JP2010058565A - Power converter and electric railroad system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently use regenerative electric power without increasing facility cost by reducing capacity of an expensive power storage device. <P>SOLUTION: The direct current power converter, which is a component of a power converter, converts direct current power in response to a direct current power feeder voltage to transfer the direct current power between the direct current power converter and the direct current power feeder. A power storage device is connected to the direct current power converter and stores power input from the power feeder via the direct current power converter, and the stored power is output to the power feeder. An AC-DC power converter connected between an alternate power supply of a power distribution system and the power storage device converts alternate current power to the direct current power. This configuration allows to efficiently store regenerative electric power and use the stored regenerative electric power as running electric power without increasing facility cost. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power converter that has a power storage device, absorbs power from a feeder line, or supplies power to the feeder line, and an electric railway system including such a power converter.

  In recent years, in an electric railway system that supplies direct current power from a substation to an electric vehicle, the electric vehicle uses a regenerative brake for the purpose of power saving. This regenerative brake converts the kinetic energy of the electric vehicle into electric energy by an in-vehicle inverter to decelerate the electric vehicle, and this electric energy is released as regenerative power to the electric wire. The regenerative power released to the feeder is consumed by being taken into another electric vehicle and converted from electric energy to acceleration energy. Thus, energy saving of the electric railway system is made by performing mutual conversion between kinetic energy and electric energy through regenerative electric power.

  As an example of such an electric railway system, in the power running mode in which the DC electric vehicle is accelerated, the stored power of the secondary battery is discharged and consumed in the DC electric vehicle, and in the regenerative mode in which the DC electric vehicle is decelerated, the DC There has been proposed a DC substation system for electric railway that charges rechargeable power generated in an electric vehicle to a secondary battery (see paragraph “0012” of FIG. 5, FIG. 5 and the like).

  In addition, a rectifier that rectifies alternating current into direct current, and a circuit that is connected in parallel with the rectifier and in which an electric double layer capacitor and a chopper are connected in series, and the electric charge charged in the electric double layer capacitor, There is known a charging facility for an electric vehicle that supplies an electric vehicle including an electric double layer capacitor and a power conversion unit having a regeneration function (see, for example, Patent Document 2).

  Moreover, in an electric railway system, by installing a power regeneration device having a power storage device in the feeder, it is possible to suppress an increase in the punter point voltage during regeneration. It is also known that in places where it is necessary to slow down the speed of a vehicle, a decrease in the punter point voltage can be suppressed by discharging from the power storage device.

JP-A-11-91415 JP 2006-232102 A

  However, since the amount of powering power is larger than the amount of regenerative power, in order to support the absorption of regenerative power and the supply of powering power with the same power storage device, it is commensurate with the powering power amount. There is a problem that a large power storage capacity is required, and the power storage medium is large and expensive.

  An object of the present invention is to provide an economical power conversion device and an electric railway system that can process both regenerative energy and powering energy without increasing the capacity of an expensive power storage device.

  In order to solve the above problems, a power conversion device of the present invention is a power conversion device including a power storage device, and is connected to a feeder, and the power input from the feeder according to the feeder voltage is DC power having a voltage lower than the feeder voltage is converted and output to the power storage device, or DC power having a voltage lower than the feeder voltage is converted to DC power having the feeder voltage and the feeder A direct current power converter that outputs power to an AC power source of a distribution system, an AC / DC converter that converts AC power into DC power, and a DC power converter that is connected between the DC power converter and the AC / DC converter. The power that stores power by receiving power from the AC power supply of the power distribution system via the AC / DC converter and performing power transfer with the feeder via the power converter By controlling the direct-current power converter according to the storage device and the voltage of the feeder line, the power transmission and reception between the feeder line and the power storage device is controlled, and the distribution system And a control device that performs control to output power from the AC power source to the DC feeder via the power storage device.

