JP3802429B2 - Railway vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a railway vehicle, and more particularly to a railway vehicle that can reduce an abnormal voltage of a vehicle body generated in a high-speed railway vehicle.
[0002]
[Prior art]
In a high-speed railway vehicle having a relatively high traveling speed and using electric power as a driving source among railway vehicles, the traveling speed is always required to be updated. Therefore, a technique has been developed in which higher voltage electric power is taken into the vehicle from the overhead line via the pantograph, thereby driving a motor having a larger capacity.
[0003]
Generally, in a high-speed railway vehicle, high voltage AC power of 25 kV is supplied from an overhead line. A vehicle equipped with a set of power devices for running a railway vehicle (train) driven by electric power is called a unit, but generally two or three vehicles constitute one unit. In terms of space, in-vehicle devices are usually distributed and mounted on the first vehicle, such as a control device and a pantograph, and on the second vehicle, such as an inverter and an electric motor. In order to supply power to each unit, a power lead-in line is installed in each vehicle, and all power is supplied from each mounted pantograph. A special high voltage cable is used as the lead-through line.
[0004]
The high voltage power taken into the car is connected to the main transformer via a breaker in the car. The primary winding ground side of the main transformer is directly connected to the vehicle body. Here, as a grounding system, for example, in the grounding device of the 0 series Shinkansen (vehicles that have started to be used when the Shinkansen is opened), the vehicle body and the carriage are directly connected. And the slip ring) and the wheel shaft, the rail is passed through.
[0005]
However, in vehicles with higher speed, if the number of pantographs is reduced to 2 in one train formation, for example, and a special high voltage cable is passed to each unit, the distribution of ground current is near the ends of the train formation. It was becoming concentrated on the vehicle.
[0006]
On the other hand, paying attention to the structure of the vehicle body and the trolley, in recent years, the trolley on which the vehicle body is mounted has been improved and the bolsterless trolley has been used, and the insulation between the vehicle body and the trolley has been reinforced. In this bolsterless bogie, in order to suppress vibration, all the mechanical connection parts are connected via an elastic body such as rubber, and the insulation between the car body and the bogie is inevitably reinforced. . As a result, the ground current between the vehicle body and the trolley has no metal contact portion and only flows through the ground resistor in the case of the bolsterless trolley.
[0007]
Regarding the grounding method from the vehicle body to the rail, the 26th and subsequent cars on the Shinkansen are used to reduce the concentration of grounding current on the vehicles at both ends of the train organization and to reduce electrical noise caused by the digitization of the control device. Then, a grounding wire was newly installed in the vehicle, the primary side of the main transformer was connected here, and the vehicle body ground was connected to this grounding wire via a grounding resistor (the order was the vehicle's (The 26th model is a vehicle manufactured around 1979-54). A grounding device including a ground brush and a slip ring of the vehicle body is connected to the grounding wire.
[0008]
[Problems to be solved by the invention]
As described above, according to the conventional technique, the number of pantographs is reduced and high voltage cables are routed from the pantographs to all the vehicles even though high voltage power of 25 kV is supplied from the overhead lines. Furthermore, the insulation between the carriage and the car body has been reinforced. For this reason, the tendency of ground current to concentrate on some vehicles has been increasing. Therefore, as a countermeasure, a ground wire and a ground resistor are provided to equalize the ground current.
[0009]
However, in the future, if the voltage is increased to further increase the speed of the vehicle, it is necessary to further increase the rating of the grounding device with respect to the increase in the grounding current, the wheel shaft bearings, etc. It may be necessary to take new measures to prevent electric corrosion that may occur. Also, an increase in electromagnetic noise due to non-uniform distribution of ground current, etc., and a short time transient when the pantograph is raised and brought into contact with the overhead line or when the pantograph is separated from the overhead line It is also necessary to consider the problem that malfunctions and breakdowns occur in in-vehicle equipment due to abnormal voltage of the vehicle body, and that burnout occurs particularly in control devices and control valves attached to the carriage. it is conceivable that.
[0010]
Therefore, the present invention has been made in consideration of the above-described problems, and is designed to make the ground current uniform during traveling, and an abnormal voltage generated in the vehicle body of a high-speed railway vehicle when the pantograph comes in contact with the overhead wire. An object of the present invention is to provide a railway vehicle that reduces damage and prevents damage to on-vehicle equipment.
