JP2011155716A - Power storage device of dc electric railway - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem, wherein an imbalance occurs between loads due to the number of trains existing on up and down feeders, a passenger load factor, and a rush-hour zone in a DC electric railway so that there are times when a DC high-speed breaker connected to the feeders is disconnected due to an overcurrent. <P>SOLUTION: A power storage device is connected to a current flow path between an optional DC high-speed breaker and a feeder. A current flowing through a connecting point of the power storage device and the feeder is detected, to control an output current from the power storage device. Furthermore, the point where the power storage device is installed may be installed so that it is connected to a feeder near to each station of the DC electric railway or a tie post installed between up and down feeders of a feeder section. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power storage device in an electric railway, and in particular, prevents current interruption due to overcurrent detection of a DC high-speed circuit breaker by outputting current to a feeder line, and also leveling load in a substation and reducing peak power It is related with the power storage device which performs.

FIG. 9 is an explanatory diagram of the relationship between the number of vehicles to be operated in the electric railway and the boarding rate.
In electric railways, the number of vehicles and the boarding rate differ greatly depending on the direction of going up and down at connecting stations. Also, the boarding rate on the upper and lower lines varies greatly depending on the rush hour and the like. For example, when considering the morning rush hour at a transit station with multiple tracks as shown in FIG. 9, the city area has a high diamond density and a large number of runs, and there are few down suburban areas. In addition, the boarding rate for the up line is high, but the boarding rate for the down line is low. In a substation that supplies power to a feeder section having such a station, the feeder current varies greatly depending on the time of day. FIG. 10 shows this state, and the incoming cable current to the city direction becomes extremely large. For this reason, the DC high-speed circuit breaker installed in the feeder line going up to the city may break due to overcurrent.

  In general, a rectifier installed in a DC electric railway substation employs a method of controlling the DC voltage to be constant as shown in Patent Document 1. Patent Document 1 describes that a necessary voltage is calculated in a feeding section of a substation adjacent to its own substation, and a thyristor rectifier provided in the own substation is controlled so as to obtain a necessary voltage. Has been.

  FIG. 11 shows a substation and a power system. Reference numeral 1 denotes a rectifier in a substation. The rectifier 1 converts alternating current into direct current, and passes through a secondary breaker (high speed breaker) 2 and a direct current high speed breaker 3 (3a, 3b, 3c, 3d). And DC power is supplied to each upstream and downstream feeder. Reference numeral 4 (4a, 4b) denotes a vehicle, and FIG. 11 shows an example in which there are two existing lines on the up line in the direction of the city.

Japanese Patent Laid-Open No. 11-91414

The following can be considered as means for preventing the DC high speed circuit breaker 3 from tripping due to overcurrent.
In order to prevent the DC high-speed circuit breaker 3a from breaking due to overcurrent, for example, when the upstream current I12 flowing through the urban upstream cable is 11000A and the maximum value of the rectifier output current Is is 9000A ,
(1) It is conceivable that the overcurrent set value of the DC high speed circuit breaker 3a itself is set to 12000A which is larger than the rising current I12. However, in this case (a). The maximum overcurrent settling value is 10000A from the standard for DC high-speed circuit breakers, and in order to achieve 12000A, it is necessary to develop a new DC high-speed circuit breaker, which is expensive.
(B). In addition, since a heavy load is applied to the DC high-speed circuit breaker 3a and the suburb is light, the bus voltage of the substation has a voltage drop due to the equivalent resistance x current of the substation and the like. The crossover currents I13 and I14 from the adjacent substations flow through. Therefore, even if a DC high-speed circuit breaker with a maximum overcurrent set value of 12000A is developed, the sum of the currents I13 and I14 flowing from the adjacent substations through the DC high-speed circuit breakers 3c and 3d (I13 + I14) is 2000A. In the above case, the secondary circuit breaker 2 set to the output current Is = 9000A does not perform the breaking operation. However, when the sum of the currents I13 and I14 (I13 + I14) is 2000 A or less, the DC high-speed circuit breaker 3a does not operate, but in this case, the secondary circuit breaker 2 performs a blocking operation. When the secondary circuit breaker 2 is operated, the substation is stopped and the feeder system is interrupted.
(2) In order to solve the problem of protection coordination described in (b) by developing the DC high speed circuit breaker of (a) above, the capacity of the rectifier 1 is increased and the overcurrent set value of the secondary circuit breaker 2 is increased. Is considered to be 12000A or more.
However, considering the entire substation, the total capacity does not increase, so increasing the capacity of the substation is uneconomical.
(3) Although it is conceivable to connect a power storage device to the feeder system and supply a compensation current from this power storage device, it is installed for the DC high-speed circuit breaker 3 that responds at a detection speed of 2 to 10 ms. The power storage device needs to respond at a high speed of 1 ms or less.
Note that Patent Document 1 describes constant DC voltage control of a substation, but does not disclose that a DC high-speed circuit breaker prevents unnecessary interruption due to overcurrent.