  An electric railway system according to the present invention is an electric railway system that includes an electric vehicle that travels by inputting electric power from a feeder, and outputs regenerative electric power to the feeder during regenerative operation, a transformer, and a power converter. The transformer is connected to a first AC power source having a first AC voltage, converts AC power having the first AC voltage into DC power having a feeder voltage, Inputting the first AC / DC power converter to output, the DC power output from the first AC / DC power converter and the regenerative power output from the feeder, and storing the power, the first A first power storage device for smoothing the output from the AC / DC power converter to the feeder line, the power converter device being connected to the feeder line and having direct current power and the wire voltage. Straight with lower voltage A DC power converter that mutually converts DC power between the power and the DC power converter, and the regenerative power is input from the feeder through the DC power converter during the regenerative operation of the electric vehicle. A second power storage device for storing and outputting the stored power to the feeder through the DC power converter during powering operation of the electric vehicle; and a second AC voltage lower than the first AC voltage. A second AC power supply having the second AC power storage device, the AC power having the second AC voltage being converted into DC power, and during the power running operation of the electric vehicle, The second AC / DC power converter for replenishing the stored power amount of the second power storage device and the output power amount from the second power storage device to the feeder line, and the DC power converter are controlled. thing More comprises a second power storage device, and said second AC-DC power converter, and a control device for controlling the transfer of power between the-out wire.

  Advantageous Effects of Invention According to the present invention, a power conversion device and an electric railway that efficiently absorb and store regenerative power of an electric vehicle, re-output it to a feeder, and save power and reduce the operating cost of the electric vehicle. A system can be provided.

  In addition, it is possible to reduce the number of substations by increasing the installation interval of substations that are connected to an extra high voltage transmission system and are expensive. it can.

  Furthermore, stable operation of the electric vehicle can be realized by suppressing an increase in the feeder voltage during the regenerative operation of the electric vehicle and a decrease in the feeder voltage during the power running operation of the electric vehicle.

  Embodiments of the present invention (hereinafter sometimes referred to as “present examples”) will be described below with reference to the drawings. The same components are denoted by the same reference numerals, and the description thereof is omitted.

First, a power converter according to a first embodiment of the present invention will be described with reference to FIG.
The power conversion device 1 of this example will be described from the feeder 3 side. The power conversion device 1 includes a DC power conversion device 16, a power storage device 8, an AC / DC power conversion device 17, and a control device 200.
The DC power converter 16 is an apparatus that is connected to the DC feeder 3 and the rail 4, converts DC power according to the DC feeder voltage, and exchanges DC power with the DC feeder. The power storage device 8 is connected to the DC power conversion device 16 and stores power by inputting power from the feeder via the DC power conversion device 16 in accordance with the DC feeder voltage and supplying the stored power to the feeder. It is the device which outputs to. The AC / DC power converter 17 is connected between the AC power supply 2 and the power storage device 8 of the distribution system, and converts AC power into DC power.

  In the power conversion device of this example, the power storage device 8 is set so that the voltage between the feeder 3 and the rail 4 (hereinafter referred to as “feeder voltage”) matches the DC voltage command value which is a predetermined value. By controlling the input / output power and the power received from the AC power supply of the distribution system, fluctuations in the feeder voltage are suppressed. Here, the voltage of the AC power source of the distribution system is, for example, 6.6 kV to 3.3 kV, and the DC feeder voltage is, for example, 700V.

  Next, each apparatus which comprises the power converter device 1 of this example is demonstrated. The DC power converter 16 includes a filter reactor 9, a capacitor 11, a step-up / down chopper circuit 20, and a boosting reactor 10 in order from the feeder line side. The step-up / step-down chopper circuit 20 is configured by connecting IGBT elements 11m and 11n in series. Here, the IGBT elements 11m and 11n refer to a circuit constituted by the IGBT shown in FIG. 1 and a diode connected in antiparallel to these IGBTs.

  The power storage device 8 includes a secondary battery 8. As the secondary battery 8, for example, a lithium ion battery mounted on a hybrid vehicle may be used. In the following, each embodiment of the present invention will be described using a secondary battery as the power storage device 8 as an example. In each embodiment of the present invention, a capacitor for storing power is used instead of the secondary battery. You can also.

  The power storage device 8 is connected between the DC power conversion device 16 and the AC / DC power conversion device 17. Secondary battery 8 is connected to a terminal for connecting IGBT elements 11m and 11n in series via step-up reactor 10 on the DC power converter 16 side.

  The AC / DC power converter 17 is connected to the transformer 5 connected to the power distribution system 2, the circuit breaker 6 connected to the transformer 5 and interrupting the current, and connected to the circuit breaker 6 and in parallel to the secondary battery 8 on the output side. And a diode rectifier 7 connected to the.

  And in the electric railway system of this invention, the power converter device 1 is provided with the control apparatus 200, and controls the direct-current power converter device 16 through the 2nd power storage device 8 and the 2nd AC / DC power converter device 17. And the transmission and reception of electric power to and from the feeder 4 are controlled.