[0011]
[Means for Solving the Problems]
In order to solve the above problems, the invention according to claim 1 is a vehicle including a plurality of sets of grounding devices that electrically connect the axle and the carriage, and the grounding wires that connect the grounding devices to each other. And a grounding resistor that connects the grounding wire and the vehicle body ground of the vehicle, is formed of a silicon carbide sintered body, and is managed to have a flat frequency characteristic at 10 Hz to 1 MHz. It is characterized by providing.
[0012]
According to the second aspect of the present invention, ½ of the thickness dimension of the cross section of the ground resistor or ½ of the diameter dimension is δ = √ (2 / μσω) (where δ is the skin thickness, μ is The magnetic permeability of the grounding resistor, σ is the electrical conductivity of the grounding resistor, and ω is the angular frequency of the electromagnetic field).
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing a device configuration of an embodiment of a railway vehicle according to the present invention. FIG. 1 shows a series of five vehicles 101, 102, 103, 104, and 105 among a plurality of vehicles that form a train on the rail 100. In this case, the vehicle 101 and the vehicle 102, the vehicle 103 and the vehicle 104, and the vehicle 105 and one or several vehicles (not shown) each constitute one unit.
[0014]
Each of the vehicles 101 to 105 is provided with four wheels 202 for each of the vehicles 201 by four bolsterless type vehicles 201 (however, in FIG. 1, the vehicle on the front surface toward the drawing). And only the wheels are shown). Each wheel 202 has a common grounding device 203 composed of a slip ring assembled on the axle of each wheel 202 and a ground brush installed on the carriage 201 so as to come into contact with the slip ring. Is provided. The grounding devices 203 are connected to each other by grounding wires 301, 302, 303, 304, and 305 that are provided for each of the vehicles 101 to 105 so as to be separated from the vehicle body ground of each of the vehicles 101 to 105. The grounding wire 301 and the grounding wire 302, the grounding wire 303 and the grounding wire 304, and the grounding wire 305 and the grounding wire of another vehicle not shown are connected by connection cables 306, 307, and 308, respectively.
[0015]
The vehicle 103 is provided with a pantograph 111, and the vehicle 105 is provided with a pantograph 112. Further, the vehicle 101, the vehicle 103, and the vehicle 105 are provided with vacuum circuit breakers 113 to 115, main transformers 116 to 118, and other control devices not shown. It is assumed that the vehicle 102 and the vehicle 104 are respectively mounted with an inverter and an electric motor (not shown).
[0016]
The pantograph 111 is connected to a cable head 121 provided in the vehicle 102 and a cable head 122 provided in the vehicle 103. The pantograph 112 is connected to a cable head 123 provided in the vehicle 104 and a cable head 124 provided in the vehicle 105.
[0017]
A special high voltage cable 131 is connected to the cable head 121, and a special high voltage cable 132 and a special high voltage cable 133 are connected to the cable head 122. A special high voltage cable 134 is connected to the cable head 123, and a special high voltage cable 135 is connected to the cable head 124. Each of these special high voltage cables 131 to 135 and each special high voltage cable 136 to 138 to be described later includes a core wire 141 to which high voltage power is supplied and a shield 142 thereof. The shield 142 is grounded to the vehicle body of any of the vehicles 101 to 105 through which the special high-voltage cables are passed.
[0018]
The above-described special high-voltage cable 131 laid in the vehicle 102 includes a special high-voltage cable straight connection 402 in the vehicle 102, a special high-voltage cable 136 for connection, and a special high-voltage cable straight connection 401 in the vehicle 101. To the special high voltage cable 137 laid in the vehicle 101. In the vehicle 101, the core wire of the special high voltage cable 137 is connected to one terminal of the vacuum circuit breaker 113, and the other terminal of the vacuum circuit breaker 113 is connected to one terminal of the primary winding of the main transformer 116. . The other terminal of the primary winding of the main transformer 116 is connected to the ground wire 301, and the ground wire 301 is grounded to the vehicle body of the vehicle 101 by the ground resistor 151. The vehicle body ground of the vehicle 101 is connected to the vehicle body ground of the vehicle 102 by a connection cable 311 and a connection cable 312. In the vehicle 102, the ground wire 302 is grounded to the vehicle body of the vehicle 102 by the ground resistor 152.
