JP7198284B2 - rail car - Google Patents

Description

TECHNICAL FIELD The present invention relates to rail vehicles powered by an on-board storage battery.

As the energy density of storage batteries such as lithium ion batteries improves, the spread of electric vehicles (EVs) is gradually expanding, and the traveling distance of a passenger car type exceeds 400 km on one charge.

Since the beginning of the development of lithium-ion batteries, lithium-ion batteries have been used as part of the regenerative energy of trains (EMUs) by utilizing their high output density characteristics. A regenerative energy absorption system that absorbs energy to prevent regenerative failure, and a hybrid diesel railcar that absorbs regenerative energy of diesel railcars (DEMU) and assists power running energy. In recent years, the development of lithium-ion batteries that achieve both high energy density and high output density has progressed, and trains equipped with power storage devices capable of traveling over 100 km on a single charge have been introduced.

Compared to ordinary train systems, electric trains equipped with on-board power storage devices can operate at the starting station, the terminal station, and in some cases, some intermediate stations even in non-electrified sections where ground facilities such as overhead lines and substations are not installed. Charging equipment is provided only at the station, and by charging the storage battery for each charging equipment, it is possible to run the section. Even on electrified lines, electric trains with on-board power storage devices can be introduced, and ground facilities such as overhead lines and substations can be eliminated on lines with low operating frequency, such as branch lines, to reduce maintenance costs. Furthermore, in the event of ground equipment failure, there is a growing need for the introduction of power storage devices that enable vehicles to travel a certain distance in order to avoid getting stuck in sections where it is difficult for passengers to evacuate, such as on bridges and tunnels.

A train equipped with such a power storage device is generally charged to a high power storage rate in order to run a predetermined distance on a single charge. In particular, when the power storage device is used for the purpose of preventing the vehicle from being stuck in the event of a ground facility failure, it is necessary to maintain a high power storage rate for a long period of time in preparation for failures that may occur.

To provide a railway vehicle driving device that controls the amount of electricity stored in an electricity storage device so as to efficiently absorb regenerative power generated during braking while securing the amount of electricity in consideration of the case where battery running is required. As a railway vehicle drive device for the purpose, there is a “railway vehicle drive device” disclosed in Japanese Patent Application Laid-Open No. 2009-183079.

The "railway vehicle drive device" disclosed in Japanese Patent Application Laid-Open No. 2009-183079 includes a power collector and a chargeable/dischargeable power storage device 7, and the power collector and the power storage device are used together when the railroad vehicle runs in a normal state. Running of the railway vehicle in an abnormal state is performed only by the power storage device. In addition, in the above publication, the amount of electricity stored in the power storage device is controlled to be greater than the threshold in a normal state, and the amount of power stored in the power storage device is allowed to be less than the threshold in an abnormal state. and/or vehicle conditions.

JP 2009-183079 A

As described above, in a railway vehicle that is driven by electric power from an onboard power storage device without power supply from a current collector such as an overhead wire, the power storage device stores the energy necessary to travel a predetermined travel section or travel distance. must be stored in advance. Furthermore, storage batteries are required to be maintained in a charged state for a long period of time.

Accordingly, an object of the present invention is to provide a new storage battery management method that is useful for long-term storage battery operation, and a railway vehicle that employs the method.

The present invention can take various embodiments in order to solve the above problems. A railway vehicle comprising at least a battery-type power storage device, comprising a control device for controlling the power storage rate of the power storage device , wherein the control device controls the progress of elapsed time from the start of use of the power storage device or the time of manufacture. a memory storing a target power storage rate that increases according to each reference time, reading out the target power storage rate at the reference time matching or close to the current time from the memory, and reading out the target power storage rate and the current storage rate, charging control or discharging control including natural discharge of the storage device is executed ."

ADVANTAGE OF THE INVENTION According to this invention, the management method of a new storage battery useful for the long-term operation of a storage battery, and the railway vehicle which employ|adopted the same can be provided.

