JP6431430B2 - Electric railway system and electric car - Google Patents

Description

  The present invention relates to an electric railway system and an electric vehicle for supplying electric power to the electric vehicle.

  In an electric railway system that supplies electric power to an electric vehicle, generally, three-phase AC power, which is multiphase AC power, is supplied to the electric vehicle. In the electric vehicle, a diode rectifier, an AC-DC converter, a thyristor Leonard, or the like is used. Three-phase AC power is converted to DC power.

  When converting three-phase AC power to DC power, large harmonics may be generated. In particular, when a diode rectifier or a thyristor Leonard is used, a large harmonic wave that is difficult to be removed even if a filter is used is generated, and the burden on the feeder side that supplies power to the electric vehicle is significantly increased. Therefore, techniques for reducing harmonics are being studied.

  For example, Patent Document 1 discloses a phase transformer that generates three sets of three-phase AC voltages each having a phase difference of 20 degrees, and three rectifiers that convert each of the generated three sets of three-phase AC voltages into DC voltages. And a rectifier that reduces harmonics by combining outputs of three rectifier circuits. By mounting such a rectifier on an electric vehicle, a DC voltage with reduced harmonics can be obtained.

JP 2005-287251 A

  In general, the phase transformer as provided in the rectifier disclosed in Patent Document 1 has a large mass. For this reason, when a rectifier equipped with a phase transformer is mounted on an electric vehicle, the vehicle mass of the electric vehicle increases and it becomes difficult to drive the electric vehicle. Therefore, there is a problem that the rectifier disclosed in Patent Document 1 is difficult to apply to an electric vehicle.

  The objective of this invention is providing the electric railway system and electric vehicle which can solve the subject mentioned above and can reduce a harmonic more easily.

  In order to solve the above problems, an electric railway system according to the present invention is an electric railway system that supplies electric power to an electric vehicle, and includes a transformer that generates a plurality of multiphase AC powers having different phases from the multiphase AC power. The electric vehicle is configured to collect a plurality of multiphase AC power generated by the transformer, and to convert each of the plurality of multiphase AC power collected by the current collector into DC power, A conversion unit that combines and outputs the converted DC powers.

  Moreover, in the electric railway system according to the present invention, it is preferable that the transformer generates two three-phase AC powers whose phases are shifted by 60 degrees.

  In order to solve the above problems, an electric vehicle according to the present invention includes a current collector that collects a plurality of multiphase AC powers having different phases, and a plurality of multiphase AC powers collected by the current collectors, respectively. Is converted to DC power, and a conversion unit that combines and outputs the converted DC power is provided.

  In the electric vehicle according to the present invention, it is preferable that the plurality of multiphase AC powers are two three-phase AC powers whose phases are shifted by 60 degrees.

  According to the electric railway system and the electric vehicle according to the present invention, harmonics can be reduced more easily.

It is a figure which shows the structure of the electric railway system which concerns on one Embodiment of this invention. It is a front view of the electric vehicle shown in FIG. It is a figure which shows an example of the output waveform of the converter shown in FIG.

  Embodiments of the present invention will be described below.

  FIG. 1 is a diagram showing a configuration of an electric railway system 1 according to an embodiment of the present invention.

  The electric railway system 1 shown in FIG. 1 includes a transformer 12 and an electric vehicle 20.

  The transformer 12 is a feeder-side device that is provided on the ground side and supplies power to the electric vehicle 20. The electric vehicle 20 operates by receiving power supply from the transformer 12.

  The transformer 12 steps down the three-phase AC power output from the AC power supply 11 that outputs the three-phase AC power, which is multiphase AC power, and generates two three-phase AC powers having different phases, and the electric wires 13a, The electric vehicle 20 is supplied via 13b. Normally, the three-phase AC power output from the AC power supply 11 is very high voltage.

