Charging device, electric vehicle, and electric vehicle charging method

Abstract

To more safely charge a storage battery mounted on an electric vehicle by validating output only when necessary and setting a condition for validating output to be the condition which is unlikely to be simulated by disturbance.SOLUTION: A charging device charges a driving storage battery which is mounted on an electric vehicle through a train line. When voltage is applied from the electric vehicle through the train line, the charging device starts charging of the storage battery.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a charging device, an electric vehicle, and a method for charging an electric vehicle. [Background technology]

[0002] In recent years, the energy density and power density of storage batteries have increased, and electric vehicles equipped with storage batteries that can run on non-electrified lines have been introduced. In such electric vehicles, storage batteries are used to secure input power to an inverter device that drives a main motor and an auxiliary power supply device that supplies power to vehicle auxiliaries such as air conditioners.

[0003] In recent years, in order to reduce the environmental impact, diesel-powered railcars have been replaced with battery-powered electric railcars in sections that include non-electrified sections. However, there is a limit to the number of batteries that can be installed on a vehicle due to the equipment used, and in sections that require a large amount of electricity, such as long lines or mountainous lines, sufficient battery capacity cannot be secured. In such cases, it is necessary to install additional charging equipment in the non-electrified sections to charge the batteries.

[0004] For example, Patent Document 1 discloses a means for providing a plurality of charging facilities on the route on which electric vehicles run, and charging the drive batteries of the electric vehicles via electric railroad tracks. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2011-004546 A Summary of the Invention [Problem to be solved by the invention]

[0006] The inventors have conducted extensive research into charging electric vehicles using a charging device and have come to the following findings.

[0007] To increase the range of electric vehicles, it is effective to provide charging facilities at midpoints along the route. However, when charging the drive battery at a midpoint along the route, the charging time is limited due to restrictions such as train schedules. In order to fully recover the charge in a limited time, charging with a large amount of power is necessary.

[0008] When charging via overhead lines, from the viewpoint of commonality with existing electric vehicle drive systems and enabling electric vehicles to be operated as trains in electrified sections, it is desirable for the voltage applied by the charging device to the overhead lines for charging to be equivalent to the voltage specifications of the overhead lines from which general electric vehicles draw power, and in this case, a high voltage is applied to the output of the charging device. For example, a voltage of 20,000V AC is applied in the case of AC overhead lines, and 1,500V DC is applied in the case of DC overhead lines.

[0009] A state in which a high voltage is applied to the output of a charging device poses the potential risk of accidents such as ground faults and electric shock. Therefore, from a safety standpoint, it is desirable for the charging device to apply voltage to the output terminal only when necessary, and it is desirable for the conditions for enabling the output to be conditions that are unlikely to be simulated by external disturbances, etc.

[0010] However, Patent Document 1 only describes the electrical flow during charging, with regard to charging of electric railcars using the normal power supply equipment, saying, "This describes a case where the normal power supply equipment is normal and the train runs while charging only using the normal power supply equipment....When charging the on-board power storage device 18, the train receives power from the electric rail line 26 via the current collector 22 at a location where the normal power supply equipment is installed, and charges the power storage device 18 via the step-up / step-down chopper device 19." (paragraphs 0066-0068) and does not state the conditions for enabling the output of the normal power supply equipment.

[0011] Regarding the charging of electric railcars by the emergency inter-station power supply equipment, the document only describes the electrical flow during charging, saying, "This section describes an example of operation when charging the on-board power storage device 18 at a ground charging post of the emergency inter-station power supply equipment. When charging the on-board power storage device 18, the train is stopped near a location where a ground charging post 24 is installed, and the on-board connector 23a on the on-board drive system side and the ground charging post side connector 23b are connected using a dedicated cable. Furthermore, the switch 32a switches the connection to a state where the inverter device 20 and the on-board connector 23a are connected. The input power of the power storage device 18 is borne by the commercial power source 27. The inverter device 20 converts the AC power from the ground charging post into DC power, the step-up / step-down chopper device 19 steps down the DC power, and the power storage device 18 is charged until the charge amount falls within a certain range." (paragraphs 0069-0070).

[0012] Therefore, an object of the present invention is to more safely charge a storage battery installed in an electric vehicle by enabling output only when necessary and by setting the conditions for enabling the output to be conditions that are unlikely to be simulated by external disturbances. [Means for solving the problem]

[0013] The present invention has been made in consideration of the above-mentioned problems. One example of the present invention is a charging device that charges a drive battery mounted on an electric vehicle via electric train lines, and starts charging the battery when a voltage is applied from the electric vehicle via the electric train lines. Effect of the Invention

[0014] According to the present invention, the output is enabled only when necessary, and the conditions for enabling the output are unlikely to be simulated by external disturbances, thereby making it possible to charge the storage battery installed in the electric vehicle more safely.

