(19)
(11)EP 2 676 834 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
02.09.2020 Bulletin 2020/36

(21)Application number: 12747709.9

(22)Date of filing:  14.02.2012
(51)International Patent Classification (IPC): 
B60L 50/20(2019.01)
B60L 58/18(2019.01)
B60M 3/06(2006.01)
B60L 58/12(2019.01)
B60L 9/04(2006.01)
(86)International application number:
PCT/JP2012/053440
(87)International publication number:
WO 2012/111679 (23.08.2012 Gazette  2012/34)

(54)

BATTERY DEVICE AND METHOD FOR INSTALLING AND OPERATING SAME

BATTERIEVORRICHTUNG UND VERFAHREN FÜR DESSEN INSTALLATION UND BETRIEB

DISPOSITIF DE BATTERIE ET PROCÉDÉ POUR L'INSTALLER ET LE FAIRE FONCTIONNER


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 14.02.2011 JP 2011028188

(43)Date of publication of application:
25.12.2013 Bulletin 2013/52

(73)Proprietor: KABUSHIKI KAISHA TOSHIBA
Minato-ku Tokyo 105-8001 (JP)

(72)Inventors:
  • NOGI, Masayuki
    Minato-ku, Tokyo 105-8001 (JP)
  • TAKAGI, Ryo
    Shinjuku-ku, Tokyo 163-8677 (JP)
  • OOTSUJI, Koji
    Minato-ku, Tokyo 105-8001 (JP)
  • MATSUI, Mitsuhiko
    Minato-ku, Tokyo 105-8001 (JP)
  • KOIZUMI, Satoshi
    Minato-ku, Tokyo 105-8001 (JP)

(74)Representative: Hoffmann Eitle 
Patent- und Rechtsanwälte PartmbB Arabellastraße 30
81925 München
81925 München (DE)


(56)References cited: : 
WO-A1-2009/107715
JP-A- 2006 062 489
JP-A- 2006 168 390
JP-A- 2008 074 180
WO-A1-2012/015042
JP-A- 2006 062 489
JP-A- 2008 074 180
  
  • OKUI A ET AL: "Application of energy storage system for railway transportation in Japan", 2010 INTERNATIONAL POWER ELECTRONICS CONFERENCE : IPEC-SAPPORO 2010 - [ECCE ASIA] ; SAPPORO, JAPAN, IEEE, PISCATAWAY, NJ, USA, 21 June 2010 (2010-06-21), pages 3117-3123, XP031727790, ISBN: 978-1-4244-5394-8
  
Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


Description

TECHNICAL FIELD



[0001] The present disclosure relates to an electric energy storage device that is utilized as, for example, a power supply source for a DC electric railroad, and an installation-operation method of such an electric energy storage device.

BACKGROUND ART



[0002] Conventionally, DC feeder systems are known as power supply systems for a DC electric railroad. Such DC feeder systems have characteristics that a load change due to start and stop of a railroad vehicle frequently occurs, and the line voltage change is large.

[0003] It is typical that DC is produced from an AC power source system using a power converter like a diode rectifier, and power regeneration to the AC power source system at the deceleration of a railroad vehicle cannot be performed without an installation of a regenerative inverter. Hence, when no regenerative inverter is present, it is difficult to perform effective regeneration unless a sufficient load that absorbs regenerative currents from the railroad vehicle is present around the railroad vehicle.

[0004] Conversely, even if the regenerative inverter is installed, if there is no load that consumes power regenerated by the inverter in the system, the regenerative power causes a reverse power flow to the power transmission-distribution system of an electric power company, and thus it is difficult for the railway business operator to accomplish an effect of reducing the amount of power to be purchased.

[0005] In order to address such a disadvantage, an electric energy storage device that absorbs regenerative power of the vehicle is installed in the feeder system in some cases . This electric energy storage device is capable of absorbing the regenerative power of a railroad vehicle, and also capable of discharging the stored energy. The installation of the electric energy storage device enables a reduction of the input energy of the transformer station for power feeding. Moreover, some electric energy storage devices have a function of suppressing a change in a line voltage. An example prior art document for such an electric energy storage system is as follow:

PRIOR ART DOCUMENT


Patent Document



[0006] Patent Document 1: JP 2006-62489 A

[0007] The technology disclosed in Patent Document 1 controls the charging/discharging of the electric energy storage device in accordance with a charging rate SOC of an electric energy storage element used in the electric energy storage device and the line voltage. For example, as illustrated in FIG. 11, it is necessary in some cases to set a floating control mode between a discharging start voltage Vc and a charging start voltage Vd for adjustment charging.

[0008] According to this conventional technology, when a line voltage V becomes high, a charging current is increased from the charging start voltage Vd to a charging current saturated voltage Ve, and the electric energy storage element SOC is charged by a maximum charging current Ic from the feeder line until the voltage reaches a charging maximum voltage Vf from the charging current saturated voltage Ve. Conversely, when the line voltage V becomes low, the discharging current is increased from the discharging start voltage Vc to a discharging current saturated voltage Vb, and discharging from the electric energy storage element SOC to the feeder line is performed by a maximum discharging current Io until the voltage reaches a discharging maximum voltage Va from the discharging current saturated voltage Vb.

