JPS5846895Y2 - DC electric railway power supply device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a power supply device for a DC electric railway in which a thyristor rectifier and a thyristor circuit breaker are applied as a source power conversion device, and in particular, it simplifies the arc extinguishing circuit of a group of thyristor circuit breakers. The present invention aims to provide a power supply device that can reduce the equipment cost of the entire power supply system.

In DC electric railway power supply equipment, it is easy to coordinate protection in the event of an accident, it is also possible to suppress voltage fluctuations between dead sections to an extremely small value, and it also eliminates the complexity of maintenance. For these reasons, in recent years, thyrisk rectifiers have been used instead of silicon rectifiers as raw power converters, and thyristor circuit breakers have been used instead of DC high-speed circuit breakers.

FIG. 1 shows the configuration of a typical power supply device to which such a thyristor rectifier and thyristor circuit breaker are applied.

In the figure, 1 is a commercial frequency power supply bus, and under this power supply bus, an AC circuit breaker 2, a transformer 3, and an AC line for a raw power converter 4 are connected. It is configured by forward bridge-connecting thyristors and converts AC power input from a commercial frequency power supply bus into DC power. 5 is a DC positive bus, and below this bus is a thyristor circuit breaker divided for each line. Group 6□~64 and disconnector group 81~
84, and each thyristor circuit breaker has a group of regeneration diodes positioned with the polarity shown in the diagram to give it substantially the same function as a conventionally known DC high-speed circuit breaker, as shown in the diagram. 71 to 74 are connected in antiparallel.

91 and 9° are feeder lines that supply the required power to each vehicle, 10□ and 10□ are rails, and 11 is a negative bus bar.

Now, the problem with such a power supply device is the configuration of the arc extinguishing circuit for extinguishing the thyristor circuit breaker.

That is, referring to FIG. 2, which shows the thyristor circuit breaker numbered 61 as a representative example in the group of thyristor circuit breakers, in order to extinguish the 6□ thyristor circuit breaker, the 12 steps shown in the figure are necessary. Auxiliary cyrisk and 13 commutation reactors and 1
As is well known, the operation of such an arc extinguishing circuit is such that the auxiliary thyristor 12 is once ignited by a detection signal at the time of an accident, and then The charged charge of the commutating capacitor 14, which is precharged by polarity, is discharged to the main thyristor 6□ side through the auxiliary thyristor 12, and the value of the discharge current that becomes free oscillation exceeds the current flowing through the main thyristor 6□. At this point, the main thyristor 6□ is forcibly extinguished, thereby selectively cutting off only the faulty line. be.

Therefore, if the power supply device shown in Figure 1 is used, a forced arc-extinguishing circuit for four electric lines would be required between each dead section, which would make the equipment cost of the substation extremely uneconomical. be.

A particularly important point is that each substation requires as many as four sets of forced arc-extinguishing circuits, so when substations are distributed over multiple locations, such as in the power supply system of DC electric railways, the power supply system It is clear how uneconomical the equipment cost of the entire system becomes.

What is more important is that if a vehicle is running regeneratively and a ground fault occurs for some reason on the DC positive bus 5 side during regenerative operation, if the regenerative current continues to flow toward the point of the fault, the accident itself will become more serious. It is to be.

That is, assuming that the electric car A is a regenerative vehicle, the fault current from the power supply bus 1 side flows into the fault point of the DC positive bus 5 through the raw power converter 4, and the regenerative current from the regenerative vehicle A flows into the fault point of the DC positive bus 5. , regeneration vehicle A → feeder line 91 → disconnector 93 →
It flows through the path from the regeneration diode 73 to the fault point of the DC positive bus 5.

In this case, the fault current from the former power supply bus 1 side is detected by a detection relay (not shown), the AC breaker 2 is tripped based on this fault detection signal, and the raw power converter 4 is gate-blocked. Although the fault current from the power supply bus 1 side is immediately cut off, the regenerative current flowing toward the fault point through the path of the regenerative loop described above continues to flow until the regenerative current is attenuated.

Therefore, in the event of an accident on the DC positive bus 5, there is a risk that not only will the accident itself be unnecessarily prolonged, but the accident will spread to the healthy circuit side and expand.

As described above, the conventional power supply device has a serious drawback in terms of protection coordination in the event of an accident when there is a regenerative vehicle.