[0015] Problems, configurations and effects other than those described above will become apparent from the following description of the preferred embodiment of the invention. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 shows a schematic configuration of an electric vehicle charging system for AC charging in the embodiment. [Diagram 2] FIG. 2 shows a schematic configuration of an electric vehicle charging system of a direct current charging specification according to the embodiment. [Diagram 3] FIG. 3 shows a schematic configuration of the AC output specification charging device 10a. [Figure 4] FIG. 4 shows a schematic configuration of a DC output specification charging device 10b. [Diagram 5] FIG. 5 shows a schematic configuration of an AC output specification charging device 10a equipped with a means for improving safety. [Figure 6] FIG. 6 shows a schematic configuration of a DC output specification charging device 10b equipped with a means for improving safety. [Figure 7] FIG. 7 shows a schematic configuration of an electric vehicle charging system equipped with an on-vehicle position sensor 41. [Figure 8] FIG. 8 shows a schematic configuration of an electric vehicle charging system equipped with a position detection ground device 52. [Figure 9] FIG. 9 shows a flow of charging the drive battery 6 mounted on an AC electric vehicle 40a by the AC output type charging device 10a. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, the embodiments will be described in detail with reference to the drawings as appropriate. Note that the same reference numerals are used to designate common parts in each drawing, and duplicated explanations will be omitted. Also, some components (sensors, controllers, etc.) may be omitted in each drawing.

[0018] (Electric vehicle charging system configuration) Fig. 1 is a diagram showing a schematic configuration of an electric vehicle charging system with AC charging specifications in this embodiment. The AC output specification charging device 10a has a pair of output terminals, and can convert the power obtained from the power source 20 into power capable of charging the drive storage battery 6 of the AC electric vehicle 40a, and output it to the electric rail 101 and the ground potential 100 which is the return line. The AC electric vehicle 40a can receive the output power of the AC output specification charging device 10a via the current collector 1 and the ground potential 100. Here, the power source 20 can be, for example, a power source from a grid, a power source from a storage battery, a power source from solar power generation, etc., and may be a combination of these, or may be built into the charging device.

[0019] The electric train line 101 may take any of several forms, such as an overhead line or a third rail. Similarly, the return path is illustrated in FIG. 1 as using rails 102, but may take other forms.

[0020] The current collector 1 is connected to an on-board main transformer 2, which can convert the voltage to a voltage suitable for input to an on-board AC-DC converter device 3a at the downstream stage. An on-board inverter device 4, a drive battery 6, and an auxiliary power supply device 7 are connected to the output side of the on-board AC-DC converter device 3a.

[0021] When the AC electric vehicle 40a runs, the on-board inverter device 4 and the auxiliary power supply device 7 are driven by the energy of the drive storage battery 6, which in turn drives the main motor 5 and the auxiliary power supply load 8 to run the vehicle.

[0022] An outline of the operation during charging of the drive battery 6 will be described. When the driver operates the control device (not shown) to recognize the need for charging, or when the AC electric vehicle 40a recognizes a request for charging by automatically determining the need for charging using information such as the state of charge (SOC) of the drive battery 6, the on-board AC-DC converter device 3a transmits AC power to the on-board main transformer 2 using the energy of the drive battery 6, and applies AC voltage to the electric rail 101 via the current collector 1. The AC output charging device 10a detects the application of voltage to the electric rail 101, and recognizes that the AC electric vehicle 40a is in a position where charging is possible and is requesting charging. The AC output charging device 10a starts outputting charging power to the electric rail 101, and the AC electric vehicle 40a charges the drive battery 6 via the current collector 1, the on-board main transformer 2, and the on-board AC-DC converter device 3a.

[0023] At this time, the on-board AC-DC converter device 3a performs control operations according to the voltage, frequency, and phase on the on-board main transformer 2 side and the voltage of the drive storage battery 6 to be charged, controls the voltage and current output to the DC side, and controls the charging current to the drive storage battery 6. For example, a desired charging current can be obtained by preventing a decrease in the charging current by increasing the conduction rate when the voltage on the on-board main transformer 2 side drops, or by stabilizing the charging current by changing the conduction rate in response to changes in the frequency and phase on the on-board main transformer 2 side.

[0024] Figure 2 is a diagram showing the schematic configuration of an electric vehicle charging system with DC charging specifications in this embodiment. Since there are many commonalities with Figure 1, only the differences from Figure 1 will be explained. In an electric vehicle charging system with DC charging specifications, DC power is provided from a DC output specification charging device 10b to a DC electric vehicle 40b via an electric rail line 101 to charge the drive storage battery 6. The DC power obtained by the current collector 1 enters an on-board DC-DC converter device 3b and charges the drive storage battery 6.

[0025] When charging is to be started, either by a driver's operation or when the DC electric vehicle 40b recognizes a charging request based on information such as the state of charge (SOC) of the drive battery 6, the on-board DC-DC converter device 3b applies a DC voltage to the electric rail 101 via the current collector 1 using the energy of the drive battery 6. The DC output specification charging device 10b detects the application of voltage to the electric rail 101 and enables charging power output.

[0026] (Charging device configuration) The configuration of the AC output charging device 10a will be described with reference to Fig. 3. The AC output charging device 10a is composed of a charging device input transformer 21, an AC-DC power converter 22, a filter capacitor 23, a voltage sensor 24 for a filter capacitor voltage, a DC-AC power converter 25, and a charging device output transformer 26, and has a function of converting the power obtained from the power source 20 into AC power suitable for feeding to the AC electric vehicle 40a. The AC power suitable for feeding to the AC electric vehicle 40a is, for example, substantially the same power as that of an overhead line installed on the line on which the AC electric vehicle 40a runs. This allows charging to be performed without adding a device for charging by the AC output charging device 10a to the AC electric vehicle 40a, thereby reducing costs.