[0009] In this case, when the charging rate SOC is at the pre-set value, no charging/discharging current flows within the line voltage range from the discharging start voltage Vc to the charging start voltage Vd in the graph of FIG. 11. According to the conventional technology setting the floating control mode, however, when the charging rate SOC is higher than the pre-set value, a floating current If is caused to flow in the discharging direction (an output current I increases) within the line voltage range from the discharging start voltage Vc to the charging start voltage Vd where no charging/discharging current flows in general. Conversely, when the charging rate SOC is lower than the pre-set value, the floating current If is caused to flow in the charging direction within the line voltage range from the discharging start voltage Vc to the charging start voltage Vd where no charging/discharging current flows in general. Accordingly, the charging/discharging current is controlled so as to maintain the charging rate to be a constant value.

[0010] Such a conventional technology is a scheme of adjusting charging/discharging so as to obtain a desired charging rate at a voltage when the feeder line is in a slightly loaded condition. Accordingly, it becomes possible to maintain the charging rate of the electric energy storage element to be an arbitrary value. However, in this case, a current from the rectifier is once accumulated in the electric energy storage element in a slightly loaded condition, and is discharged again. Hence, a charging/discharging loss is caused, which is not suitable from the standpoint of energy saving. Moreover, generally, charging/discharging is not performed within a range from the discharging start voltage Vc to the charging start voltage Vd, however, as a result of the floating control, charging/discharging is performed even within the range. Thus, the charging/discharging cycles of the electric energy storage device increase. This results in the increase of an RMS current, a temperature rise of the electric energy storage element, and the increase of the charging/discharging cycle energy, and thus the lifetime of the element is reduced.

[0011] In another way, in order to realize a high-output electric energy storage device, a large number of electric energy storage elements are connected in series and in parallel, but when a large number of elements are connected, there is a disadvantage that the reliability of the device decreases. When a large number of elements are connected in series, basically, a substrate for monitoring the charging rate of each element becomes necessary, and when the respective elements are connected in series and in parallel, the number of this monitoring substrates increases , resulting in a decrease of the reliability of the whole system. Moreover, the use of a large number of elements and monitoring substrates results in the increase of the device costs.

[0012] Furthermore, the electric energy storage element used in the electric energy storage device has disadvantages such that the element does not have an excellent durability against heat, and the lifetime of the element is reduced when a deep charging/discharging depth is set. The same is true of the electric circuit substrate with respect to the durability against heat, and heat generation largely affects the lifetime of the substrate, resulting in a reduction of the reliability.

[0013] DC power distributing systems other than the feeder system for a DC electric railroad, such as a power distributing system to a drive system of an elevator, and a charging/discharging system of a solar power generation (PV) device, likewise have the same disadvantages.

[0014] An embodiment of the present invention has been made in order to address the above-explained disadvantages of the conventional technology. That is, it is an object of an embodiment of the present invention to provide an electric energy storage device which can enhance a reliability and a redundancy, and which can accomplish both long-life of a feeder system and energy saving.

SUMMARY



[0015] The invention is defined in the independent claim. Advantageous embodiments are set out in the dependent claims. Aspects or embodiments that do not fall under the scope of the claims are useful to understand the invention.

BRIEF DESCRIPTION OF DRAWINGS



[0016] 

FIG. 1 is a block diagram illustrating a first embodiment;

FIG. 2 is a graph indicating a relationship between a line voltage and an output current according to the first embodiment;

FIG. 3 is a graph indicating a discharging characteristic according to the first embodiment;

FIG. 4 is a graph illustrating a charging characteristic according to the first embodiment;

FIG. 5 is a block diagram illustrating a second embodiment;

FIG. 6 is a block diagram illustrating a modified example of the second embodiment;

FIG. 7 is a wiring diagram illustrating a connection structure of an electric energy storage element according to each embodiment;

FIG. 8 is a graph indicating a restricted characteristic of input/output currents according to a third embodiment;

FIG. 9 is a graph indicating a relationship between an installation location of an electric energy storage device and a charging/discharging control characteristic according to a fourth embodiment;

FIG. 10 is a graph indicating a relationship between an installation location of an electric energy storage device and a capacity of electric energy storage device according to a fifth embodiment; and

FIG. 11 is a graph indicating a relationship between a line voltage of a conventional technology with a floating control mode and an output current.


DETAILED DESCRIPTION



[0017] Embodiments will be explained below with reference to the accompanying drawings.

[A. First Embodiment]


[Structure of First Embodiment)



[0018] A first embodiment will be specifically explained with reference to FIG. 1.

[0019] FIG. 1 illustrates a whole structure of a feeder system including an electric energy storage device according to this embodiment. According to the feeder system of this embodiment, the power from a transmission line 1 is converted by a power converter device 2 at the transmission line side, and the DC power is supplied to a feeder line 3. In this case, the rated voltage of the feeder line 3, that is a DC power source, is a voltage when the power converter device 2 at the transmission-line side is outputting a current that permits a successive operation. The power converter device 2 at the transmission-line-1 side includes a diode rectifier or a PWM converter, etc. Voltages of the feeder line 3 are, for example, DC 600 V, 750 V, 1500 V, and DC 3000 V, and a voltage fluctuation occurs at voltages therearound.

[0020] The feeder line 3 is connected with an electric energy storage element 4 for storing electric energy through a power converter device 5 provided at the side of the electric energy storage element. The electric energy storage element 4 is, for example, a battery like a lithium-ion battery or a nickel hydride battery. Moreover, an electric double-layer capacitor can be available as the electric energy storage element 4. The power converter device 5 at the side of the electric energy storage element is, for example, a booster/step-down chopper circuit that controls switching elements through respective gates, and is capable of arbitrarily controlling charging/discharging currents to the electric energy storage element 4. The element used for this power converter device 5 is a self-turn-off element like an IGBT, which is subjected to a PWM drive, thereby controlling charging/discharging currents to the electric energy storage element 4. Multiple power converter devices 5 may be connected to the feeder line so as to operate the multiplexed electric energy storage element 4.

