individual phases of the line. However, when the line is operated in a block with a transformer with a star-delta winding connection circuit and a generator to prevent the arc from being fed from the generator, which ensures reliable suppression in the dead time of the AR, you must additionally select the phase lagging behind the damaged one using block 13 and turn it off switch side 3 The requirement to fulfill the requirement is explained by the nature of the distribution of currents shown in figure 2, where the damaged phase A of switch 3 is shown to be turned off. In the presence of power from the system and the generator 6, there is no supply of feed current of the short circuit, 19 from phase A on the star side of the transformer 2 by disconnecting the phase a on the circuit breaker 5 of the phase B switch 3. In this case, the phase current a on the side of the triangle of the transformer 2 will be equal to zero : J as each of the terms of this sum separately will be zero. Thus, the current transformation Feeder places k.z. in phase A of the star of transformer 2 from the side of the triangle of this tpaHCformat will be absent. Conditions are created for the redemption of the arc. 19 and the likelihood of successful re-activation of the block, realized by acting on the block 11 (18), is again increased on the switch 3 (5) after a period of time required | To deionize the medium of the damaged section of the transmission line and determined by the delay of the block 10 (17) .

The same result is achieved when the phase is disconnected from the switches 3 and 5 in this case will be equal to zero then the basics on the side of the triangle of transformer 2: 3c, sff since each of the terms of this sum will be separately equal to zero. FIG. 1, blocks 13 and 16 reveal the line phase ahead of the damaged line and it is additionally turned off using block 12 and 16, respectively.

With rare interphase short circuit. On line 1 from block 9, all three phases of switch 3 are disconnected.

The implementation of the proposed method is possible in connection with the presence of phase-by-phase control of both switch 3 and generator switch S

The economic effect from the introduction of the proposal is the ability to eliminate the undersupply of electricity from the generator to the network at the most particles / 90% / single-phase short-circuit. on short power lines, since when three faults of the breakers disconnect according to the existing norms, the generator field should be suppressed, and its subsequent commissioning is associated with a large (hours, hours) time. Short-term asymmetrical mode of operation; netors in the cycle of automatic reclosing for the majority of tirovoorudovaniya valid. Thus, the de-energization of a damaged phase in a single-phase short circuit on a power line when it is operated in a block with a generator having a switch and a transformer with a star-triangle without a switch with a high voltage circuit allows

S; maintain communication over an incomplete number of phases of the power line, which increases the reliability of the system.

Claims (2)

1. Rules of electrical installations. Ed. , M., Energie, 1965, p.25 “-258. 2. Bogorad AM, Nazarov Yu. G. Automatic re-activation in the power systems. M., Energie, 1969, p. (prototype). D d