JPS6215140A - Direct current feeding device - Google Patents

Abstract

PURPOSE:To enhance the system reliability preventing troubles from occurring by configurating a device in such a way that a combination of both a circuit breaker and a diode bridge is provided for each of upper and lower lines, a stopper diode between bi-directional power converters can be shortcircuited, and a diode is provided so as to interrupt electric current flow due to troubles. CONSTITUTION:Circuit breaker 8a through 8d are combined with diode bridge circuits 21 and 41, and each of the said combination is provided for each of upper and lower lines, and stopper diodes 28 and 48 which can be grounded by direct current disconnectors 35 and 36, are connected to lines between contacts 25 and 45 on the anode side and a regenerative bus-bar 29. And a diode series circuit 30 is provided for a line to the regenerative bus-bar. Accordingly, this configuration allows two sets of bridge circuits 21 and 41 to form a mutual reserve system. Even if the circuit breaker on one side fails, electric current can be fed from the circuit breaker on the other side to the line where the breaker fails. At this moment, if a trouble due to grounding occurs, the interruption of the breaker on the sound line side does not permit electric current to flow a bi-directional power converter 34 to a troubled point side preventing the trouble from expanding with the provision of the improved system reliability.

Description

[Detailed Description of the Invention] A. Field of Industrial Application: The invention relates to a power supply device for electric railways, and particularly to a power supply device for electric railways that converts alternating current power into direct current power and supplies it as a driving source for electric cars. Regarding a power supply device.

B9 Summary of the Invention This invention provides a power supply device for a DC electric railway that combines a circuit breaker and a diode bridge circuit so that current during power running and current during regeneration flow through the same circuit breaker. One set is provided for each downlink electric train line, and the stopper diodes are short-circuited with a DC disconnector so that each bridge circuit can have mutual backup (power interchange), and the forward power of the bidirectional power converter is converter(
Even if a ground fault (or commutation failure of a bidirectional power converter) occurs on the contact line side during reverse power conversion), a diode is installed to block the fault current, thereby preventing an accident on the contact line side. It is possible to significantly improve the reliability of the system, and also to make effective use of the four roundworm currents, and also to enable mutual backup power supply.

C1 Prior Art Conventionally, DC substations installed at appropriate intervals along railway lines are configured with one to several sets of converters. Further, the DC output side of each converter is connected to a DC high-speed speed change switch 7 dedicated to the converter, and the AC input side of the converter is connected to a common bus conductor. That is, a power supply system including a forward power converter and a DC high-speed circuit breaker is connected in parallel between substations to constitute a DC power source of the DC substation.

On the other hand, tram tracks are generally divided between adjacent substations and by track, and the tram tracks are connected to their respective positive bus bars at each substation via DC high-speed circuit breakers dedicated to each line. Connected to the negative bus.

Generally, adjacent substations are configured as a power supply circuit that supplies power in parallel to the divided electric train tracks.

Figure 2 shows a conventional power supply device, where 1 is a forward power converter consisting of a thyristor control element that converts AC power into DC power, and 2
is an inverse power converter consisting of a thyristor control element that converts DC power into AC power.

3 is a DC bus bar, 4a to 4d are power running circuit breakers (
(hereinafter referred to as power running circuit breakers), 5a to 5d are roundworm diodes, the anode sides of these diodes 5a to 5d are connected to the cathodes of the power running circuit breakers 4a to 4d, and the cathodes of the diodes 5a to 5d are connected together. It is connected to the anode of a regenerative thyristor circuit breaker 6 (hereinafter referred to as a regenerative circuit breaker). The cathode of the roundworm circuit breaker 6 is connected to the DC bus 3. A reverse power converter 2 is installed on the DC bus 3.
is connected. 8a to 8d are DC disconnectors, 9a, 9b
and loa, lOb are the 1st, 2nd and 3rd . This is the 4th train track.

Next, the operation shown in FIG. 2 will be described. First, power for powering an electric vehicle is obtained by converting the three-phase AC voltage received from a commercial frequency power bus (not shown) through an AC breaker (not shown) into an appropriate voltage using a transformer (not shown) at a substation. The forward power converter 1 converts into DC power and separates the first.
Second train track 9a.