1 shows a schematic configuration of a railway vehicle system in one embodiment of the present invention; 1 shows a schematic configuration of a drive system; 4 shows a schematic configuration of a storage battery control unit; The basic idea of the proposed storage rate management method is shown. An outline of processing when implementing the proposed storage battery management method is shown. The relationship between the storage rate and the capacity retention rate in the proposed storage battery management method is shown. The relationship between the storage capacity and the storage rate in the initial use of the proposed storage battery management method is shown. The relationship between the storage capacity and the storage rate at the end of use in the proposed storage battery management method is shown. The relationship between the target value of the storage rate and the reference time in the proposed storage battery management method is shown. 2 shows the relationship between the storage capacity and the storage rate at the initial stage of use in a comparative example. 2 shows the relationship between the storage capacity and the storage rate at the end of use in a comparative example. 1 shows a schematic configuration of a railway vehicle system in another embodiment of the present invention; 4 shows a schematic configuration of a modification of the drive system;

The present invention is a technique for managing a storage battery used for running a railway vehicle, and provides a railway vehicle equipped with a storage battery managed by this technique. Storage batteries to be managed include lead storage batteries, lithium ion secondary batteries, nickel/hydrogen storage batteries, nickel/cadmium storage batteries, silver oxide/zinc storage batteries, and other chargeable/dischargeable chemical batteries.

A storage battery managed by this method is configured to be connectable to a traction motor, and the type of the traction motor may be either an AC motor or a DC motor. Alternatively, the present invention may be applied to an electric railcar that is equipped with an internal combustion engine and runs on electric power generated by the internal combustion engine. In addition, the present invention can be applied not only to passenger trains but also to freight trains, and can be applied to transportation equipment that is configured to be able to run on tracks and that can use a storage battery for running.
BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the following examples are examples of application of the present invention, and the invention is not limited to these examples. All or part of the embodiments can be exchanged and combined according to the conditions of application. In addition, it is possible to change, combine, or omit the types of parts to be employed as appropriate.

FIG. 1 shows a schematic configuration of a railway vehicle drive system that is an embodiment of the present invention. This railway vehicle is a so-called AC electric train, and the vehicle runs by applying a driving force generated from an AC rotary machine to a mechanical driving device.

The basic configuration of a railroad vehicle is vehicles 1a and 1b. These are vehicles constituting a train set or a part thereof, and a vehicle 1a and a vehicle 1b are connected by an inter-vehicle coupler 6, and each vehicle has a bogie. A bogie 2a (also the bogie 2b) has wheelsets 3a and 3b, and wheels are fixed to the respective wheelsets, and runs on the rail surface. The vehicle 1b also has a bogie 2c and a bogie 2d, and is supported on the rail surface by wheelsets 3e, 3f, 3g, and 3h, which are parts of the respective bogies.

In this way, every car is supported from the rail surface by the bogie, and at least one car has a drive system, and power is transmitted from the drive system to the bogie to realize running of the train set. In the train formation shown in FIG. 1, the vehicle 1a is a driving vehicle having a driving system, and the vehicle 1b is a trailing vehicle having no driving system.

The drive system mounted on the vehicle 1a includes a current collector 5, a transformer 7 (Transformer), a main converter 8 (Traction Converter), an electric motor 17, a power storage device 9 (Traction Battery), and an integrated control device 11 (Control Unit). as a basic configuration. In addition, as a main power-utilizing device that is not included in the drive system, an auxiliary power supply 10 (APS (Auxiliary Equipment Power Supplier)) is provided in parallel with the power storage device 9 for the main converter 8 . This converts the AC power Pd1 of the main converter 8 into a constant voltage and constant frequency (CVCF) AC power Pa3, and supplies power to the vehicle auxiliary equipment 19, which is represented by the lighting and air conditioning system in the vehicle. do. It should be noted that the drive system does not have to be centrally installed in one car, and may be installed in a distributed manner in any one of the cars in the formation (including a one-car formation with both cabs).

The general control device 11 also has at least one CPU, a storage device configured to communicate with the CPU, and an input/output interface, and generates control commands. The states of controlled devices are obtained through input interfaces, and control commands for them are output through output interfaces. These interfaces specifically include a PCI bus, DI/DO interfaces connected thereto, signal cables, and relays. In addition to the CPU, the arithmetic function employs logic circuits such as ASIC, FPGA, PLD, and PLC, and includes implementation by these.