  In the power conversion device 1 according to the first embodiment of the present invention, the terminal voltage of the capacitor 11 is first detected by the voltage sensor 30. The voltage value detected by the voltage sensor 30 is compared with a DC voltage command value that is set to a predetermined value in advance. During power running of an electric vehicle (not shown), the electric vehicle obtains electric power from the feeder. Along with this, the feeder voltage decreases, and the voltage value detected by the voltage sensor 30 becomes smaller than the DC voltage command value.

  As described above, when the voltage value detected by the voltage sensor 30 is smaller than the DC voltage command value, the power conversion device 1 determines the IGBT element 11m of the chopper circuit 20 based on the gate signal output from the control device 200. By switching 11n and boosting the output voltage of the secondary battery 8, the electric power obtained from the secondary battery 8 or the diode rectifier 7 is output to the feeder line side. Thereby, the fall of feeder voltage is suppressed.

  During regenerative operation of an electric vehicle (not shown), the electric vehicle discharges regenerative power to the feeder. Thereby, the feeder voltage rises and the terminal voltage of the capacitor 11 also rises. Along with this, the voltage value detected by the voltage sensor 30 becomes larger than the DC voltage command value. As described above, when the detection value of the voltage sensor 30 is larger than the DC voltage command value, the power conversion device 1 absorbs power from the feeder 3 and steps down the power by switching the chopper circuit 20 to perform secondary operation. Charge the battery 8. Thereby, the rise in feeder voltage is suppressed.

  Next, the control operation of the power conversion device 1 will be described below with reference to FIG. In the control device 200 of the power conversion device 1, the voltage value detected by the voltage sensor 30 and the DC voltage command value set in advance to a predetermined value are input to the subtractor 201. Then, the subtractor 201 calculates a voltage deviation between the DC voltage command value and the terminal voltage of the capacitor 11.

  This voltage deviation is output to the voltage controller (AVR) 202. Then, the voltage controller (AVR) 202 performs a PI operation so that the voltage deviation is zero, and calculates a current command value that is the sum of the output currents of the secondary battery 8 and the diode rectifier 7.

  The current command value is output to the limiter 203. The limiter 203 performs an upper / lower limiter calculation using the lower limit value of the current command value as the device rated charging current value, the upper limit value as an output value of a divider 206, which will be described later, and the output as a new current command value. Output to.

  The subtractor 207 calculates a current deviation between the new current command value and the detected value of the current sensor 31, and outputs this current deviation to the current controller (ACR) 208. The current controller 208 performs a PI operation so that the deviation between the current command value and the detection value of the current sensor 31 is zero, calculates a command value of the input voltage Vin of the chopper circuit 20, and outputs the command value to the PWM controller 209. .

  The PWM controller 209 receives the output of the current controller (ACR) 208 and the triangular wave that is the output of the carrier generator 210 as inputs, the output of the current controller 208 as a modulated wave, and the output of the carrier generator 210 as a carrier wave. PWM calculation is performed, and gate signals of the IGBT elements 11m and 11n of the chopper circuit 20 are output. These gate signals are input to the IGBT gates of the IGBT elements 11m and 11n, and the IGBT elements perform a switching operation according to the gate signals.

  Thereby, in the power converter device 1 of this example, the sum of the output currents of the secondary battery 8 and the diode rectifier 7 can be made to follow the current command value. This current command value is a value calculated so that the terminal voltage of the capacitor 11 matches a predetermined value. Therefore, the power converter 1 can control the output current of the secondary battery 8 or the diode rectifier 7 so that the terminal voltage of the capacitor 11 is constant.

  In the steady state, the terminal voltage of the capacitor 11 matches the feeder voltage of the feeder 3. Therefore, the power conversion device 1 detects the terminal voltage of the capacitor 11 using the voltage sensor 30 and controls the charge / discharge of the secondary battery 8 and the current flow from the diode rectifier 7. Thereby, the feeder voltage can be maintained at a predetermined value.

  Next, a method for calculating the upper limit value of the limiter 203 in this example will be described. The function of the limiter 203 in this example is to limit the output power of the rectifier 7 so as to be a predetermined value or less. Moreover, in the power converter device of this example, the AC / DC power converter device 17 is connected to a power distribution system that is relatively easy to install, and receives AC power from the power distribution system.