9b and 3rd. It is supplied to the fourth electric train tracks 10a and 10b.

The electric cars 13 on the fourth overhead contact line 10b are powered by the DC power supplied as described above.

Next, when the electric car 13 is in regenerative operation, regenerative power is supplied from the fourth overhead contact line tab to the DC bus 3 via the regenerative diode 5d and the regenerative circuit breaker 6.

The regenerated power supplied to the bus 3 is regenerated to the first to third contact tracks 9a to 10a on which power running electric cars (not shown) are operated, or is passed through the inverse power converter 2 to the power supply bus. will be regenerated.

D Problems to be solved by the invention (+) In the conventional example configured as shown in Fig. 2,
Since the forward power converter 1 and the reverse power converter 2 are directly connected in anti-parallel via the DC bus 3, when the commutation of the reverse power converter 2 fails, fault current is supplied from the forward power converter 1 side. There is a problem that accidents may be amplified.

(2) In FIG. 2, when the regenerative circuit breaker 1 is shut off, the following problem occurs.

(a) If an attempt is made to mirror stop only a desired end-type section during extended power supply, the end-type of the other adjacent tramway will also be stopped, which will hinder the operation of electric cars.

(b) Regenerative current that flows from the train tracks in the event of an accident.

If the extended power supply current is to be interrupted only by the regenerative circuit breaker 6, the breaking capacity of the circuit breaker 6 will be the same as that of the power running circuit breakers 4a to 4.
If the number of DC circuits into which d is inserted is four circuits (in the case of multiple circuits), at least four times as many power running circuit breakers are required.

(c) Therefore, the breaking capacity of the regenerative circuit breaker 6 is reduced,
If the capacity is set to a level that can interrupt the regenerative current, if a regenerative vehicle is present at the time of an accident, the regenerative circuit breaker 6 will not be able to interrupt the extended power supply current. For this reason, it is necessary to interrupt the current flowing to the fault point at the adjacent substation, which complicates the protection sequence in the event of a fault and reduces the reliability of the system.

(d) In the case of four electric circuits as described above, the power running circuit breakers 4a to 4d are inserted in each DC circuit, making the substation extremely uneconomical.

(e) Also, since the substation equipment becomes larger, the equipment cost for construction will increase by a large amount.

E1 Means for Solving Problems This invention provides a forward power converter that converts AC power into DC power, and a bidirectional power converter that is connected to a regeneration bus and converts DC power into AC power or AC power into DC power. a converter;
A power running bus connected to the forward power converter, two sets of diode bridge circuits whose cathodes are commonly connected to the power running bus, and separately provided for these two sets of diode bridge circuits. two sets of circuit breakers connected in common between the anode side and the cathode side connected to the power running bus of the bridge circuit; and cathodes of diodes constituting each side of the two sets of diode bridge circuits. The 1st, 2nd, and 3rd . A fourth overhead contact line, two sets of stopper diodes whose respective anodes are separately connected to the commonly connected anode sides of the two sets of diode bridge circuits, and whose cathodes are commonly connected; and these two sets of stoppers. It consists of a DC disconnector connected in parallel to each diode, and a series circuit of diodes connected between the commonly connected cathode side of the two sets of stopper danodes and the power running bus, The common connection point of the series circuit is connected to the regeneration bus bar.

F1 action As mentioned above, even if only one of the two sets of circuit breakers is shut off during extended power supply and only the desired end section is stopped, the other circuit breaker remains conductive, so the other train Line extension power supply can be continued.

In addition, since the two sets of diode bridge circuits are each equipped with a circuit breaker, even if a ground fault occurs on the electric train track side connected to one of the bridge circuits, the diode bridge circuit can be connected via the stopper diode. Therefore, if the bridge circuit breaker on the fault line side is shut off, current will not flow from the healthy line bridge circuit side to the fault point.

Furthermore, since a DC disconnector is connected in parallel to the stopper diode to create a mutual backup system in which power is mutually exchanged between the two diode bridge circuits, even if one circuit breaker fails, the other circuit breaker will be disconnected. Power can be supplied to the train track on the fault circuit breaker side through the cable.

