JPH0420813B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a power supply device for electric railways, and more particularly to a power supply device for DC electric railways that converts AC power into DC power and supplies it as a drive source for electric cars. It is something.

(Prior art and problems) In general, a power supply device for a DC electric railway converts AC power input from a commercial frequency power supply bus into DC power using a forward power converter, and then converts the DC power to DC power via a contact line. A system similar to that used to supply electric cars is being adopted.

An example of a conventional DC electric railway power supply device is shown in FIG. In Figure 1, SS ₁ , SS ₂ , SS ₃
are first to third DC substations each converting AC power input from a commercial frequency power supply bus (not shown) into DC power. 3 is a tram line, and this tram line 3
DC power is supplied from the three substations to relieve the voltage drop. In other words, the output power of the first to third DC substations SS ₁ , SS ₂ , SS ₃ is the output power of the DC buses 1a, 1b, 1c,
It is supplied to an electric car (not shown) via a, 2b, 2c and the overhead contact line 3. Note that 4a and 4b are sections for dividing each overhead contact line. In the device configured as described above, if a ground fault occurs at point F of the overhead contact line 3, the substation SS ₁ ,
Fault current flows from SS ₂ and SS ₃ to fault point F via DC buses 1a, 1b, 1c and DC high-speed circuit breakers 2a, 2b, 2c. In order to interrupt this fault current, it is necessary not only to open the DC high-speed circuit breakers 2b and 2c installed at positions sandwiching point F in the diagram, but also to open the DC high-speed circuit breaker 2a on the substation SS ₁ side. Must be. For this reason, it becomes impossible to supply power to a power running electric car (not shown) existing near the common connection point A between the overhead contact line 3 and the circuit breaker 2a. As described above, the above-mentioned device has the disadvantage that not only the protective operation for interrupting the fault current becomes complicated, but also that the range of power outage is expanded because it is not possible to classify the fault when it occurs. Moreover, the above device has 3
Since multiple DC high-speed circuit breakers are provided, there are drawbacks such as an increase in the installation area of the device and a marked increase in the cost of the device.

(Object of the Invention) The present invention was made in view of the above points, and it not only simplifies the configuration of the device and significantly reduces the cost of the device, but also enables accident classification when an accident occurs. The purpose of this invention is to provide a power supply device for a DC electric railway that can minimize the extent of power outage in the event of an accident.

(Summary of the Invention) The present invention provides first to third contact lines divided by two sections on the output side of one substation, and a diode is installed at the DC output end of the forward power converter of the substation. The input ends of the first to third bridge circuits formed by bridge connection are connected together, the output end of the first bridge circuit is connected to the first overhead contact line, and the output end of the second bridge circuit is connected to the second overhead contact line. , the output ends of the third bridge circuit are respectively connected to the third overhead contact line, and
- The positive side output ends of the third bridge circuit are all connected to one end of the switching control element, and the negative side output ends are all connected to the other end of the switching control element.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. In FIG. 2, reference numeral 11 denotes a commercial frequency power supply bus, and the input end of a forward power converter 14 is connected to this bus 11 via an AC breaker 12 and a transformer 13. 15a is a diode 16
This is a first bridge circuit formed by bridge-connecting the circuits a to 16d, and the input side of the first bridge circuit 15a is connected to the output end of the forward power converter 14. The output side of the first bridge circuit 15a is the first
It is connected to the overhead contact line 17a. 15b is a second transistor formed by bridge-connecting diodes 16e to 16h.
This second bridge circuit 15 is a bridge circuit.
The input side of b is commonly connected to the output end of the forward power converter 14. The output side of the second bridge circuit 15b is connected to a second overhead contact line 17b provided to the first overhead contact line 17a via a first section 18a. 15c is a diode 16i~1
The input side of this third bridge circuit 15c is commonly connected to the output end of the forward power converter 14. The output side of the third bridge circuit 15c is connected to a third overhead contact line 17c provided on the second overhead contact line 17b via a second section 18b. The diodes 16a, 16c, 16e, 1
The cathodes of 6g, 16i, and 16k are collectively connected to a switching control element, such as a thyristor circuit breaker 19.
connected to the anode of the The diode 1
6b, 16d, 16f, 16h, 16j, 16l
The anodes of the thyristor circuit breaker 19 are collectively connected to the thyristor circuit breaker 19.
connected to the cathode of 20 indicates an electric car. Note that the commutation circuit of the thyristor circuit breaker 19 and the output side of the bridge circuits 15a to 15c and the overhead contact line 17
Overcurrent relays and the like inserted into the DC circuits connecting terminals a to 17c are not shown. Furthermore, the illustrated device shows one substation, and the overhead contact line 17a,
It is assumed that predetermined DC power is also supplied to each of the substations 17c from an adjacent substation (not shown).