  However, in receiving power from the distribution facility side, there is a limit to the power capacity that can be received from the distribution system and supplied to the electric wires because the transmission capacity of the distribution system is limited. For example, the power transmission capacity of one feeder of a distribution substation is about 2 MW, but the required supply power to the feeder line is almost more than 3 MW. For this reason, the power supplied from the power distribution system, that is, the output power of the rectifier, is limited to the transmission capacity of the distribution system or less, and the power supply from the power distribution system to the power line exceeds the power transmission capacity of the power distribution system. It is necessary to prevent this.

  Further, the output current of the diode rectifier 7 is detected by the current sensor 33. The terminal voltage of the secondary battery 8 equal to the output voltage of the diode rectifier 7 is detected by the voltage sensor 32. The detection values detected by the current sensor 33 and the voltage sensor 32 are multiplied by the multiplier 204, and the output power value of the diode rectifier 7 is obtained.

  A predetermined maximum rectifier output value determined from the output power value of the diode rectifier 7 and the capacity of the distribution system is input to the output power regulator 205. The output power adjuster 205 calculates and outputs an adjustment value of the output power upper limit value of the power conversion device 1 so as to keep the output power of the diode rectifier 7 below the rectifier output maximum value.

  The output of the output power adjuster 205 is input to the divider 206. The terminal voltage of the secondary battery 8 is also input to the divider 206. Then, the divider 206 calculates a value obtained by dividing the output of the output power adjuster 205 by the terminal voltage of the secondary battery 8 and outputs the value to the limiter 203.

  With the above calculation, in the power conversion device 1 of this example, the output power of the diode rectifier 7 can be limited to a predetermined value or less.

  Next, the calculation of the output power adjuster 205 used in this example will be described with reference to FIG. First, the output power of the rectifier 7 is input to the output power regulator 205, and the output voltage of the rectifier 7 is compared with the maximum value of the rectifier output power determined from the allowable power of the distribution system (step S1). If it is determined in step S1 that the output power of the rectifier 7 is smaller than the maximum value of the rectifier output power, the value of the difference power is added to the output power upper limit value in the previous calculation to obtain a new output power. The upper limit value is set (step S2). Then, after the newly set output power upper limit value is limited so as not to exceed the rated power of the rectifier 7 (step S3), it is output to the divider 206 (step S6).

  If it is determined in step S1 that the output power of rectifier 7 is larger than the maximum value of rectifier output power (YES in step S1), the difference power value is subtracted from the output power upper limit value at the previous calculation. Then, a new output power upper limit value is set (step S4). The new output power upper limit value is limited so as not to become a negative value (step S5), and then output to the divider 206 (step S6). When the processes in steps S1 to S6 are completed, the process returns to the first process.

  Next, based on FIG. 3, a second embodiment of the present invention will be described. Among the constituent elements of the second embodiment of the present invention, those having the same functions as those of the first embodiment of the present invention are denoted by the same reference numerals and description thereof is omitted. In the second embodiment of the present invention, instead of the diode rectifier 7 used in the first embodiment, a separately-excited or self-excited device capable of controlling a DC voltage using a semiconductor device such as a thyristor or IGBT. An AC / DC semiconductor converter 34 is used.

  The basic operation of the power conversion device 1 according to the second embodiment is the same as the operation of the power conversion device 1 according to the first embodiment described above. However, in the power conversion device 301 according to the second embodiment, the power flowing from the distribution system is restricted by the semiconductor converter 34 itself that limits the power from the distribution system connected in parallel to the secondary battery 8. Can be more reliably and variably limited.

  That is, according to the second embodiment of the present invention, from the output of the current sensor 33 measuring the output current of the semiconductor converter 34 and the voltage sensor 32 indicating a voltage equal to the output voltage of the semiconductor converter 34. , Calculating power. This calculated power can limit the power from the distribution system to a limit value or less (usually 1 feeder 2 MW or less) by limiting the energization current of the semiconductor converter 34. Thus, in the second embodiment of the present invention, the semiconductor converter 34 limits the output current of the semiconductor converter 34 for the purpose of limiting the power flowing from the distribution system. Therefore, the limiter 213 provided in the control device 400 limits the value of the current flowing through the DC power converter 16 for the purpose of protecting the DC power converter 16 without monitoring the output current of the semiconductor converter 34. It becomes possible to do.

  As described above, the power converter 301 according to the second embodiment of the present invention does not monitor the power from the distribution system, and the voltage of the feeder line measured by the input voltage sensor 30 and the voltage sensor 32. The operating point can be determined based on the terminal voltage of the secondary battery 8 measured in step (1).

