BG98524A - Design solution for a rectifier substation circuitry - Google Patents

Abstract

A circuitry is disclosed for traction current supply rectifier substations having a central rectifier unit that may be controlled, semi-controlled or non-controlled. The line exit is supplied by a quick disconnector (13, 14) whose pole on the side of the line is linked to a coupling subassembly (6, 7) that leads through two looped lines (20, 21) to a switching arrangement (9) composed for example of a switching thyristor (12) and at least one turn-off arm and coupling diodes with a direct current bus bar (3). When a central thyristor semi-block (1) is available, it further contains its own turn-off arrangement (8). This circuitry is suitable for all rectifier substations having a direct current bus bar.

Description

The present invention relates to a structural solution of a railway substation rectification scheme, where the substation has a central rectifier section. The correcting section can be performed as a control, respectively. semi-adjustable or unmanageable.

In rectifying substations for power supply to electrified DC lines, known outgoing circuit breakers are used in the output bus sections, which - being adjustable to a certain actuation value - are able to safely cut off the overload current, respectively. short circuit current. However, in terms of their design, circuit breakers of this type are relatively expensive and due to the electrical arc produced between the contacts of the circuit breaker create some problems with the safety of the equipment. In addition, these circuit breakers, inter alia due to the electrical arc of the switch, are subject to wear and tear, which requires the maintenance of high-speed circuit breakers for relatively short periods of time.

Thyristor circuit breakers on the DC busbar are also known from EP-A-206 150. However, the substation contains additional semiconductor switches in the energy flow to the rectifier, which results in higher costs and losses for the entire facility and also requires greater investment. In addition to this, additional valves should be used to ensure that it is possible through the station, ie. through the substation, re-energize the brake energy.

Another solution with thyristor circuit breakers on a three-phase busbar to exclude parasitic interference linear clones is also known from DD-A-261 485.

Abstracted from the requirement that additional valves must also be provided here to provide re-supply of the brake energy, such a decision to exclude an output bus from the section with any interference from the substation from the type described in the introductory part is inappropriate and due to the fact that, because of the required short-circuit endurance, for example for 200 milliseconds, thyristor switches should be economically disadvantageous.

In the meantime, it has also been suggested that the central rectifier should be half-built as a thyristor block, which can be used for central, fast shut-off by means of an extinguishing circuit, whereby in a non-voltage pause that will be brief, the fast-acting disconnector is excluded from the corresponding output tire. In this way, further work can be carried out. However, short breaks without tension will always occur.

Therefore, the object of the invention is to provide a constructive solution for cxebia for the operation of a rectifying substation for the supply of a direct-current electrified railway line, using a central rectifier unit and high-speed disconnectors in the output busbars and sections, which is a one-stop solution be cheap and, on the other hand, be able to switch both reverse and short-circuit currents while providing the ability to easily check on the plot.

According to the invention, the problem is solved by the following scheme:

The existing output busbars of the section are fed via a high-speed disconnector and a current transformer, respectively, on the plus DC busbar. The DC busbar is in turn powered by a central rectifier. It can be implemented as a controllable, preferably semi-controllable, or as an unmanageable rectifier unit. At each pole of the high-speed disconnector at the site is a connection node consisting of two anti-parallel valves, preferably diodes, each leading to a contact wire to which the switching device is connected. The latter has a connection to the positive pole of the central rectifier. (Of course, reverse polarity is possible).

In the event that the central rectifier is configured as a control unit, an extinguisher is also provided for the central rectifier unit with connection to the three-phase busbar.

The switching device consists predominantly of a switching thyristor to which at least one quenching branch is attached.

The quenching circuit is advantageously made in a well-known manner, namely a quenching thyristor and a quenching capacitor. The circuit is preferably connected via a diode to the switching thyristor.

In another preferred embodiment, the switching unit may also be composed of only one extinguisher when its own switching thyristor is assigned to each high-speed disconnector. In this case, a corresponding switching thyristor and an extinguishing circuit are provided, preferably for each direction of the current.

The scheme works as follows:

In the embodiment with a control rectifier as a central rectifier, short-circuit currents of high value to the defective point are eliminated by quenching the thyristor unit by means of a central rectifier block extinguisher. Power to the defective point from remote power points is fed through the switching device and then switched off via the switching circuit of the switching device. This is done in such a way that when the overcurrent current is detected, the respective high-speed disconnector is forced to open, while the ignition pulses for the central rectifier block are interrupted. At the same time, the extinguishing thyristor of the extinguishing device is ignited for a short time, and then the switching thyristor of the extinguishing device with an appropriate ignition duration, and after a certain period of time or after a signal from the high-speed switch of the extinguisher circuit of the switching device this switches off the current for the corresponding output bus.

