JPH046568B2 - - 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.

(Problems with the prior art) In general, DC power supply equipment for electric railways 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 into electricity via overhead contact lines. A system is adopted in which the regenerative energy generated during regenerative operation of the electric vehicle is converted into alternating current power by an inverse power converter and regenerated to the commercial frequency power supply bus side. ing.

An example of a conventional DC electric railway power supply device is shown in FIGS. 1 and 2. In Figure 1,
1 is a forward power converter that converts AC power sent from a commercial frequency power supply bus (not shown) into DC power, and 2 is a reverse power converter that converts DC power into AC power. The output power of the forward power converter 1 is transmitted through the DC bus 3 and the power running thyristor circuit breakers 4a, 4.
b, 4c, 4d and overhead contact lines 5a, 5b, 5c,
5d to a power running vehicle (not shown) located under the overhead contact line. Further, when an electric car (not shown) performs regenerative operation, the regenerative power of the electric car is transmitted through the contact wires 5a, 5b, 5c, 5d, the diodes 6a,
6b, 6c, 6d, regenerative thyristor circuit breaker 7,
It is regenerated to a commercial frequency power supply bus (not shown) via the DC bus 3 and the inverse power converter 2. A thyristor circuit breaker for power running, for example 4a, is turned off by a control circuit (not shown) when a ground fault occurs on the overhead contact line 5a. This prevents fault current from flowing into the fault point (not shown) via the thyristor circuit breaker 4a. The power running thyristor breakers 4b, 4c, and 4d also have the same functions as described above. Furthermore, the regenerative thyristor circuit breaker 7 is turned off by a control circuit (not shown) when a short-circuit accident occurs as described above, so that the regenerative thyristor circuit breaker 7 is turned off by a control circuit (not shown) when a short-circuit accident occurs.
From the regenerative electric car (not shown) located below, the contact line 5d, diode 6d, regeneration thyristor breaker 7, DC bus 3, and power running thyristor breaker 4
This prevents regenerated power from flowing into the accident point via a.

In addition, in FIG. 2, the same parts as in FIG. 1 are indicated by the same reference numerals, and the explanation thereof will be omitted. The feature of the power supply device shown in FIG. 2 is that regenerative thyristor breakers 7a, 7b, 7c, and 7d are connected in antiparallel to both ends of the power running thyristor breakers 4a, 4b, 4c, and 4d, respectively, as shown in the polarity. . That is, the regenerative electric power of the regenerative electric cars (not shown) existing under the overhead contact lines 5a, 5b, 5c, and 5d is transmitted via the regenerative thyristor circuit breakers 7a, 7b, 7c, and 7d, the DC bus 3, and the reverse power converter 2. It is regenerated to the commercial frequency power supply bus (not shown). The operation for supplying running power and the operation for interrupting fault current are performed in the same manner as in the power supply device shown in FIG.

In the device configured as described above, in the case of the device shown in Figure 1, when an accident occurs on the contact line side, the fault current flows into the fault point from the regenerative electric car under the healthy contact line or the healthy substation adjacent to the faulty substation. It is necessary to provide a regenerative thyristor circuit breaker 7 to cut off the power. Therefore, the number of thyristor circuit breakers increases. Furthermore, in the case of the apparatus shown in FIG. 2, four sets of regenerative thyristor circuit breakers 7a, 7b, 7c, and 7d are provided, so the number of thyristor circuit breakers increases significantly. What the conventional devices shown in Figures 1 and 2 have in common is that a large number of regenerative thyristor circuit breakers are installed, which makes the protective operation in the event of an accident very complicated and reduces reliability. However, the equipment area of the device is increased, and the entire power supply device becomes extremely expensive.

(Object of the Invention) The present invention has been made in view of the above points, and it is possible to simplify the configuration of the device, improve reliability, significantly reduce the cost of the device, and improve the operating condition of an electric vehicle. A direct current electric railway system that can reliably supply or regenerate power according to the situation, and can also secure safety by cutting off the fault current even if a ground fault occurs on any contact line. The purpose is to provide a power supply device.

(Summary of the Invention) The present invention involves inserting bridge circuits each composed of a diode into a plurality of DC electric lines connecting a DC bus bar provided on the output side of a forward power converter and a plurality of overhead contact lines separated by sections. A switching control element (for example, a thyristor circuit breaker) is connected between the terminals of the bridge circuit, thereby greatly reducing the number of switching control elements (thyristor circuit breakers) required for the entire power supply device. The device is characterized by a simplified device configuration and a reduced device cost.