Even if a ground fault occurs on the contact line on the fault circuit breaker side during power supply, if the circuit breaker on the healthy contact line side is shut off, a diode will be inserted in the electrical path between the bidirectional power converter and the mutual standby power supply circuit. Therefore, current will not flow from the bidirectional power converter toward the fault point side, and the expansion of the fault can be prevented.

G. Embodiment FIG. 1 is a circuit diagram showing an embodiment of the present invention, and the same parts as in FIG. 2 will be described with the same reference numerals.

In FIG. 1, 21 and 41 are four diodes 22a to 22d and 42a to 4 arranged as shown in the polarity.
2d. This first and second diode bridge circuit 2
Diodes 22a, 22c and 4 in 1 and 41
The cathode sides of 2a and 42c are connected to the power running bus 3. 23 and 43 are the first and second Cyrisk circuit breakers (
This circuit breaker may be a DC high-speed circuit breaker), and the anode sides of the first and second circuit breakers 23 and 43 are connected to the power running bus 3, that is, diodes 22a, 22c, and 4.
Points 24 and 4 where the cathodes of 2a and 42c are commonly connected
Connected to 4. Further, the cathode sides of the first and second thyristor circuit breakers 23 and 43 are connected to diodes 221+, 22
Point 2 where the anodes of d, 42b and 42d are commonly connected
5 and 45.

The first and second diode bridge circuits 21 and 41
The common connection points 26 and 46 of the diodes 22a and 22b and 42a and 42b are connected to the first and third overhead contact lines 9a and 10a via DC disconnectors 8a and 8c. Further, the common connection points 27 and 47 of the diodes 22c and 22d and 42c and 42d of the first and second diode bridge circuits 21 and 41 are connected to the second and fourth electric train lines 9b via DC disconnectors 8b and 8d. and tab.

28 and 48 are stopper diodes, and the anode sides of these diodes 28 and 48 are connected to the respective common connection points 25 and 45, and the cathode sides thereof are connected together to form a mutual spare bus 37. 30 is a series circuit consisting of diodes 31 and 32 connected in series, and the anode side of this series circuit 30 and diode 31 is connected to the stopper diode 2.
Connected to the cathode side of 8.48.

The cathode side of the diode 32 is connected to the power running bus 3. Common connection point 33 of the diodes 31 and 32
A regeneration bus bar 29 is connected to. This regeneration bus bar 29
A bidirectional power converter 34 for converting direct current to alternating current or alternating current to direct current is connected to.

DC disconnectors 35 and 36 are connected in parallel between the anode and cathode of the stopper diodes 28 and 48 to enable mutual backup.

Next, the operation of the above embodiment will be described. When the thyristor circuit breakers 23 and 43 are kept in the normally closed state, the power running current of the forward power converter 1 is changed to the thyristor circuit breaker 2.
3.43 → Diode 22b, 42b → DC circuit 8
a, 1st through 8c. Third train track 9a, 10a
At the same time, it is supplied to the 2nd and 4th contact lines 9b and 10b via the cyrisk circuit breaker 23.43 -> the diode 22d, 42d - the DC disconnector 8b, 8d.

In addition, the regenerative current generated in the first overhead contact line 9a is supplied to the second overhead contact line 9b via the DC disconnector 8a → diode 22a → thyristor circuit breaker 23 → diode 22d → DC disconnector 8b, or the diode 22a → Powering busbar 3
→Thyristor breaker 43→Diode 42b or 42d→
The third or fourth overhead contact line 10 is connected via a DC disconnector 8c or 8d.
a, 10b, or to the regeneration bus 29 via the stopper diodes 28, 48 (the DC disconnectors 35, 36 are open) and the diode 31. In addition, the second. 3rd and 4th tram tracks 9b, 10a and 1
Similarly, the regenerative current generated at the 1st. It flows through the second diode bridge circuit 21.41 and is supplied to each electric train line or regeneration bus 29.