As already described in the prior art, the dash half-block can then be switched on again to continue powering the correct section.

Further, in the event of an arbitrary shutdown of an output bus from a section, the high-speed disconnector is actuated and at the same time the switching thyristor is ignited, so that the current passes from the current bus of the high-speed disconnector to the switching thyristor within a short period of time. After a fixed delay period for the ignition of the switching thyristor, respectively. after a signal from the high-speed disconnector, the switching circuit of the switching device is ignited and, regardless of the direction of the current, a disconnect is made via the power electronics via the high-speed disconnector.

In the embodiment with an uncontrolled central rectifier, all disconnections of the output bus section, and therefore the disconnections at short-circuit current, are carried out in the manner just described.

After switching off an arbitrary output bus of a section, the switching of the thyristor can be performed by checking the section without the need for a special control resistor. With the existing quenching circuit, the control current can be switched off again and the test section possibly connected again, as is already well known in the prior art.

If a thyristor is used for the reverse current valves of the connection units, according to another advantageous variant, both valves of the connection units can be connected to a single contact wire, which in this case will serve as an idle contact wire , as well as a contact wire for reverse power.

Other advantageous embodiments of the subject matter of the invention are presented in the additional claims.

The invention will now be described in detail by way of exemplary embodiments. The corresponding drawings show: Fig. 1 - Design solution of a circuit according to the invention for a rectifying substation with a central, semi-controlled rectifier;

FIG. 2 is a schematic diagram of a solution according to the invention for a rectifying substation, with an uncontrollable, central rectifier;

Fig. 3 is an embodiment of the scheme according to Fig. 2 with an additional standby extinguishing capability, and

Figure 4 - Variant with only one contact wire.

An advantageous exemplary embodiment of a rectifier rectifier with a semi-controlled rectifier is shown schematically in FIG.

The central rectifier consists of a thyristor half-block and a diode half-block 2. The rectifier feeds, for example, the plus DC bus 3. On the plus DC busbar 3, there are approximately two output busbars 4 and 5 per section, each with one connection node 6 and 7 according to the invention. The exclusion of the section in this example is realized in such a way that in the road sections of the line, parallel to the shown substation, power can be supplied from other rectifying substations, so that a continuous connection is obtained between all road sections of the line, here this connection is not an image of. The thyristor technique substation according to the invention also includes an extinguishing device 8 and a switching device 9. These two devices can perform any kind of defect shutdown as well as site inspection.

In case of fault in the output bus 5 of the section the following operations will be performed:

- Blocking of thyristor half block 1,

- ignition of the extinguishing thyristors 10 and 11,

- actuation of the high-speed disconnector 14,

- switching of the switching thyristor 12 and

- for example, after a fixed delay time - ignition of the first quencher thyristor 15 by the switchgear 9.

By closing the thyristor half block 1 and igniting the extinguisher 8, the short-circuit current of high value at the nearby rectifying station is immediately switched off. The high-speed disconnector 14 is then opened, and the resulting voltage drop on the opening disconnecting section is short-circuited by the switching thyristor 12, since from now on the current from the more remote rectifying substations is no longer passed through the high-speed disconnector 14, but through the high-speed disconnector 14. diode 17 through the RL combination 67, the lit switching thyristor 12, the connecting wire 18 to the idle contact wire 20 and then through the auxiliary switch 25 and the idling diode 27 to the defective point n and the output bar 5 of the section.

After switching off the random output bus section and ignition of the thyristor half block 1, a section check can be performed by means of the connecting diode 1 7 and the switching thyristor 12, and the control current through the extinguishing circuit is a quenching thyristor

15, respectively. 31, damping capacitor 35, respectively. 36 - is off again. If necessary, the faulty outlet section of the section can then be reconnected. Otherwise, if the output bus 5 is switched off continuously, the two-pole auxiliary disconnector 24, 25 may be opened so that the output to the section 5 of the flyline is completely galvanically separated.

The normal disconnection of a line output bus is explained by turning off the reverse power supply. When a back-up current flows from the output bus 5 of the section to the output bus 4 and it must be switched off, the high-speed switch 14 is actuated and the switch thyristor 12. The reverse current is switched by the open high-speed switch 14 in the following circuit: reverse power diode 29, auxiliary disconnector 24, reverse power contact wire 21, connecting wire 19, through the ignited switching thyristor 12, the RL combination 66, and the connecting diode 16 to the flux dc plow 3, and from there the circuit closes to the output bus 4, where the reverse power should flow. Parallel to the connecting diode 16, a portion of the back-supply current flows through the connecting wire 18, the auxiliary disconnector 23 and the idling diode 26 to the output bus 4 of the section.