In the drive system shown in FIG. 1, the first drive mode by the first drive system that converts electric power into driving force is defined as follows. First, AC power Pa0 is supplied from the overhead wire 4 to the transformer 7 via the current collector 5 . The transformer 7 converts the voltage Va0 of the AC power Pa0 into the AC power Pa1 of a lower voltage Va1, and supplies the AC power Pa1 to the main converter 8 . The main converter device 8 is composed of a converter device 14 and an inverter device 15. The converter device 14 converts the AC power Pa1 into the DC power Pd1 and controls the DC power Pd1 to a predetermined voltage Vd1.

The inverter device 15 is a VVVF inverter that variably controls the voltage and frequency, converts the DC power Pd1 into AC power Pa2, and inputs it to the electric motor 17 to control its torque. The torque of the electric motor 17 is transmitted to all or any of the wheelsets 3a, 3b, 3c, 3d as rotational torque to rotate the wheels fixed to the wheelsets. A tread force acts between the rotating wheel and the rail surface, and this tread force accelerates or decelerates the vehicle 1a.

The inverter device 15 is controlled by an inverter control unit 22, and according to a command from the overall control unit 20, generates a torque current command for generating drive torque for the electric motor 17 that accelerates or decelerates the vehicles 1a, 1b. More specifically, constant current control is performed so that the torque current calculated based on the motor currents Imu, Imv, and Imw detected by the alternating current detector 18 follows the torque current command, and switching of the inverter device 15 is performed based on the output. A PWM pulse for operating the circuit is generated and input to the inverter device 15 .

In response to a command from the integrated control unit 20, the storage battery control unit 23 restricts charging/discharging (input/output) of the storage means by closing/releasing the storage power circuit breaker 23c. : SOC, storage battery temperature Tb, etc.) are aggregated and transmitted to the integrated control unit 20 .

Based on the voltage Vbat of the power storage device 9, the integrated control unit 20 sets a voltage command Vbd that is higher than Vbat by ΔVbat when charging the power storage device 9, and a voltage lower than Vbat by ΔVbat when discharging the power storage device 9. Calculate the command Vbd. The magnitude of the charge/discharge current generated with respect to ΔVbat is determined by the internal resistance value of power storage device 9 .

By adjusting the charge/discharge power Pbat of the power storage device 9 with the above configuration, the SOC is managed so as to match the target value of the power storage rate: SOC(t). The target value of the power storage rate: SOC(t) is determined based on the elapsed time from the start of use of the power storage device 9 and the storage battery temperature Tb of the power storage device 9 . The elapsed time from the start of use of the power storage device 9 can be obtained by accumulating the time from the start of use of the power storage device 9 with the timer 20b provided in the integrated control unit 20. You can also enter the time value manually. The storage battery temperature Tb of the power storage device 9 can be detected as state information from the power storage device 9, but the average temperature in the environment in which the power storage device 9 is used may be stored in advance.

The second driving mode by the second driving system that converts electric power into driving force is defined as follows. The second drive system realizes running only by the power storage device 9, and the power storage device 9 supplies electric power to the main converter 8 (more specifically, the inverter device 15 of the main converter 8). The same device configuration as in the first system is adopted for the configuration after the power is input to the main converter 8, and the tread force is generated using these.

The power storage device 9 in the second drive system has, for example, a lithium-ion storage battery 9a that stores power, and includes a power storage circuit breaker 23c that limits charging/discharging (input/output) of the stored power, and a storage power circuit breaker 23c. A power storage controller 23a for controlling is provided. The power storage controller 23a has a function of monitoring the state of the storage battery 9a, and the objects to be monitored are, for example, the voltage between the terminals of the storage battery 9a, the internal resistance of the storage battery 9a, the surface temperature or internal cell temperature of the storage battery 9a (so-called storage battery temperature), and the storage battery 9a. ambient temperature, etc. In FIG.2(b), the example which installed the thermometer 23b which measures the surface temperature of the storage battery 9a is shown.