[0027] The power obtained from the power source 20 enters the charging device input transformer 21, where the voltage is stepped down, and enters the AC-DC power converter 22. A filter capacitor 23 is provided on the DC output side for voltage stabilization, and is connected to the DC-AC power converter 25 in the subsequent stage. As described in detail below, unless the filter capacitor 23 is charged, the DC-AC power converter 25 cannot be started, so the filter capacitor 23 has a function of contributing to the safety of charging by the AC output type charging device 10a as one of the charging start conditions of the AC output type charging device 10a. The output of the DC-AC power converter 25 is stepped up by the charging device output transformer 26, and is supplied to the AC electric car 40a via the electric railroad tracks 101.

[0028] When charging is not performed, at least one of the AC-DC power converter 22 and the DC-AC power converter 25 is stopped to disable output, and the electric rail 101 is in a non-pressurized state.

[0029] When the electric railroad car 101 is energized in response to a charge request from the AC electric car 40 a, the filter capacitor 23 is charged in the path of the charging device output transformer 26 and the DC-AC power converter 25 .

[0030] When the detected voltage of the filter capacitor voltage sensor 24 reaches a certain level or higher, a charging request is recognized, and the AC-DC power converter 22 and the DC-AC power converter 25 are started to enable the charging power output.

[0031] The configuration of the DC output specification charging device 10b is shown in Figure 4. The difference from the AC output specification charging device 10a is that since the output is DC power, the charging device output transformer 26 is not required, and a DC-DC power converter 27 is provided instead of the DC-AC power converter 25. During charging, when the electric railcar 40b applies pressure to the overhead line 101, the filter capacitor 23 is charged, and when the detected voltage of the filter capacitor voltage sensor 24 reaches a certain voltage or higher, a charging request is recognized, and the AC-DC power converter 22 and the DC-DC power converter 27 are started to enable the charging power output.

[0032] As described above, by using the charging of the filter capacitor 23 as a charging request from the electric car 40 (AC electric car 40a or DC electric car 40b), it is possible to disable the charging power output except when charging. Since the capacity of the filter capacitor 23 is several mF to several tens of mF in a typical design, it is extremely unlikely that the detection value of the voltage sensor 24 for the filter capacitor voltage will rise to the determination threshold for a charging request due to disturbances such as static electricity, and it is possible to realize a highly safe charging device with low possibility of erroneously recognizing a charging request.

[0033] (Methods to improve the safety of charging equipment) Means for improving the safety of the charging device 10 (AC output type charging device 10a or DC output type charging device 10b) will be described with reference to Figs.

[0034] FIG. 5 shows a configuration in which a contactor 33, a voltage sensor 34 for the electric rail voltage, a current sensor 35 for the charging device output, and a capacitor discharge circuit 39 have been added as means for further enhancing safety, compared to FIG. 3 which shows the basic configuration of the charging device 10a with AC output.

[0035] By adding the contactor 33 and keeping the contactor 33 open except during charging operation, it is possible to physically cut off the power transmission path in the AC output specification charging device 10a. Since it is possible to physically cut off the path, it is possible to configure a system in which voltage is not applied to the electric rail 101 from the AC output specification charging device 10a even if the software of the AC-DC power converter 22 or the DC-AC power converter 25 goes out of control and these operate except during charging.

[0036] In addition, in FIG. 5, the contactor 33 is disposed between the DC-AC power converter 25 and the charging device output transformer 26, but in order to achieve the above-mentioned effect, the contactor 33 may be disposed at any position where the power transmission path from the power source 20 to the electric rail 101 can be electrically interrupted.

[0037] Here, if the contactor 33 is disposed between the filter capacitor 23 and the electric rail 101, for example, between the DC-AC power converter 25 and the charging device output transformer 26, it is necessary to make the contactor 33 conductive in order to charge the filter capacitor 23. Therefore, if such an arrangement is selected, it is necessary to make the contactor 33 conductive when a charging start request is received from the AC electric car 40a. One method for this is to dispose a voltage sensor 34 for the electric rail voltage. Since the AC electric car 40a energizes the electric rail 101 as a charging request, when the voltage sensor 34 for the electric rail voltage detects the energization of the electric rail 101, the contactor 33 is closed and the filter capacitor 23 is charged with power from the AC electric car 40a, and the charging power output is enabled after the voltage sensor 24 for the filter capacitor voltage detects the charging of the filter capacitor 23.

[0038] When charging of the AC electric car 40a from the AC output charging device 10a is completed, the output of charging power is disabled to ensure safety. A charging device output current sensor 35 is provided as a means for detecting the end of charging. The charging state information of the drive storage battery 6 is recognized by the AC electric car 40a, and when the AC electric car 40a determines that charging is complete based on conditions such as the state of charge (SOC) reaching a predetermined value, or when charging is terminated based on the decision of the driver, the AC electric car 40a stops charging and the current from the AC output charging device 10a to the electric rail 101 stops. This current is monitored by the charging device output current sensor 35, and when the current falls below a certain threshold, the end of charging of the AC electric car 40a is detected, and the charging power output is stopped by stopping the AC-DC power converter 22 and the DC-AC power converter 25 and opening the contactor 33.

[0039] A further measure to improve safety is to provide a capacitor discharge circuit 39. Even if the charging power output is stopped after the charging operation, a charge remains in the filter capacitor 23 and a high voltage is applied across both ends. Since there is a risk that the voltage of the filter capacitor 23 will be output to the electric rail 101 due to an abnormality in the downstream DC-AC power converter or the contactor 33, it is desirable to discharge the filter capacitor 23 when the charging operation is completed.