[0021] Charging/discharging currents (Output Current) input to and output from the electric energy storage element 4 relative to the feeder line 3 by the power converter device 5 at the side of the electric energy storage element is set by an output current controller 6 provided on the power converter device 5. The output current controller 6 is connected with a line-voltage detector 7 that detects a line voltage (Line_Voltage) of the feeder line 3, and is connected with a charging-rate detector 8 that detects a charging rate SOC of the electric energy storage element 4.

[0022] The output current controller 6 is connected with a control table 9 which determines, based on the line voltage and the charging rate detected by the line-voltage detector 7 and the charging-rate detector 8, the charging/discharging operations of the electric energy storage element 4, i.e., charging/discharging start voltages (charge_th_Low, discharge_th_high), and charging/discharging current saturated voltages (charge_th_high, discharge_th_low). The control table 9 is provided with a data inputter/outputter 10 which permits a user to set various values to be stored in the control table 9 and which is for checking the set values, input/output currents, and other data.

[0023] The output current controller 6 changes the charging/discharging currents (Output Current) of the power converter device 5 at the side of the electric energy storage element side in accordance with a detected line voltage (Line_Voltage), the charging rate SOC, and a charging/discharging characteristic set in the control table 9. An explanation will now be given of the charging/discharging characteristic set in the control table 9 with reference to FIGS. 2 to 4.

[0024] FIG. 2 illustrates a relationship between the line voltage (Line_Voltage) that is a horizontal axis and an output current (Output Current) of the electric energy storage element 4 that is a vertical axis. That is, when the line voltage becomes lower than a preset value (the center of the graph horizontal axis) and reaches the discharging start voltage (discharge_th_high), the output current from the electric energy storage element 4 increases, and after the line voltage reaches the discharging current saturated voltage (discharge_th_low), the discharging current maintained at the maximum value is kept being output. Conversely, when the line voltage becomes higher than the preset value (center of the graph horizontal axis) and reaches the charging start voltage (charge_th_low), the charging current to the electric energy storage element 4 increases, and after the line voltage reaches the charging current saturated voltage (charge_th_high), charging is performed with the charging current being maintained at the maximum value.

[0025] FIG. 3 illustrates an example of discharging characteristic based on the line voltage (Line_Voltage) and the charging rate SOC. As illustrated in FIG. 3, according to this embodiment, the charging characteristic (discharge_th_high, discharge_th_low) is set within a line voltage range from 1380 V to 1500 V. In this case, the discharging start voltage (discharge_th_high) is set to be low at a lower range of the charging rate (equal to or lower than 40 % in the figure) so as not to start discharging as long as the line voltage does not become low. Likewise, the discharging current saturated voltage (discharge_th_low) is set to be low at a lower range of the charging rate (equal to or lower than 40 % in the figure) so as to cause the maximum discharging current to flow at the low line voltage. As a result, setting is made in such a way that no discharging is performed at the lower range of the charging rate as long as the line voltage does not become low (equal to or lower than 1450 V).

[0026] Conversely, at a higher range of the charging rate (equal to or greater than 85 % in the figure), the discharging start voltage (discharge_th_high) is set to be high (1450 V) so as to start discharging even the line voltage is high. Likewise, at the higher range of the charging rate (equal to or greater than 85 % in the figure), the discharging current saturated voltage (discharge_th_low) is set to be high so as to allow the maximum discharging current to flow at a high line voltage (1500 V).

[0027] FIG. 4 is an example of discharging characteristic based on the line voltage (Line_Voltage) and the charging rate SOC. As illustrated in FIG. 4, a characteristic is set in such a way that the set values of the charging start voltage (charge_th_low) and the charging current saturated voltage (charge_th_high) become high as the charging rate becomes high, and the set values become low as the charging rate becomes low relative to the line voltage. As a result, when the charging rate of the electric energy storage element 4 is low, charging is started although the line voltage is low, and when the charging rate is high, no charging is performed unless the line voltage becomes high.

[0028] According to this embodiment, within the all range of the charging rate, the highest value of the discharging start voltage (discharge_th_high) in FIG. 3 is 1500 V, and the lowest value of the charging start voltage (charge_th_low) in FIG. 4 is 1620 V. That is, according to this embodiment, regardless of the range of the charging rate being present, no charging/discharging is performed at least within a range where the line voltage is from 1500 V to 1620 V.

[0029] The above-explained charging/discharging characteristics of this embodiment illustrated in FIGS. 3 and 4 are indicated by dotted lines in the graph of FIG. 2. As is clear from the dotted lines, according to this embodiment, when the charging rate SOC of the electric energy storage element changes, unlike the conventional technology illustrated in FIG. 11, no floating current If is caused to flow within a portion from the discharging start voltage (discharge_th_high) to the charging start voltage (charge_th_low) . According to this embodiment, at least one of the charging start voltage (discharge_th_high) and the charging start voltage (charge_th_low) is changed in accordance with the charging rate. Accordingly, the output current controller 6 refers to the control table in FIG. 3 or FIG. 4, terminates charging/discharging operations when the line voltage is within a range from the discharging start voltage (discharge_th_high) to the charging start voltage (charge_th_low), and can perform appropriate charging/discharging operations in accordance with the charging rate SOC and the line voltage within a range where the line voltage is higher than a rated voltage by a preset voltage or is lower than the rated voltage by the preset voltage.