  Therefore, the purpose of the present invention is to detect the power running state of the vehicle and predict an increase in negative overcurrent in the initial stage, and to output current before the operation of the DC high-speed circuit breaker to the feeder line, Providing a power storage device for DC electric railways that can reduce the current flowing through the DC high-speed circuit breaker to prevent unnecessary interruptions due to overcurrent detection of the high-speed circuit breaker, and also realize load leveling and peak power reduction at substations There is to do.

The present invention is installed in a feeding system of a DC electric railway having a plurality of DC high-speed circuit breakers connected to the secondary side of a DC feeding substation, and feeders connected to each DC high-speed circuit breaker. In the power storage device,
The control unit of the power storage device is provided with a determination unit that predicts and determines an increase in load current, and outputs current to the feeder system when the control unit predicts and determines an increase in load current. It is.

  The determination means of the present invention is provided with a current detector for detecting a current flowing through the feeder feeder on the feeder side from the connection point when the power storage device is connected to the feeder feeder, and is detected by the current detector. It is characterized in that the load current is predicted to increase when the current exceeds a predetermined current value.

  The judging means of the present invention is provided with a current detector for detecting a current flowing through a feeder when a power storage device is connected to a feeder or tie post, and the current detected by the current detector is equal to or greater than a predetermined current value. In this case, the load current is predicted to increase.

  The judging means of the present invention is provided with a current detector for detecting a current flowing in the feeder branching device when the power storage device is connected to any one or more of feeder feeders, feeders, and tie posts. The load current is predicted to be increased when the current detected by the detector exceeds a predetermined current value.

  The judging means of the present invention is provided with a current detector for detecting a current flowing in the feeder branching device when the power storage device is connected to any one or more of feeder feeders, feeders, and tie posts. Determining whether or not the traveling vehicle is in a powering state or a repowering state based on the current detected by the device, and predicting that the load current is increased when it is determined as the powering state or the repowering state. It is a thing.

  The judging means of the present invention is provided with a voltage detector for detecting a feeder voltage when a power storage device is connected to any one or more of feeder feeders, feeders and tie posts, and is detected by this voltage detector. The load current is predicted to be increased when the measured voltage becomes equal to or lower than a predetermined voltage value.

As described above, according to the present invention, the load current flowing in the feeder feeder or the voltage of the feeder system is monitored, and the increase in the load current is predicted and determined at the initial stage based on the detected current value or the detected voltage value. Since current output is performed from the power storage device to the feeder system, the current flowing through the DC high-speed circuit breaker can be reliably reduced. Also, by outputting current from the power storage device to the feeder system, load leveling of the substation and peak power reduction are performed. Furthermore, when the power storage device is installed near a load such as a station, transmission loss can be reduced and voltage drop relief can be achieved.
In addition, the current flowing through the feeder branching device is detected to determine the driving state of the electric vehicle before and after the feeder branching device, and when the powering vehicle is present and the load current is predicted to be increased, A compensation current is output from the storage device. As a result, current output control from the power storage device can be performed without delaying the breaking operation of the DC high-speed breaker.
As a result, the current output from the power storage device can be controlled without delaying the operation of the DC high-speed circuit breaker, and unnecessary interruptions due to overcurrent detection of the DC high-speed circuit breaker and substation blackouts can be prevented.

The block diagram which shows embodiment of this invention. The block diagram of an electric power storage apparatus. The schematic block diagram of a tie post. The schematic block diagram of a feeder system. The block diagram which shows the other Example of this invention. The block diagram which shows the other Example of this invention. The equivalent circuit diagram of a feeder circuit. Current waveform diagram for explanation. Explanatory drawing of the number of vehicles and a boarding rate. Explanatory drawing of feeder system and load current. Explanatory drawing of a substation and a power system.

  The present invention relates to a power system of a DC electric railway, in which a power storage device is connected to a current flow path of an arbitrary DC high-speed circuit breaker and an electric wire, and the load current is detected and the load current increases during power running The current output is performed before the operation of the DC high-speed circuit breaker to the feeder line from the power storage device. This will be described in detail below based on examples.

