BG61223B1 - A rectifier substation circuitry - Google Patents

Abstract

The invention relates to a circuitry component of a ractifier substation for the electrical suuply of a raiway line which has a central rectifier unit executed as controllable, semi-controllable or non-controllable. The circuitry component is suitable for all types of rectifier substations having a DC collecting bus. The output bus of the sector is supplied across a fast-operating disonnector (13 & 14) the pole on the side of the sector being connected to a connection node (6 & 7) which across two contact wires (20 & 21) leads to a switching device (9). The latter may consist, for example, of a switching thyristor (12) and at least one quenching ircuit and connection diodes to a DC collecting bus (3). If there is a central thyristor semi-unit (1) it has a supplimentary quenching device (8).

Description

TECHNICAL FIELD

The present invention relates to a circuit for a substation for power supply to electrified railways, where the substation has a central rectifier section. The correcting section can be implemented as a control section, respectively

semi-controlled or unmanaged.

BACKGROUND OF THE INVENTION

In rectifying substations for the supply of electrified DC lines in the output bus sections, the already known high-speed circuit breakers are used which, being tuned to a certain actuation value, are in a safe state

to exclude 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 switches are subject to wear due to the electric arc of the switch, which requires the maintenance of high-speed circuit breakers for relatively short periods of time.

Thyristor switches on the DC busbar are also known from EP A 206 150. The substation, however, contains additional semiconductor switches to the rectifier for power distribution, which results in higher costs and losses for the entire facility and also requires greater investment. In addition, additional valves must be used to ensure that brake energy can be re-energized through the substation.

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

Abstracting from the requirement that you should here as well

additional valves shall be provided to provide back-up power from the decision to exclude interruptions of part type, the required continuation should have corrected the unsuitable stability of the brake energy, such an output bus from the section with any substation described in the introductory one and due to the fact that due to short circuit for example, at 200 milliseconds, thyristor switches are economically disadvantaged.

of bi

In the meantime, it was suggested that the central rectifier be used, by means of a half-thyristor block, to be used for a central, quick shut-off, in which, at a voltage-free pause, which would be short, the exclusion of a high-speed disconnector from the corresponding output bus . In this way, the further operation of the scheme can be carried out. However, short breaks without tension will always occur.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a circuit for a power substation of a power substation

DC electrified line using a central rectifier unit and high-speed disconnectors in the output bus sections, which on the one hand is cheap and on the other is able to override both reverse currents and currents short circuit while also providing an opportunity for easy site inspection.

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, from the section ^ there is a connecting group consisting of an idle valve, an anti-parallel back-feed valve and auxiliary disconnectors thereto. A diode or thyristor can be used as an idle valve, and a reverse power diode or a thyristor for a power supply as a backflow valve.

Each valve in the coupling group leads to a contact wire to which a switching device consisting of one or more switching thyristors is connected to which at least one quenching circuit is connected in parallel.

The switching thyristor is connected on both sides to the positive DC busbar via a respective connecting diode and / or R-L group.

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

The quenching circuits are also connected to the negative conductor by a support circuit consisting of ohmic resistance and inductance.

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

In the case that the central rectifier is designed as a control unit, a separate extinguisher is provided for the central rectifier with connection to the three-phase busbar.

The scheme works as follows.

In the embodiment of a control rectifier as a central rectifier, short-circuit currents of high value to the defective point are switched off by extinguishing 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 a congestion is detected, the corresponding high-speed disconnector is forced to open, while the ignition pulses for the central rectifier block are interrupted. At the same time, the extinguisher thyristor from the extinguisher is ignited for a short time, and then the switching thyristor from the extinguisher - 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, which this switches off the current for the corresponding output bus.

As already described in the prior art, the thyristor half-block can then be switched on again to continue supplying 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 current, the power electronics disconnect through the high-speed disconnector.

In the embodiment with an uncontrolled central rectifier, all disconnections of the output bus section, and therefore disconnections in the case of short circuit current, are performed as described.

After switching off an arbitrary output bus of a section with the help of the switching thyristor, a check of the section can be carried out without the need for a special control resistor. With the existing quenching circuit, the control current can be switched on again, as is already well known in the art.

If a thyristor is used for the reverse current valves of the connection nodes, then according to another variant, both valves of the connection nodes can be connected to a single contact wire, which in this case will serve as a contact wire at idle as well. and for the contact wire for re-supply.