[0040] The capacitor discharge circuit 39 is composed of a capacitor discharge switching element 37 and a discharge resistor 38. When the capacitor discharge switching element 37 is turned on, the charge of the filter capacitor 23 is consumed by the discharge resistor 38, and the filter capacitor 23 is discharged.

[0041] Fig. 6 is an example in which the same content as in Fig. 5 is applied to a DC output specification charging device 10b. The difference from the AC output specification charging device 10a is that the DC-AC power converter 25 is replaced with a DC-DC power converter 27, and the charging device output transformer 26 is not required.

[0042] (Structure and operation of electric vehicles) The configurations and operations of the AC electric car 40a and the DC electric car 40b will be described with reference to Figs.

[0043] First, the configuration and operation of an AC electric car 40a will be described with reference to Fig. 1. The AC electric car 40a comprises a current collector 1, an on-board main transformer 2, an on-board AC-DC converter device 3a, an on-board inverter device 4, a main motor 5, a drive battery 6, an auxiliary power supply device 7, and an auxiliary power supply device load 8.

[0044] When the AC electric car 40a runs in a non-electrified section, during powering, the electric power from the traction battery 6 is used to drive the on-board inverter device 4 and the auxiliary power supply device 7, and to operate the main motor 5 and the auxiliary power supply device load 8. During deceleration, electrical control is performed using the main motor 5 and the on-board inverter device 4, and the traction battery 6 is charged.

[0045] When the AC electric car 40a runs in an electrified section, it obtains power for driving from the electric train line via the current collector 1. When powering, the power obtained by the current collector 1 is stepped down by the on-board main transformer 2 and input to the on-board AC-DC converter device 3a to be converted into DC power. The DC power is used to drive the on-board inverter device 4 and auxiliary power supply device 7 to allow the car to run. When decelerating, electrical control is performed using the main motor 5 and the on-board inverter device 4, and the recovered energy is returned to the electric train line or used to charge the drive storage battery 6.

[0046] Next, the configuration of the DC electric vehicle 40b will be described with reference to Fig. 2. The differences from the AC electric vehicle 40a are that the on-board main transformer 2 is not required, and the on-board AC-DC converter device 3a is replaced with an on-board DC-DC converter device 3b. Note that in a DC electric vehicle that does not have a drive storage battery 6, it is possible to adopt a configuration in which the input of the current collector 1 is directly connected to the on-board inverter device 4 without providing the on-board DC-DC converter device 3b, but in the case of the DC electric vehicle 40b that has a drive storage battery 6, the on-board DC-DC converter device 3b is required to control charging of the drive storage battery 6.

[0047] The drive storage battery 6 can be charged when power is flowing into the DC voltage stage of the electric vehicle 40 to which the output terminal of the drive storage battery 6 is connected. Specifically, for example, this occurs when the electric vehicle 40 is connected to overhead lines in an electrified section, when the electric vehicle 40 is operating under electrical control while traveling in a non-electrified section and decelerating, when the electric vehicle 40 is connected to the charging device 10 according to this embodiment, etc.

[0048] This embodiment is characterized in that the electric car 40 applies voltage to the electric rail line 101 via the current collector 1 in response to a request to charge the drive battery 6, and the voltage used for this application uses the energy of the drive battery 6, and in the case of the AC electric car 40a, it is applied by an on-board AC-DC converter device and on-board main transformer 2, and in the case of the DC electric car 40b, it is applied by an on-board DC-DC converter device 3b.

[0049] (Method for improving safety of charging condition determination using position detection means) A method for improving the safety of charging condition determination using a position detection means will be described with reference to Figures 7 and 8. In the following, a combination of an AC output specification charging device 10a and an AC electric vehicle 40a will be described, but the same effect can be obtained with a combination of a DC output specification charging device 10b and a DC electric vehicle 40b.

[0050] 7 shows an example in which an on-board position sensor 41 is mounted on an AC electric car 40a as a position detection means. When the on-board position sensor 41 detects that the AC electric car 40a is in a position where it can be charged by the AC output type charging device 10a, the detection result is treated as one of the AND conditions for permission conditions for the AC electric car 40a to apply electric power to the overhead contact line in order to request the start of charging.

[0051] Here, the position where the AC electric car 40a can be charged by the AC output charging device 10a is, for example, a position where the electric train line 101 connected to the AC output charging device 10a and the pantograph of the AC electric car 40a can come into contact. Treating as one of the AND conditions of the permission conditions means that the progression of the hardware or software sequence at the start of charging is stopped until the detection result is satisfied. For example, there is a method of prohibiting the sending of a charging start command sent by a control device (not shown) to the on-board AC-DC converter device 3a by the operation of a driver or automatic judgment until the detection result is satisfied, or a method of prohibiting the current collector 1 from being connected to the electric train line 101 until the detection result is satisfied.

[0052] As a result, it is possible to prevent the AC electric car 40a from applying voltage to the current collector 1 at a location other than where the AC electric car 40a can be charged by the AC output type charging device 10a, thereby improving safety.