(Action and Advantage of First Embodiment)



[0030] As explained above, according to this embodiment, the characteristic transitions so as to facilitate discharging even at a high line voltage as the charging rate becomes high, and to cause less charging at the low line voltage. Conversely, as the charging rate becomes low, the characteristic transitions so as to cause less discharging at the low line voltage, and to facilitate charging at the low line voltage.

[0031] As a result, according to this embodiment, charging/discharging operations, like the floating current control, become unnecessary within a range where charging/discharging is not needed essentially. Frequent charging/discharging to the electric energy storage element is suppressed, thereby accomplishing the energy saving and the longer lifetime. That is, since the conventional adjustment of charging/discharging ,like the floating control, is not performed, no waste charging/discharging cycle energy is produced, thereby extending the lifetime of the electric energy storage element.

[0032] Moreover, charging is preferentially performed from a voltage range where regeneration is highly possibly canceled (e.g. , when the rated line voltage of the feeder line is DC 1500 V, a range from 1650 V to 1800 V), and discharging is intensively performed at a range where the feeder voltage becomes low, excessive regenerative energy can be absorbed, and a power feeding loss in the feeder system (a loss caused in the feeder line and in a rail where a return current flows) can be suppressed.

(Modified Example of First Embodiment)



[0033] The above-explained first embodiment may employ the following modified example.
  1. (1) According to this embodiment, it is not always necessary to change both of the charging start voltage (charge_th_low) and the discharging start voltage (discharge_th_high) in accordance with the charging rate. Either one voltage may be maintained as a fixed value, and the other of the charging start voltage (charge_th_low) or the discharging start voltage (discharge_th_high) may be changed in accordance with the charging rate. The same advantage can be also accomplished in this case.
  2. (2) When the set values of the charging current saturated voltage (charge_th_high) and the charging start voltage (charge_th_low) are set to be equal to or lower than a no-load feeding voltage of a transformer station regardless of the charging rate SOC, charging from the transformer station in a slightly-loaded condition is enabled. This is effective for a line where regenerative energy level is extremely low, and charging can be performed in advance when the feeder system is in a slightly-loaded condition.
  3. (3) Contrary to the above-explained (2), in the case of a system in which regenerative energy can be expected, the set values can be set to be equal to or higher than the no-load feeding voltage of a transformer station, and thus the charging rate can be adjusted by charging based on only the regenerative energy. This suppresses a charging and discharging of feeder energy of the transformer station to the electric energy storage element in a case that no regenerative energy from a train is present, thereby suppressing a deterioration of the feeder efficiency.
  4. (4) The discharging current saturated voltage (discharge_th_low) and the discharging start voltage (discharge_th_high) are set to be active at a voltage equal to or lower than a feeder line rated voltage (e.g., 1500 V in the case of a feeder system of DC 1500 V). By this, the discharging is intensively performed in a condition in which the line voltages really drops largely so as to compensate the line voltage drop, thereby reducing the feeder loss.
  5. (5) In order to decrease the loss of the power converter device 5 at the side of the electric energy storage element 4 between line voltages where no charging/discharging is performed (from discharging start voltage (discharge_th_high) to charging start voltage (charge_th_low)) to accomplish the energy saving, the booster/step-down chopper circuit of the power converter device 5 may be subjected to gate blocking.

[B. Second Embodiment]



[0034] FIG. 5 illustrates a second embodiment. According to the second embodiment, a second power source 11 is connected to the electric energy storage element 4. As an example of the second power sources 11, power generators, such as solar power generator may be used, wind power generator, and hydro-power generator. Both DC power source and AC power source are available as the second power source 11. In the case of the DC power source, the output power thereof is directly input into the electric energy storage element 4. When the second power source is an AC power source, an AC power obtained by rectifying an original output power is supplied to the electric energy storage element 4.

[0035] When power is supplied to the electric energy storage element 4 from the second power source 11, like the above-explained first embodiment, the output current controller 6 adjusts the charging/discharging characteristics from the feeder line 3 in accordance with the charging rate SOC and the line voltage detected by the detectors 7 and 8, and the set values in the control table 9. That is, direct connection of the second power source 11 to the electric energy storage element 4 causes the charging rate of the electric energy storage element 4 to be changed from moment to moment by the power from the second power source 11. In the embodiment illustrated in FIG. 5, the output current controller 6 refers to both charging rate changing from moment to moment as well as changing line voltage so as to control charging/discharging. Accordingly, the same advantage as that of the first embodiment can be expected. In particular, the power from the second power source 11 can be used for compensating the feeder voltage, the feeder loss is further reduced, and the energy saving effect can be further enhanced.

[0036] In the second embodiment, the second power source 11 must not be directly connected to the electric energy storage element 4. As illustrated in FIG. 6, , the second power source 11 can be connected to the DC feeder line 3 connected with the electric energy storage element 4 near the electric energy storage element 4. In this case, the second power source 11 accomplishes the same function as a regenerative vehicle connected to the feeder line 3, and the same advantage as that of the first embodiment can be expected.