The state of charge/discharge by the power storage device 9 is determined based on a comparison between the voltage Vd1 of the DC power Pd1 of the main converter 8 and the voltage Vbat of the power storage device 9 . In a situation where charging/discharging is unnecessary, the storage battery controller 23a operates the storage power breaker 23c to disconnect the storage battery 9a from the main converter 8. FIG.

Charge/discharge control is performed as follows. First, a voltage Vd1 is acquired based on measurement or estimation of the voltage applied to the power bus connecting the converter device 14 and the inverter device 15 in the main converter device 8 . Voltage Vd1 may be estimated based on control data of converter device 14 or inverter device 15 .

Subsequently, the output voltage of the power storage device 9 connected to the main converter 8 is acquired as the voltage Vbat. The voltage Vbat is obtained by measuring the voltage between the terminals of the power storage device 9, or by adopting an estimated value based on the relationship between the SOC (SOC: State Of Charge) obtained in advance by a discharge test or the like and the discharge voltage. be.

With respect to the voltage Vd1 and the voltage Vbat obtained in this manner, if the main converter 8 is operated so that the voltage Vbat becomes lower than the voltage Vd1, the storage battery 9a is charged, and conversely, the voltage Vbat becomes higher than the voltage Vd1. When the control is performed as described above, the electric storage device 9 discharges.

These charge/discharge controls are executed based on control commands from the integrated control device 11 . The integrated control device 11 calculates a voltage command Vbd that is higher than the voltage Vbat by ΔVbat when the power storage device 9 is charged, and a voltage command Vbd that is lower than Vbat by ΔVbat when the power storage device 9 is discharged. do. Subsequently, the integrated control device 11 outputs the calculated voltage command Vbd to the main converter 8, and the main converter 8 follows the voltage command Vdb with the voltage Vd1. At this time, the magnitude of the charge/discharge current generated with respect to ΔVbat is determined by the internal resistance value of power storage device 9 .

In this embodiment, the converter device 14 included in the main converter device 8 plays a central role in the voltage follow-up control. The operation of the converter device 14 of this embodiment is controlled by a converter control unit 21, which is a host device.

Converter control unit 21 is connected to AC voltage detector 12, AC current detector 13, DC voltage detector 51, and DC current detector 52, and controls the operation of converter device 14 based on the measurement results of these measuring means. . Specifically, based on the AC voltage Va0 collected by the AC voltage detector 12 and the AC current Ia1 collected by the AC current detector 13, the DC voltage Vd1 is controlled to follow the voltage command Vbd, and the SOC is managed so as to match the target value of power storage rate (SOC(t)).

On the other hand, when it is not normal, that is, when sufficient power cannot be supplied from the current collector 5 for some reason and the driving force is obtained by the second system, based on the required driving force and the current SOC, DC power to be supplied to the inverter device 15 is determined. The integrated control device 11 operates the converter device 14 so as to receive the DC power and supplies power to the inverter device 15 .

Here, in order to operate the power storage device 9 in a charged state for a long period of time, a new management method is applied to the storage battery 9a. Specifically, the charging rate target value (hereinafter referred to as SOC(t)) is appropriately adjusted, and the charging rate is maintained at a value that matches or is close to SOC(t) by charge/discharge control in normal times. The SOC(t) can be adjusted by using at least elapsed time information from the start of use of the power storage device 9 to the present (hereinafter referred to as elapsed time), and further by using the storage battery temperature (Tb) of the power storage device 9. preferable.

Each piece of information may be automatically collected by the central control unit 20, the storage battery control unit 23, or the power storage device 9, or may be configured to be manually input. FIG. 2B shows an example of automatically collecting information, and the elapsed time from the start of use of the power storage device 9 is obtained by the integrated control unit 20 which is a part of the integrated control device 11 . The integrated control unit 20 has a timer 20b and can integrate the elapsed time from the start of use of the power storage device 9 . The method of accumulating the time may be, for example, any of days, weeks, and months, or may be counted in arbitrarily set units. Further, instead of the timer 20b, the elapsed time from the start of use may be manually input, or the power storage device 9 may have the timer 20b.