Similarly, switching off the reverse current through the high-speed switch 13 in the output bus 4 by switching on the diode 28 for reverse power, the auxiliary switch 22, the contact wire 21 for the reverse power and the switching thyristor 12.

Since the same sequence of processes is always obtained, regardless of the direction of the current, it is not necessary to measure the current direction by some measurement.

In order to obtain simple duplication, two quenching circuits are advantageously provided within the switching device 9, whereby one quenching circuit with the quenching capacitors 35, 36 always extinguishes the switching current through the switching thyristor 12, and in turn by switching on the corresponding quenching thyristor 15 , resp. 31 after a specified delay time with respect to the ignition of the switching thyristor 12.

The extinguishing capacitor 30 in the extinguisher 8 is recharged for a very short time through the auxiliary circuit 32 by igniting the charging thyristors 33, 34 after the process of extinguishing the thyristor half unit 1, even before its re-ignition, so no duplication is required here. The thyristor half block 1 is preferably switched on approximately 6 milliseconds. after clogging. Vehicles located on sections unaffected by these processes do not notice a voltage drop.

Advantageously, the idle diode 38 establishes the connection between the running rail (anode) and the output busbar section (cathode), so as not to produce overvoltages in the inductances of the supply wires in the event of rapid short circuits.

The connecting diode 37 provides a flawless switching of the leakage current from the thyristor half-block 1 to the extinguishing capacitor 30 and at the same time separates the supporting circuit 32 from the plus DC busbar 3.

The advantageously used connecting diode 39 provides a faultless switching of the disconnectable current through the switching thyristor 12 to the quenching capacitor 35, respectively. 36 and at the same time separates the auxiliary circuit 32, which is electrically connected to the quenching capacitors 35, 36 via a connecting wire 40, from the control currents and other currents flowing through the switching thyristor 12.

The rectifying substation according to the preferred embodiment according to FIG. 2 has a central supply with a plus DC current busbar 3 from which the output busbars 4 and 5 are output to a section. The output busbars 4, 5 can be separated from the DC busbar 3 by the high-speed disconnectors 13, 14. One fastener 6, 7 is connected to each high-speed disconnect switch 13, 14. The connecting nodes 6, 7 consist, respectively, of each of the idle diodes 26, 27, as well as of the anti-parallel diodes 28, 29 behind them, which are connected to the pole of the high-speed disconnectors 13, 14 from the section. They lead through the auxiliary disconnectors 22, 23, 24, 25 to the contact wire 21 for back-feed respectively. on the idle contact wire 20, which in turn lead to the switching device 47.

The switching device 47 consists predominantly of at least two quenching circuits: one reciprocating quenching circuit consisting of quenching thyristor 15 and quenching capacitor 35, and a quenching circuit with quenching capacitor 41 and quenching thyristor 42 for reverse direction.

Switching thyristors 43, 45, respectively. 44, 46 in this example are respectively arranged parallel to the high-speed disconnectors

13, 14.

When the output bus 4 or 5 is switched off, the respective high-speed switch 13, 14 is forced to open, while the corresponding switch thyristor 43, 44 is lit. The current is switched by the open high-speed switch 13, 14 on the corresponding switch thyristor 43, 44. With some delay in time, respectively. through the contact of the opening high-speed disconnector 13, 14 the quenching thyristor 15 is ignited and the current through the switching thyristor 43, respectively. 44 through the first quenching circuit consisting of a quencher thyristor 15 and a quenching capacitor 35 is again disconnected.

With the help of parallel switches 13, 14 switching thyristors 43, 44, the site can now be checked and, depending on its result, the corresponding output bus 4, 5 can be switched on again.

Quenching of any reverse current, for example, when a current flows from the output bus 4 through the plus DC current bus 3 to the output bus 5, proceeds in the same way, only through the switching thyristor 45, the switching thyristor 42 and the quenching capacitor 41.