EXPLANATIONS OF THE FIGURES Attached

The invention is presented in detail using the exemplary embodiments described below. The relevant drawings show:

FIG. 1 is a diagram of a rectifying substation according to the invention with a central, semi-controlled rectifier;

FIG. 2 is a diagram of a rectifying substation with an unmanaged central rectifier;

Fig. 3 is an embodiment of the scheme according to Fig. 2 with an additional redundant quenching capability; and Fig. 4 is a variant with only one contact wire.

EXAMPLES FOR THE IMPLEMENTATION OF THE INVENTION

An advantageous exemplary embodiment of a rectifier substation diagram with a semi-rectifiable rectifier is shown schematically in Fig. 1.

The central rectifier consists of a thyristor half block 1 and a diode half block 2. The rectifier feeds, for example, the plus DC busbar 3. On the plus DC busbar 3 there are approximately two output busbars 4 and 5 per section, each having one connecting group 6 and 7 The exclusion of the section in this example is realized in such a way that in the road sections of the line ^, in parallel with the shown substation,

supply power from other rectifying stations. This results in a continuous connection between all road sections of the line, without showing this link. The thyristor 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,

- ignition of the switching thyristor 12 and ignition of the first quenching thyristor 15 of the switching device 9, for example after a fixed delay time.

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 instantly switched off. The high-speed disconnector 14 is then opened, and the resulting voltage drop on the opening disconnecting section is shortened by the switching thyristor 12, since from now on, the current from the more distant rectifying stations no longer flows through the high-speed disconnector 14, but through the connecting diode 17, through the RL group 67, the ignited switching thyristor 12, the connecting wire 18 to the contact wire 20 for idling and then through the auxiliary disconnector 25 (FIG. 2/) and the idling diode 27 to the defective point at odyashtata rail 5 of the section.

After switching off the random output bus section and ignition of the thyristor half-block 1, the section can be checked by means of the connecting diode 17 and the switching thyristor 12, and the control current through the extinguisher circuit - extinguishing thyristor 15, respectively.31, extinguishing condenser , respectively.36 - switches off again. If necessary, the faulty outlet section of the section can then be switched on again. 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 roadway is completely galvanically separated

The normal shutdown of an output section is explained by turning off the power supply. When the reverse current from the output feeder 5 of the section to the output feeder 4 flows and it must be switched off, the high-speed switch 14 is activated and the switching thyristor 12 is started. The reverse current is switched from 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 circuit 66 and the connecting diode 16 to the positive DC current rn 3, and hence the circuit is closed to the output bus 4, where it should be performed on the current feedback.

Parallel to the connecting diode 16, a portion of the reverse current flows through the connecting wire 18, the auxiliary

disconnector 23 and idle 26 for idling to the output bus 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.

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

In order to obtain a simple redundancy within the switching device 9, two quenching circuits are preferably provided, whereby one quenching circuit with the quenching capacitors 35, 36 always extinguishes the switching current through the switching thyristor 12, and more precisely by switching on the corresponding quenching thyristor. 15, respectively. 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 a maintenance 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. Thyristor half block 1 switches back on approximately 6 milliseconds after closure. Vehicles located on sections unaffected by these processes do not notice a voltage drop.

Advantageously, the idle diode 38 creates the connection between the running rail (anode) and the output busbar section (cathode) so as not to produce overvoltages in the inductance of the supply wires in the event of rapid short circuits. The connecting diode 37 provides a faultless switching of the leakage current from the thyristor half-block 1 to the extinguishing capacitor 30 and at the same time separates the support circuit 32 from the plus DC busbar 3.

The connecting diode 39 used provides a flawless switching of the disconnecting current through the switching thyristor 12 to the quenching capacitor 35, respectively. 36 ^ and at the same time separates a support circuit 32 which is electrically connected to the quenching capacitors 35, 36 by a connecting conductor 40 from the control currents and other currents flowing through the switching thyristor 12.

The rectifying substation according to a preferred embodiment according to FIG. 2 has a central supply with a plus DC busbar 3 from which output busbars 4 and 5 are output to a section. Output busbars 4, 5 can be separated from the DC busbar 3 by means of high-speed disconnectors 13, 14. Each high-speed disconnect bus 13, 14 has one connection group 6, 7 for connection. Each of the connecting groups 6, 7 consists, respectively, of the idle diodes 26, 27, as well as of the reverse power supply diodes 28, 29, 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 and 25 on the contact wire 21 for re-supply, respectively. on idle contact wire 20, which in turn

lead to the switching device 47.

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

Switching thyristors 43, 45, respectively. 44, 46 _m in this example are respectively connected in parallel to the high-speed disconnectors 13, 14.

