JPS6350177Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a power supply system for electric railways using a double section system, and in particular aims to provide an improved power supply system that promotes contactless technology and facilitates protection coordination in the event of an accident. It is something.

In DC electric railway power supply equipment, a dead section is installed to separate the feeding circuits, but as is well known, this dead section is a single-layer system from the viewpoint of economical equipment costs for the feeding system. For example, if a short-circuit accident occurs for some reason and a vehicle enters the dead section of the accident line, the fault current will flow to the vehicle through the vehicle's panda graph, and the vehicle's A circuit is created in which the fault current flows to the fault point through the other pantograph, and when the pantograph of the vehicle moves away from the dead section, an arc will occur between the dead section and the pantograph, and this arc heat will not only damage the dead section, but also the dead section. A serious accident may occur in which the pantograph is also destroyed. As a method to prevent such serious failures, a double section system in which the dead section is duplicated has recently been introduced, further increasing the reliability of the power feeding system. However, a problem with such a double section system is that, for example, in the past, when a newly installed section and a DC positive bus of a substation were connected to form a feeder circuit, a DC high-speed circuit breaker was used. As is well known, the main part of such a DC high-speed circuit breaker is a mechanical structure in which the current is switched by an air arc, so it is troublesome to maintain the surface due to wear of the contacts. Furthermore, since the operating speed in the event of an accident is slow, there are problems in terms of protection, which is not at all desirable. One possible way to solve this problem is to use a thyristor circuit breaker, which has reverse blocking thyristors connected in reverse parallel to have the same function as a DC high speed circuit breaker, but Considering short-circuit current, etc., it is necessary to use a stack configuration in which a plurality of forward-direction thyristors and reverse-direction thyristors are each connected in parallel. Such a method would increase the size of the circuit breaker itself and would be extremely uneconomical. Therefore, it is possible to consider a method in which the forward direction thyristor has exactly the same structure as that described above, and only the reverse direction element uses a diode. Using this method, it is possible to miniaturize the device and realize an economical device, but the problem is that if an accident occurs on the DC positive bus of a substation, the DC positive bus is The fault current will continue to flow to the fault point.
The reason for this is that the diode group does not have a current interrupting function, and a new problem arises in that the diode group itself is thermally destroyed by the fault current.

The present invention was devised in view of this point, and the main feature of the present application is that a diode in the reverse direction of the thyristor circuit breaker is provided on the side of the existing regenerative thyristor circuit breaker. The details will be explained based on the following.

In the embodiment shown in the figure, 1 is a forward power converter that converts commercial frequency AC input power into DC power, and in the figure, a silicon rectifier is applied as the forward power converter.
This rectifier may also have the function of an inverter, so that regenerated power generated during braking of the vehicle is regenerated to the commercial frequency power source through the rectifier. 2 is a DC positive electrode bus bar for guiding the required power to the feeder line 7 ₁ - 7 ₂ side, and 3 ₁ to 3 ₆ are thyristor circuit breakers, respectively.As these thyristor circuit breakers are well known, For example, when selecting and breaking only the thyristor breaker connected to the fault line side, which is composed of a reverse-blocking main thyristor and a forced arc-extinguishing circuit consisting of an auxiliary thyristor, a commutating capacitor, a commutating diode, and a charging circuit,
By discharging the charge in the commutation capacitor to the main thyristor through the ignited auxiliary thyristor, the main thyristor is forcibly extinguished and the fault current is cut off. In addition, thyristor circuit breaker group 3
In ₁ to 3 ₆ , each of the thyristor circuit breakers 3 ₁ - 3 ₂ and 3 ₅ - 3 ₆ are existing ones installed in the case of the single section system, and the thyristor circuit breakers 3 ₃ - 3 ₄ are included in the present application. In the case of the double section system, the capacity of the newly installed 3 ₃ - 3 ₄ thyristor circuit breaker is 8 ₁ - 8 ₃ , 8 between the double sections compared to the existing one. _{2-8 4} is short (this distance is the length of the vehicle plus the length of α), and since it is only necessary to supply power to the area between the double sections, the capacity of the existing thyristor circuit breaker can be reduced. A relatively small capacity one is sufficient. Reference numeral 5 denotes a regenerative bus bar, and a group of stopper diodes 4 ₁ to 4 ₆ are connected in parallel under the bus bar, and the anode side of each diode group is connected to the corresponding thyristor circuit breaker, so that the regenerative power from the regenerative vehicle and In the event that the power supply to the relevant substation is stopped in the event of an accident, this substation is used to guide the loop power flowing in from the healthy substation adjacent to this substation. In the stopper diode group 4 ₁ to 4 ₆ , diodes 4 ₁ to 4 ₂ and 4 ₅ to 4 ₆ are existing ones provided in the case of the single section system, and diodes 4 ₃ to 4 ₄ are not included in the present application. This is newly provided in the case of such a double section system, and one feature of the present application is that it is arranged in parallel with the existing diode group. 6 is a thyristor circuit breaker for regeneration, and this circuit breaker has exactly the same circuit configuration as the thyristor circuit breaker for power running power supply, and in the event of an accident, the regenerative power led from the stopper diodes, and the circuit breaker from the adjacent substation. In cases where power is temporarily cut off, or when an inverter dedicated to regeneration is installed at the substation shown, or the forward power converter 1 shown has a regeneration function, or the substation itself has a regeneration function. If the inverter fails to commutate and a large fault current flows, it has a function to instantly cut off the fault current and protect the inverter or stopper diode group. Another feature of the present application is that the 4 ₃ -4 ₄ stopper diodes newly provided in the double section system are provided on the regenerative thyristor circuit breaker side.