In addition, the power storage device 9 has a storage unit in which its own date of manufacture is registered, and a timer 20b that operates using the power stored by itself, and outputs the time elapsed from the date of manufacture to the outside. may be configured to In this case, it is more desirable that the power storage device 9 has an output interface for elapsed time, and the storage battery control unit 23 has an input interface that can be connected to the output interface.

Further, the storage battery temperature Tb of the storage battery device 9 is configured so that a signal is input from the thermometer 23b to the storage battery controller 23a of the storage battery control unit 23, and is grasped based on the acquired signal. If there is no temperature measurement function, the average temperature in the environment where the power storage device 9 is used may be stored in advance. In the case of railway vehicles in particular, since the routes on which they are operated are limited to some extent, it is also possible to acquire temperature information for areas around the operating routes based on past weather data published by the Internet or public institutions.

The storage battery control unit 23 acquires these pieces of information from the time when communication with the power storage device 9 becomes possible, that is, when the operation of the power storage device 9 is started, and starts managing the power storage device 9 shown in FIG. .

The storage battery control unit 23 changes the power storage rate (SOC) according to the elapsed time when the operation of the power storage device 9 is started. FIG. 3 is a diagram showing transitions in the capacity maintenance rate of the storage battery 9a and transitions in the storage rate corresponding thereto. On the horizontal axis, T0 indicates the start point of use of the power storage device 9, and on the vertical axis, the capacity retention rate of the power storage device 9. FIG. Note that the capacity retention rate is a capacity ratio that relatively represents the storage capacity at each point in time when the storage capacity at the start of use is set to 100.

As shown in FIG. 3, the storage battery control unit 23 sets the SOC(t) to 50% in the section T0→T1, to 60% in the section T1→T2, to 70% in the section T2→T3, and to T3 → Maintain at 80% in the T4 section. In order to realize such management, storage battery control unit 23 stores information on SOC(t) and reference time for updating SOC(t) in memory 20c. It has an arithmetic unit 20a that outputs an SOC.

The reference time may be set arbitrarily. For example, if the operation period of the power storage device 9 is 16 years, each section may be 4 years. Alternatively, T0→T1 may be set as 7 years, T1→T2 as 5 years, T2→T3 as 3 years, and T3→T4 as 1 year.

The SOC(t) update process is executed by the process steps shown in FIG. 4, for example.

First, the storage battery control unit 23 operates a timer when information indicating the start of use of the storage battery device 9 is input (Step 1). At the same time, the central control unit 20 calls the closest reference time (T1) from among the reference times registered in the memory 20c and holds it as the reference time to be queried (inquiry reference time) (Step 2). If the reference time is held as a serial value and the timer is implemented by count values of a periodic clock signal, then that serial value is set as the inquiry reference time. In addition, the integrated control unit 20 may be configured to store the usage start time of the power storage device 9 and appropriately calculate the difference from the current time to acquire the operating period. Further, as the usage start time, the production date of the storage battery 9a may be used instead of the time when the operation of the power storage device 9 is started.

The computing device 20a periodically acquires a value (timer value) from the timer 20b and compares the timer value with the inquiry reference time (Step 3). As a result of the comparison, if the timer value matches or exceeds the inquiry reference time, the SOC (T1) corresponding to the inquiry reference time is read (Step 4). The arithmetic unit 20a transmits the information of SOC (T1) to the general control unit 20 (Step 4). At this time, the current value of the charge rate is also transmitted to the integrated control unit 20 . The current value of the power storage rate is acquired using the voltage across the terminals of the storage battery 9a or an existing estimation algorithm.

The integrated control unit 20 compares the SOC (T1) received from the storage battery control unit 23 and the latest power storage rate information (Step 5), and if the SOC (T1) is greater than the latest SOC, Charge control is executed (Step 6). Conversely, if the SOC(T1) is smaller than the latest SOC, wait for the SOC(T1) to match the latest SOC due to natural discharge, and the SOC(t) update process itself ends. If power is sent to overhead lines or available for running, the power storage device 9 may be discharged toward them. Note that the comparison operation may be performed by the storage battery control unit 23 .