[0019]
The special high-voltage cable 133 laid in the vehicle 103 is connected to the special high-voltage cable straight line connection 403 in the vehicle 103, the connection special high-voltage cable 138, and the special high-voltage cable straight line connection 404 in the vehicle 104. The special high voltage cable 134 laid in the vehicle 104 is connected. In the vehicle 103, the core wire of the special high voltage cable 132 is connected to one terminal of the vacuum circuit breaker 114, and the other terminal of the vacuum circuit breaker 114 is connected to one terminal of the primary winding of the main transformer 117. . The other terminal of the primary winding of the main transformer 117 is connected to the ground wire 303, and the ground wire 303 is grounded to the vehicle body of the vehicle 103 by the ground resistor 153. The vehicle body ground of the vehicle 103 is connected to the vehicle body ground of the vehicle 102 by the connection cable 313, and is connected to the vehicle body ground of the vehicle 104 by the connection cable 314 and the connection cable 315. In the vehicle 104, the ground wire 304 is grounded to the vehicle body of the vehicle 104 by the ground resistor 154.
[0020]
In the vehicle 105, the core wire of the special high voltage cable 135 is connected to one terminal of the vacuum circuit breaker 115, and the other terminal of the vacuum circuit breaker 115 is connected to one terminal of the primary winding of the main transformer 118. ing. The other terminal of the primary winding of the main transformer 118 is connected to a ground wire 305, and the ground wire 305 is grounded to the vehicle body of the vehicle 105 by a ground resistor 155. The vehicle body ground of the vehicle 105 is connected to the vehicle body ground of the vehicle 104 by a connection cable 316, and is connected to the vehicle body ground of an adjacent vehicle not shown by the connection cable 317 and the connection cable 318.
[0021]
In the above configuration, the vehicle bodies of the vehicles 101 to 105 are connected to the grounding wires 301 to 305 via the grounding resistors 151 to 155, respectively. And the grounding circuit is comprised from the wheel shaft of each wheel 202 to the rail 100 via the earthing | grounding apparatus 203,203, ... which consists of an earth brush, a slip ring, etc. from the earthing wires 301-305.
[0022]
When the pantographs 111 and 112 are raised and brought into contact with the overhead wire with respect to the vehicle body as described above, or are lowered and separated, the core wire 141 of the extra high voltage cables 131 to 138 is suddenly brought into contact with or separated from the body. A voltage change occurs and a high voltage is induced in the shield 142. Since the shield 142 is connected (grounded) to the vehicle body, a potential is generated in the vehicle body, a ground current flows transiently between the vehicle body and the rail 100 for a short time, and a surge voltage due to the ground current is generated in the vehicle body. At this moment, a surge voltage due to the ground current is applied to the in-vehicle device mounted on the vehicle body and grounded. When using high-voltage power accompanying the speeding up of the vehicle, depending on the magnitude of the surge voltage, breakdown may occur in weakly insulated parts depending on the situation, and the equipment may be damaged or malfunction. Therefore, reducing the surge voltage is an important issue.
[0023]
Therefore, in this embodiment, the grounding resistors 151 to 155 provided between the grounding wires 301 to 305 that connect the grounding devices 203, 203,... And the vehicle body grounds of the vehicles 101 to 105. By managing the frequency characteristics within a predetermined range, the generation of surge voltage is reduced. That is, the impedance of the ground resistors 151 to 155 in a low frequency region such as a direct current or a commercial frequency region is set and managed within a predetermined range, and an impedance change at a high frequency (for example, a frequency range of about 10 kHz to 1 MHz) is less than a predetermined value. (Or to have a flat characteristic), the surge voltage is reduced. The management of impedance at high frequency is managed not only at the design stage, but also during the manufacturing process, when actually manufacturing a train organization having the structure shown in FIG. 1, or during inspection of each vehicle during manufacturing or when it is completed. It is desirable to implement.
[0024]
An important factor for reducing impedance in the high frequency range is to reduce the inductance determined by the number of magnetic fluxes linked to the outside of the resistor and the magnetic permeability of the medium, and the skin produced by the effect of the inductance inside the resistor. It is thought that the influence of the effect is kept small. That is, the shape of the current circuit (current path) flowing through the resistor is set so as not to increase the number of magnetic fluxes linked to the circuit as much as possible when the current flows through the circuit, and the circuit. It is considered to be important to set the magnetic permeability of the medium of magnetic flux interlinking with the resistor so as not to increase as much as possible and to set the resistor so as not to increase the internal inductance as much as possible. In order to solve these problems, for example, the shape of the resistor is kept as short as possible in the direction in which the current flows, and is linear, that is, perpendicular to the direction in which the current flows, such as a rectangular parallelepiped or an elliptic cylinder. In order to achieve a three-dimensional shape with a central axis and to suppress the skin effect, the thickness and thickness of the cross section of the resistor should be kept small, and the material of the resistor should be made as small as possible in terms of permeability. It is important to design Furthermore, it is required to satisfy the characteristics of the allowable current with respect to the ground current and to have environmental resistance characteristics such as earthquake resistance, water resistance, and fire resistance suitable for use in a railway vehicle.
