JPS5912492B2 - Variable load response device for electric railways - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a power supply system for electric railways fed with direct current.

In other words, a new variable load response device including a storage battery is provided in order to respond to changes in train load.

The conventional power supply system for electric railways is to install substations for electric railways at approximately fixed intervals of the track, for example, every 10 to 15 km, and to supply power through rectifiers for electric railways with a rating of several i ooo kilowatts installed within the substations. Met.

The load on electric railways, that is, the current consumption of trains, is characterized by a significantly large difference between the peak current at startup and the average current.

Moreover, if the overhead wire voltage were to drop significantly relative to this peak current, normal operation of the train would be hindered.

In order to prevent this, various measures are currently being taken, such as narrowing the installation interval of substations, increasing the diameter of feeder wires, or increasing the number of feeder wires.

Furthermore, it is undesirable from the viewpoint of power supply that the load at the substation fluctuates greatly and the load factor is low.

The present invention provides a new and useful variable load response device including a storage battery that cooperates with a conventional rectifier for electric railways in order to alleviate the above-mentioned problems of the conventional electric railway power supply system. Its characteristics are: 1) A storage battery having a capacity and voltage that is approximately equal to the nominal voltage of the overhead contact line during discharge and capable of bearing part or most of the load current of the overhead contact line.

ii) In order to charge the storage battery in cooperation with a rectifier for electric railways, a DC output voltage corresponding to the difference voltage between the required charging voltage of the storage battery and the normal voltage of the overhead contact line at the storage battery installation point, and the storage battery. A rectifier with the output current capacity necessary to charge.

1 [i) A thyristor switch device comprising a thyristor having a current capacity capable of passing the normal discharge current of the storage battery, an auxiliary thyristor for extinguishing the thyristor, an arc extinguishing circuit device consisting of a capacitor, a choke coil, etc. .

The rectifying device is connected in a direction in which its DC output is harmonically connected in series with the overhead line voltage to charge the storage battery, and the thyristor switch device is connected in a direction in which the discharge current of the storage battery is passed through. The rectifier is connected between the output terminals of the rectifier.

Next, the present invention will be specifically described with reference to embodiments illustrated in the drawings.

FIG. 1 is a wiring diagram showing an embodiment of the present invention. In the figure, 1 is an overhead contact line, 2 and 2' are rectifiers for electric railways, 3 is a load consisting of an electric train, and 4 is a variable load response for electric railways according to the present invention. Device,
5 is a storage battery, 6 is a rectifier, and 7 is a thyristor switch device.

The rectifier 6 includes a transformer 61, a thyristor 62, a thyristor control device 63, a choke coil 64, a breaker 65, an electromagnetic switch 66, a voltage detection lead 67, and a current detection lead 68.
It consists of etc.

The thyristor switch device 7 includes a main thyristor 71, an auxiliary thyristor 72, a commutating capacitor 73, a commutating choke coil 74, a diode 75, a current limiting resistor 76, and a control device 1.
It consists of 7 mag.

Here, the rated voltage of the overhead contact line is 1500V, and the substation 2 for the electric railway
, 2' rated capacity is 3000ff each, voltage current characteristic es = 1650 - 0.075 I (where 1 is load current ampere, es is voltage volt at the substation end) The distance between substations is 30 section line. The resistance of 0.040/Km,
(Total resistance of feeder wire, trolley wire, rail, etc.)
The peak value of the train current is assumed to be 200OA.

If there is no variable load response device 4 and the train is started at substation intermediate point B, assuming that a peak current of 2000 A flows, then by simple calculation the voltage at point B is 975.
It becomes v.

Usually, a minimum voltage of about 1100V is required for normal operation of a train, and such a low value is unacceptable.

Therefore, the conventional design method was to install an electric railway substation similar to electric railway substations 2 and 2' at this intermediate point B, but according to the present invention, a variable load response is installed near this intermediate point B. Install device 4.

The storage battery 5 is made up of 750 500AH lead-acid batteries connected in series.

The output voltage variation range of the rectifier 6 is 0 to 350V, and the current capacity is 200A.

A positive terminal 51 of the storage battery is connected to the positive terminal (feeder line) of the overhead contact line 1 via a high-speed breaker 8 and a disconnector 9, and a negative terminal 52 is connected to a negative terminal 69 of the rectifier 6.

The positive terminal 691 of the rectifier 6 is connected to the negative terminal of the overhead contact line 1, that is, the ground terminal 11 via the choke coil 10 and the disconnector 91.
connected to.

As described above, the DC output of the rectifier 6 is harmonically connected in series with the overhead line voltage, and is connected in a direction to charge the storage battery 5.

The voltage of the overhead contact line at point B is as follows, except when the starting peak current or running current of the train flows near point B.
Even if a current of 20 OA is consumed to charge the storage battery, a value of about 1350 to 1500 V is expected.

As will be described in detail later, the storage battery 5 is discharged through the thyristor switch device 7 when the train is started in the vicinity of the intermediate point B, thereby increasing the overhead contact line voltage in the vicinity and helping the train to operate normally. .

On the other hand, at other times, the thyristor switch device 7 is rendered non-conductive, and the above-mentioned overhead line voltage is added to the output voltage of the rectifier 6 to charge the storage battery 5.

How the storage battery 5 is charged will be explained using FIGS. 3 and 4.

Figure 3 shows the voltage at each part, and the terminal voltage of the storage battery 5 (voltage applied to the storage battery 5) eB is the sum of the voltage vB of the overhead contact line near point B and the output voltage vR of the rectifier 6. become.

