SU1363363A1 - Arrangement for protecting from damage neutral inserts of traction substations - Google Patents

Abstract

The invention relates to electrical engineering, in particular, to power supply devices for electrified railways, and can be applied in alternating current areas to protect against damage to the neutral inserts of the contact network during a short circuit caused by the overlap of two air gaps. The purpose of the invention is reliability. This is achieved by additionally introducing a summing three-pole current transformer 3 ,. a down transformer 6, an adjustable resistor 7. In the absence of an overlap on the neutral insert, a current flows through the power relay 5, leading to a voltage proportional to the sum of the load currents and the additional generated current. The voltage vectors supplied to the power relay 5 are oriented so that the relay is in the jamming zone. When a short circuit occurs on the snapped neutral insert, the resulting load current and short circuit, summing up with the unchanged additionally generated current, flows through the power relay 5 and passes the latter into the zone of positive moments. 3 il. a С с СГ5 СО СО о о: со

Description

The invention relates to electric transport, in particular to electric power supply devices of electrified railways, and can be applied in alternating current areas to protect against damage to the neutral inserts of the contact network during a short circuit caused by the overlap of two air gaps.

1 (one of the inventions is increased reliability.

 FIG. Figure 1 shows a diagram of the installation of two semi-complete sets of devices on the mobile substations; FIG. 2 is a diagram of a semi-kit responsive to the current of the feeder zone, fed by the lagging phase of the substation; in FIG. 3 a b is a vector diagram of the operation of a hemisphere.

Semi-kit 1 contains an isolating current transformer 2, the primary winding of which is included in the current circuit of the input phase of 27.5 kV, summing the three-pole current transformer 3 of the current 4 relay, two power relays 5, as well as a down transformer 6 and a resistor 7, forming an additional generated current . The isolation transformer 2 of the primary winding is included in the current circuit of the corresponding input phase of 27.5 kV. Thus, the polar terminal of the secondary winding is connected to the beginning of the winding of the summing transformer 3 of the current consisting of two equal parts located on the extreme cores of the magnetic circuit. The magnetic fluxes of these parts of the winding are subtracted on the average MarHHTonpo rod. - the water on which the winding is located is included in the additional current circuit - and summarized in the extreme rods. on one of which is located the secondary winding.

The primary winding of the step-down transformer 6 is connected to the secondary circuits of a 27.5 kV bus adapter so that the polar end of the secondary winding is connected to the beginning of the winding located on the middle core of the magnetic circuit. The end of the secondary winding cy of the connecting transformer 3 in series with the winding of the current relay is connected to the polar terminal of the current winding of the power relay 5. Winding voltage relay 5 power

taking into account the polarity, they are connected to the secondary voltage buses of 27.5 kV voltage transformers.

Semi-set works as follows.

A current proportional to the input load of 27.5 kV from the current transformer 2 is supplied to the winding located on the two extreme rods of the transformer 3 magnetic circuit. A source of additional generated current is connected to the winding located on the middle rod. Secondary winding

The summing transformer 3 is located on one of the outermost cores of the magnetic circuit and is loaded with a current relay 4 and current windings of the relay. five

power.

0

The primary winding of the transformer 6 must be supplied with such a voltage that the vector of the additionally generated current is directed against the 5 oppositely averaged load vector, and modulo it is close to its maximum value, taking into account the passage of high-mass trains. For this purpose, for example, one of the voltages (linear or phase) of the secondary winding of a voltage transformer (TN-27.5 kV) is used. The value of the additionally generated current is controlled by the resistor 7.

The operation of the half-set is illustrated by the vector diagram of FIG.

In the absence of overlapping of the neutral insert, a current flows through the power relay 5, the value of which is proportional to the sum of the load current 1, and the additional generated current ISQJ ,. The voltage vectors Upj and Upj supplied to the power relay 5 are oriented in such a way that the relays are in the jamming zone. Maximum sensitivity angle

wto5

five

the first relay (f,) is equal to 30 pogo (Cf.u,) - (+70).

In the event of a short delay 0 kani on the protected neutral insert, the resultant current (load current I (j and short circuit current Ii,, ,, a), is summed up with unchanged5

K.-j, c, e. By the additional current generated

Additional flows through the power relay 5. and transfers the latter to the zone of positive moments.

Operation of the power relay 5 leads to disconnection of the feeders of the overhead contact network adjacent to the protected inset insert, and breaks the circuit of the flow of short circuit current.

Semi-kit 8 is installed on the substations, and 9 and turns on the current of the feeder zone, fed by the substation 10 by the advanced phase.

As follows from the vector diagram (Fig. 3b), the half-block 8 differs from the half-set 1 by installing one power relay with an angle of maximum sensitivity 30, which is due to the arrangement of the load current and short-circuit vectors on the neutral insert.

Claims (1)

Invention Formula : A device for protection of neutral inserts of traction substations against damage, containing a current relay, the first power relay, the polarity winding of which is connected to the secondary linear voltage with regard to polarity, the output of the current relay connected to the polar terminal of the current winding of the first power relay, l and ch e e - so that, in order to maintain reliability, an isolating current transformer, a step-down transformer, an adjustable resistor, a second power relay summing a three-rod transformer the current matrix, the first winding of which is located on the extreme rods of the magnetic circuit, is connected to an insulating current transformer, the first winding of which is connected successively with the secondary circuits of the corresponding input phase of 27.5 kV, while the beginning of the first winding of the summing current transformer is connected with a polar terminal of the secondary winding of an isolating current transformer, the second winding of a summing current transformer located on the middle core of the magnetic circuit, through an adjustable resistor connected to the secondary The primary winding of which is connected, taking into account polarity, to the secondary phase voltage of a 27.5 kV voltage transformer, while starting the second winding of the summing current transformer is connected to the under terminal of the secondary winding of the step-down transformer, the end of the third winding a summing current transformer located on one of the extreme cores of the magnetic circuit is connected to the current winding of the second power relay, the polar terminal of which is connected to the current winding of the first relay Power, the voltage winding of the second power relay is connected in parallel with the voltage winding of the first power relay. Oa HM.g,