[0025]
The material of the resistor (resistor) is a substance or a composite that can realize a desired resistance value in a direct current or low frequency range, and its magnetic characteristics are strong such as iron, nickel, cobalt, etc. Aluminum, palladium, platinum, which is not a magnetic material or a composite of ferromagnetic materials mainly composed of these substances, but is a non-magnetic material (here, a non-ferromagnetic material is a non-magnetic material) It is preferable to use a paramagnetic material such as silver, lead, copper, carbon, silicon, or a diamagnetic material, or a composite thereof. Further, as a shape dimension, a length of ½ of the thickness (or diameter) of the cross section of the resistor is a standard length in which the influence of the skin effect becomes remarkable, the skin thickness δ = √ (2 / Μσω) or less (where μ is the magnetic permeability of the resistor, σ is the electrical conductivity of the resistor, and ω is the angular frequency of the electromagnetic field).
[0026]
More specifically, it is desirable to use a non-magnetic material that satisfies the electrical and structural requirements of the shape described above as the material of the resistor. As an example of such a material, for example, there is a silicon carbide sintered body described in Japanese Patent Application Laid-Open Nos. 2001-76902 and 2001-244103.
[0027]
In addition, as a grounding resistor made of another material of a non-magnetic material, for example, a resistor composed of stainless steel formed by containing iron with about 10% or more chromium or a carbon resistor can be considered. However, when the grounding resistor is made of stainless steel, the electrical conductivity of the stainless steel is relatively high, so that a certain length is required to satisfy the desired allowable current value and to obtain the desired resistance value. However, it is difficult to keep the inductance of the grounding resistor low. In addition, in a grounding resistor using carbon or a composite material of carbon and aluminum oxide, since the carbon itself is hygroscopic, the resistance value is not stable due to the influence of moisture, and the mechanical strength is also low. In applications where vibrations such as vehicles occur, there is a problem that damage such as cracking or chipping occurs in some cases.
[0028]
FIG. 2 is a comparison of the measured value of the frequency characteristics (solid line) of the ground resistors 151 to 155 formed of the silicon carbide sintered body as an example of the present embodiment with the characteristic of the conventional resistor (broken line). In the figure, the horizontal axis is a logarithmic value of a frequency of 10 Hz to 10 MHz, and the vertical axis is a logarithmic value of an impedance (Ω). As a conventional resistor, a resistor formed of a non-magnetic corrosion-resistant stainless material made of iron, chromium, and aluminum was used. In the example shown in FIG. 2, both have an impedance of about 0.45Ω in the commercial frequency range, whereas in the ground resistor of this embodiment, the frequency is about 0.46Ω at 700 kHz and about 0.53Ω at 1 MHz. As compared with the conventional resistors having a resistance of about 43Ω and about 65Ω, respectively, a significant improvement in characteristics is achieved in a high frequency region of 1 MHz or less.
[0029]
In the example shown in FIG. 2, in the conventional resistor, the inductivity tends to increase as the frequency becomes higher in the frequency range of 1 kHz to 700 kHz. When a resistor having such characteristics is used, resonance with a stray capacitance of a vehicle or the like may be caused depending on conditions. In that case, it is considered that the high frequency component of the frequency increases near the resonance point, and the surge voltage increases. However, when the frequency characteristics of the ground resistor are managed at the design and manufacturing stage as in this embodiment, it is possible to easily prevent the influence of such resonance.
