JP2796306B2 - Feeding system for DC electric vehicles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a feeding system for a DC electric vehicle.

(Prior Art) FIG. 4 shows a conventional feeding system for a DC electric vehicle. In the figure, 100, 200, and 300 substations for feeder, 10
1,102,201,202,301,302 are service lines connected to separate special high-voltage power systems, 400 is a feeder line supplied with DC voltage from substations 100,200,300, 500 is a trolley wire connected to feeder line 400, and 600 is a train (DC electric car) , 601 is a panda graph for receiving power, 700 is the current flowing through the train 600, and
Rails that return to 0,300 are shown.

This conventional DC feed system is a system in which the substation 100, 200, 300 is fed directly to the train 600 via the feeder line 400 and the trolley wire 500, and in consideration of the voltage drop of the feeder line 400, etc., the substation 100, 200, 300 The output voltage is set slightly higher than the train voltage. For example, if the train voltage is 1500V
, The substation output voltage is about 1650V.

In addition, the interval between the substations 100, 200, and 300 is such that the train voltage does not fall below a specified value (for example, 1100 V when the voltage of the trolley wire 500 is 1500 V) even when the train is operated in consideration of an abnormal situation such as a stoppage of power supply at some substations. It is determined not to be, especially, since the feeder line 400 carries a maximum current of several thousand A equal to the train current, so even if such a large current flows, it is necessary to secure the train voltage, for example, at intervals of 2 to 10 km Is set. Further, as the feeding wire 400, an aluminum wire having a current area of, for example, about 510 mm ² is used.

On the other hand, DC electric railways have long been used as mass transit systems,
This is addressed by increasing the number of vehicles per train and shortening the driving interval. That is, no matter what countermeasures are taken, the feeder load will increase when viewed from the whole feeder system. In this case, the ground equipment such as substations and feeder lines remain intact, so that the train voltage falls below the specified value. This will cause the situation to fall below.

For this reason, to cope with the increase in feeder load, it is conceivable to reduce the line resistance by adding substations and feeder wires. As a general order, add feeder wires (from one To substations), and then additional substations.

The problems associated with the expansion of substations will be described below. First, FIG. 5 shows a configuration of a substation for feeding power, for example, the substation 100 in FIG. This substation 100 is connected via extra high voltage service lines 101 and 102.
They are connected to separate special high-voltage power systems 801, 802, respectively, in order to increase the reliability of power reception. The two service lines 101 and 102 are connected to extra-high voltage (hereinafter referred to as extra-high) disconnectors 103 and 1 respectively.
04 and an extra high-voltage circuit breaker 105 are connected to the primary side of a transformer 106, and the secondary side is connected to a feeder line 400 via an AC / DC converter 107, a DC disconnector 108 and a high-speed DC circuit breaker 109. A DC voltage of a predetermined magnitude is fed from the feeder wire 400.

(Problems to be Solved by the Invention) As described above, in the feeding substation, it is necessary to install various special high-voltage devices, and a large installation space is required in consideration of insulation and the like. In addition, special high-voltage power systems are often already installed, and often require long service lines to the substation construction site.

In terms of substation construction costs, these costs can be broadly classified into equipment costs such as extra-high-voltage circuit breakers and transformers, substation location (land) costs, and extra-high-cost service lines.
Since many DC electric railways are located in or near a city, the above-mentioned substation installation costs have a higher specific gravity.

Further, since the additional substations are usually provided between the existing substations, the total number of the additional substations is substantially equal to that of the existing substation.

As described above, in the past, adding substations would cost a lot of cost per substation, and adding many substations would require enormous costs as a whole. Existed.

The present invention has been proposed to solve the above-described problem, and an object thereof is to cope with an increase in an electric load in a feeding system for a DC electric vehicle by reducing the number of additional substations. To provide an economical feeding system for DC electric vehicles.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a DC electric vehicle with a DC power supply via a first feeder line directly connected to an output side of a first feeder substation. A second feeder substation (extension substation) that outputs a DC voltage higher than the output voltage of the first feeder substation (existing substation). A second feeder (auxiliary feeder) directly connected to the output side of the second feeder substation, and a second feeder connected between the first feeder and the second feeder. And a DC / DC converter capable of performing forward / reverse conversion such as a quadrant chopper.

It is desirable that the output voltage of the DC / DC converter on the first feeder side be reduced as the output current on the first feeder side increases.