  Specifically, the transformer 12 has a three-phase transformer 12a in which the primary side is Y-connected and the secondary side is Δ-connected (Y-Δ connection), the primary side is Y-connected, and the secondary side is Y-connected (Y-Y). Connected) three-phase transformer 12b. Three-phase current power output from the AC power supply 11 is input to the three-phase transformer 12a and the three-phase transformer 12b, respectively. Since the three-phase transformer 12a is Y-Δ-connected and the three-phase transformer 12b is Y-Y-connected, the three-phase AC power P output from the three-phase transformer 12a and the three-phase AC output from the three-phase transformer 12b The phase is shifted 60 degrees from the electric power P ′.

  The three-phase AC power P output from the three-phase transformer 12a is supplied to the electric vehicle 20 via the electric wire 13a. Further, the three-phase AC power P ′ output from the three-phase transformer 12b is supplied to the electric vehicle 20 through the electric wire 13b. As described above, the two three-phase AC powers P and P ′ having different phases output from the transformer 12 are supplied to the electric vehicle 20 via the electric wires 13a and 13b, respectively.

  FIG. 2 is a front view of the electric vehicle 20. In FIG. 2, an example is shown in which a side current collecting method for collecting current from an electric wire arranged on a side of a rail on which the electric vehicle 20 travels is used as a current collecting method for the electric vehicle 20.

  When the side current collecting method is used, the electric wires 13a and 13b are arranged along two rails (not shown) on which the electric vehicle 20 travels. The electric wire 13a is arranged along one of the two rails on which the electric vehicle 20 travels, and includes electric wires U, V, and W corresponding to the three phases of the three-phase AC power P. The electric wire 13b is arranged along the other of the two rails on which the electric vehicle 20 travels, and includes electric wires U ', V', and W 'corresponding to the three phases of the three-phase AC power P'.

  The electric vehicle 20 includes a current collector 21 and a converter 22.

  The current collector 21 includes current collectors 21a and 21b. The current collectors 21a and 21b collect the three-phase AC power P and P ′ output from the transformer 12 via the wires 13a and 13b.

  The current collector 21a is provided on the electric wire 13a side, and collects the three-phase AC power P from the electric wire 13a. The current collector 21b is provided on the electric wire 13b side, and collects the three-phase AC power P ′ from the electric wire 13b.

  The converter 22 converts the three-phase AC power P and P ′ collected by the current collector 21 into DC power, combines the converted DC power, and supplies the combined DC power to the load of the electric vehicle 20. Note that the DC power output from the converter 22 may be converted into AC power by an inverter (not shown) and supplied to a main motor that drives the electric vehicle 20 or the like.

  The conversion unit 22 includes rectifiers 22a and 22b. The rectifier 22a converts the three-phase AC power P collected by the current collector 21a into DC power and outputs it. The rectifier 22b converts the three-phase AC power P ′ collected by the current collector 21b into DC power and outputs it. Then, the output of the rectifier 3 a and the output of the rectifier 3 b are combined and output from the converter 22. As the rectifiers 22a and 22b, a diode rectifier, an AC-DC converter, a thyristor Leonard, or the like can be used.

  Normally, when the side current collecting system is used, the electric vehicle 20 has a current collecting device on both sides of the vehicle corresponding to each of the two rails in order to cope with the turning operation in the upward direction and the downward direction. Is provided. Therefore, in the present embodiment, it is not necessary to newly provide a current collector in the electric vehicle 20 in order to collect the three-phase AC powers P and P ′ having different phases, and an increase in the number of parts of the electric vehicle 20 is suppressed. can do.

  Further, usually, in the side current collecting system, an electric wire for supplying power to the electric vehicle 20 is often provided corresponding to one of the two rails (for example, the rail on the side away from the home). However, it is not particularly difficult to provide the electric wires 13a and 13b corresponding to the two rails as in this embodiment.

  FIG. 3 is a diagram illustrating an example of an output current waveform of the conversion unit 22 at a point A illustrated in FIG. In FIG. 3, the current waveform when the method according to the present embodiment is used is indicated by a solid line, and for comparison, a conventional method (method of converting one three-phase AC power into DC power) is used. The current waveform in the case of being present is indicated by a broken line. In FIG. 3, description of the DC component is omitted, and only the distortion component (harmonic component) is shown.