[C. Third Embodiment]



[0037] In the respective embodiments explained above, the electric energy storage element 4 can be configured by a plurality of electric energy storage elements. More specifically, as illustrated in FIG. 7, a large number of electric energy storage elements 4 (hereinafter, referred to as an electric energy storage element module) connected in series are connected in multiple rows in parallel. In this case, each electric energy storage element module may be configured to be released from the system through a release contactor 4a. However, in order to detect how many modules are released among the plurality of electric energy storage element modules, as illustrated in FIG. 1, a detector 12 is connected to the output current controller 6, and the output current controller 6 restricts charging/discharging currents supplied to the power converter device 5 for the electric energy storage elements in accordance with the number of detected modules.

[0038] More specifically, the output current is restricted by multiplying the output current instruction generated by the output current controller 6 by a value obtained by dividing the number of parallel rows of the electric energy storage element modules after the release by the number of parallel rows of the electric energy storage element modules connected before the release. Accordingly, the modules can be kept in use without increasing the temperature of each electric energy storage element configuring the module. Moreover, an output current instruction in accordance with the number of released electric energy storage element modules may be stored in the control table 9 in advance as a database, and the database may be referred in accordance with the number of released electric energy storage element modules to determine the maximum output current.

[0039] The output current instruction of the power converter device 5 by the output current controller 6 may be restricted by the output current controller based on the RMS (effective value) current of the electric energy storage element 4, the RMS current of the power converter device 5, and a temperature detected at the electric energy storage element 4. For example, regarding the above-explained RMS current, an integration cycle of the RMS current may be set for each time slot to calculate the RMS current. The regenerative vehicle basically connected to the feeder line has a cyclic nature in its operation diagram, and thus an RMS current having that diagram cycle as an integration time period can be calculated.

[0040] In this case, the output current controller 6 is provided with an RMS current detector 13 for the electric energy storage element 4 or the power converter device 5 as illustrated in FIG. 1. Furthermore, a characteristic is set in the control table 9, the characteristic restricting the charging/discharging currents of the electric energy storage element 4 as the detected RMS current becomes close to a preset value set in advance. More specifically, as is indicated by the dotted lines in FIG. 8, the characteristic that restricts a discharging stop voltage (Low_Limiter), the discharging current saturated voltage (discharge_th_low), the charging start voltage (charge_th_low), the charging current saturated voltage (charge_th_high), and a charging stop voltage (high_Limiter) is set in the control table 9.

[0041] The current limiting characteristic on the basis of the RMS current may be changed in accordance with the temperature of the electric energy storage element and an external temperature. That is, the characteristic in FIG. 8 differs for each temperature of the electric energy storage element and each external temperature, and therefore different charging/discharging characteristics can be set for each temperature. Accordingly, even if the battery temperature and the external temperature rise, it does not deteriorate the lifetime of the electric energy storage element.

[D. Fourth Embodiment]



[0042] The electric energy storage device of this embodiment can be installed at an arbitrary location. According to a fourth embodiment illustrated in FIG. 9, however, the electric energy storage device located closer to a feeder transformer station, the discharging current saturated voltage (discharge_th_low) or the discharging start voltage (discharge_th_high) are set to be a higher value on the line voltage axis. That is, FIG. 9 illustrates an example of a feeder system of rated DC 1500 V, and the electric energy storage devices located near the feeder transformer stations 14a and 14b have the discharging current saturated voltage (discharge_th_low) or the discharging start voltage (discharge_th_high) set to be 1590 V. In contrast, the electric energy storage devices located at distant locations from the feeder transformer stations 14a and 14b have the discharging current saturated voltage (discharge_th_low) or the discharging start voltage (discharge_th_high) set to be 1500 V.

[0043] As a result, the location on the feeder line 3 having the larger feeder voltage drop and distant from the feeder transformer station has lower discharging current saturated voltage or the discharging start voltage to the feeder line 3 from the electric energy storage device, thereby compensating the voltage drop of the feeder line 3.

[E. Fifth Embodiment]



[0044] A fifth embodiment illustrated in FIG. 10 causes the electric energy storage device to have a larger capacity as becoming more distant from the feeder transformer stations 14a, 14b. According to such a fifth embodiment, the feeder loss caused by the flow of the feeder current can be reduced, thereby enhancing the energy saving effect. In this case, regarding the way of increasing the capacity of the electric energy storage device, the more distant the electric energy storage device is from the transformer station, the larger the number of electric energy storage device operated in parallel becomes, thereby increasing the capacity.

[0045] Moreover, each electric energy storage device of this embodiment may be installed at a station, and in this case, the electric energy storage device having a larger capacity is installed at a station having a larger number of stopping trains, thereby accomplishing a large energy saving effect. Conversely, when the large-capacity and high-output electric energy storage device is installed at a station having a small number of stopping trains, the regenerative energy of the distant train is excessively absorbed, and thus the energy saving effect is deteriorated due to the increase of the feeder line loss. Hence, by installing the electric energy storage device having a larger capacity and a high output at a station having a larger number of stopping trains, the reduction effect of the feeder line loss can be enhanced, thereby realizing an effective energy saving of the feeder system.

[F. Other Embodiments]



[0046] The above-explained embodiments are exhibited by way of example only in this specification, and are not intended to limit the scope of the present disclosures.

[0047] In particular, the respective embodiments explained above utilize the feeder line connected with a regenerative railroad vehicle as the DC power source, but the present disclosure is applicable to DC distributing systems other than the feeder system of the DC electric railroad, such as a distributing system to a drive system of an elevator, and charging/discharging systems of a solar power generator (PV) .