  FIG. 1 is a block diagram showing a first embodiment of the present invention. The same reference numerals are given to the same or corresponding parts as in FIG. That is, according to the present invention, the power storage device 5 is connected to the feeder feeder A between the feeder line and the DC high speed circuit breaker 3 (3a to 3d), which are judged to increase the load current. Here, it is connected to the feeder feeder A between the feeder line and the high-speed circuit breaker 3a in the city area at the substation. However, the installation of the power storage device 5 is not limited to the substation and is in the vicinity of the station. You may install in the tie post which has the high speed circuit breaker HSCB etc. which are provided between the up-and-down feeder line in the feeder line and the feeder line. 6 is a current detector, and when the power storage device 5 is connected to the feeder feeder A, it is installed on the load side (feeding wire side) from the connection point of the power storage device 5.

  The power storage device 5 includes, for example, a filter reactor 11 and a capacitor 12, a step-up / down chopper 13 and an electric double layer capacitor 14 as shown in FIG. A voltage detecting means 8 is connected between the positive and negative electrodes, and a voltage monitoring means 9 for monitoring the voltage detected by the voltage detecting means 8 is provided. The voltage monitoring unit 9 controls the step-up / step-down chopper 13 via a control unit (not shown) when the voltage detected by the voltage detection unit 8 becomes equal to or higher than a set value, and executes charging control for the electric double layer capacitor 14.

  Further, the control unit of the power storage device 5 determines whether or not the current value detected by the current detector 6 is a threshold value (greater than or equal to a predetermined current set value), and predicts that the negative overcurrent increases when the current value is reached. The step-up / step-down chopper 13 is controlled so as to output the current Icp after determination.

In the configuration as shown in FIG. 1, if the output current of the power storage device 5 is Icp and the current flowing to the load side of the current detector 6 is IT, the current flowing through the DC high speed circuit breaker 3a is IT-Icp. It becomes. Therefore, considering the example shown in FIG. 9, assuming that the output current Icp of the power storage device 5 is equal to or greater than 3000A, when the current of IT = 11000A flows, the current I12 flowing through the DC high speed circuit breaker 3a is 8000A (= 11000-3000), the overcurrent set value of the DC high-speed circuit breaker 3a can be set to 8000A, and it will not be overcurrent. Is possible.
As a result, if the overcurrent setting value of the secondary circuit breaker 2 is 9000A, the DC high speed circuit breaker 3a detects and shuts down when an overcurrent fault occurs, and the secondary circuit breaker 2 does not shut off the overcurrent. There is no power outage for the entire station.

  In addition, since the detection speed of the DC high-speed circuit breaker is generally about 2 to 10 ms, it is necessary to set the response speed of the power storage device 5 to 1 ms or less in order to suppress overcurrent interruption. . In addition, the rising of the current when an overcurrent occurs rises with a certain slope instead of a step shape. Therefore, the control unit of the power storage device 5 (not shown) is set to a value (8000A-x) lower than the overcurrent settling value 8000A of the DC high speed circuit breaker 3a in consideration of the response speed of 1 ms. By providing a judgment means for monitoring current, predicting that an overcurrent has occurred when the load current increases to a value of (8000 A−x), and outputting an operation signal of the power storage device 5 from the judgment means. The current output from the power storage device 5 is performed before reaching the overcurrent set value of the DC high-speed circuit breaker 3a, and the current flowing through the DC high-speed circuit breaker 3a, which is expected to increase the load current, can be reduced. It becomes possible.