When charge control or discharge control is executed and the SOC of power storage device 9 matches SOC(T1) or enters a predetermined allowable range, overall control unit 20 terminates the update process of SOC(t), It shifts to a state of waiting for the next update (Step 7).

Furthermore, the general control unit 20 updates the inquiry reference time. Specifically, the nearest reference time in the future is read from the memory and held as a new reference time (Step 8). For reference times that have already been used, the data is deleted or a setting disabled flag is assigned so as not to be set again by mistake. In addition, the SOC(t) and inquiry reference time may be newly set only when they increase from the current set values. By doing so, it is possible to suppress the possibility that a low SOC(t) is erroneously set and the amount of stored electricity becomes less than the required amount.

Further, among the processes described above, only the charging control process can be executed by the vehicle, and the other processes can be executed by a management device provided separately from the vehicle. In this case, the management device is provided with a database that stores the identification information of the power storage device 9, the start time of use, and the information of the line section on which the vehicle equipped with the power storage device 9 is operated. A command to update SOC(t) is notified by communication or the like. By consolidating the management devices on the ground and configuring the vehicle to operate based on the information notified from the management device, events that make it difficult to continue management, such as timer failures and memory corruption, can be avoided. This makes it easier to manage long-term storage batteries. In addition, it is also possible to manually execute processes other than charge control, and depending on the application target, the processes executed manually and the processes executed by a computer or the like may be combined as appropriate.

The mechanism by which the storage battery amount is appropriately retained by the storage battery management method by the storage battery control unit 23 described above will be explained as follows.

FIG. 5 is a characteristic diagram showing general changes in the capacity retention rate of a storage battery with respect to elapsed time when the storage rate of the storage battery is maintained constant. FIG. 5 shows changes in the capacity retention rate from T0 to T4 when the SOC is maintained at 50%, 60%, 70%, and 80%. In general high-capacity high-output storage batteries such as lithium-ion batteries, the more time passes from the initial state (T0) with a capacity retention rate of 100% (that is, the more T0 → T1 → T2 → T3 → T4), the more the capacity retention rate shows a decreasing trend.

In addition, especially when the SOC exceeds 50%, the higher the SOC is maintained, the more the capacity retention rate decreases over time. Therefore, in the region where the SOC is approximately 50% or more, the decrease in the capacity retention rate over time can be suppressed by lowering the SOC.

On the other hand, lowering the SOC means limiting the amount of electricity that can be used. Therefore, if the storage rate is lowered in a state where the capacity retention rate has decreased with the passage of time, there is a risk that the required amount of stored electricity cannot be secured.

In order to avoid this situation, it is desirable to set the SOC(t) of the power storage device 9 as small as possible in the initial stage of operation within the range in which the required amount of stored electricity is secured, and to change the SOC(t) according to the elapsed time. . (See dotted line notation in Figure 5)

In the storage battery management method shown in FIG. 3, as the time progresses from T0→T1, T1→T2, T2→T3, and T3→T4, the SOC(t) is gradually increased to 50%, 60%, 70%, and 80%. increase. By adopting this management method, it is possible to slow the decline in the capacity retention rate while the operation period is short, and to suppress deterioration more than when the storage rate is kept constant at 80%. It should be noted that changes in the capacity retention rate in each section of T0→T1, T1→T2, T2→T3, and T3→T4 are equivalent to changes in the capacity retention rate at the corresponding SOC in FIG.

Note that the capacity retention rate of the storage battery with respect to the passage of time shown in FIG. 5 exhibits characteristics that differ depending on the temperature of the storage battery in addition to the storage rate. Lithium ion storage batteries generally have the characteristic that the higher the storage rate and the higher the ambient temperature, the more likely the storage battery will deteriorate (that is, the capacity retention rate will decrease). They are often designed to minimize degradation.

Also, when the SOC shown in FIG. 3 is changed over time, it is assumed that the transition of the capacity maintenance rate of the storage battery at each point in time also differs for each temperature of the storage battery because the management is over a long period of time. Considering this effect, the storage battery is controlled so as to sequentially change the SOC(t) according to the temperature of the storage battery at that time, or to correct the SOC(t) according to the long-term trend of temperature change (for example, seasonal fluctuation). A unit 23 may be configured.