That is, e B = VB + VR Here, vb is equal to the voltage es of the railway rectifier 2 (or 2') when the train current is not flowing, but generally due to the voltage drop due to the line resistance R, it is less than this. The voltage will be low.

FIG. 4 shows VB+vR horizontally, ignoring the back electromotive force of the choke coil 64.10 and the storage battery 5. By changing the control angle α of the thyristor 62 from 00 to 90°, vR becomes 350 V. It changes from to Ov.

In order to properly charge the storage battery 5, the output voltage of the rectifier 6 is set so that the storage battery voltage is a constant value, for example, 750×2.25V=16
It is automatically controlled to be 87.5V.

The output voltage VR of the rectifier 6 is not constant, and the thyristor 620 control angle α is controlled so that the sum eB of the variable voltage vB of the overhead contact line is constant.

Further, in order to prevent the output current of the rectifier 6 from becoming excessive, the control angle α of the thyristor 62 is controlled by a current detection device so that it does not exceed 200A.

The thyristor switch device 7 operates as follows.

When igniting the thyristor switch device I, the electromagnetic switch 6
The output circuit of the rectifier 6 is separated by appropriate means such as opening the rectifier 6.

To make the thyristor switch device 7 conductive, the main thyristor 71 can be turned on.

This allows the storage battery 5 to supply power to the train load 3 through the main thyristor 71.

To make the thyristor f-touch device 7 non-conductive, the auxiliary thyristor 72 can be turned on.

This turns off the main thyristor 71.

The thyristor switch device 1 is activated when it detects that the voltage near point B has fallen below a set voltage (for example, 1,250V), and detects that the outflow current has decreased below a certain value (for example, 600A). The arc is extinguished.

FIG. 2 illustrates how the contact line voltage is improved by the variable load response device 4. In the figure, S
. There is.

Curves A, A/, and A'' are the voltages at each point when there is no variable load response device 4 or when it is assumed that the thyristor switch device 7 is non-conducting and a starting current of 2000 A flows at each point of the overhead contact line. , the curves C, C', C
" indicates the same voltage as above when the thyristor switch device 7 is conductive.

As is clear from the figure, if the variable load response device 4 is not installed, 1,100
However, if the voltage at 8 points is detected in such a case and the thyristor switch device 7 is turned on, the voltage of the overhead contact line becomes c and c'.

It is greatly improved as shown in "C".

Note that if the electric current of the train decreases, even if the thyristor switch 7 is turned off, the voltage of the overhead contact line will be the same as the broken line A, A"' + A"
As it is expensive, there is no problem.

In order to reduce the required capacity of the storage battery 50, the thyristor switch 7 is turned off upon detecting that the outflow current from the storage battery has decreased.

The extinguishing condition for the thyristor switch may also be determined by detecting abnormal overdischarge of the storage battery.

Since the present invention is configured as described above, it has the following effects compared to conventional devices.

G) The rectifier 6 may have a much smaller capacity than a rectifier for electric railways.

For example, the latter is rated at 100K for the 3000KWD type.
W is sufficient.

Therefore, even if there is no large-scale power substation near point B, it can be handled by receiving power from a small-capacity power distribution network.

The installation cost is also low, even including the storage battery.

(b) Most of the electric power for charging the storage battery will be supplied from now on when the electric railway rectifiers 2, 2' are under light load.

Therefore, the peak power reception of the electric railway rectifier itself is reduced, and at the same time, the base is increased, and the load factor of the electric railway rectifier is improved.

(c) In some cases, regenerated electric power from trains can be used to charge storage batteries, making effective use of electric power and preventing abnormal rises in overhead line voltage.

Although the thyristor switch device 7 has been shown as an example in which the thyristor switch device 7 is simply controlled in two positions, ie, conduction and non-conduction, it may also be made to continuously repeat conduction and de-conduction to perform a so-called chopper operation to obtain an intermediate voltage.

[Brief explanation of the drawing]

FIG. 1 is a wiring diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing changes in overhead line voltage, FIG. 3 is a circuit diagram showing the charging operation of the storage battery in the device of the present invention, and FIG. FIG. 3 is a diagram showing the relationship between overhead line voltage and output voltage of a rectifier. 1... Electric line, 2, 2'... Rectifier for electric railway, 3... Load, 4... Fluctuation load response device, 5... ... Storage battery, 6 ... Rectifier, 7 ... Thyristor switch device.

Claims (1)

[Scope of Claims] 1 A device used in combination with a rectifier for electric railways, which: i) is approximately equal to the nominal voltage of the overhead contact line during discharge and is capable of bearing part or most of the load current of the overhead contact line; A storage battery with a capacity and voltage that allows 1i) In order to charge the storage battery in cooperation with a rectifier for electric railways, a DC output voltage corresponding to the difference voltage between the required charging voltage of the storage battery and the normal voltage of the overhead contact line at the storage battery installation point, and the storage battery. A rectifier with the output current capacity necessary to charge. 1ii) A thyristor switch device comprising a thyristor having a current capacity capable of passing the normal discharge current of the storage battery, and an arc extinguishing circuit device comprising an auxiliary thyristor, a capacitor, a choke coil, etc. for extinguishing the thyristor. The rectifying device is connected in a direction in which its DC output is harmonically connected in series with the overhead line voltage to charge the storage battery, and the thyristor switch device is connected in a direction to conduct the discharge current of the storage battery. , a variable load response device used in an electric railway, characterized in that it is connected between the DC output terminals of the rectifier.