[0053] FIG. 8 shows a schematic configuration of an electric vehicle charging system that uses a position detection ground device 52 as a position detection means. The position detection ground device 52 is a ground device that detects that the AC electric vehicle 40a is in a position where it can be charged from the AC output specification charging device 10a and issues the detection result as a ground charging position confirmation flag. By sending the detection result to the AC output specification charging device 10a as a permission condition for starting charging, the output of the AC output specification charging device 10a can be invalidated except when the AC electric vehicle 40a is in a position where it can be charged. Furthermore, by sending the detection result to the AC electric vehicle 40a and having the position detection information receiving device 51 receive it, the same effect as when the on-board position sensor 41 is used can be obtained. Also, the same effect can be obtained even if the position detection ground device 52 sends the detection result directly to the AC electric vehicle 40a instead of to the AC output specification charging device 10a and has the position detection information receiving device 51 receive it.

[0054] (Charging sequence when charging an electric vehicle using a charging device) A charging sequence when an AC electric vehicle 40a is charged by the AC output type charging device 10a according to this embodiment will be described with reference to FIG.

[0055] Step1: It is determined whether the AC electric vehicle 40a is in a position where charging is possible. The on-board position sensor 41 or the position detection ground device 52 is used for this determination. If the determination result is Yes, the charging operation can proceed to Step 2 and thereafter. If the determination result is No, this charging sequence is terminated. This step is one of the conditions for safely enabling the output of the AC output specification charging device 10a, and may be omitted.

[0056] Step2: The pantograph is raised, and the current collector 1 and the electric rail 101 are electrically connected.

[0057] Step3: The on-board AC-DC converter device 3 a is started, and the AC electric car 40 a applies voltage to the electric railcar 101 using the energy of the traction storage battery 6 .

[0058] Step4: The electric rail voltage sensor 34 provided in the AC output charging device 10a detects whether the voltage of the electric rail 101 is equal to or higher than a predetermined threshold. If the result is Yes, the AC output charging device 10a recognizes that the electric rail 101 is pressurized by the AC electric car 40a and that there is a charging request from the AC electric car 40a. If the result is No, this sequence ends.

[0059] Step5: The AC output charging device 10a closes the contactor 33 to conduct the power transmission path in the AC output charging device 10a. This causes the AC electric vehicle 40a to start charging the filter capacitor 23 in the AC output charging device 10a. Steps 4 and 5 are one of the conditions for safely enabling the output of the AC output charging device 10a, and may be omitted.

[0060] Step6: The charging of the filter capacitor 23 started in Step 5 increases the voltage of the filter capacitor 23. This voltage is monitored by the filter capacitor voltage sensor 24, and if this voltage reaches a voltage equal to or higher than a predetermined threshold within a predetermined time (if Yes), the process moves to the next step. If this voltage does not reach the threshold (if No), some abnormality may have occurred in the AC output specification charging device 10a or the AC electric vehicle 40a, so the charging sequence is stopped.

[0061] Step7: When the filter capacitor 23 is charged to a value equal to or higher than the threshold value, the AC output specification charging device 10a starts the AC-DC power converter 22 and the DC-AC power converter 25. This starts charging the drive storage battery 6 by the AC output specification charging device 10a. At that time, the in-vehicle AC-DC converter device 3a performs charging control.

[0062] Step8: It is determined whether charging of the drive storage battery 6 has started within a predetermined time. If charging has started (Yes), the process proceeds to the next step, but if for some reason the vehicle-mounted AC-DC converter device 3a does not start the charging operation within the predetermined time (No), it is determined that there is some abnormality in the AC electric vehicle 40a, and this charging sequence is terminated.

[0063] Step9: The control device of the AC electric vehicle 40a (not shown) monitors the charging state of the drive battery 6 and determines whether a charging completion condition such as a predetermined condition is met. For example, the predetermined condition is met when a predetermined charging rate (SOC: State Of Charge) is reached. When the charging completion condition is met, the process proceeds to the next step.

[0064] Step10: When the charging completion condition described in the previous step is met, the operation of the in-vehicle AC-DC converter device 3a is stopped, and charging is stopped.

[0065] Step11: Since the current flowing from the AC output specification charging device 10a to the train line 101 stops due to the charging being stopped as described in the previous step, whether or not the current is below a threshold value is detected using the charging device output current sensor 35. If it is detected that the current is below the threshold value, the AC output specification charging device 10a determines that the AC electric car 40a has finished charging, and proceeds to the next step.

[0066] Step12: When the AC output specification charging device 10a detects the end of charging of the AC electric vehicle 40a using the method described in the previous step, the output of charging power is stopped. Specifically, the AC-DC power converter 22 and the DC-AC power converter 25 of the AC output specification charging device 10a are stopped, and the contactor 33 is opened, thereby stopping the output of the AC output specification charging device 10a.

[0067] Step13: Finally, the filter capacitor 23 is discharged by the capacitor discharge circuit 39. Since the DC-AC power converter 25 cannot be started unless the filter capacitor 23 is charged, the output of the AC output specification charging device 10a can be more reliably disabled until the filter capacitor 23 is charged again by the AC electric car 40a.

[0068] The functions that can be added for each step and the effects that can be obtained are described below.

[0069] In Step 3, the AC electric car 40a energizes the electric rail 101 using the energy of the traction battery 6, but if the traction batteries 6 are configured in parallel, it is desirable to energize the electric rail 101 using the energy of only the traction battery 6 with a high charge, for example, the traction battery 6 with a charge rate equal to or higher than a predetermined threshold, in order to prevent further consumption of the traction batteries 6 with a low charge. This makes it possible to suppress deterioration of the traction batteries 6 due to overdischarge, etc.