In order to have spare quenching capacitors for the two-way quenching, the two quenching circuits of the preferred embodiment according to Fig. 3 are constructed so that the quenching capacitors 35, 41 are arranged in the direction of the contact wire 20 for idling respectively to the contact conductor 21 and the electrodes of the damping capacitors 35, 41 pointing to these conductors are connected through the thyristors 48 and 50 to the positive DC busbar 3, and the other electrodes are connected diagonally to each other through the thyristors 51, 49. In this way, for the second quenching process, for example, after quenching by means of the quenching capacitor 35, the quenching capacitor 41 is available by ignition of the thyristors 50, 51.

The switching off of the output bus 4 is performed by the switching thyristor 43, which is ignited, and when the current threshold value set by the current transformer information is exceeded, the switching thyristor 15 is automatically ignited, thus switching off the set leakage. current. If the current threshold is not exceeded, after a control time of about 3 seconds, the high-speed disconnector 13 closes, resulting in the restoration of the normal power supply to the output bus 4.

In Fig. 4, in another advantageous embodiment, two rectifying substations with power supplies 1a and 16 are shown, the first rectifying substation being made in more detail than the second. The rectifying substations shown here are constructed uniformly and, due to the known scheme shown here, are all interconnected, so that the double-track section is fully integrated. The second substation may be constructed differently, for example, it may also be equipped with high-speed circuit breakers.

The depicted substation consists of a plus DC busbar 3 from which, for example, four output busbars A, B, C and D emerge, which are indicated by the following elements in the drawing: high-speed disconnector 13, 14, current transformer 52, diodes 26, 27 idle, reversing valves 28, 29 and auxiliary disconnectors 23, 25. Auxiliary disconnectors 23, 25 are connected to the idle contact wire 20. In the preferred embodiment, it consists of a switching thyristor 12 and a quenching circuit, which in turn is composed of a quenching thyristor 15, a quenching capacitor 35 and a connecting diode between the Pus DC DC busbar 3 and the contact wire 20 for idling. 39.

Further, between the ground line, in this case the negative w pole, and the contact wire 20, an overhead line diode 38 is included.

on

The two anodes, the name diode 39 and that of the diode 38, are connected by means of an auxiliary circuit 32 consisting of inductance and resistance. In the same way as the output buses A through D and the switching device 9, the same elements are found in the second rectifying substation and in the following.

The sections 53, 54, 55, 56, 57 and 58 are connected to the following output buses: 53 with B, 54 with D and B2, 55 with D2, 56 with A, 57 with C and A2 'W' and 58 with C2 . In addition, a cross-section is shown by means of the switching device 59. The switching device 59 is switched on.

The operating mode will be explained by means of malfunctioning exceptions, by first assuming that there is a short circuit 60 in section 54. It is further assumed that the output buses D and B are switched on and the output buses A and C are excluded. This also applies to the second rectifying substation and to the next, as it is also assumed that the actuation value is only reached by the output buses D and B2. Other output buses could be actuated by the di / dt protection not shown at this point.

Switching off the output buses D and B2 will be described by the example of switching off the output bus D. The high-speed disconnect switch 63 on the output bus D will receive the PIT command; at the same time the switching thyristor 12 and the (not shown) back-up thyristor (by analogy 28 and 29 respectively) are ignited, so that the current is switched from the opening high-speed switch 63 to the switching thyristor 12 on the contact wire 20 for free running through the auxiliary the disconnector 61 and the freewheeling diode 62 of the output bus D to that output bus D, so that the short-circuit current at the time of shortening 80 then passes in the following way: irkh from the positive DC busbar 3 through the switching thyristor 12, through the freewheel contact wire 20, the disconnector 61, the idle diode 62 and the current transformer 52 of the output bus D.

In the same way, switching in the output bus B2 should be considered, with the switching device 9 of the second rectifying station involved.

After a specified time, respectively. after contact is made by the opening high-speed disconnector 63 of the output bus D, the extinguishing thyristor 15 is ignited, which absorbs the current of the switching thyristor 12 (negative potential at the anode of the switching thyristor 12 due to the capacitor output voltage), which is subsequently inverted the extinguishing capacitor 35 blocks the extinguishing thyristor 15, thus terminating the shutdown of the output bus D. After the ignition of the extinguishing thyristor 15, a short pulse current flows through all the connecting circuits (diodes and freewheels and auxiliary disconnectors), provided that the high-speed disconnectors are closed, therefore, the output bus B. is affected in the accepted example, the magnitude of this impulse current is limited by the resistor 64. The impulse current, for example through the elements of the output bus B , is completely avoided when idle diodes are replaced by thyristors and only those thyristors are lit, the output bus of which must therefore be included in the example only by the output bus D.