The present invention has been devised in view of this point, and in particular, the present invention uses a commutating capacitor and a commutating reactor in common in a forced arc extinguishing circuit to forcibly extinguish a group of thyristor circuit breakers for four circuits. In addition, a DC switch is provided that can cut off the regenerative power from the regenerative vehicle and the circulating power from the adjacent substation, and the arc extinguishing circuit that forcibly extinguishes this DC switch is also used as the forced arc extinguishing circuit. It is characterized by the fact that

A detailed description will be given below based on the embodiment shown in FIG.

In the embodiment shown in Fig. 3, the same parts as in Fig. 1 are given the same reference numerals, and in the same figure, 15 is a DC switch, and this DC switch is used to control the regenerative power from the regenerative vehicle and the surroundings from the adjacent substation. It has the ability to cut off the built-in power, and in particular, as a DC switch, for example, a thyristor breaker or a DC high-speed breaker can be used, but the power supply device itself is becoming contactless. Currently, it is most desirable to apply the former thyristor breaker.

A series circuit of this reactor 16 and the DC switch 15 is connected to the DC positive electrode bus 5 as shown in the figure.
and the cathode side connecting wires of the regeneration diode groups 7□ to 74.

17 is a commutating capacitor which is always positioned according to the charging polarity shown in the figure, 18 is a commutating reactor, and an arc extinguishing circuit between these commutating capacitors and the commutating reactor has one end connected to the DC switch 15 and the reactor as shown in the figure. 16, and the other end is connected to the auxiliary thyristor group 20□ to 204.
Furthermore, diode groups 191 to 194 positioned in the illustrated flow direction are inserted into the cathode sides of the auxiliary thyristor groups 201 to 204, respectively, and these diode groups 191 to 194
The cathode sides of the thyristor breaker groups 61 to 64 and the disconnector groups 81 to 84 of each DC circuit are connected to the connection lines of the thyristor breaker groups 61 to 64 and the disconnector groups 81 to 84, respectively, so that the thyristor breaker groups and the DC switches are integrated into a common arc extinguishing circuit. The power supply device itself is configured to forcibly extinguish the arc.

A reactor 16 connected in series with a button DC switch 15
is for suppressing the regenerative power led from the regenerative diode and the loop power from the adjacent substation, and there is no problem in operation even if the reactor 16 is removed.

Furthermore, 19 provided corresponding to each auxiliary iris register,
The diodes 194 to 194 are inserted for the purpose of guiding the charge in the commutation circuit to each of the thyristor circuit breakers 6□ to 64, and there is no problem in operation even if they are deleted.

Furthermore, as for the arc extinguishing circuit, the commutating capacitor 1 of this circuit
In 7, a charging circuit composed of an AC power supply and a rectifier circuit (not shown) is installed in parallel, and this charging circuit is charged with charge in advance with the polarity shown, and the arc extinguishing circuit is not shown. Although omitted, a reversing thyristor (not shown) is provided in parallel as in a general commutation device, and the charged charge (at the time of commutation) is reversed to return to the initial state of the polarity shown.

Now, to describe the operation of the present application configured as above, normally the applicable frequency power supply bus 1 → AC circuit breaker 2 → transformer 3 → forward power converter 4 → DC positive electrode bus 5 → thyristor circuit breaker group 61 to 64 →Disconnector group 8□~84→Feeder line 9□~94→
Drives a group of vehicles (not shown) by power applied via a path of vehicles (not shown);
For example, if there is a vehicle in regenerative operation under the feeder line 91, the regenerative power from this regenerative vehicle will be transferred to the regenerative vehicle (not shown)→
Feeding wire 91 → Disconnector 8 → Regeneration diode 72 → Reactor 16 → DC switch 15 → DC positive bus 5 → Thyristor circuit breaker 6 or 64 → Disconnector 81 or 84 → Feeder wire 92 → This feeder wire 9° The regenerated electric power flows through a path of a vehicle (not shown) connected below, and the regenerated power itself is supplied as necessary power to a group of vehicles connected below the other feeder line.

Assuming that a regenerative inverter (also called a reverse power converter) is installed at the substation, the regenerative power from the regenerative vehicle will be transferred to the diode 7° → reactor 16 → DC switch 15 → DC positive pole. It goes without saying that a part of the regenerative power is shunted to the commercial frequency power source bus side via the path of bus 5 → regenerative inverter (not shown) → commercial frequency power source bus 1.

In the present application which performs the above-mentioned constant operation, for example, there is a regenerative vehicle under the feeder line 9, and during this regenerative operation, near the connection point that connects the raw power converter 4 and the DC positive bus 5. In the event that a ground fault occurs for some reason, the following predetermined protective actions are performed in this application.