[0070] In addition, the frequency of the charging power output by the AC output charging device 10a in Step 7 may be the same as that of a general electric train line, for example, an electric train line installed in an electrified section of the same line on which the AC electric car 40a runs, or may be a different frequency, so that information such as the type of the AC output charging device 10a can be transmitted from the AC output charging device 10a to the AC electric car 40a. The AC output charging device 10a may have a plurality of specifications depending on the capacity, space, cost, etc. of the power source for each installation location. Therefore, by changing the frequency during charging output by the AC output charging device 10a, the AC electric car 40a can be made to identify the type of the AC output charging device 10a, which can be used to change the setting of the maximum value of the charging current that the AC electric car 40a takes in from the electric train line 101 for charging. This can prevent the power source 20 from being overloaded. For example, if the power source 20 is a system, the risk of a power outage can be reduced.

[0071] As an example, when the capacity of the power source 20 to which the AC output charging device 10a is connected is relatively small and it is necessary to limit the output to ensure the stability of the power supply system, the frequency of the charging power output by the AC output charging device 10a to the AC electric vehicle 40a is changed to a standard value, for example, from 60 Hz to 57 Hz. The AC electric vehicle 40a determines the frequency using the on-board AC-DC converter device 3a and recognizes that the AC output charging device 10a to which the vehicle is connected has a current limit. As a result, the on-board AC-DC converter device 3a limits the charging current to the drive storage battery 6 and performs charging operation so as not to exceed the output current limit value of the AC output charging device 10a.

[0072] Next, a charging sequence when the DC electric vehicle 40b is charged by the DC output specification charging device 10b according to this embodiment will be described, focusing on differences from the case when the AC electric vehicle 40a is charged by the AC output specification charging device 10a.

[0073] This charging sequence is the same as Step 1 to Step 13 in the charging sequence, except that "AC electric vehicle 40a" is replaced with "DC electric vehicle 40b," "AC output specification charging device 10a" is replaced with "DC output specification charging device 10b," "vehicle-mounted AC-DC converter device 3a" is replaced with "vehicle-mounted DC-DC converter device 3b," and "DC-AC power converter 25" is replaced with "DC-DC power converter 27" (referred to as Step 1b to Step 13b, respectively). This charging sequence can provide the same effects as when charging an AC electric vehicle 40a with an AC output specification charging device 10a.

[0074] Furthermore, in Step 3b, the DC electric car 40b energizes the electric rail 101 using the energy of the traction battery 6. It is preferable to energize the electric rail 101 using the energy of only the traction battery 6 having a high charging rate, which also makes it possible to suppress deterioration of the traction battery 6.

[0075] (Effects of the embodiment) According to this embodiment, the electric vehicle 40 uses the drive storage battery 6 when applying voltage to the charging device 10 via the electric rail line 101, but this voltage is a high voltage that is unlikely to be simulated by external disturbances, and the output of the charging device 10 can be safely enabled. At this time, the electric vehicle 40 applies voltage using only storage batteries with high charging rates, thereby preventing over-discharging of the storage batteries and suppressing deterioration of the storage batteries.

[0076] Furthermore, according to this embodiment, unless the filter capacitor 23 is being charged from the electric car 40 via the electric railcar line 101, the DC-AC power converter 25 (DC-DC power converter 27) cannot be started, and therefore the output from the charging device 10 can be safely enabled.

[0077] Furthermore, according to this embodiment, the charging device 10 is equipped with the voltage sensor 34 for the electric rail voltage and the contactor 33. When a voltage is applied to the electric rail 101 by the electric car 40 and it is detected that the voltage of the electric rail 101 has reached a predetermined voltage or higher, the charging device 10 can start charging the filter capacitor 23 by closing the contactor 33, thereby enabling the output of the charging device 10 even more safely.

[0078] Furthermore, according to this embodiment, the determination by a position detection means such as the on-board position sensor 41 or the position detection ground device 52 that the electric vehicle 40 is parked in a position where it can be charged is made one of the AND conditions for enabling the output of the charging device 10, thereby making it possible to enable the output of the charging device 10 even more safely.

[0079] Furthermore, according to this embodiment, when the charging completion condition is met, the electric car 40 stops the operation of the on-board AC-DC converter device 3a (on-board DC-DC converter device 3b). As a result, the current flowing through the electric rail 101 becomes small, but the charging device 10 monitors the current in the electric rail 101 using the charging device output current sensor 35, and when it detects that the current in the electric rail 101 has fallen below a predetermined threshold, it quickly stops charging, thereby reducing the risk of electric shock and improving safety.

[0080] Furthermore, according to this embodiment, after charging is stopped, the filter capacitor 23 is quickly discharged by the capacitor discharge circuit 39 to reduce the voltage, thereby reducing the risk of voltage being output from the filter capacitor 23 to the electric rail 101, and further improving safety.

[0081] Furthermore, according to this embodiment, the charging device 10 is capable of charging with a large amount of power during charging, but when not charging, the charging device 10 disables the output by stopping at least one of the AC-DC power converter 22 or the DC-AC power converter 25 (DC-DC power converter 27), and the electric rail 101 is in an unpressurized state. Therefore, when not charging, the risk of electric shock or the like caused by the electric rail 101 can be reduced, and safety can be improved.