Next, the operation of the apparatus configured as described above will be described. As shown in the figure, while the electric car 20 under the overhead contact line 17a is in power running, DC power is supplied from the forward power converter 41 to the electric car 20 via the diode 16a, the thyristor circuit breaker 19, the diode 16b, and the overhead contact line 17a. At the same time, desired DC power is also supplied to the electric car 20 from an adjacent substation (not shown). Further, DC power is supplied to the power running vehicle (not shown) existing under the overhead contact line 17b from the forward power converter 14 via the diode 16e, the thyristor circuit breaker 19, the diode 16f, and the overhead contact line 17b in the same manner as described above. . Further, in the power running vehicle (not shown) existing under the overhead contact line 17c, the forward power converter 14 is connected to the diode 16i, the thyristor circuit breaker 19, and the diode 1 as described above.
Direct current power is supplied via the contact line 6j and the overhead contact line 17c, and desired direct current power is also supplied from an adjacent substation (not shown). Furthermore, when the electric car 20 existing under the overhead contact line 17a performs regenerative operation, the regenerative power is transferred to the overhead contact line 17a, the diode 16c, the thyristor circuit breaker 19, and the diode 1.
6f (or 16j) to contact line 17b (or 1
7c) It is supplied to the power running vehicle (not shown) located below. Even when regenerative vehicles exist under the overhead contact lines 17b, 17c, the regenerated electric power is supplied to other power running vehicles under the overhead contact lines in the same manner as described above.

During such steady operation, for example, the overhead contact line 17
Suppose that a ground short accident occurs at point F in c. Due to this accident, a fault current flows from the output terminal of the forward power converter 14 to the fault point F via the diode 16a, the thyristor circuit breaker 19, and the diode 16j, and at the same time, a fault current flows from the output terminal of the forward power converter 14 to the fault point F, and from the electric car that is in regenerative operation at this time, for example, the electric car 20. Tram line 17a, diode 16c,
Regenerative power flows into the fault point F via the thyristor circuit breaker 19 and the diode 16j, and a loop current from an adjacent healthy substation (not shown) also flows into the fault point F. When the fault current flows to the fault point F through the above path, the bridge circuit 15c
An overcurrent relay (not shown) inserted into the DC circuit connecting the output side of the contact line 17c and the contact line 17c detects the fault current, and this detection signal is used to activate the thyristor circuit breaker 19.
is turned off by a commutation circuit (not shown). The fault current flowing into the fault point F is cut off by such a protective operation in the event of a fault. At this time, tram line 17b
Since there is no voltage, the so-called section over phenomenon that occurs at the section does not occur. Moreover, even if a ground fault occurs at point F in the diagram and the thyristor circuit breaker 19 is turned off as described above, the contact line 17
Since power is supplied to station a from an adjacent healthy substation (not shown), the electric cars (for example, electric car 20) located under the overhead contact line 17a continue to operate stably without being affected by the accident. can do. The same operation as described above is also performed when an accident occurs on the overhead contact lines 17a, 17b.

Note that the switching control element is not limited to the thyristor circuit breaker, but other devices having similar functions may be used.

(Effects) As described above, according to the present invention, the second contact line is provided to the first contact line via the first section, and the third contact line is provided to the second contact line via the second section, The input ends of first, second, and third bridge circuits each having bridge-connected diodes are connected to the direct current output end of the forward power converter, and the output end of the first bridge circuit is connected to the first contact line. The output end of the second bridge circuit is connected to the second overhead contact line, the output end of the third bridge circuit is connected to the third overhead contact line, and the positive output terminals of the first, second and third bridge circuits are connected to the second overhead contact line. are all connected to one end of the switching control element, and the negative side output terminal is all connected to the other end of the switching control element, so the number of switching control elements (thyristor circuit breakers) required for the entire power supply device is reduced. Since only one is required, the cost of the device can be significantly reduced. Also,
It is possible to reliably supply power or regenerate power depending on the operating status of the electric vehicle, and to ensure safety by cutting off the fault current even if a ground fault occurs on any contact line. can. In addition, the switching control element (thyristor circuit breaker) is simply one
Since it is a base, protective operation in the event of an accident is very easy, and the protective device itself can be simplified. Further, when an accident such as a ground fault occurs, the second overhead contact line provided between the first overhead contact line and the third overhead contact line can be made to have no voltage, so that it is possible to prevent the so-called section over phenomenon from occurring. Moreover, even if the switching control element is turned off when an accident such as a ground fault occurs, the power outage range can be minimized.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an example of a conventional power supply device,
FIG. 2 is a circuit diagram showing one embodiment of the present invention. 11... Commercial frequency power supply bus, 14... Forward power converter, 15a, 15b, 15c... Bridge circuit, 16a to 16l... Diode, 17a, 1
7b, 17c...telephone line, 18a, 18b...section, 19...thyristor circuit breaker.

Claims (1)

[Claims] 1. AC power input from a commercial frequency power supply bus is converted into DC power by a forward power converter, and the DC power is supplied to a plurality of overhead contact lines divided by sections. In the power supply device for a DC electric railway, a second contact line is provided to the first contact line via the first section, and a third contact line is provided to the second contact line via the second section, and the above steps are performed. The input ends of first, second and third bridge circuits formed by bridge-connecting diodes to the DC output end of the power conversion device are connected together, and the output end of the first bridge circuit is connected to the first overhead contact line, The output end of the second bridge circuit is connected to the second overhead contact line, the output end of the third bridge circuit is connected to the third overhead contact line, and the positive output ends of the first, second and third bridge circuits are connected together. What is claimed is: 1. A power supply device for a DC electric railway, characterized in that the switching control element is connected to one end of the switching control element, and the negative side output terminal is collectively connected to the other end of the switching control element. 2. Claim 1, wherein the switching control element comprises a thyristor circuit breaker.
The DC electric railway power supply device described in 2.