When the output bus 4 or 5 is switched off, the corresponding high-speed switch 13, 14 is forced to open, while the corresponding switching thyristor 43, 44 is lit. The current is switched by the open high-speed switch 13, 14 on the corresponding switching thyristor 43, 44. With some delay in time, respectively.

through the contact of the opening high-speed disconnector 13, 14, the extinguishing thyristor 15 is ignited and the current through the switching thyristor 43, respectively. 44 through the first quenching circuit, consisting of a quenching thyristor 15 and a quenching capacitor 35, is switched off again.

Using parallel switches 13, 14 switching thyristors arranged parallel to the high-speed disconnectors

43, 44 now can be checked on plot and c dependency on hers result again may be included corresponding outbound tire 4, 5 • Extinguishing on some the opposite current, for example at

current flows from the output bus 4 through the plus DC collector bus 3 to the output bus 5 flows in the same way, only through the switching thyristor 45, the switching thyristor 42 and the quenching capacitor 41.

In order to have spare damping capacitors in both directions of the current, the two damping circuits of the preferred embodiment according to Fig. 3 are constructed so that the damping capacitors 35, 41 are arranged in the direction of the contact wire 20 for idling or respectively. to the contact wire 21 for re-supply. the electrodes of the quenching capacitors 35. 41 are connected to these wires 41 through the thyristors 48 and 50 with the positive DC busbar 3, and the other electrodes through the thyristors 51, 49 are connected diagonally to each other. Thus, 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.

Checking the switched-off output bus 4 is performed by the switching thyristor 43, which is lit and when the threshold for the current set is exceeded.

from the transformer current information, the extinguishing thyristor 15 is automatically started and thus the set leakage current is switched off. If the current threshold is not exceeded, after a control time of about 3 seconds for example, the high-speed disconnector 13 closes, resulting in the restoration of normal power supply to the output bus 4.

In Fig. 4 in another preferred embodiment, two rectifier substations 1a and 2 are shown.

16, the first rectifying substation being presented in more detail than the second. The rectifying substations shown in the diagram are constructed in the same way and are interconnected so that the two-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 feeders A and D emerge, which are indicated by the following elements in the figure:

high-speed disconnector

13,

14, current transformer 52, idle diodes 26, 27, valves 28.

back-up auxiliary disconnectors

23,

The auxiliary disconnectors 23 are connected to the idle contact wire 20. Between the positive DC busbar and the contact wire 20 for idling is located the switching device 9 preferred embodiment it consists of a switching thyristor quenching circuit, which in turn is composed of a quenching thyristor

15, the quenching capacitor 35 and the connecting diode 39.

Further, a diode is inserted between the ground line, the negative pole case, and the contact wire 20.

on the overhead line

The two anodes, namely the connecting diode and that of diode 38, are connected by a support circuit 32 consisting of inductance and resistance. Thus, both the output feeders A through D and the switching device 9 in the second rectifying substation and in the following are the same elements

The sections 53, 54, 5 5 , 56, 57 and 58 are related to the following outgoing : feeders: 53 with B, 54 with D and with B2, 55 with D2, 56 with A, 57 with C and A2 and 58 p C2. Except this is depicted and crosswise connection through switch 59.

Switch 59 is on.

The operating mode will be clarified by means of malfunctioning exceptions, first assuming that there is a short circuit 60 in section 54. It is further assumed that the output feeders D and B are on and the output feeders A and C are excluded. This also applies to the second substation and to the next one, assuming that the actuation value reaches only the output feeders D and B2. Other outbound feeders could be triggered by the di / dt protection not shown here.

Switching off the output buses D and B2 will be described by the example of switching off the output feeder D. The high-speed disconnector 63 of the output feeder D receives the OFF command. At the same time, the switching thyristor 12 and / not shown / back-up thyristor / by analogy 28, respectively. 29 /, so that the current is switched from the opening high-speed disconnector 12 on the freewheel contact wire 20, through the auxiliary disconnector 61 and the freewheel diode 62 of the output feeder D to that output feeder D, so that the current is short-circuited at the moment the shortening 80 then proceeds as follows: from the positive DC busbar 3 through the switching thyristor 12, through the contact wire 20 for idling, the disconnector 61, the diode 62 for idling and the current transformer 52 of the output feeder D.

Exactly the same way follows Yes is being considered switching in the outbound feeder B2, as there takes part commuting device 9 on the second corrective substation.

