JPS5828130B2 - DC electric railway power supply method - Google Patents

Description

[Detailed description of the invention] The present invention relates to a power supply method for a DC electric railway,
At the substation, the positive electrode bus is divided, a power feeding circuit is divided corresponding to the divided positive electrode bus, and a forward power converter is provided for each of the divided positive electrode buses (hereinafter referred to as positive electrode bus split forward power converter independent power feeding). The purpose of this system is to convert the regenerated power of each of the above-mentioned divided power supply circuits into three-phase AC power using a common reverse power converter, thereby simplifying equipment and rationalizing investment.

Conventionally, DC substations installed at appropriate intervals along railway lines are generally equipped with one or several sets of converters, and the positive side of each converter is equipped with a dedicated DC breaker (hereinafter referred to as converter). They are connected to a common conductor (hereinafter referred to as the positive electrode bus) via a device DC breaker), and the negative electrode side is directly connected to the common conductor (hereinafter referred to as the negative electrode bus).

In other words, each converter is connected in parallel within the substation to constitute the DC power source of the DC substation, while the electric train tracks are generally divided into adjacent substations and on the track side (hereinafter referred to as power supply lines). The overhead contact lines of the divided power supply lines are connected to the positive busbars at each substation via DC circuit breakers dedicated to each line (hereinafter referred to as power supply DC circuit breakers), and the rails are directly connected to the negative busbars. Ru.

That is, generally, a power supply circuit is constructed in which adjacent substations supply power in parallel to the divided electric train tracks.

The DC breaker that constitutes the power supply circuit has a mechanical structure that has electrodes that cut off current in the air, and most of the substation maintenance effort is spent on cleaning and maintaining the electrodes that are consumed when cutting off the current. In addition, since each substation is generally connected in parallel through each power supply circuit, a short-circuit fault current on the positive bus in any parallel substation will be added to the fault current supplied from the fault substation, and from each adjacent substation. Since the fault current supplied through the power supply line is added, there is a risk that damage in the event of an accident may be expanded.

In order to solve the above-mentioned problems, the applicant has filed an application for a power supply method as shown in FIG.

That is, in FIG. 1, 1, 2 and 3 are DC substations, 4 and 4' are three-phase AC transmission lines, 5 and 5' are three-phase AC circuit breakers, 6 and 6' are converter transformers, and 7 .7' is a forward power converter, 8, 8' is a reverse power converter, 9, 9' is a substation positive electrode bus, 10 is a substation negative electrode bus, 11, 11' is a divided overhead contact line, 12 is a rail, 13 and 13' are electric cars in power regeneration operation.

The example shown in FIG. 1 will be explained.

Figure 1 shows an example in which three substations supply power in parallel to a general power supply circuit with substation positive bus bar division and forward power converter independent power supply; substation 2 is equipped with a reverse power converter, and This is an example in which an electric vehicle is operated under power regeneration control.

In Fig. 1, the electric power for running the electric car is obtained by converting the 3-phase AC voltage received from the general commercial frequency 3-phase AC transmission line 4 through the AC breaker 5 at each substation into an appropriate voltage at the transformer 6. The forward power converter 7, 7' converts the power into DC power, and connects it to the positive bus 9γ and each sectioned overhead contact line 11.1.
1' is supplied to the electric car.

The regenerated power of the electric cars 13, 13' during the power regeneration operation reaches the divided positive electrode buses 9, 9' of the substation 2 via the overhead contact lines i i, 1i', and is transferred by the reverse power converters 8, 8'. Each of the three-phase AC power is converted into three-phase AC power and supplied to the three-phase AC transmission line 4' via a transformer 6' and a breaker 5'.

In other words, the DC positive electrode bus is divided.

In order to convert the regenerative power generated on the electric train tracks connected to each positive bus to AC and supply it to the AC power supply, a reverse power converter corresponding to each divided DC positive bus is required, and the example shown in Figure 1 is In this case, the number of DC positive electrode busbar divisions is two, and two inverse power converters are required.