DESCRIPTION OF REFERENCE NUMERALS



[0048] 

1 Transmission line

2 power converter device at the side of the transmission line

3 Feeder line

4 Electric energy storage element

4a Release contactor

5 power converter device at the side of the electric energy storage element

6 Output current controller

7 Line voltage detector

8 Charging rate detector

9 Control table

10 Data inputter/outputter

11 Second power source

12 Detector for release contactor

13 RMS current detector

14a, 14b Feeder transformer station




Claims

1. An electric energy storage device comprising:

an electric energy storage element (4) connected to a DC power source (3) via a power converter device (5); and

an output current controller (6) which is connected to the power converter device and which is configured to control charging/discharging current of the electric energy storage element relative to the DC power source,

the output current controller (6) being connected with a voltage detector (7) configured to detect a voltage of the DC power source, a charging rate detector (8) configured to detect a charging rate of the electric energy storage element, and a control table (9) having set therein charging/discharging characteristics, and

the charging / discharging characteristics are determined based on the voltage of the DC power source detected by the voltage detector (7) and the charging rate of the electric energy storage element detected by the charging rate detector (8),

the voltage of the DC power source is selected from at least one of a charging start voltage, a discharging start voltage, a charging current saturated voltage and a discharging current saturated voltage of the electric energy storage element,

the charging/discharging characteristics stored in the control table (9) being set such that at least one of the charging start voltage, the discharging start voltage, the charging current saturated voltage and the discharging current saturated voltage is set to a higher value at higher charging rate of the electric energy storage element than at lower charging rate thereof, and the output current controller is configured to terminate charging or discharging operations within a range from the discharging start voltage to the charging start voltage when charging rate of the electric energy storage element changes.


 
2. The electric energy storage device according to claim 1, wherein
a power source voltage from the DC voltage is supplied through the power converter device (2) - configured to convert AC voltage to DC voltage,
a no-load feeding voltage of the DC power source changes in accordance with a change in the AC voltage, and
the charging/discharging characteristics stored in the control table is set such that the DC voltage of the DC power source performing a charging operation to the electric energy storage element is set to be higher than the voltage of the DC power source changed in accordance with the voltage change in the AC voltage.
 
3. The electric energy storage device according to claim 2, wherein a rated voltage of the DC power source is a DC power source voltage when the power converter device (2) that is a voltage source of the DC power source is outputting a current that enables a continuous operation.
 
4. The electric energy storage device according to claim 1, wherein the power converter device (2) connected to the electric energy storage element comprises a plurality of power converters connected in parallel.
 
5. The electric energy storage device according to any one of claims 1 to 4, wherein
the power converter device (2) connected to the electric energy storage element is a power converter device that is configured to operate through a gate drive on a switching element, and
the gate drive is terminated when the voltage of the DC power source is lower than the no-load feeding voltage and is higher than the rated voltage of the DC power source.
 
6. The electric energy storage device according to claim 1, wherein a second power source (11) is connected to at least one of the electric energy storage element and the DC power source.
 
7. The electric energy storage device according to any one of claims 1 to 6, wherein the DC power source is a feeder line connected to a transformer station and a regenerative train.
 
8. The electric energy storage device according to any one of claims 1 to 7, further comprising:

a plurality of electric energy storage element series modules each including a plurality of the electric energy storage elements connected in series, the plurality of electric energy storage element series modules being connected in parallel;

a release contactor provided between each of the plurality of electric energy storage element series modules connected in parallel and the power converter device; and

a release contactor detector which is configured to detect a number of released electric energy storage element series module and which is provided at the output current controller,

wherein the output current controller limits charging/discharging currents in accordance with the number of electric energy storage element series modules detected by the release contactor detector.


 
9. The electric energy storage device according to any one of claims 1 to 8, further comprising a detector which is configured to detect at least one of a temperature of the electric energy storage element, an RMS current, and an external temperature and which is provided at the output current controller,
wherein the output current controller is configured to limit charging/discharging currents in accordance with at least one value of the temperature of the electric energy storage element, the RMS current, and the external temperature detected by the detector.
 


Ansprüche

1. Stromspeichervorrichtung, die Folgendes umfasst:

ein Stromspeicherelement (4), das mit einer Gleichstromquelle (3) über eine Leistungsumwandlungsvorrichtung (5) verbunden ist; und

eine Ausgangsstromsteuereinheit (6), die mit der Leistungsumwandlungsvorrichtung verbunden und konfiguriert ist, um den Lade-/Entladestrom des Stromspeicherelements bezüglich der Gleichstromquelle zu steuern,

wobei die Ausgangsstromsteuereinheit (6) mit einem Spannungsdetektor (7) verbunden ist, der konfiguriert ist, um eine Spannung der Gleichstromquelle zu erfassen, einem Ladestromstärkendetektor (8), der konfiguriert ist, um eine Ladestromstärke des Stromspeicherelements zu erfassen, und einer Steuertabelle (9), in der Lade-/Entlademerkmale eingestellt sind, und

die Lade-/Entlademerkmale basierend auf der Spannung der Gleichstromquelle, die von dem Spannungsdetektor (7) erfasst wird, und der Ladestromstärke des Stromspeicherelements, die von dem Ladestromstärkendetektor (8) erfasst wird, bestimmt werden,

die Spannung der Gleichstromquelle aus mindestens einer von einer Ladestartspannung, einer Entladestartspannung, einer gesättigten Ladestromspannung und einer gesättigten Entladestromspannung des Stromspeicherelements ausgewählt ist,

wobei die Lade-/Entlademerkmale, die in der Steuertabelle (9) gespeichert sind, derart eingestellt sind, dass mindestens eine von der Ladestartspannung, der Entladestartspannung, der gesättigten Ladestromspannung und der gesättigten Entladestromspannung auf einen höheren Wert an einer höheren Ladestromstärke des Stromspeicherelements eingestellt ist als eine niedrigere Ladestromstärke davon, und

die Ausgangsstromsteuereinheit konfiguriert ist, um Lade- oder Entladevorgänge innerhalb eines Bereichs von der Entladestartspannung zu der Ladestartspannung, wenn sich die Ladestromstärke des Stromspeicherelements ändert, zu beenden.