After a specified time, respectively. after contact is made by the opening fast-acting disconnector 63 of the output feeder D, the extinguishing thyristor 15 is started. of the quenching capacitor 35 blocks the quenching thyristor 15, thus ending the shutdown of the output feeder D. After the quenching of the quencher 15, a short pulse current flows through all the connecting circuits / diodes for Oboodi move and auxiliary disconnectors / provided that are sealed semiconductor circuit breakers, as in the accepted example of this is affected by the output? feeder C. The magnitude of this pulse current is limited by the resistor 64. The pulse current, for example through the elements of the output feeder B, is completely avoided when the idle diodes are replaced by thyristors and only the thyristor whose ignition feeder is to be ignited included - hence only the output feeder D. in the example.

Maintenance circuit 32 serves to safely disengage the section if the sections are idle. The idle 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 at a small distance in time through the train composition 65 electrically connects the dividing point between the outlet feeders D. Then a current is flowing through B through B, which would be able to reach the value of the actuation, so that the high-speed disconnector 14 opens from the output feeder B and the switching thyristor 12, and back feeder thyristor 29 are again lit by the output feeder B. Here goes another switching current and more asno become effective replacement extinguishing thyristor 31 and a damping capacitor 36 to be turned off without residue, as described above, the whole

short circuit current from the first substation.

It is further considered that the malfunctioning declared prior to the description. In addition, it is accepted that all outbound feeders A, B, C and D. are included. It may be necessary to exclude outbound feeders B, C and D, and possibly outbound feeder A. In this case, the assumption was made that the event for a fault current, indicated by the assembly 65 of the composition, an unfavorable moment occurs, where it is necessary to ignite the standby thyristor 31, since the first quenching capacitor has been recharged.

Feedback currents, for example through the aging fast-acting switch 13 of the output feeder A to the output feeder 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 of the output Fider A.

The current switches on the following circuit:

- Reverse Power Tristor 28 from Output Feeder A.

- auxiliary disconnector 23,

- idle contact wire 20,

- diode 62 for idling the output feeder D to the same

Feeder D.

The reverse power 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 quencher: quenching thyristor15, quenching capacitor 35 and connecting diode 39. is again switched off.

The scheme according to the invention makes it possible to include fault currents and load currents, regardless of their direction, to or from the DC busbar, where only the information on the current value / absolute value / output feeder is required. The site inspection can be carried out

without the resistance for section inspection, as for this one aim use built in technically funds on the connecting one quenching groups.

Patent Claims

Claims (7)

Patent Claims 1. Scheme of a DC substation with a DC busbar to which several output feeders of the section are connected via high-speed disconnectors and a central rectifier unit, characterized in that on the pole from the section of each high-speed disconnector / 13, 14, 63 / is a connecting group / 6, 7 / which is output to a contact wire / 20 / for idling and a contact wire / 21 / for reverse power, which in turn are connected to a switching device / 9 /, consisting of one or more switches the thyristor (12) to which at least one quenching circuit is connected in parallel. The scheme of claim 1. characterized in that the central rectifier unit is a controllable rectifier. The scheme of claim 1, wherein the central rectifier unit is an unmanageable rectifier. Scheme according to Claims 1 and 2, characterized in that the central rectifier unit is a semi-adjustable rectifier. 5. A circuit according to claim 1 or 2, characterized in that a separate quenching device is connected to the thyristor half block (1) of the central rectifier unit. The circuit according to claim 1, characterized in that the switching thyristor (12) is connected on both sides to the positive DC busbar (3) through a respective connecting diode (16, 17) and / or RL group (66, 76) . The circuit according to claim 1, characterized in that the coupling group consists of an idle valve, an anti-parallel backpressure valve and associated auxiliary disconnectors (22, 23, 24, 25). 8. Scheme according to claim 7, characterizing with this, that it's like an idle valve used diode / 26 , 27. 62 /. 9. Scheme, according to claim 7, characterizing with this, that as an idle valve a thyristor / 26 was used. 27 /. 10. Scheme according to claim 7, characterizing with this, that as a backpressure valve is used diode reverse power supply / 28 , 29 /. 11. Scheme - according to claim 7, characterizing with the fact that a thyristor (28, 29) is used as the recharge valve. 1 2. Scheme according to claim 1, characterizing with this. that quenching chain consists of a quenching thyristor / 15. 31 / i damping capacitor / 35, 36 /. 13. Scheme according to claim 11, characterizing with the fact that one or more quenching circuits are connected to the switching thyristor / 12 / via a connecting diode / 39 /. 14. The circuit of claim 11, wherein the one or more quenching circuits are connected to the negative conductor by a support circuit (32) consisting of ohmic resistance and inductance. The circuit according to claim 1, characterized in that a idle diode (38) is included between the running rail and the contact wire (20) for idling.