In other words, in the power supply circuit of the DC electric railway shown in Figure 1, the positive bus division of the substation and the single forward power converter power supply circuit are important for controlling the fault current in the event of a positive bus ground fault and for ensuring the reliability of the power supply circuit protection. It has advantages such as simplifying the equipment and improving protection reliability, such as the ability to omit a DC high-speed breaker without reducing the power, but when installing power regeneration equipment such as a reverse power converter, it is necessary to use a separate positive electrode. Since it is necessary to install it for each bus bar, the power regeneration equipment becomes uneconomical.

The present invention has been made in view of the above points, and a power supply method for a DC electric railway according to an embodiment thereof will be explained below with reference to FIG.

FIG. 2 shows an example of the configuration of a power supply circuit for carrying out the power supply method according to this embodiment, and the same or corresponding parts as those in FIG. 1 are designated by the same reference numerals.

In Fig. 2, 1', 2', and 3' are substations, and instead of the reverse power conversion equipment installed in substation 2 in Fig. 1, the DC positive electrode is divided as in substation 2'. Positive electrode bus bars 9, 9' are separated by diodes 14 and 14' between the bus bars 9, 9', and the anodes of the respective diodes are divided.
The cathodes of the respective diodes are commonly connected to the reverse power conversion bus 15, and the positive side of the reverse power conversion device 8 is connected to this reverse power conversion bus 15. The configuration is exactly the same as that shown in FIG.

Therefore, the electric power for running the electric car is supplied through the same route as in FIG. 1, but in FIG. 9, the diode 14 and the reverse power conversion bus 1
5 and reaches an inverse power converter 8.

In addition, the regenerated power of the electric car 13' reaches the DC positive bus γ of the substation 2' via the overhead contact line 11', passes through the diode 14' and the reverse power conversion bus 15, and reaches the reverse power conversion device 8.
It is combined with the regenerated power of the electric car 13 and converted into three-phase AC power by the reverse power converter 8, which is then sent to the converter 6' and the breaker 5.
' is supplied to the three-phase AC power supply 4'.

In other words, the regenerated power generated in the divided power supply circuits is collected together by the diodes 14 and 14', so even if the DC positive bus is divided and the forward power converter is fed alone, there is only one reverse power converter. Also, between the divided power supply circuits, diodes 14,
Since 14' is a vertically connected connection with reverse polarity, it is almost open, so it is possible to reduce the capital investment for the reverse power converter without sacrificing the advantages of dividing the positive bus of the substation and the forward power converter independent power supply circuit. , the utilization rate of power regeneration equipment will be improved.

Note that each forward power conversion device 7. The positive electrode side of T is directly connected to each positive electrode bus 9°γ without a DC breaker.

Furthermore, each positive electrode bus 9 of each substation. Each contact line 11 is divided between adjacent substations by omitting a DC breaker for power supply.
, 11', and on the other hand, the negative bus 10 of each substation is directly connected to the rail 12 to form a power supply circuit.However, since each DC breaker is omitted, short circuit accidents in the power supply circuit are caused by three-phase AC. It is protected by a circuit breaker 6.

Therefore, for example, when there is an electric car 13 on the overhead contact line between substations 1' and 2' in FIG. 2, the positive electrode bus γ is , and from the substation 7, from the positive side of the raw power converter 7 of the substation τ, via the positive electrode bus 9, the overhead contact line 11 to which the converters 7', 7 of the substations 1', 2' are connected in parallel. More current is supplied.

Now, if a short circuit accident occurs between the overhead contact line 11 and the rail 12 as shown at 16 at the location of the electric car 13 in the overhead contact line 11 section, for example, the AC breaker 6 of the substation 1' and the substation 2 will be activated. Since each is cut off, substation 1/,
2/ is no longer present, and the current that flows from the converter of another substation (not shown) adjacent to substation 1' through the overhead contact line and into the section of overhead contact line 11 where the accident occurred is transferred to substation 1. The current that is blocked by the raw power converter 7 at the substation 7 and flows from the converter at another substation adjacent to the substation 7 through the contact line to the section of the contact line 11 where the accident occurred is blocked by the power converter 7 at the substation τ. Since it is blocked by the converter 7', the fault current disappears and the fault is protected.