That is, a fault current flows into the fault point of the DC positive bus 5 from the power supply bus 1 side through the raw power converter 4, and
Regeneration vehicle (not shown) → Feeder wire 91 → Disconnector 8 → Regeneration diode 7° → Reactor 16 → DC switch 15 →
Regenerative current flows through the path of the fault point on the DC positive bus 5.

In this case, the fault current from the power bus 1 side is detected by a relay (not shown), and based on this fault detection signal, the AC breaker 2
At the same time, the source power converter 4 is gate-blocked to immediately cut off the fault current flowing from the power supply bus 1 side.

In parallel with this operation, a suitable thyristor from among the auxiliary thyristors 20□-204, such as the auxiliary thyristor 201, is fired based on the accident detection signal, and the DC switch 15 is turned off to cut off the inflow of regenerative power.

That is, when the auxiliary thyristor 20□ fires, the commutating capacitor 7 is charged with the polarity shown, and the charged charge is transferred from the commutating capacitor 7 to the commutating reactor 18 to the auxiliary thyristor 2.
07→diode 19□→thyristor circuit breaker 64→DC switch 15. When the value of the discharge current that becomes free oscillation exceeds the level of the regenerative current flowing through the DC switch 15, the DC switch 15 is forcibly turned off. The thyristor circuit breaker 64 is also turned off.

Thereafter, the discharge current flows along the path of commutating reactor 18 → auxiliary thyristor 201 → diode 19□ → diode 7 → reactor 16 → commutating capacitor 7, and commutating capacitor 7 is recharged with a polarity opposite to that shown in the figure.

In this commutation process, the DC switch 15 is forcibly extinguished, and the regenerative current is then commutated to the auxiliary thyristor 20 side, and is transferred from the regenerative vehicle (not shown) to the feeder line 91 to the disconnector 8 to the regenerative diode 72 to the reactor 16. It flows through the path of → commutation capacitor 7 → commutation reactor 18 → auxiliary thyristor 201 → diode 191 → disconnector 84, and the reverse charging of commutation capacitor 7 progresses further.

When the reverse charging voltage of the commutated Contin Surf reaches a predetermined level, the auxiliary thyristor 201 is naturally extinguished and the regenerative current is completely cut off.

When the regenerative current is cut off and the recirculation loop of regenerative energy disappears, the DC voltage of the feeder line 9 tries to rise due to the regenerative power, but at this point the regenerative energy is also attenuated and the regenerative vehicle side is not able to use the regenerative power. Since the predetermined narrowing operation is performed, the DC voltage of the feeder line 9 will not increase.

Namu auxiliary thyristor 20. A The charge charged in the commutating capacitor 17 after being suddenly extinguished can be changed to a polarity opposite to that shown in the figure by, for example, firing a reversing thyristor (not shown) installed in parallel with the commutating reactor 18 and the commutating capacitor 17. The reversely charged charge charged in is reversed to the illustrated polarity, and the charge lost in the commutation process is replenished by a charging circuit (not shown) to return to the initial state.

As described above, according to this embodiment, even if there is a vehicle in regenerative operation at the time of an accident on the DC positive bus, the accident current flowing into the accident point can be immediately interrupted, and the spread of the accident can be prevented. Next, a ground fault occurred near the connection point between the DC line including the disconnector of No. 84 and the feeder wire of No. 9, and regenerative operation occurred under the feeder wire of No. 91 at the time of the ground fault. In the case where there is a vehicle at a certain time, the following predetermined protection operation is performed in this embodiment.

That is, at the fault point, the source power converter 4 → DC positive bus 5 →
The fault current flows along the fault point path of thyristor circuit breaker 64 → disconnector 84 → feeder line 92, and the regenerative vehicle (not shown) → feeder line 9□ → disconnector 83 → regeneration diode 72 →
Reactor 16 → DC switch 15 → DC positive bus 5 →
A regenerative current flows in the path of the fault point of the thyristor circuit breaker 64 → the disconnector 84 → the feeder line 92.

It is detected by a relay (not shown) installed in parallel with these incoming fault lines, and based on this fault detection signal, an ignition signal is given to the auxiliary thyristor 201 for selectively interrupting the fault line to fire it.

When the auxiliary thyristor 201 fires, the commutating capacitor 17
→ Commutation reactor 18 → Auxiliary thyristor 201 → Diode 191 → Thyristor circuit breaker 64 → DC positive bus 5 →
Through the path of the DC switch 15, the commutating capacitor 17 is charged with the polarity shown and discharged.