As mentioned above, the power running current is applied to each electric train line 9a, 9b and 1.
0a, when supplying to Job, two sets of 1st. Since control can be performed simply by inserting the second cyrisk circuit breaker 23, 43, there is an advantage that two sets of expensive cyrisk circuit breakers can be omitted compared to the one shown in FIG. This allows the power supply device to be manufactured at low cost. Also, when controlling the regenerative current generated in each electric train line 9a, 9b and 10a, 10b, the first. The second cyrisk circuit breaker 23°43 and the first. Diode 22 of second diode bridge circuit 21.41
a to 22d and 42a to 42d and stopper diode 2
Since only 8.48 can be controlled, there is an advantage that a regenerative circuit breaker is not required.

Furthermore, both the powering current and the regenerative current are the same as the first one. Since it passes through the second thyristor circuit breaker 23.43, by opening that circuit breaker 23.43, the two sets of thyristor circuit breakers 23.43 can interrupt both the power running and regeneration currents. , the protection sequence can be simplified. By using the Cyrisk circuit breaker that has the function of interrupting both power running and regenerative currents in this way, for example, when a ground fault occurs at point F of the first overhead contact line 9a in FIG. When opened, the power running current is cut off. After that, if the DC disconnector 8a is opened and the thyristor circuit breaker 23 is closed again, even if the regenerative electric car 14 is operated on the second overhead contact line 9b, the regenerative current will be transferred to the regenerative bus bar 2 as described above.
9th or 3rd. It is supplied to the fourth electric train tracks 10a and 10b. In addition, in the case of the above-mentioned ground fault accident, 1. Since the second diode bridge circuit 21.41 is connected via the stopper diode 28.48, the first circuit breaker 23.
Just by opening the thyristor circuit breaker 4, the fault current
It does not flow through 3. This can prevent the spread of accidents.

Above 1. The second diode bridge circuit 21.41 and the first diode bridge circuit 21.41. At the time of extended power supply using the second cyrisk circuit breaker 23.
When stopping power supply to only b), only the first thyristor circuit breaker 23 is opened, so extended power supply can be continued to the end sections on the third and fourth contact lines 10a and 10b, and the electric car This enables smooth operation.

If an accident occurs during the extended power supply, the thyristor circuit breaker 23 or 43 connected to the faulty line will shut it off, so there is no need to shut it off at the adjacent substation that supplies the extended power supply current. Therefore, the protection sequence can be further simplified, the effects of accidents can be minimized, and the operating efficiency of electric vehicles can be improved.

In the above embodiment, the first thyristor circuit breaker 23 has now failed, and the first thyristor circuit breaker 23 has failed. Assume that power cannot be supplied to the second electric train tracks 9a and 9b. At this time, the stopper diode 28.
If the DC disconnectors 35 and 36 connected in parallel to 48 are closed, the 1st. Power can be supplied to the second overhead contact lines 9a and 9b using the following circuit. That is, power running bus bar 3
→Second thyristor circuit breaker 43→DC disconnector 36-mutual spare bus 37→DC disconnector 35→diode 22b or 22
The first circuit passes through the circuit d. Second train track 9a.

Power can be supplied to 9b. Therefore, the reliability of the system itself can be improved.

From the power supply circuit and bidirectional power converter 34 as described above, the diode 32 - the power running bus 3 - the second cyrisk circuit breaker 4
3 - When performing mutual standby power supply on the route from DC disconnector 36 to mutual standby bus 37, even if a ground fault occurs at the two points in Figure 2, the second thyristor circuit breaker 43 is connected to the fault current loop. Therefore, the fault current is cut off. This is because the diode 31 is connected to the mutual spare bus 37 in the polarity shown, so that the fault current is not directly supplied to the bus 37. Therefore, the spread of accidents can be prevented and reliability is further improved.

In addition to the above, since the diode 32 is inserted between the power running bus 3 and the regeneration bus 29, the bidirectional power converter 34
Even if commutation fails during reverse power conversion operation, the diode 32 can prevent current from flowing into the bidirectional power converter 34 side. Thereby, even if there is a commutation failure during the reverse power conversion operation of the bidirectional power converter 34, the expansion of the accident can be prevented. By making the bidirectional power converter °34 a forward power converter and supplying power running current, it is possible to reduce the capacity of the forward power converter l, and even in the event of a failure, it is possible to cause a power outage at the substation. Powering current can be supplied without any problems.