[0082] Furthermore, according to this embodiment, if the control device (not shown) of the electric car 40 cannot detect charging of the traction battery 6 even after a predetermined time has elapsed since starting application of voltage to the electric rail, the electric car 40 determines that some abnormality has occurred and stops applying voltage to the electric rail 101. This prevents high voltage from being applied to the electric rail 101 except when charging, reduces the risk of electric shock, and increases safety.

[0083] Furthermore, according to this embodiment, by setting the frequency of the charging power output by the AC output specification charging device 10a to a frequency different from that of a general electrified overhead line, information such as the type of the AC output specification charging device 10a can be transmitted from the AC output specification charging device 10a to the AC electric car 40a, and overloading of the power source 20 can be prevented.

[0084] Furthermore, according to this embodiment, the activation of the output of the charging device 10 by the electric vehicle 40 and the charging of the drive battery 6 by the charging device 10 are performed via the electric railroad tracks 101, so there is no need to add terminals for charging to the electric vehicle 40 and the charging device 10, thereby reducing costs.

[0085] The present invention is not limited to the above-mentioned embodiment, and various modifications are included. For example, the above-mentioned embodiment has been described in detail to easily explain the present invention, and is not necessarily limited to those having all the described configurations. It is also possible to add, delete, or replace a part of the configuration of the embodiment with another configuration. In addition, each of the above-mentioned configurations, functions, processing units, processing means, etc. may be realized in hardware by designing a part or all of them as an integrated circuit, for example. In addition, each of the above-mentioned configurations, functions, etc. may be realized in software by a processor interpreting and executing a program that realizes each function. Information such as a program, table, file, etc. that realizes each function can be placed in a memory, a recording device such as a hard disk or SSD (Solid State Drive), or a recording medium such as an IC card, SD card, or DVD.

[0086] The following are some possible embodiments of the present invention, but the present invention is not limited to these.

[0087] (Aspect 1) A charging device that charges a drive battery mounted on an electric vehicle via an electric train line, When a voltage is applied from the electric vehicle via the electric rail line, charging of the storage battery is started. A charging device characterized by:

[0088] (Aspect 2) In the charging device according to aspect 1, a power converter that converts power input from a power source into DC power and outputs the DC power to the electric power line side; A filter capacitor provided on the electric power converter's side, Equipped with When the filter capacitor is charged by applying a voltage from the electric vehicle via the electric rail, the power converter starts charging the storage battery. A charging device characterized by:

[0089] (Aspect 3) In the charging device according to aspect 2, A voltage sensor for measuring a voltage of the electric rail; A contactor that cuts off power from the electric rail to the filter capacitor; Equipped with When the voltage sensor detects that a voltage is applied to the electric rail, the contactor is closed. A charging device characterized by:

[0090] (Aspect 4) In the charging device according to aspect 2 or 3, When the electric car receives a signal notifying that the electric car is in a position where it can be charged through the electric rail based on a detection result from a ground device for position detection that detects that the electric car is in a position where it can be charged through the electric rail and the filter capacitor is charged, charging of the storage battery is started. A charging device characterized by:

[0091] (Aspect 5) In the charging device according to any one of aspects 2 to 4, A current sensor that detects a current in the electric rail, When the current detected by the current sensor falls below a predetermined threshold, the power converter is stopped. A charging device characterized by:

[0092] (Aspect 6) In the charging device according to aspect 5, a discharge circuit including a resistor and a switching element connected in series, the discharge circuit being provided in parallel with the filter capacitor; After the power converter is stopped, the filter capacitor is discharged using the discharge circuit. A charging device characterized by:

[0093] (Aspect 7) An electric vehicle equipped with a storage battery for driving, When the electric vehicle recognizes a request to charge the storage battery, the electric vehicle applies a voltage to a charging device via an electric train line using the power of the storage battery. An electric vehicle characterized by

[0094] (Aspect 8) In the electric vehicle according to aspect 7, A voltage is applied to the charging device via the electric train line using the power of the storage battery whose charging rate is equal to or higher than a predetermined value. An electric vehicle characterized by

[0095] (Aspect 9) In the electric vehicle according to aspect 7 or 8, a position sensor that detects whether the electric vehicle is in a position where it can be charged through the electric railroad tracks; When the position sensor detects that the electric vehicle is in a position where it can be charged through the electric rail, the electric vehicle applies a voltage to the charging device through the electric rail. An electric vehicle characterized by

[0096] (Aspect 10) In the electric vehicle according to the seventh or eighth aspect, When the electric vehicle receives a signal indicating that it is in a position where it can be charged through the electric rail, based on a detection result from a ground device for position detection that detects that the electric vehicle is in a position where it can be charged through the electric rail, the electric vehicle applies a voltage to the charging device through the electric rail. An electric vehicle characterized by

[0097] (Aspect 11) In the electric vehicle according to any one of aspects 7 to 10, If charging of the storage battery cannot be detected even after a predetermined time has elapsed since the electric vehicle started applying a voltage to the electric rail, application of a voltage to the electric rail is stopped. An electric vehicle characterized by

[0098] (Aspect 12) In the electric vehicle according to any one of aspects 7 to 11, an on-board power converter provided between the electric rail and the storage battery; The charging of the storage battery is terminated by stopping the operation of the in-vehicle power converter. An electric vehicle characterized by

[0099] (Aspect 13) An electric vehicle charging method for charging a drive storage battery mounted on an electric vehicle using a charging device, comprising: When the electric vehicle applies a voltage to the charging device via the electric railroad tracks using the power of the storage battery, the charging device starts charging the storage battery. A method for charging an electric vehicle.