This discharge current becomes a free oscillation, and when it exceeds the value of the discharge current or the fault current flowing through the thyristor circuit breaker 64 (the total value of the regenerative current and the current from the bus bar), the 64
The thyristor circuit breaker is forcibly extinguished, and the DC switch 15 is also extinguished.

Thereafter, the discharge current flows through the path of commutating capacitor 1γ→commuting reactor 18→auxiliary thyristor 201→diode 191→diode 71→reactor 16, and commutating capacitor 17 is charged with a polarity opposite to that shown in the figure.

On the other hand, after the thyristor circuit breaker 64 is forcibly extinguished, the regenerative current is commutated to the auxiliary thyristor 20, and the regenerative current is transferred to the regenerative vehicle → feeder line 91 → disconnector 83 → diode 72 → reactor 16 → commutation capacitor. 17 → commutation reactor 18 → auxiliary thyristor 20□ → diode 19□ → fault line disconnector 84 → feeder line 9□. When the voltage level reaches a predetermined value, the auxiliary thyristor 20□ naturally extinguishes, the inflowing regenerative current is completely cut off, and the disconnection occurs when the current flowing through the fault line disconnector 84 becomes approximately zero. The circuit 84 is opened to disconnect only the faulty line from other healthy lines.

Note that after only the faulty circuit is selectively cut off, the regenerative current is transferred from the regenerative vehicle to the feeder line because an ignition signal is given to the DC switch 15 again on the condition that the faulty circuit is disconnected from other healthy circuits. 91 → Disconnector 83 → Regeneration diode 7° → Reactor 16 → DC switch 15 → DC positive electrode bus 5
→Thyristor circuit breaker 6, (or 6°)→Disconnector 8□ (or 82)→Flows through the path of feeder line 9□ (or 9,), and provides power to the vehicle (not shown) below the healthy feeder line. Supplied.

As described above, in the present invention, the commutating capacitor and commutating reactor of the forced arc-extinguishing circuit are shared by the thyristor breaker group and the DC switch, and the regenerative power and the circulating power from the adjacent substation are Since a DC switch that can cut off the current is provided, various effects can be achieved as shown below.

■ Since the forced arc extinguishing circuit is shared between the thyristor breaker group for 4 electrical circuits and the DC switch, the circuit configuration of the substation can be simplified and a very economical device can be realized.

(1) Considering the advantages mentioned in (1) above, the greater the number of substations installed in the power supply system of a DC electric railway, the more advantageous it is that the equipment cost of the entire system can be reduced.

■ Even if there is a vehicle in regenerative operation and an accident occurs on another feeder line or DC bus bar adjacent to the Tonoki power line, a newly installed DC switch will regenerate the regenerative power from the vehicle and the adjacent substation. Since it is designed to instantly cut off the power that goes around the system, it is possible to instantly selectively cut off only the faulty line, thereby preventing the spread of the fault.

■ The provision of a DC switch not only makes it easier to coordinate protection in the event of an accident, but it also makes it possible to minimize accidents and create a highly reliable power supply device. This has the advantage of improving the operational efficiency of the entire system.

[Brief explanation of the drawing]

Figure 1 is a specific circuit diagram showing the configuration of a typical power supply device that uses a thyristor breaker and a thyristor rectifier, and Figure 2 shows a conventional thyristor breaker applied to the power supply equipment and its forced extinguisher. FIG. 3 is a specific circuit configuration diagram of a power supply device showing an embodiment of the present invention. 1 is a commercial frequency power supply bus, 2 is an AC breaker, 3 is a transformer, 4 is a raw power converter, 5 is a DC positive electrode bus, 6□~64
are thyristor breaker, 7□~74 and 19□~194
is a diode, 11 is a negative electrode bus, 15 is a DC switch,
16 and 18 are commutating reactors, 17 is a commutating capacitor, and 201 to 204 are auxiliary thyristors.

Claims (1)

[Scope of utility model registration request] AC power is converted to DC power by a raw power converter and supplied to the DC positive bus bar side, and this DC power is sent to multiple feeder lines via multiple DC circuits in which thyristor circuit breakers and disconnectors are connected in series. In the device configured to supply power, a regeneration diode whose anode side is connected to each connection line between each thyristor circuit breaker and disconnector of the plurality of DC circuits, and a common connection between the cathode sides of these diodes. between the line and the DC positive bus, the anode is connected to a DC switch having a cathode connected to the positive bus, and an arc extinguishing circuit connected to the anode of the DC switch and including at least a commutating capacitor and a commutating reactor. 1. A power supply device for a DC electric railway, characterized in that the cathode is comprised of an auxiliary thyristor separately connected to the cathode of each thyristor circuit breaker in the DC line.