 
2. Stromspeichervorrichtung nach Anspruch 1, wobei
eine Stromquellenspannung von der Gleichstromspannung durch die Leistungsumwandlungsvorrichtung (2), die konfiguriert ist, um Wechselstrom in Gleichstrom umzuwandeln, geliefert wird,
eine Speiseleerlaufspannung der Gleichstromquelle sich in Übereinstimmung mit einer Änderung der Wechselspannung ändert, und
die Lade-/Entlademerkmale, die in der Steuertabelle gespeichert sind, derart eingestellt sind, dass die Gleichspannung der Gleichstromquelle, die einen Ladevorgang zu dem Stromspeicherelement ausführt, eingestellt ist, um höher zu sein als die Spannung der Gleichstromquelle, die in Übereinstimmung mit der Spannungsänderung der Wechselspannung geändert wird.
 
3. Stromspeichervorrichtung nach Anspruch 2, wobei eine Nennspannung der Gleichstromquelle eine Gleichstromquellenspannung ist, wenn die Leistungsumwandlungsvorrichtung (2), die eine Spannungsquelle der Gleichstromquelle ist, einen Strom ausgibt, der einen ununterbrochenen Betrieb ermöglicht.
 
4. Stromspeichervorrichtung nach Anspruch 1, wobei die Leistungsumwandlungsvorrichtung (2), die mit dem Stromspeicherelement verbunden ist, eine Vielzahl von Leistungswandlern, die parallelgeschaltet ist, umfasst.
 
5. Stromspeichervorrichtung nach einem der Ansprüche 1 bis 4, wobei
die Leistungsumwandlungsvorrichtung (2), die mit dem Stromspeicherelement verbunden ist, eine Leistungsumwandlungsvorrichtung ist, die konfiguriert ist, um durch eine Gate-Ansteuerung auf einem Schaltelement zu arbeiten, und
die Gate-Ansteuerung beendet wird, wenn die Spannung der Gleichstromquelle niedriger ist als die Speiseleerlaufspannung und höher ist als die Nennspannung der Gleichstromquelle.
 
6. Stromspeichervorrichtung nach Anspruch 1, wobei eine zweite Leistungsquelle (11) mit mindestens einem von dem elektrischen Stromspeicherelement und der Gleichstromquelle verbunden ist.
 
7. Stromspeichervorrichtung nach einem der Ansprüche 1 bis 6, wobei die Gleichstromquelle eine Zubringerleitung ist, die mit einem Umspannwerk und einem regenerativen Zug verbunden ist.
 
8. Stromspeichervorrichtung nach einem der Ansprüche 1 bis 7, die weiter Folgendes umfasst:

eine Vielzahl serieller Stromspeicherelementmodule, die jeweils eine Vielzahl der Stromspeicherelemente, die in Serie geschaltet sind, beinhalten, wobei die Vielzahl serieller Stromspeicherelementmodule parallelgeschaltet ist;

einen Freigabeschütz, der zwischen jedem der Vielzahl serieller Stromspeicherelementmodule, die parallelgeschaltet sind, und der Leistungsumwandlungsvorrichtung bereitgestellt ist; und

einen Freigabeschütz, der konfiguriert ist, um eine Anzahl freigegebener serieller Stromspeicherelementmodule zu erfassen, und der an der Ausgangsstromsteuereinheit bereitgestellt ist,

wobei die Ausgangsstromsteuereinheit Lade-/Entladeströme in Übereinstimmung mit der Anzahl serieller Stromspeicherelementmodule, die von dem Freigabeschützdetektor erfasst wird, einschränkt.


 
9. Stromspeichervorrichtung nach einem der Ansprüche 1 bis 8, die weiter einen Detektor umfasst, der konfiguriert ist, um mindestens eine von einer Temperatur des Stromspeicherelements, einem Effektivstrom und einer externen Temperatur zu erfassen, und der an der Ausgangsstromsteuereinheit bereitgestellt ist,
wobei die Ausgangsstromsteuereinheit konfiguriert ist, um Lade-/Entladeströme in Übereinstimmung mit mindestens einem Wert der Temperatur des Stromspeicherelements, des Effektivstroms und der externen Temperatur, die von dem Detektor erfasst werden, einzuschränken.
 