[0100] (Aspect 14) In the electric vehicle charging method according to aspect 13, When a filter capacitor provided in the charging device is charged, the charging device starts charging the storage battery. A method for charging an electric vehicle.

[0101] (Aspect 15) In the electric vehicle charging method according to aspect 13 or 14, The frequency of the output voltage for charging the storage battery by the charging device is set to a frequency different from the overhead line voltage of the electrified section. A method for charging an electric vehicle. [Explanation of symbols]

[0102] 1...current collecting device, 2...vehicle-mounted main transformer, 3a...vehicle-mounted AC-DC converter device, 3b...vehicle-mounted DC-DC converter device, 4...vehicle-mounted inverter device, 5... main motor, 6... drive battery, 7... auxiliary power supply unit, 8... auxiliary power supply unit load, 10...Charging device, 10a...AC output specification charging device, 10b...DC output specification charging device, 20...power source; 21...charging device input transformer; 22...AC-DC power converter; 23...filter capacitor, 24...voltage sensor for filter capacitor voltage, 25... DC-AC power converter, 26... charging device output transformer, 27... DC-DC power converter, 33... contactor, 34... voltage sensor for electric power line voltage, 35... current sensor for charging device output, 37... Capacitor discharge switching element, 38...discharge resistor, 39...capacitor discharge circuit, 40... electric car, 40a... AC electric car, 40b... DC electric car, 41... on-board position sensor, 51...position detection information receiving device, 52...position detection ground device, 100...ground potential, 101...electric line, 102...rails.

Claims

1. A charging device that charges a drive battery mounted on an electric vehicle via an electric train line, When a voltage is applied from the electric vehicle via the electric rail line, charging of the storage battery is started. A charging device characterized by:

2. 2. The charging device according to claim 1, a power converter that converts power input from a power source into DC power and outputs the DC power to the electric power line side; A filter capacitor provided on the electric power converter's side, Equipped with When the filter capacitor is charged by applying a voltage from the electric vehicle via the electric railroad tracks, the power converter starts charging the storage battery. A charging device characterized by:

3. The charging device according to claim 2, A voltage sensor for measuring a voltage of the electric rail; A contactor that cuts off power from the electric rail to the filter capacitor; Equipped with When the voltage sensor detects that a voltage is applied to the electric rail, the contactor is closed. A charging device characterized by:

4. The charging device according to claim 2, When the electric car receives a signal notifying that the electric car is in a position where it can be charged through the electric rail based on a detection result from a ground device for position detection that detects that the electric car is in a position where it can be charged through the electric rail and the filter capacitor is charged, charging of the storage battery is started. A charging device characterized by:

5. The charging device according to claim 2, A current sensor that detects a current in the electric rail, When the current detected by the current sensor falls below a predetermined threshold, the power converter is stopped. A charging device characterized by:

6. 6. The charging device according to claim 5, a discharge circuit including a resistor and a switching element connected in series, the discharge circuit being provided in parallel with the filter capacitor; After the power converter is stopped, the filter capacitor is discharged using the discharge circuit. A charging device characterized by:

7. An electric vehicle equipped with a storage battery for driving, When the electric vehicle recognizes a request to charge the storage battery, the electric vehicle applies a voltage to a charging device via an electric train line using the power of the storage battery. An electric vehicle characterized by

8. The electric vehicle according to claim 7, A voltage is applied to the charging device via the electric train line using the power of the storage battery whose charging rate is equal to or higher than a predetermined value. An electric vehicle characterized by

9. In the electric vehicle according to claim 7 or 8, a position sensor that detects whether the electric vehicle is in a position where it can be charged through the electric railroad tracks; When the position sensor detects that the electric vehicle is in a position where it can be charged through the electric rail, the electric vehicle applies a voltage to the charging device through the electric rail. An electric vehicle characterized by

10. In the electric vehicle according to claim 7 or 8, When the electric vehicle receives a signal indicating that it is in a position where it can be charged through the electric rail, based on a detection result from a ground device for position detection that detects that the electric vehicle is in a position where it can be charged through the electric rail, the electric vehicle applies a voltage to the charging device through the electric rail. An electric vehicle characterized by

11. In the electric vehicle according to claim 7 or 8, If charging of the storage battery cannot be detected even after a predetermined time has elapsed since the electric vehicle started applying a voltage to the electric rail, application of a voltage to the electric rail is stopped. An electric vehicle characterized by

12. In the electric vehicle according to claim 7 or 8, an on-board power converter provided between the electric rail and the storage battery; The charging of the storage battery is terminated by stopping the operation of the in-vehicle power converter. An electric vehicle characterized by

13. An electric vehicle charging method for charging a drive storage battery mounted on an electric vehicle using a charging device, comprising: When the electric vehicle applies a voltage to the charging device via the electric railroad tracks using the power of the storage battery, the charging device starts charging the storage battery. A method for charging an electric vehicle.

14. The electric vehicle charging method according to claim 13, When a filter capacitor provided in the charging device is charged, the charging device starts charging the storage battery. A method for charging an electric vehicle.

15. The electric vehicle charging method according to claim 13 or 14, The frequency of the output voltage for charging the storage battery by the charging device is set to a frequency different from the overhead line voltage of the electrified section. A method for charging an electric vehicle.

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