[0030]
Next, the effect of reducing the surge voltage according to the present embodiment will be described with reference to FIG. FIG. 3 shows a case where the low induction type grounding resistors 151 to 155 of the present embodiment are connected between the vehicle body and the grounding wires 301 to 305, and the grounding resistor 151 to the continuous rectangular traveling wave propagating through the vehicle body. It is a figure which shows the composite wave of the incident voltage wave (abnormal voltage) and reflected voltage wave which arrives at the connection point P of 155, and the transmitted voltage wave. In FIG. 3, (a) is a diagram showing a state before the surge voltage (incident wave) arrives at the connection point P, and (b) shows the surge voltage (incident wave) arrives at the connection point P. It is a figure which shows a state when an incident wave continues after the transmitted wave and the reflected wave generate | occur | produced.
[0031]
In the circuits shown in FIGS. 3A and 3B, the incident wave voltage at the connection point P is E1, the transmitted wave voltage is E2, the reflected wave voltage is E3, and the surge impedance of the line before and after the connection point P is shown. When Z0 and the resistance value of the ground resistor are R, the transmitted wave voltage E2 is given by E2 = 2R · E1 / (2R + Z0), and the reflected wave voltage E3 is given by E3 = −Z0 · E1 / (2R + Z0). Here, if the ground resistors 151 to 155 are 0 (= R), the voltage E2 is 0. When the ground resistors 151 to 155 are ∞ (= R), the voltage E2 is equal to E1.
[0032]
As in this embodiment, when the connection point P is grounded with the grounding resistors 151 to 155 in which the impedance value in the high frequency region is controlled to be equal to or lower than a predetermined value, the grounding resistors 151 to 155 are used during traveling. While suppressing the inflow of ground current to the vehicle body side, it is easy to suppress incoming waves that arrive continuously due to reflected waves from the connection point P and to suppress transmitted waves that pass from the connection point P to the vehicle body end. It becomes possible. In this case, the same transmitted voltage wave propagates to the ground resistor at the same time.
[0033]
The embodiment of the present invention is not limited to the above-described configuration. For example, the train organization method, the arrangement of each device, pantograph, special high-voltage cable, grounding wire, grounding device, and grounding resistor The number can be changed, increased or increased / decreased as appropriate.
[0034]
Further, when considering a manufacturing method of a railway vehicle as an aspect of the present invention, for example, a process of connecting a ground wire to a grounding device in each vehicle and an impedance in a high frequency region (for example, a region of about 10 Hz to 700 kHz or about 1 MHz or less) Or a predetermined range within the above range, or a process of connecting the ground wire to the vehicle body ground of the vehicle by a controlled grounding resistor so as to have a flat characteristic or less. Like that. In addition to these processes, in the high frequency region between the ground wire and the vehicle body ground (for example, a frequency within a predetermined range within 10 Hz to 700 kHz, a frequency of about 1 MHz or less, or one or a plurality within a predetermined range thereof) And measuring the ground impedance (at the frequency point).
[0035]
【The invention's effect】
In the present invention as described above, by using a low induction type grounding resistor, an abnormal high voltage generated in the vehicle body when the pantograph is in contact with or away from the overhead wire when the pantograph is raised or lowered is reduced. Can do.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing a configuration of an embodiment of a railway vehicle according to the present invention.
FIG. 2 is a characteristic diagram showing an example of frequency characteristics of the ground resistors 151 to 155 in FIG. 1;
3 is an explanatory diagram for explaining the effect of surge voltage suppression by the ground resistors 151 to 155 of FIG. 1, in which (a) is a state before an incident wave arrives at a connection point P, and (b) is an illustration. The state after arrival is shown.
[Explanation of symbols]
100 Rails 101 to 105 Vehicles 111 to 112 Pantographs 131 to 138 Special high voltage cables 151 to 155 Grounding resistor 201 Carriage 202 Wheel 203 Grounding devices 301 to 305 Grounding wire

Claims (2)

A vehicle comprising a plurality of grounding devices for electrically connecting an axle and a carriage,
A grounding wire for connecting the grounding devices to each other;
The grounding wire is connected to the vehicle body ground of the vehicle, and includes a grounding resistor formed of a silicon carbide sintered body and managed so as to have a flat frequency characteristic at 10 Hz to 1 MHz. A railway vehicle characterized by 1/2 of the cross-sectional thickness dimension of the ground resistor or 1/2 of the diameter dimension is
  δ = √ (2 / μσω)
  (Where δ is the skin thickness, μ is the permeability of the grounding resistor, σ is the electrical conductivity of the grounding resistor, and ω is the angular frequency of the electromagnetic field)
  The railway vehicle according to claim 1, wherein the thickness is set to be equal to or less than a skin thickness δ calculated by the following formula.

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