(Description of one embodiment of the present invention) Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In FIG. 3, the same parts as in FIG. 1 are designated by the same reference numerals, and their explanation will be omitted. 11
A is a first bridge circuit formed by bridge-connecting diodes 12a to 12d. The input side of this first bridge circuit 11a is connected to the DC bus 3,
The output side is connected to the overhead contact line 5a via a disconnector 13a. Between the terminals of the first bridge circuit 11a, there is a switching control element, for example a first
The thyristor circuit breaker 14a is connected. 11b
is a second bridge circuit formed by bridge-connecting diodes 12e to 12h. The input side of this second bridge circuit 11b is connected to the DC bus 3, and the output side is connected to the overhead contact line 5b via a disconnector 13b. A switching control element, for example a second thyristor circuit breaker 14b of the polarity shown, is connected between the terminals of the second bridge circuit 11b. 11c
is a third bridge circuit formed by bridge-connecting diodes 12i to 12l. The input side of the third bridge circuit 11c is connected to the DC bus 3, and the output side is connected to the overhead contact line 5c via a disconnector 13c. A switching control element, for example, a third thyristor circuit breaker 14c of the illustrated polarity is connected between the terminals of the third bridge circuit 11c. 11d
is a fourth bridge circuit formed by bridge-connecting diodes 12m to 12p. The input side of this fourth bridge circuit 11d is connected to the DC bus 3, and the output side is connected to the overhead contact line 5d via a disconnector 13d. A switching control element, for example a fourth thyristor circuit breaker 14d of the polarity shown, is connected between the terminals of the fourth bridge circuit 11d. Reference numeral 15 indicates an electric car, 16a and 16b dead sections for separating the overhead contact lines, and 17a and 17b rails. In addition, the thyristor circuit breakers 14a, 14b, 1
4c, 14d commutation circuit and bridge circuit 11
Overcurrent relays for selective cutoff, etc., which are inserted into the DC circuits connecting the DC output sides of the cables a to 11d and the overhead contact lines 5a to 5d, are not shown. Furthermore, the illustrated device shows one substation, and each overhead contact line 5a to 5
It is assumed that a predetermined DC power is also supplied to d from an adjacent substation (not shown).

Next, the operation of the apparatus configured as described above will be described. As shown in the figure, when the electric car 15 under the overhead contact line 5c is in power running, the forward power converter 1, the DC bus 3, the diode 12j of the third bridge circuit 11c, the third thyristor circuit breaker 14, the diode 12k, and the disconnection are disconnected. DC power is supplied to the electric car 15 via the power line 13c and the contact line 5c, and the electric car 15 is also supplied from an adjacent substation (not shown).
The desired DC power is supplied to. Also, train line 5a
(or 5b or 5d) A power running vehicle (not shown) existing under
2n), thyristor circuit breaker 14a (or 14b or 14d), diode 12c (or 12g or 12
o), the desired DC power is supplied via the disconnector 13a (or 13b or 13d) and the overhead contact line 5a (or 5b or 5d), and the desired DC power is also supplied from the adjacent substation (not shown). Supplied. Next, when the electric car 15 existing under the overhead contact line 5c performs regenerative operation, the regenerative energy of this electric car 15 is transferred to the disconnector 13c, the diode 12
i, thyristor breaker 14, diode 12l,
It is regenerated to the commercial frequency power supply bus (not shown) via the DC bus 3 and the reverse power converter 2, and the disconnector 13c, the diode 12i, the thyristor breaker 14, the diode 12l, the DC bus 3, and the above-mentioned power running power supply path. Tram line 5 via
It is also supplied to a power running vehicle (not shown) connected below a (or 5b or 5d).

For example, suppose that a short-circuit accident occurs at point F of the overhead contact line 5a during such steady operation. Due to this accident, a fault current flows from the output side of the forward power converter 1 to the fault point F via the DC bus 3, diode 12b, thyristor breaker 14, diode 12c, and disconnector 13a, and at this time, the fault current flows into the fault point F from the output side of the forward power converter 1. A disconnector 13 from an electric car, for example, an electric car 15
c, diode 12i, thyristor breaker 14
c, diode 12l, DC bus 3, diode 12b, thyristor breaker 14a, diode 1
2c and the disconnector 13a, a fault current flows into the fault point F, and a loop current from a healthy substation adjacent to the faulty substation also flows through this loop. When a fault current flows through the above path to the fault point F, the fault current is detected by an overcurrent relay (not shown) inserted into the DC line connecting the DC output side of the bridge circuit 11a and the overhead contact line 5a. Using this detection signal, the control terminal of the forward power converter 1, for example, if the converter 1 is composed of a thyristor rectifier, narrows the gate to the minimum position to limit the fault current flowing from the power supply side. let At the same time, a detection signal from the overcurrent relay (not shown) is transmitted to the thyristor circuit breaker 14a.
is turned off by a commutation circuit (not shown). By such a protective operation at the time of an accident, the fault current flowing into the fault point F is cut off, and when the fault current becomes zero, the disconnector 13a is opened to selectively cut off only the fault circuit, and the forward power converter 1 to restart power supply, thereby allowing electric cars (not shown) running under other sound contact lines to maintain stable operating conditions without being affected by the ground fault accident. I can do it.