To describe the operation of this embodiment configured as above, during steady state, the forward power converter 1 → DC positive bus 2 → each thyristor circuit breaker 3 ₁ to 3 ₆ → feeder line 7 ₁ or 7 ₂ → not shown The required power running power is supplied to the power running vehicle through the vehicle path, and if there is a regenerative vehicle, the feeder line on the regenerative vehicle side → stopper diode → regenerative bus 5 → regenerative thyristor circuit breaker 6
→ DC positive electrode bus 2 → Supply regenerative power to the power running vehicle through the route of the power running vehicle that exists under other feeder lines, or furthermore, if an inverter exclusively for regeneration is installed, the power running and regeneration can be connected via this inverter. If the forward power conversion device has both functions, regenerated power is regenerated to the commercial frequency power source side through the conversion device. During this steady state, a short circuit occurs at the indicated point for some reason, and at the time of this short circuit, 7 ₁
It appears that a vehicle under the feeder line entered the existing dead section ₈₁ , and after a certain time the vehicle entered the newly established dead section ₈₃ , and the pantograph of the vehicle passed through the dead section ₈₁ . In such a case, an arc will occur between the dead section and the pantograph as described in the conventional device, leading to a serious failure. However, in the case of such an accident, according to the present application, each of the thyristor circuit breakers 3 ₁ to 3 ₆ By means of a voltage differential relay (not shown) installed in the electrical circuit, the thyristor circuit breaker 3 closest to the fault point is first
The selective cutoff relay on the ₆ side operates to selectively cut off only the relevant electrical circuit, and then the conditions are that there is no voltage on the accident section side (point side) that sandwiched the dead section ₈₃ , and that the voltage between the dead sections ₈₁ and ₈₃ is " Under the condition that "voltage is present," the voltage differential relay (not shown) on the newly inserted thyristor circuit breaker ₃₄ side operates to cut off the current circuit. In this way, the condition that there is no voltage on the fault section side and the healthy section side (showing the electrical circuit of the thyristor circuit breaker in 3 ₂ )
However, under the condition that "voltage is present", a voltage differential relay (not shown) on the ₃₂ side operates and immediately interrupts the electrical circuit.With this series of interrupting operations, a short circuit occurs between the sections where the vehicle is located. When an accident occurs,
Since the area immediately becomes a non-electronic section, even if a vehicle enters a dead section, serious failures that occur with conventional devices can be prevented. In addition, in the event of a short-circuit accident, for example, if there is a regenerative vehicle on the healthy line ₇₂ adjacent to the faulty line, the regenerative current flowing from this regenerative vehicle will flow into the stopper diode ₄₁ or ₄₃ , _45.
The regenerative thyristor circuit breaker 6 uses the output signal of the selective cutoff relay, which operates at the same time as the accident occurs, to instantly cut off the regenerative current, as well as the wraparound current flowing from the adjacent substation, so that it does not flow toward the fault point through the fault. so that it is shut off. In this way, if the regenerative current, etc. is cut off at the time of an accident, and the thyristor circuit breaker 6 for regeneration is turned on again when the accident section side has completely cut off, the regenerated electric power can be supplied to the powering vehicle on the healthy line side after the reheating circuit breaker 6 is turned on again. It has the advantage that it can be supplied as power for power running.

As described above, in the case of a double section feeding system, a thyristor breaker is installed in the newly inserted dead section, and the stopper diode of this breaker is connected to the existing regenerative thyristor breaker. Since it is inserted into the vessel side, it has various effects as shown below.

Even if a vehicle enters the accident section during a short-circuit accident, the system immediately shuts off the accident section at the same time as the accident occurs, and the power feeding system does not apply pressure to the vehicle, which increases the reliability of the power feeding system itself. can significantly improve performance.

Since all of the circuit breakers themselves are thyristor circuit breakers, protective operations can be performed quickly in the event of an accident, and the spread of the accident can be prevented.

Since the stopper diodes of all thyristor circuit breakers are concentrated on the side of the existing regenerative thyristor circuit breaker, there is no need for these stopper diodes to have a capacity that can carry large fault currents such as short circuit currents. Therefore, equipment costs can be reduced significantly.

All use thyristor circuit breakers, so
It is possible to provide an extremely reliable power feeding system without any troublesome maintenance.

[Brief explanation of drawings]

The figure is a specific circuit configuration diagram of a power supply device according to an embodiment of the present invention when applied to a double section system. 1 is a forward power converter, 2 is a DC positive electrode bus, 3 _1
36 are thyristor breakers, ₄₁ to 46 are stopper diodes, ₅ is a regenerative bus, 6 is a regenerative thyristor breaker, ₇₁ to ₇₂ are feeder lines, and ₈₁ to ₈₄ are dead sections.

Claims (1)

[Scope of utility model registration request] A forward power conversion device that converts commercial frequency AC input power into DC power, a DC positive bus that feeds the DC power led from this device to the feeder line side of the double section system, and each of the double section systems. A plurality of thyristor circuit breakers that feed DC power that is divided into each line and is input from the positive DC bus to each feeder line, and an adjacent substation that is installed in correspondence with these thyristor circuit breakers and is led from the feeder line side. A plurality of stopper diodes output the circulating power, regenerative power, etc. to the regenerative bus side, and output the circulating power, regenerative power, etc., which is normally input from the regenerative bus, to the DC positive bus side. A power supply device for a DC electric railway, comprising a regenerative thyristor circuit breaker that cuts off input power only and then turns on again after selectively cutting off a faulty line.