However, even if substations 1' and 2' are stopped, the contact line between the other substations and substations will be operated by the DC power source of the converter of the other substation, and the contact line 11 between substations 7 and 3/ ' is substation 3'
Power is supplied by the DC power supply of the converter 7.

For example, if a short-circuit accident occurs at the positive bus 9 of the substation γ, protection will be provided in the same way as in the case of a short-circuit accident at the location of the electric car 13 in the overhead contact line 11 section, but the fault current will be transferred to the substation 7. Current from device 7 and adjacent substation 1
The fault current is the sum of the currents flowing from the converter γ′ in the converter γ′ through the contact line 11, and compared to the case of a fault in a conventional DC electric railway power supply circuit, the number of parallel substations and power supply lines is reduced, so the fault current is reduce

In addition, although this example illustrated the case where the positive electrode bus is divided into two, the number of positive electrode buses can be three or more, and in this case, the raw power conversion device and the number corresponding to the diodes 14 and 14
It is obvious that the number ' corresponds only to the number of divided positive electrode busbars, and the number of inverse power converters may be one cylinder.

That is, FIG. 3 shows another embodiment of the present invention, in which four positive electrode busbars 9°γ, 9'' and Y are provided, and these positive electrode busbars 9, 9', 9
"and γ" are the raw power converters 7, 7' and 7, respectively.
and 7'' to the transformer 6, and to the reverse power conversion bus 15 via diodes 14, 14', 14'' and 14'', with the same effect as in the embodiment described above. , has an effect.

Further, in each of the above embodiments, the circuit breaker 5.5', the transformer 6
, 6' are used to construct the conversion equipment, however, in the present invention, any type of these may be used, or even if these are omitted, the power supply method of the present invention can be implemented.

Furthermore, according to the present invention, those skilled in the art can arbitrarily select whether the raw power converters 7 to 7'' are constructed simply by diodes or by silice or the like.

As explained above, the present invention is a substation of a general DC electric railway power supply circuit in which the substation positive bus bar is divided and the original power converter is supplied separately. This converts AC power into AC power using an inverse power converter and supplies it to the power source, which simplifies power regeneration equipment, thereby reducing capital investment and improving utilization rates. The effect is also a dog.

[Brief explanation of the drawing]

FIG. 1 shows the progress of the present invention and is a schematic diagram of a power supply circuit when a reverse power converter is installed in a DC positive bus split forward power converter single power supply circuit of a substation, and FIG. FIG. 3 is a circuit diagram used in a power feeding method showing another embodiment of the present invention. 1', 2', 3' are DC substations, 4, 4' are 3-phase AC transmission lines, 5, 5' are 3-phase AC circuit breakers, 6, 6' are converter transformers, 7, 7' is a raw power converter, 8, 8' is a reverse power converter, 9, 9' is a substation positive electrode bus, 10 is a substation negative electrode bus, i i , i i' are divided overhead contact lines, 12 is a rail, 13, 13' are electric cars, 14°14
', 14'', 14'// are diodes, and 15 is a reverse power conversion bus.

Claims (1)

[Claims] 1 Multiple forward power converters that convert commercial frequency AC power into DC power, and a reverse converter that converts regenerative power from a regenerative vehicle back into AC power and regenerates this AC power to the commercial frequency power supply bus. A power conversion device is provided, and a desired DC power is supplied to the feeder line divided for each line through the DC positive electrode bus bar provided on each side of the plurality of forward conversion devices. Diodes with the DC line side as an anode and the reverse power conversion bus side as a cathode are installed between arbitrary points of each DC circuit between the DC positive bus and the electric wire and the reverse power conversion bus, and regeneration input through these diodes is provided. A power supply method for a current-type electric railway, characterized in that power is guided to a reverse power converter side.