As mentioned above, since the power running current flowing to the electric car one contact line below and the regenerative current flowing from the electric car one contact line below to the DC bus side both flow through a common thyristor circuit breaker, the power supply device The total number of thyristor circuit breakers required is extremely small, and the cost of the device can be significantly reduced. In addition, the thyristor circuit breaker 14a of each DC circuit
~14d blocks the fault current from the forward power converter, the regenerative power, the circulating power, etc. flowing into the fault point at the time of a ground fault, so the protective operation in the event of a fault is very easy and the protection system is This not only simplifies the process and improves reliability, but also allows stable operation over the entire operating range.

(Description of other embodiments of the present invention) Next, other embodiments of the present invention will be described. FIG. 4 shows a thyristor converter controlled to have both the functions of a forward converter and an inverse converter, and a regenerative power running switching device provided between the DC side of the thyristor converter and the overhead contact line. FIG. 2 is a circuit diagram when applied to a power supply device for a DC electric railway equipped with the present invention. In FIG. 4, the same parts as in FIG. 3 are indicated with the same reference numerals.
The explanation will be omitted. Reference numeral 21 denotes a thyristor converter that converts AC power into DC power and supplies it to the power running vehicle, and converts the DC regenerative power of the regenerative vehicle into AC.The AC side of this thyristor converter 21 is connected to a transformer 22a and It is connected to a commercial frequency power supply bus (not shown) via an AC breaker (not shown). One end of the thyristor converter 21 on the DC side is connected to the DC bus 3 via a diode 24a having the polarity shown. The thyristor converter 21
The other end on the DC side is connected to the rails 17a, 17b via the diode 24b of the polarity shown and the negative bus 31.
It is connected to the. A thyristor switch 23a with the illustrated polarity and a reactor 25 for suppressing circulating current are inserted in the electric path connecting the cathodes of the diodes 24a and 24b.
A thyristor switch 23b is inserted in the electric path connecting the anodes of the thyristor switch 24b with the polarity shown. These thyristor switches 23a, 23
b, reactor 25 and the diode 24
A and 24b constitute a regenerative power running switching device 32. A forward power converter 26 is installed in parallel with the thyristor converter 21 and converts AC power into DC power. The AC input side of the forward power converter 26 is connected to a commercial frequency power supply bus (not shown) via a transformer 22b and an AC breaker (not shown). The positive output ends of the forward power converters 26 are commonly connected to the DC bus 3, and the negative output ends are commonly connected to the negative bus 31.

Next, the operation of the apparatus configured as described above will be described. When the electric car 15 existing under the overhead contact line 5c performs power running as shown in the figure, the thyristor converter 21 is driven as a forward converter by a control circuit not shown, and the thyristor switches 23a and 23b are not shown. When turned off by the control circuit, from one end of the DC side of the thyristor converter 21 to the diode 24a, the DC bus 3, the diode 12j of the third bridge circuit 11c, the thyristor circuit breaker 14, the diode 12k, the disconnector 13c, and the contact line. Direct current power is supplied to the electric car 15 via 5c, and direct current is similarly supplied from the positive output end of the forward power converter 26. Next, for example, when the electric car 15 existing under the overhead contact line 5c performs regenerative operation, the thyristor converter 21 is driven as an inverse converter by a control circuit (not shown), and the thyristor switch 23a,
23b is turned on by a control circuit (not shown). Then, the regenerated energy of the electric car 15 is transferred to the disconnector 13c, the diode 12i, and the thyristor circuit breaker 1.
4c, the diode 12l, the DC bus 3, the thyristor switch 23a, the reactor 25, the thyristor converter 21, and the transformer 22a. At this time, the regenerated energy of the electric car 15 is also supplied to a power running vehicle (not shown) connected below the overhead contact line 5a, 5b, or 5d, as in the case of FIG. 3 above.