  Next, based on FIG. 4, the example of an electric railway system provided with the power converter device which concerns on this invention is demonstrated. An electric railway system 500 shown in FIG. 4 includes a feeder 3, a rail 4, an electric vehicle 501 that travels between the feeder 3 and the rail 4, a transformer 502, and the power converter 1 according to the present invention. It has. The electric vehicle 501 travels by inputting electric power from the feeder 3. In addition, the electric vehicle 501 generates power using the braking energy generated when the brake is operated, and outputs the generated regenerative power to the feeder 3.

  The substation device 502 includes a first AC / DC power conversion device 505 having a transformer 503 and a rectifier 504. The first AC / DC power converter 505 is connected to a first AC power supply 510 having a first AC voltage, converts AC power having the first AC voltage into DC power having a feeder voltage, and Output to the electric wire 3.

  In addition, the transformer 502 receives the DC power output from the first AC / DC power converter 505 and the regenerative power from the electric wire 3 and stores the power in the first power storage device 506. Then, the transformer 502 smoothes the output from the first AC / DC power converter to the feeder 3 via the power storage device 506.

  The substation device 502 has a main role of stepping down the AC power of extra high voltage, for example, 66 kV to 22 kV, converting it to DC power, and supplying it to the feeder 3. Further, the transformer 502 has a first power storage device 506 connected to the feeder 3 via the chopper circuit 507 in addition to performing the main role of supplying DC power to the feeder 3. It also absorbs and stores regenerative power.

  The electric railway system of the present invention includes the above-described power conversion device according to the present invention. The electric railway system of the present invention will be described below by taking the power conversion apparatus according to the first embodiment of the present invention as an example.

  The power converter provided in the electric railway system of the present invention includes a DC power converter 16, a second power storage device 8, a second AC / DC power converter 17, and a control device (not shown) for controlling them. And have. The DC power conversion device 16 is connected to the feeder line 3 and mutually converts the DC power between the DC power having a feeder voltage and the DC power having a voltage lower than the feeder voltage.

  In the power converter provided in the electric railway system of the present invention, the second power storage device 8 is connected to the DC power converter 16 and regenerative power from the feeder 3 through the DC power converter 16 during the regenerative operation of the electric vehicle 501. Is input and stored, and the stored electric power is output to the feeder 3 through the DC power converter 16 when the electric vehicle 501 is powered.

  In the power converter of the present invention, the second AC / DC converter 17 is connected to, for example, the second AC power supply 2 of the distribution system having 6.6 kV to 3.3 kV, and the second power storage device 8. The AC power having the second AC voltage is converted into DC power. Here, the voltage of the second AC power source to which the second AC / DC power converter 17 is connected is the first AC voltage of the AC power source having an extra high voltage to which the transformer 502 is connected, for example, 66 kV to 22 kV. Lower.

  And the 2nd AC / DC power converter 17 carries out the power storage amount of the 2nd power storage device 8, and the output power amount to the feeder 3 from the 2nd power storage device 8 at the time of the power running operation of the electric vehicle 501. refill. That is, the AC power supply of the distribution system to which the power converter is connected supplements the stored power amount of the second power storage device 8 and the output power amount from the second power storage device 8 to the feeder 3.

  In the electric railway system of the present invention, by providing the power conversion device of the present invention between the transformer and the transformer, the regenerative power of the electric vehicle is absorbed, stored, and re-output to the feeder line efficiently. It is possible to save power and reduce power costs.

  In the electric railway system of the present invention, by providing the power conversion device of the present invention between the substations, the interval between the substations can be increased. As a result, it is possible to reduce the number of substations connected to an extra high voltage and expensive equipment by providing power conversion equipment that is connected to the power distribution system and has low equipment costs. Equipment costs can be reduced.