As described above, the power storage device 5 is connected to the output feeder of the DC high speed circuit breaker 3a connected to the feeder system, and the current flowing from the connection point to the feeder feeder is monitored. The output current Icp from the power storage device 5 is supplied to the feeder. In general control in electric railways, voltage control is performed so that the target voltage is set to the target voltage. In this case, current compensation is uncertain because the compensation current value is unknown, but this implementation In the example, since the load current is monitored by the judging means, the increase in the load current is predicted and judged, and the current is output from the power storage device 5, so that the current flowing through the DC high-speed circuit breaker 3a can be reduced without delay. Unnecessary interruption due to overcurrent detection of the connected DC high speed circuit breaker 3a and power failure of the substation can be surely prevented. In addition, by controlling the power storage device 5, load leveling of the substation and peak power reduction can be achieved. Furthermore, when the power storage device 5 is installed on a feeder near the load such as a station, transmission loss is reduced. Reduction and voltage drop relief are possible.
When the power storage device 5 is connected to a feeder or tie post other than the substation, it is installed at an arbitrary position of the feeder. FIG. 3 is a configuration diagram in the case where the power storage device 5 is connected to the tie post 40, and between the bridge point and the rail of the high-speed circuit breakers HSCB 20 and 30 connected in series between the upstream and downstream wires of the tie post 40. The power storage device 5 is connected. With this configuration, when a direct current is supplied from the down (or up) feeder side to the up (or down) feeder side, the high-speed circuit breakers HSCB 20 and 30 included in the tie post 40 are inserted. Can be executed. At that time, when the current flowing through the feeder connected to each DC high-speed circuit breaker is detected by the current detector and the control unit predicts that there is a DC high-speed circuit breaker that increases the load current, The chopper of the storage device 5 is controlled to output a current Icp from the electric double layer capacitor 14 to the feeder via the bridge point. Thereby, the current flowing through the DC high-speed circuit breaker, which is predicted to increase the load current, can be reduced.
For example, as shown in FIG. 4, a tie post 40 having a power storage device 5 is connected between the incoming and outgoing wires between substation A and substation B, and is installed in the feeder of DC high speed circuit breaker 54F21. When it is predicted that the load current of the current detector will increase, at this time, it is foreseen that there are many powering vehicles acting as loads between the DC high speed circuit breaker 54F21 and the tie post 40, and the current flowing through the tie post 40 is Current output from the DC high speed circuit breaker 54F24 of the substation B, the DC high speed circuit breaker 54F22 of the substation A, and the power storage device 5, and the current of the DC high speed circuit breaker 54F21 corresponding to the current flowing through these tie posts Is reduced.

That is, when the vehicle current is IT, the currents flowing through the DC high speed circuit breakers 54F21 to 54F24 are I21, I22, I23, and I24, respectively, and the output current of the power storage device 5 is Icp,
If there is no power storage device 5,
IT = I21 + I22 + I23 + I24 (1)
The vehicle current IT is the sum of the currents flowing through the DC high-speed circuit breakers 54F21 to 54F24, and the current flowing through the DC high-speed circuit breaker 54F21 at this time is expressed by equation (2).
I21 = IT-I22-I23-I24 (2)
On the other hand, if there is a power storage device 5,
IT = I21 + I22 + I23 + I24 + Icp (3)
The vehicle current IT is the sum of the currents flowing through the DC high-speed circuit breakers 54F21 to 54F24 and the output current of the power storage device 5, and the current flowing through the DC high-speed circuit breaker 54F21 at this time is expressed by equation (4). .
I21 = IT-I22-I23-I24-Icp (4)
From the above, the DC high speed is estimated that the power storage device 5 is installed in the tie post 40 and the load current increases by detecting the current flowing through the feeders connected to the DC high speed circuit breakers 54F21 to 54F24. By outputting a current from the power storage device 5 when there is a circuit breaker, the load current of the DC high-speed circuit breaker is reduced by the output current of the power storage device 5.

  Even when the power storage device 5 is connected to the tie post 40 as shown in FIG. 3, the current flowing through the DC high-speed circuit breaker 3 can be reduced as in the configuration of FIG. 1. In the configuration of FIG. 3, the DC high speed circuit breaker 3 in which the negative overcurrent increases depending on the vehicle position, and the DC high speed circuit breaker 3 that is predicted to be determined to increase the negative overcurrent is determined based on the vehicle position. Further, in the configuration of FIG. 3, it is possible to exchange current with one power storage device 5 for the upstream and downstream electric wires as compared with the case where individual power storage devices are connected to the upstream and downstream electric wires. .

  FIG. 5 shows a second embodiment. In the first embodiment shown in FIG. 1, a power storage device is connected to the output side of the DC high-speed circuit breaker and the bridge between the upstream and downstream wires of the tie post 40, and the load current is monitored by a current detector. When it is predicted that the current will increase, the current is output from the power storage device to the feeder system, but in the embodiment shown in FIG. 5, in order to detect the electric wire (trolley wire) voltage instead of the current detector. The voltage detector 8 is provided, and this voltage detector 8 predicts and determines an increase in load current. Although the voltage detector 8 is connected between the positive and negative electrodes of the power storage device 5 here, it may be connected to a feeder system such as between a feeder (trolley wire) and a rail. Is output to the voltage monitoring means 9 of the control section. The voltage monitoring means 9 detects that the electric wire (trolley wire) voltage has fallen due to an overload condition. The voltage of the feeder voltage is 1500 V, and the voltage corresponding to the overcurrent settling value 9000 A of the secondary circuit breaker 2 is set. In the case of 1300V, the voltage monitoring judgment means 9 is set to a value slightly higher than 1300V (1300V + α) in consideration of the response speed of the power storage device 5, and reaches the overcurrent set value of the DC high speed circuit breaker. Before starting, current is output from the power storage device 5 to the feeder (trolley wire).