  As shown in FIG. 3, in the method according to the present embodiment, the number of distortion component peaks (frequency at which peaks appear) increases compared to the case where the conventional method is used. Reduce (eg, halve). In general, it is known that the distortion rate of current is as large as about 20% in the conventional method. On the other hand, as a result of examination by the inventors of the present application, it was found that the strain rate can be reduced to about 5% by reducing the peak in the method according to the present embodiment.

  In the system according to the present embodiment, a plurality of three-phase AC powers having different phases are generated by the transformer 12 provided on the ground. Therefore, since it is not necessary for the electric vehicle 20 to have a configuration such as a phase transformer for generating a plurality of three-phase AC powers having different phases, the method according to this embodiment can be easily applied to the electric vehicle 20. Therefore, harmonics can be reduced more easily.

  In addition, according to the method according to the present embodiment, it is possible to use an inexpensive filter as compared with the conventional method as a filter for removing the harmonics provided on the feeding side by reducing the peak of the harmonics. it can.

  In the present embodiment, the example in which the phase difference between the three-phase AC powers P and P ′ is 60 degrees has been described. However, the present invention is not limited to this. The phase difference between the three-phase AC powers can be an arbitrary value as long as it is allowed in the electric railway system 1.

  Moreover, although this embodiment demonstrated using the example which supplies the two three-phase alternating current electric power from which a phase differs to the electric vehicle 20, it is not restricted to this. The number N of the three-phase AC powers with different phases supplied to the electric vehicle 20 may be three or more. When the number of three-phase AC powers with different phases supplied to the electric vehicle 20 is N, the harmonics can be reduced most by setting the phase difference of each three-phase AC power to 120 / N degrees. .

  Thus, according to the present embodiment, the electric railway system 1 includes the transformer 12 that generates a plurality of multiphase AC powers having different phases from the multiphase AC power output from the AC power supply 11. The electric vehicle 20 collects a plurality of multi-phase AC power generated by the transformer 12 and converts each of the plurality of multi-phase AC powers collected by the current collector 21 into DC power. And a conversion unit 22 that combines and outputs each DC power.

  A plurality of multiphase AC powers having different phases are generated on the feeding side, and the electric vehicle 20 makes it difficult to drive the electric vehicle 20 by converting and synthesizing each multiphase AC power into DC power. Harmonics can be reduced more easily without causing an increase in vehicle mass.

  Although the present invention has been described based on the drawings and embodiments, it should be noted that those skilled in the art can easily make various variations or modifications based on the present disclosure. Therefore, it should be noted that these variations or modifications are included in the scope of the present invention. For example, functions included in each block or the like can be rearranged so that there is no logical contradiction, and a plurality of blocks can be combined into one or divided.

DESCRIPTION OF SYMBOLS 1 Electric railway system 11 AC power supply 12 Transformer 13 Supply means 13a, 13b Electric wire 12a, 12b Three-phase transformer 20 Electric vehicle 21 Current collection part 21a, 21b Current collection apparatus 22 Conversion part 22a, 22b Rectifier

Claims (4)

An electric railway system for supplying electric power to an electric vehicle,
A transformer is provided on the ground side and generates a plurality of multiphase AC powers having different phases from the multiphase AC power,
The electric car is
A current collector that collects a plurality of multiphase AC power generated by the transformer;
A converter that converts each of the plurality of multiphase AC powers collected by the current collector into DC power, and combines and outputs the converted DC powers;
An electric railway system comprising: The electric railway system according to claim 1,
The electric railway system, wherein the transformer generates two three-phase AC powers whose phases are shifted by 60 degrees. A current collector that collects a plurality of multiphase AC powers having different phases;
A converter that converts each of the plurality of multiphase AC powers collected by the current collector into DC power, and combines and outputs the converted DC power;
An electric vehicle comprising: The electric vehicle according to claim 3,
The plurality of multi-phase AC powers are two three-phase AC powers whose phases are shifted by 60 degrees.

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