(Operation) According to the present invention, the additional substation feeds the auxiliary feeder with a higher output voltage than the existing substation, and the feeder voltage is DC /
After being appropriately stepped down by a DC converter, the DC electric vehicle is fed via an existing feeder line. That is, when the feeder load increases, the additional substation and the DC / DC converter act to compensate for the decrease in the train voltage caused only by the existing substation.

Also, by setting the voltage-current characteristics of the DC / DC converter as described above, the current required by the train is DC / DC.
The power is supplied not only from the DC converter but also from the adjacent existing substation, and the load on the DC / DC converter can be relatively small.

(Embodiment) Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. First
The figure shows the configuration of a feeder system for a DC electric vehicle according to the present invention. In the figure, 100, 200, and 300 are existing substations for feeder as the first substation, 101, 102, 201,
202,301,302 are extra high service lines connected to separate extra high voltage power system, 400 is existing feeder as first feeder connected to substation 100,200,300, 500 is trolley wire connected to feeder 400 , 600 denotes a train, 601 denotes a panda graph for receiving power, and 700 denotes a rail.

Reference numeral 900 denotes an additional substation as a newly added second substation, and its internal configuration is the existing substations 100, 200, and 200.
It is the same as 300, and the extra high voltage is similarly received by the extra high drop-in lines 901 and 902. The DC feed voltage, which is the output of this additional substation, is set higher than the existing substations 100, 200, 300, and the output voltage is applied between the high-voltage auxiliary feeder 10 as the second feeder and the rail 700. ing.

Further, between the existing substations 100, 200, 300,...
0, 50,... Are provided, and the DC / DC converters 20,
The input sides of 30, 40, 50,... Are connected to the high voltage auxiliary feeder 10, and the output side is connected to the feeder 400 and the rail 700, respectively.

Here, the DC / DC converters 20, 30, 40, 50,.
In order to allow a direct current to flow in two directions in accordance with the powering operation and the regenerative operation, the two-quadrant choppers have the same configuration, and an example of the configuration is shown in FIG. That is, for example, the DC / DC converter 20 includes a DC disconnector 21, a reactor 22, a reverse conducting GTO thyristor 23, a reactor 24 and a DC disconnector 25 connected in series between the high-voltage auxiliary feeder 10 and the electric wire 400.
And the capacitor 26 connected between the anode of the reverse conducting GTO thyristor 23 and the rail 700, and the anode connected to the cathode of the reverse conducting GTO thyristor 23, and the cathode connected to the rail.
Reverse conducting GTO thyristor 27 connected to 700 and reactor
It consists of a capacitor 28 connected between 24 and rail 700.

The reactor 22 and the condenser 26 constitute an input filter of a chopper, and the reactor 24 and the capacitor 28 constitute an output filter of the chopper.

Thus, in the DC / DC converter 20, when power is supplied from the high-voltage auxiliary feeder line 10 to operate the electric train 600, the reverse conduction GTO thyristor 23 is controlled to operate as a step-down chopper. When power is supplied to the high-voltage auxiliary feeder line 10 side by the regenerative braking operation of the train 600, the reverse conducting GTO thyristor 27 is controlled to operate as a step-up chopper.

Next, the operation of the feeder system will be described. As shown in FIG. 1, the electric train 600 is operating in power near the existing substation 200, and the existing substation 200 is out of order due to failure. Then, in this case, the electric power for the train 600 is supplied from the existing substations 100 and 300 via the feeder line 400 and the trolley line 500 by a so-called extended feeder system.

Therefore, when viewed from the existing substations 100 and 300, the feeder distance increases, and the voltage drop of the line increases, which in turn causes a decrease in the voltage of the trolley wire 500 and, in turn, the train voltage. 10 to DC / DC converters 30, 4
Since electric power is supplied to the electric wire 400 via 0, a decrease in the train voltage is compensated. When the electric train 600 performs the regenerative braking operation, the electric power from the electric train 600 is supplied to the high-voltage auxiliary feeder line 10 through the DC / DC converters 30 and 40,
It is supplied to another train (not shown) via another DC / DC converter 20 or 50.

Here, the voltage-current characteristics on the DC side of all the existing substations are shown in FIG. 3 (b) in order to make the electric train 600 running between each substation smoothly feed from both sides. As shown by the solid line, the voltage gradually decreases as the current increases. Similarly, the DC / DC converter 20
It is desirable that the voltage-current characteristics of .about.50 are as shown in FIG. That is, the solid line in the figure is, for example, a voltage-current characteristic on the feeder line 400 side of the DC / DC converter 30, and as the current increases, the voltage becomes the no-load voltage V _0.
And gradually decrease.