  Therefore, the overload state of the feeder line section is predicted and judged, and when the feeder voltage drops to a value slightly higher than 1300V (1300V + α), the judgment means 9 generates an operation signal so that the DC high speed cutoff The current is output before reaching the overcurrent settling value of the device. This embodiment also has the same effect as the first embodiment.

  FIG. 6 is a block diagram showing a third embodiment of the present invention. In this embodiment, the feeder branch device 7 is provided between the feeder and the trolley wire, and the same reference numerals are given to the same or corresponding parts as in FIG. The power storage device 5 is connected to a feeder that is predicted to generate an overcurrent due to an increase in load current. Here, the power storage device 5 is connected between the feeder line going up in the city direction at the substation and the high-speed circuit breaker 3a. Connected. The feeder branching device 7 that connects between feeders and trolley wires is disposed with a predetermined distance interval, for example, every 250 m. The current detector 6 for detecting the load current is disposed in an arbitrary feeder branch device 7, detects the current flowing through the feeder branch device 7, and supplies electricity from the power storage device 5 via a control unit (not shown). The current Icp is output from the double layer capacitor 14 to the feeder.

In the feeder system having the feeder branch device 7, the feeder circuit, the trolley wire, and the feeder branch device form a bridge circuit except for the section where the vehicle is present as shown in the equivalent circuit diagram of FIG. No current flows through the branch device 7.
Where R11 to R1m are feeder resistances, R21 to R2m are trolley wire resistances, Rt1 and Rt2 are rail resistances, R1n is the feeder resistance of the vehicle existing section, AS / S is the A substation, BS / S is the B substation It is a place. The current Ib flowing through the feeder branching device 7 is only the feeder branching device 7 in which the vehicle 4 is located in the vicinity. By detecting this current Ib, the position of the current section of the vehicle can be detected.

As a cause of the large current flowing through the DC high-speed circuit breaker 3, a large current flows when a plurality of vehicles are on the same electric wire as described above and each vehicle is in a power running state. The detected current value can be analyzed as follows.
(1) When the detected current flows from the trolley wire to the feeder line: The vehicle is in a regenerative state.
(2) When the absolute value of the current is not more than a certain current: The coasting state.
(3) When the absolute value of the current is equal to or greater than a certain current and the rise (di / dt) is large and is less than the vehicle maximum current after the rise: Repowering.
(4) When the absolute value of the current is greater than or equal to a certain current and the rise (di / dt) is within a certain range: Power running.
(5) When the current rise (di / dt) is large and the absolute value is equal to or greater than the vehicle maximum current: an accident current such as a short circuit.
By grasping the phenomena (3) and (4) from the analysis results of (1) to (5), it is possible to predict the increase in load current.

  In other words, in this embodiment, the presence or absence of a powering vehicle is detected from the current flowing through the feeder branching device 7, and by detecting the phenomenon that the load current IT increases, it is predicted at an early stage that the load current will increase. By outputting current from the power storage device 5, the current flowing through the high-speed circuit breaker 3 is reduced without requiring high-speed response. That is, the current of the feeder branch device 7 in the section considered to be powered is detected, and whether the vehicle 4 is present before and after the feeder branch device, or from the results of (1) to (5) above, The operation state (power running, coasting, regeneration, etc.) is determined by the determination means in the control unit of the power storage device 5, and when the vehicle 4 exists and is in the power running state, a constant current Icp is supplied to the power storage device 5 Is output.

Hereinafter, a specific description will be given on the basis of FIG. 8 assuming a vehicle driven by a VVVF inverter.
FIG. 8 shows that the overcurrent detection of the secondary circuit breaker 2 shown in FIG. 6 is 9000 A, the load current IT is 11000 A, the overcurrent settling value of the DC high-speed circuit breaker 3 a is 8000 A, and the current output Icp of the power storage device 5 is 3000 A. This is the case. In FIG. 8, (a) is a current waveform of the preceding vehicle 4a, (b) is a current waveform of the following vehicle 4b, and both the vehicles 4a and 4b are assumed to be in a power running state. At time t1, the vehicle 4b is powered at time t2. (C) is the load current IT, which is the sum of the vehicles 4a and 4b. (D) is a waveform diagram of the current Icp output from the power storage device 5, and the output of the current Icp starts the timer at the monitoring start time t2 and ends at the time t3, but the load disappears within that time Is finished when the output voltage of the power storage device 5 is detected to rise. (E) is the current I12 flowing through the DC high-speed circuit breaker 3a.