The supporting circuit 32 serves to safely disengage the section if the sections are idling. The idling diode 38 has a positive effect on the reduction of switching voltages.

It is further assumed that a short circuit 60 is present and at the same time or with a small distance at time through the assembly 65 of the composition electrically connects the dividing point between the output buses of sections B and D. Then to the short circuit 60 through B a current is flowing that would be able to reach the actuation value so that the high-speed disconnector 14 is opened from the output bus B, and the switching thyristor 12, as well as the feeder thyristor 29, are again ignited by the output bus B, respectively. another switching current flows here, and a spare quencher thyristor 31 and a quenching capacitor 36 are subsequently put into operation to shut off without residual, as described above, all short-circuit current from the first rectifying substation.

It is further considered that the malfunctioning declared prior to the description. It is further accepted that all are included

output buses A, B, C, D. Here it may be necessary to exclude the output buses B, C and D, possibly also the output bus A. In this case, it was also assumed that the fault event indicated by node 65 of the composition occurs at an unfavorable moment, where it is necessary to ignite the backup thyristor 31, since the first quenching capacity has already been recharged.

Feedback currents, for example through the opening high-speed switch 13 of the output bus A to the output bus D, are switched on as follows:

- command to open to high-speed switch 13,

- ignition of the switching thyristor 12 and, at the same time, the ignition of the feeder thyristor 28 on the output bus A.

The current switches according to the following trajectory:

- Feedback thyristor 28 from output bus A,

- auxiliary disconnector 23,

- freewheel contact wire 20,

- diode 62 for free travel of output bus D output bus D.

The reverse thyristor 28 is not switched off and switches off automatically when the brake current drops to zero.

After any switch-off, a section check can be performed by the switching thyristor 12, whereby the control current through the quenching circuit: quenching thyristor 15, quenching capacitor 35 and connecting diode 39 is again switched off.

Thanks to the circuit device according to the invention, it is possible to include fault currents and load currents, regardless of their direction to or from the DC busbar, where only information on the output value (absolute value) of the output bus is required.

The inspection of the section can be carried out without the resistance to check the sections, since the built-in technical means of the connecting and quenching arrangement are used for this purpose.

References:

/ 1 / EP-A-206 150/2 / DD-A-261 485

Claims (10)

1. Schematic arrangement for a rectifying substation with a DC busbar to which several output busbars of the section are connected via high-speed disconnectors, as well as a central rectifier unit, characterized in that on the pole from the section of each high-speed disconnector (13, 14 , 63) a connecting node (6, 7) is disposed, which is led to a freewheel contact wire (20) and a reverse power contact wire (21), which in turn lead to a switching device (9) consisting of one or more switches It will thyristor (12) to which is svarzanav parallel to at least one blanking circuit. 2. Schematic arrangement according to claim 1, characterized in that the central rectifier unit is a controllable rectifier. 3. Schematic arrangement according to claim 1, characterized in that the central rectifier unit is an unmanageable rectifier. 4. Schematic arrangement according to claims 1 and 2, characterized in that the central rectifier unit is a semi-adjustable rectifier. Circuit arrangement according to claims 1 and 2 or 4, characterized in that a separate quenching device is attached to the thyristor half block (1) of the central rectifier unit. The circuit arrangement according to claim 1, characterized in that the switching thyristor (12) is connected on both sides to the plus DC busbar (3) through a respective connecting diode (16, 17) and / or RL combination (66) , 76). The circuit arrangement according to claim 1, characterized in that the connecting assembly consists of a freewheel valve, anticharally disposed to it a back-feed valve and associated auxiliary disconnectors (22, 23, 24, 25). 8. Schematic arrangement according to claim 7, characterized se p that as a valve for free the course serves diode (26, 27, 62) for freewheeling. 9. Schematic layout, according to claim 7, characterizing se p that as a valve for free the course serves thyristor. 10. Schematic layout, according to claim 7, characterizing se p that as a valve for back power supply serves as a diode for early on ι power supply (28, 29). 11. Schematic layout, according to claim 7, characterizing se p that as a valve for back power supply serves thyristor (28 29) for reverse power supply. 12. Schematic layout, according to claim 1, characterizing in that the quenching circuit consists of a quenching thyristor (15, 31) and a quenching capacitor (35, 36). The circuit arrangement according to claim 11, characterized in that one or more quenching circuits are connected to the switching thyristor (12) through a connecting diode (39). A circuit arrangement according to claim 11, characterized in that one or more quenching circuits are connected to the negative conductor by an auxiliary circuit (32) consisting of ohmic resistance and inductance.