Now, as shown in FIG. 3C, the electric train 600 is slightly running from the DC / DC converter 30 near the existing substation 100, and the existing substation 200 on the opposite side is out of order due to failure. In this case, the electric power to the train 600 is supplied from other than the existing substation 200. At this time, the train 600
Since it is running near the DC converter 30, the feeder line 400 and the trolley line between the DC / DC converter 30 and the train 600
The voltage drop of 500 can be ignored, and if the train voltage is V, this voltage V is also the output voltage of the DC / DC converter 30.

Here, as described above, the voltage of the DC / DC converter 30 −
Assuming that advance the current characteristics as a decreasing characteristic as the solid line in FIG. 3 (b), a current I ₁ flows toward the train 600,
On the other hand, from the existing substation 100 having the same characteristics, the current I ₂ which is the difference between the current I ₁ from the current I ₀ and the DC / DC converter 30 which requires a train 600 in FIG. (B) is Train 600
Will be supplied.

That is, as shown by a dashed line in FIG.
If the DC converter 30 always outputs a constant voltage irrespective of the magnitude of the current, the DC / DC converter 30 will bear all the current I ₀ , but the characteristics are as shown by the solid line. As a result, the DC / DC converter 30 and the existing substation 100 share the current to the train 600, so that the DC / DC converter 30
Can be made relatively small in capacity and size.

The above characteristics of the DC / DC converters 20 to 50 are the same as the voltage-current characteristics on the DC side of the existing substations 100 to 300, and are constant due to the existing substation and the feeder of the DC / DC converter. May be made in consideration of the voltage drop. Furthermore, train
The position of 600 is always detected by the DC / DC converter,
When traveling near the DC converter, the slope of the voltage-current characteristic is increased, and when traveling far away, the slope is reduced to the contrary, taking into account the voltage drop to the power supply position. In any case, these characteristics can be freely set.

In the above description, the case where the feeding load of another substation has increased due to the failure of one substation has been described. Needless to say, it is also effective against the increase. Further, the circuit configuration of the DC / DC converter is not limited to the example shown in FIG.

(Effects of the Invention) As described above, according to the present invention, a voltage higher than the feeding voltage of the existing substation is fed to the high-voltage auxiliary feeding wire by the additional substation, and installed at appropriate intervals from the feeding wire. In order to increase the feeder load due to various factors, the additional substation is replaced with the existing substation as in the past. For almost the same number, it is possible to compensate for the decrease in the train voltage without building.

That is, in the present invention, the number of additional substations with high equipment costs is only a fraction of the conventional number, and the required number of relatively inexpensive DC / DC converters composed of choppers can be increased. There is an effect that the feeding capacity can be increased.

In addition, by setting the characteristics of the DC / DC converter as described above, the load on the DC / DC converter can be reduced, and the DC / DC converter can be reduced in capacity and size to further reduce the price. Can be planned.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention, FIG. 2 is a configuration diagram of a DC / DC converter, and FIG. 3 (A) is a voltage-current characteristic of an existing electric wire side of the DC / DC converter. FIG. 4 (b) is a DC-side voltage-current characteristic diagram of the existing substation, FIG. 4 (c) is an explanatory diagram showing the positional relationship between the electric train, the existing power plant and the DC / DC converter, and FIG. FIG. 5 is an explanatory diagram showing an example, and FIG. 5 is an internal configuration diagram of a substation. 10 High voltage auxiliary feeder 20, 30, 40, 50 DC / DC converter 100, 200, 300 Existing substation, 400 Feeder 500 500 Trolley, 600 Train 601 Pandagraph 700 …… Rail 900 …… Substation 101,102,201,202,301,302,901,902 …… Service line

Claims (2)

(57) [Claims] 1. A feeder system for a DC electric vehicle for supplying DC power to a DC electric vehicle via a first feeder line directly connected to an output side of a first feeder substation, wherein: A second feeder substation that outputs a DC voltage higher than the output voltage of the feeder substation, and a second feeder wire directly connected to the output side of the second feeder substation. And a DC / DC converter capable of forward / reverse conversion connected between the first feeder line and the second feeder line. 2. A direct current (DC) converter according to claim 1, wherein the output voltage of the DC / DC converter on the first feeder side is reduced as the output current on the first feeder side increases. Feeding system for electric vehicles.