The current I12 flowing through the DC high-speed circuit breaker 3a shown in FIG. 6 is IT-Icp. By setting the output current Icp of the power storage device 5 to Icp = 3000A, the load current IT is excessive in the DC high-speed circuit breaker 3a. Even if IT = 11000A which is a current breaking current flows, the current I12 which actually flows through the DC high speed circuit breaker 3a is 8000A (= 11000-3000). Therefore, the overcurrent set value of the DC high-speed circuit breaker 3a can be set to 8000A, and the overcurrent can be sufficiently suppressed even with the existing DC high-speed circuit breaker.
In addition, even if the overcurrent settling value of the secondary circuit breaker 2 is set to 9000A, the DC high speed circuit breaker 3a will shut off by detecting overcurrent when an overcurrent accident occurs, and the secondary side circuit breaker 2 will turn off the overcurrent. Power outage of the entire substation does not occur.

  Furthermore, since the detection speed of the DC high speed circuit breaker is about 2 to 10 ms, it has been conventionally necessary to set the response speed of the power storage device 5 to 1 ms or less in order to suppress overcurrent interruption. In the present embodiment, the determination means provided in the control unit of the power storage device 5 determines whether or not the vehicle existing in the feeder line is in a power running state from the detected current flowing through the feeder branching device, and driving the vehicle When it is determined that the load current increases from the state, the power storage device 5 is operated to output a current. As a result, the compensation current can be reliably supplied to the feeder without delaying the breaking operation of the DC high-speed breaker.

  As described above, according to this embodiment, in addition to the effects of the first and second embodiments, the current flowing through the feeder branching device is detected, and the driving state of the vehicle existing before and after the feeder branching device is determined and powering is performed. When it is predicted that the load current will increase due to the presence of a vehicle, current is output from the power storage device without delaying the interruption operation of the DC high-speed circuit breaker by outputting current from the power storage device to the feeder. Is possible.

DESCRIPTION OF SYMBOLS 1 ... Rectifier 2 ... Secondary breaker of rectifier 3 ... DC high speed circuit breaker 4 ... Vehicle 5 ... Power storage device 6 ... Current detector 7 ... Feeding branch device 20, 30 ... Tie post

Claims (6)

In a power storage device installed in a feeding system of a DC electric railway having a plurality of DC high-speed circuit breakers connected to the secondary side of a DC feeding substation, and feeders connected to each DC high-speed circuit breaker ,
The control unit of the power storage device is provided with a determination unit that predicts and determines an increase in load current, and outputs a current to the feeder system when the control unit predicts an increase in load current. Electric railway power storage device. The determination means is provided with a current detector for detecting a current flowing through the feeder feeder closer to the feeder from the connection point when the power storage device is connected to the feeder, and the current detected by the current detector is 2. The power storage device for a DC electric railway according to claim 1, wherein the load current is predicted to increase when the current value exceeds a predetermined current value. The determination means includes a current detector that detects a current flowing through the feeder when a power storage device is connected to the feeder or tie post, and the current detected by the current detector is equal to or greater than a predetermined current value. 2. The power storage device for a DC electric railway according to claim 1, wherein the load current is predicted to increase when The determination means includes a current detector that detects a current flowing through the feeder branching device when the power storage device is connected to any one or more of feeder feeders, feeders, and tie posts. 2. The power storage device for a DC electric railway according to claim 1, wherein when the detected current becomes equal to or greater than a predetermined current value, the load current is predicted to be increased. The determination means includes a current detector that detects a current flowing through the feeder branching device when the power storage device is connected to any one or more of feeder feeders, feeders, and tie posts. It is determined whether or not the traveling vehicle is in a powering state or a repowering state based on the detected current, and the load current is predicted to be increased when it is determined as a powering state or a repowering state. Item 1. A power storage device for a DC electric railway according to Item 1. The determination means includes a voltage detector that detects a feeder voltage when a power storage device is connected to any one or more of feeder feeders, feeders, and tie posts, and the voltage detected by the voltage detector. 2. The power storage device for a DC electric railway according to claim 1, wherein the load current is predicted to be increased when becomes less than a predetermined voltage value.

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