Effects of H0 Invention As described above, according to this invention, the following effects can be obtained.

a. Even if the power supply is stopped only in the desired end section during extended power supply, extended power supply can be continued between the @electric diagrams on the other side of the electric train line, allowing smooth operation of electric cars.

b. In the event of an accident during extended power supply, the extended power supply current is interrupted by a circuit breaker connected to the fault line, so there is no need to interrupt the extended power supply current at the adjacent substation that supplies the extended power supply current. Therefore, it is possible to further simplify the protection sequence and minimize the effects of an accident, and it is possible to improve the efficiency of carrying the electric vehicle.

Since a C9 stopper diode is installed, even if a ground fault occurs on one side of the train line, if one of the two sets of circuit breakers on the accident side is tripped, the accident will be stopped from the other circuit breaker. No current flows in, and the spread of the accident can be prevented.

d. Since a series circuit of diodes is inserted between the power running bus and the regeneration bus, even if commutation fails during reverse power conversion, the fault current from the forward power converter flowing into the bidirectional power converter side will be reduced. Since this can be blocked by a diode, it is possible to prevent an accident from occurring in a bidirectional power converter from expanding.

e. Compared to the conventional example, a circuit breaker for roundworms and two sets of circuit breakers for power running are not required, so the equipment cost is very advantageous. Also, since the number of circuit breakers is reduced - the protection sequence is simplified and reliability is improved.

f. Since power running power can be supplied by the forward power converter operation of the bidirectional power converter, the power capacity of the forward power converter can be reduced, and even if the forward power converter fails, power running power can be supplied, so it is possible to reduce the power running power at substations. There will be no power outage.

g. By connecting a DC disconnector in parallel to the stopper diode and closing it, mutual backup power supply becomes possible, which dramatically improves the reliability of the system.

h. Even if an accident occurs on the overhead contact line during mutual backup power supply, the current is interrupted by the Cyrisk circuit breaker, so that the current that attempts to flow directly to the accident point side during the forward power conversion operation of the bidirectional power converter is blocked by the diode. blocked in a series circuit. Therefore, the spread of accidents can be prevented and the reliability of the system can be further improved.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a circuit diagram showing a conventional example. l... Forward power converter, 3... Bus bar for power running, 9a,
9b. 10a, 10b...first to fourth electric train tracks, 21.
41...1st degree second diode bridge circuit, 23.
43...1st. 2nd Cyrisk circuit breaker, 28.48・
... Stopper diode, 29 ... Regeneration bus bar, 30
... Diode series circuit, 34... Bidirectional power converter, 35.36... DC disconnector, 3.7... Mutual spare bus bar. Figure 2 Procedural Amendment (Showa, June 18, 1961)

Claims (1)

[Claims] (1) A forward power converter that converts AC power to DC power,
A bidirectional power converter connected to the regeneration bus and converting DC power to AC power or AC power to DC power, a power running bus connected to the forward power converter, and a power running bus connected in common to the power running bus. two sets of diode bridge circuits to which the cathode sides of the two sets of diode bridge circuits are connected, and a common connection between the anode side of these bridge circuits and the cathode side connected to the power running bus bar, which are separately provided in these two sets of diode bridge circuits. two sets of circuit breakers connected to the circuit breaker, and a dead section forming a double line, each of which is separately connected to a connection point where the cathodes and anodes of the diodes constituting each side of the two sets of diode bridge circuits are commonly connected. The respective anodes are separately connected to the commonly connected anode sides of the first, second, third, and fourth overhead contact lines and the two sets of diode bridge circuits, and the cathodes are commonly connected. two sets of stopper diodes,
It consists of a DC disconnector connected in parallel to each of the two sets of stopper diodes, and a series circuit of diodes connected between the commonly connected cathode sides of the two sets of stopper diodes and the power running bus. , a DC power supply device comprising a common connection point of the series circuit of diodes connected to the regeneration bus bar.