Revendications

1. Dispositif de stockage d'énergie électrique comprenant :

un élément de stockage d'énergie électrique (4) connecté à une source de courant continu CC (3) via un dispositif convertisseur de puissance (5) ; et

un dispositif de commande de courant de sortie (6) qui est connecté au dispositif convertisseur de puissance et qui est configuré pour commander un courant de chargement/déchargement de l'élément de stockage d'énergie électrique par rapport à la source de courant continu CC,

le dispositif de commande de courant de sortie (6) étant connecté à un détecteur de tension (7) configuré pour détecter une tension de la source de courant continu CC, à un détecteur de régime de chargement (8) configuré pour détecter un régime de chargement de l'élément de stockage d'énergie électrique et à une table de commande (9) dans laquelle sont réglées des caractéristiques de chargement/déchargement, et

les caractéristiques de chargement/déchargement sont déterminées sur la base de la tension de la source de courant continu CC détectée par le détecteur de tension (7) et du régime de chargement de l'élément de stockage d'énergie électrique détecté par le détecteur de régime de chargement (8),

la tension de la source de courant continu CC est sélectionnée dans au moins l'une d'une tension de démarrage de chargement, d'une tension de démarrage de déchargement, d'une tension saturée de courant de chargement et d'une tension saturée de courant de déchargement de l'élément de stockage d'énergie électrique,

les caractéristiques de chargement/déchargement stockées dans la table de commande (9) étant réglées de sorte qu'au moins l'une de la tension de démarrage de chargement, de la tension de démarrage de déchargement, de la tension saturée de courant de chargement et de la tension saturée de courant de déchargement soit réglée à une valeur plus élevée à un régime de chargement plus élevé de l'élément de stockage d'énergie électrique qu'à un régime de chargement inférieur de celui-ci, et

le dispositif de commande de courant de sortie est configuré pour terminer les opérations de chargement ou de déchargement dans une plage allant de la tension de démarrage de déchargement à la tension de démarrage de chargement lorsque le régime de chargement de l'élément de stockage d'énergie électrique varie.


 
2. Dispositif de stockage d'énergie électrique selon la revendication 1, dans lequel :

une tension de source de courant venant de la tension CC est fournie à travers le dispositif convertisseur de puissance (2) configuré pour convertir une tension de courant alternatif CA en tension de courant continu CC,

une tension d'alimentation sans charge de la source de courant continu CC varie conformément à une variation dans la tension de courant alternatif CA, et

les caractéristiques de chargement/déchargement stockées dans la table de commande sont réglées de sorte que la tension de courant continu CC de la source de courant continu CC effectuant une opération de chargement sur l'élément de stockage d'énergie électrique soit réglée pour être plus élevée que la tension de la source de courant continu CC modifiée conformément à la variation de tension dans la tension alternative CA.


 
3. Dispositif de stockage d'énergie électrique selon la revendication 2, dans lequel une tension nominale de la source de courant continu CC est une tension de source de courant continu CC lorsque le dispositif convertisseur de puissance (2) qui est une source de tension de la source de courant continu CC délivre un courant qui permet un fonctionnement continu.
 
4. Dispositif de stockage d'énergie électrique selon la revendication 1, dans lequel le dispositif convertisseur de puissance (2) connecté à l'élément de stockage d'énergie électrique comprend une pluralité de convertisseurs de puissance connectés en parallèle.
 
5. Dispositif de stockage d'énergie électrique selon l'une quelconque des revendications 1 à 4, dans lequel
le dispositif convertisseur de puissance (2) connecté à l'élément de stockage d'énergie électrique est un dispositif convertisseur de puissance qui est configuré pour opérer à travers une commande de grille sur un élément de commutation, et
la commande de grille est terminée lorsque la tension de la source de courant continu CC est inférieure à la tension d'alimentation sans charge et est supérieure à la tension nominale de la source de courant continu CC.
 
6. Dispositif de stockage d'énergie électrique selon la revendication 1, dans lequel une deuxième source de courant (11) est connectée à au moins l'un de l'élément de stockage d'énergie électrique et de la source de courant continu CC.
 
7. Dispositif de stockage d'énergie électrique selon l'une quelconque des revendications 1 à 6, dans lequel la source de courant continu CC est une ligne d'alimentation connectée à une station de transformation et à un train régénérateur.
 
8. Dispositif de stockage d'énergie électrique selon l'une quelconque des revendications 1 à 7, comprenant en outre :

une pluralité de modules sériels d'éléments de stockage d'énergie électrique comprenant chacun une pluralité des éléments de stockage d'énergie électrique connectés en série, la pluralité des modules sériels d'éléments de stockage d'énergie électrique étant connectés en parallèle ;

un contacteur de libération disposé entre chacun de la pluralité de modules sériels d'éléments de stockage d'énergie électrique connectés en parallèle et le dispositif convertisseur de puissance ; et

un détecteur de contacteur de libération qui est configuré pour détecter un certain nombre de modules sériels d'éléments de stockage d'énergie électrique libérés et qui est disposé au niveau du dispositif de commande de courant de sortie,

dans lequel le dispositif de commande de courant de sortie limite les courants de chargement/déchargement conformément au nombre de modules sériels d'éléments de stockage d'énergie électrique détectés par le détecteur de contacteur de libération.


 
9. Dispositif de stockage d'énergie électrique selon l'une quelconque des revendications 1 à 8, comprenant en outre un détecteur qui est configuré pour détecter au moins l'un d'une température de l'élément de stockage d'énergie électrique, d'un courant RMS et d'une température externe et qui est disposé au niveau du dispositif de commande de courant de sortie,
dans lequel le dispositif de commande de courant de sortie est configuré pour limiter les courants de chargement/déchargement conformément à au moins une valeur de la température de l'élément de stockage d'énergie électrique, du courant TMS et de la température externe détectée par le détecteur.
 




Drawing























Cited references

REFERENCES CITED IN THE DESCRIPTION



This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description