For example, suppose that a short-circuit accident occurs at point F of the overhead contact line 5a during such steady operation. Due to this accident, the fault point
Fault current flows from the thyristor converter 21 to the fault point F via the diode 24a, the DC bus 3, the diode 12b, the thyristor circuit breaker 14a, the diode 12c, and the disconnector 13a.
A fault current flows into the electric car that is in regenerative operation, for example, the electric car 15, to the disconnector 13c, the diode 12i, the thyristor breaker 14, the diode 12l, the DC bus 3, the diode 12b, the thyristor breaker 14a, and the diode. A fault current flows into the fault point F via the disconnector 12c and the disconnector 13a. When a fault current flows through the above path to the fault point F, the fault current is detected by an overcurrent relay (not shown) inserted into the DC path connecting the DC output side of the bridge circuit 11a and the overhead contact line 5a. Using this detection signal, the thyristor circuit breaker 14a is turned off by a commutation circuit (not shown). By such a protective operation at the time of an accident, the fault current flowing into the fault point F is cut off, and when the fault current becomes zero, the disconnector 13a is opened to selectively cut off only the fault circuit. As a result, electric cars (not shown) running under other healthy overhead contact lines can maintain stable operating conditions without being affected by the short circuit accident.

As mentioned above, since the power running current flowing to the power running vehicle one contact line below and the regenerative current flowing from the regenerative vehicle one contact line below to the DC bus side both flow through a common thyristor circuit breaker, the power supply device The total number of thyristor circuit breakers required is extremely small, and the cost of the device can be significantly reduced. In addition, thyristor circuit breakers 14a to 14d are provided for each DC circuit connecting the DC bus 3 and the contact lines 5a to 5d.
As a result, it is possible to selectively cut off only the DC circuit where a short-circuit accident has occurred, and as a result, electric cars running under other sound contact lines are not affected by the short-circuit accident and are kept in a stable operating state. can be maintained.

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

(Effects of the Present Invention) As described above, according to the present invention, there is provided a forward power conversion device that converts AC power input from a commercial frequency power supply bus into DC power and supplies power running power to an electric vehicle;
A plurality of DC electric lines connecting a DC bus bar provided on the output side of the forward power converter and a plurality of overhead contact lines separated by sections, and regenerated power led through the plurality of DC electric lines are inversely converted into alternating current. A power supply device for a DC electric railway having a reverse power conversion device for regenerating power to the commercial frequency power supply bus side, comprising: a bridge circuit configured by bridge-connecting diodes and inserted into each of the plurality of DC circuits; Since switching control elements are connected between the positive and negative output terminals of the bridge circuit, the configuration of the device is simplified and reliability is improved, and the number of switching control devices is extremely small, reducing the device cost. Significantly cheaper. In addition, it is possible to reliably supply power or regenerate power depending on the operating status of the electric car, and to ensure safety by reliably cutting off the fault current even if a ground fault occurs on any contact line. I can do it. Furthermore, since only the DC circuit where a ground fault has occurred can be cut off, electric cars running under other healthy overhead contact lines can maintain stable operating conditions without being affected by the ground fault. . Furthermore, the regenerative energy of the regenerative electric cars that exist under one contact line is not only regenerated to the commercial frequency power supply bus side, but also supplied to the power running electric cars that exist under other contact lines, so the power utilization rate is reduced. Significantly improved. Furthermore, since a thyristor circuit breaker for regeneration is not required at all, protective operation in the event of an accident is extremely easy, and the protection system itself can be simplified.

[Brief explanation of drawings]

1 and 2 are both circuit diagrams showing a conventional DC electric railway power supply device, FIG. 3 is a circuit diagram showing one embodiment of the present invention, and FIG. 4 is a circuit diagram showing another embodiment of the present invention. FIG. 1, 26...Forward power converter, 2...Reverse power converter, 3...DC bus, 5a, 5d...Telephone line, 11a-11d...Bridge circuit, 12a-
12p...Diode, 14a-14d...Thyristor circuit breaker, 15...Electric car, 16a, 16b
...Section, 21...Thyristor converter, 2
3a, 23b...thyristor switch, 24a,
24b...Diode, 25...Reactor for suppressing circulating current, 32...Regenerative power running switching device.

Claims (1)

[Scope of Claims] 1. A forward power converter that converts AC power input from a commercial frequency power supply bus into DC power and supplies power to an electric vehicle, and a DC power converter provided on the output side of the forward power converter. A plurality of DC electric lines connecting the busbar and a plurality of overhead contact lines separated by sections, and reverse power that converts the regenerated power guided through the plurality of DC electric lines into alternating current and regenerates it to the commercial frequency power supply bus side. A power supply device for a DC electric railway having a converter device includes a bridge circuit configured by bridge-connecting diodes, the input side of which is inserted into each of the plurality of DC circuits, and a bridge circuit between the positive and negative output terminals of the bridge circuit, respectively. A power supply device for a DC electric railway, comprising a switching control element connected thereto. 2. Claim 1, wherein the switching control element comprises a thyristor circuit breaker.
The DC electric railway power supply device described in 2.