It is a figure which shows the whole structure of the power converter device which concerns on the 1st Embodiment of this invention. It is a figure which shows the flowchart of the process in the output power regulator of the power converter device of FIG. It is a figure which shows the whole structure of the power converter device which concerns on the 2nd Embodiment of this invention. It is a figure which shows the whole structure of an electric railway system provided with the power converter device of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,301 ... Power converter device, 2 ... Distribution system, 3 ... Feed wire, 4 ... Rail, 5,503 ... Transformer, 6 ... Circuit breaker, 7, 504 ... Diode rectifier, 8, 506 ... Secondary battery, 9 DESCRIPTION OF SYMBOLS ... Filter reactor, 10 ... Boosting reactor, 11 ... Capacitor, 11m, 11n ... IGBT element, 16 ... DC power converter, 17, 18, 505 ... AC / DC power converter, 20 ... Chopper circuit, 30 ... Input voltage sensor, 31 DESCRIPTION OF SYMBOLS ... Current sensor, 32 ... Voltage sensor, 33 ... Current sensor, 34 ... AC / DC semiconductor converter, 200 ... Control circuit part, 201 ... Subtractor, 202 ... Voltage controller, 203, 213 ... Limiter, 204 ... Multiplier 205 ... Output voltage regulator, 206 ... Divider, 207 ... Subtractor, 208 ... Current controller, 209 ... PWM controller, 210 ... Carrier wave generator, 500 ... Electric railway system Temu, 501 ... electric vehicle, 502 ... power transformation device, 507 ... semiconductor device

Claims (6)

A power conversion device including a power storage device,
In accordance with the feeder voltage, the power input from the feeder is converted into DC power having a voltage lower than the feeder voltage and output to the power storage device, or from the feeder voltage A DC power conversion device that converts DC power having a low voltage into DC power having the feeder voltage and outputs the DC power to the feeder; and
An AC / DC converter connected to an AC power source of the distribution system and converting AC power into DC power;
It is connected between the DC power converter and the AC / DC converter, and transmits and receives power to / from the feeder via the DC power converter, and the power distribution system via the AC / DC converter It said power storage device for storing electric power by receiving power from an AC power source,
By controlling the DC power conversion device according to the voltage of the feeder line, control of power transfer between the feeder line and the power storage device is performed, and from the AC power source of the distribution system, A control device that performs control to output power to the feeder via the power storage device;
A power conversion device. When the voltage of the feeder is smaller than a predetermined DC voltage command value, the control device outputs the power stored in the power storage device and / or the power obtained from the AC / DC converter to the feeder. When the voltage of the feeder is greater than the predetermined DC voltage command value, the DC power converter is controlled so that the power of the feeder is output and charged to the power storage device.
The power conversion device according to claim 1. The DC power converter includes a chopper circuit in which a first semiconductor device and a second semiconductor device are connected in series, and the chopper circuit is connected in parallel to the feeder, and the power storage device and the AC / DC converter The device is connected in parallel with a terminal connecting the first semiconductor device and the second semiconductor device, respectively.
The power conversion device according to claim 1 or 2, wherein The control device controls the DC power converter so as to limit a maximum value of output power output from the AC / DC converter;
The power converter according to any one of claims 1 to 3, wherein The AC / DC converter includes a self-excited or separately-excited semiconductor converter that rectifies AC power from a distribution system and converts it into DC power,
The said semiconductor converter restrict | limits the maximum value of the output electric power output from the said AC / DC converter, The power converter device of any one of Claims 1-3 characterized by the above-mentioned. An electric railway system composed of an electric vehicle that travels by inputting electric power from a feeder and outputs regenerative power to the feeder during regenerative operation, a transformer, and a power converter,
The transformer is
A first AC / DC power converter connected to a first AC power source having a first AC voltage, converting AC power having a first AC voltage into DC power having a feeder voltage, and outputting the DC power to the feeder. Equipment,
DC power output from the first AC / DC power converter and the regenerative power output from the feeder are input to store the power, and output from the first AC / DC converter to the feeder A first power storage device for smoothing,
The power converter is
A DC power converter that is connected to the feeder and converts DC power between the DC power having a feeder voltage and the DC power having a voltage lower than the feeder voltage;
The DC power conversion device is connected to the regenerative operation of the electric vehicle, the regenerative power is input from the feeder through the DC power conversion device and stored, and the stored electric power is stored in the DC power conversion operation of the electric vehicle. A second power storage device that outputs to the feeder through a power converter;
Connected to a second AC power source having a second AC voltage lower than the first AC voltage and the second power storage device, and converting AC power having the second AC voltage into DC power; A second power supply for replenishing the stored power amount of the second power storage device and the output power amount from the second power storage device to the feeder line through the DC power conversion device during the power running operation of the electric vehicle. AC / DC power converter,
By controlling the DC power conversion device, a control device for controlling power transfer between the second power storage device, the second AC / DC power conversion device, and the feeder line,
An electric railway system characterized by comprising:

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