More specifically, the setting of SOC(t) will be described with reference to the control upper limit value S1 of the power storage rate and the control lower limit value S2 of the power storage rate shown in FIGS. do).

6(a) and 6(b) show the relationship between the capacity retention rate of the storage battery and the range of the charge rate that is allowed to be used, and FIG. , and FIG. 6(b) shows the relationship at the end of use, for example. In FIG. 6(b), the portion corresponding to the region R is the lost capacity with respect to the storage capacity at the initial stage of operation.

Storage battery control unit 23 sets management upper limit value S1 and management lower limit value S2 for SOC when operation of power storage device 9 is started. These management upper limit value S1 and management lower limit value S2 are used to determine the safety and soundness of the storage battery, and the amount of discharged electric power E1 (hereinafter referred to as electric power E1) required for driving the vehicles 1a and 1b for a predetermined distance or section. determined based on

Specifically, the management upper limit value S1 is set as a value obtained by taking a margin from an SOC range (for example, 90% or higher) whose use is not recommended from the viewpoint of the soundness and safety of the storage battery, based on the SOC of 100%. . Further, since the SOC is maintained higher than the initial period in the final period of use, deterioration may be accelerated even at room temperature, and it is desirable to set the control upper limit value S1 to a value considering this possibility. For example, if the ambient temperature of the operating environment fluctuates, for example, from −10 to 40° C., if the management upper limit value S1 is determined in consideration of 40° C., even if a separate cooling facility such as a cooling fan is not provided, the storage battery 9a can be placed in a state where it is difficult for them to deteriorate, and restrictions on mounting space when mounted on a vehicle can be relaxed.

On the other hand, the management lower limit value S2 is set as a value obtained by adding a margin to the lower limit value of the power storage rate at which the power storage device 9 can appropriately discharge. At the end of use, the internal resistance of the storage battery 9a may increase and the voltage across the terminals may drop, so the control lower limit value S2 may be set higher at the end of use than at the beginning of use.

After determining the management upper limit value S1 and the management upper limit value S2 that can secure the electric power E1 at the end of use in this manner, the capacity of the storage battery that satisfies these conditions is specified. For example, if the storage capacity at the end of use is 20% smaller than the storage capacity at the beginning of use, and the control upper limit value S1 at that time is set to 70% and the control lower limit value S2 is set to 20%, the initial use (that is, At the time of introduction) The capacity required for the storage battery is required to be 2.5 times the power E1. When the travel distance is determined according to the installed storage battery, the electric power E1, the management upper limit value S1 and the management lower limit value S2 may be set after the power storage device 9 is installed in the vehicle.

After the management upper limit value S1 and the management lower limit value S2 are set, in principle, the operation of the power storage device 9 does not cause the SOC to be charged to exceed the management upper limit value S1 or to be discharged so as to fall below the management lower limit value S2. managed as That is, the portions of the SOC represented by regions N1 and N2 are capacities that are not used in the operation of power storage device 9 .

After setting the power E1, the management upper limit value S1, and the management lower limit value S2, the overall control unit 20, as shown in FIG. Limit of Charge). As shown in FIG. 6(c), this utilization upper limit value LC is held according to the number of reference times (T0, T1, T2, . . . ), and SOC (T1, T2, T3 …). The usage upper limit value LC at the initial stage of usage corresponds to SOC (T0). The use upper limit value LC may be set to a different value for each reference time, or may be held at a constant value depending on the SOC setting from the start of use to the middle period of operation.

FIG. 6(b) shows the end of use of the storage battery, and the capacity retention rate has decreased over time. However, the electric power E1 is ensured by setting the utilization upper limit LC to be higher than the control upper limit S2 than at the time of the reference time (T0) and making it approximately equal to the control upper limit S1. This state is also a state in which the capacity retention rate is more likely to decrease.

On the other hand, as a comparative example, FIGS. 7A and 7B show a case where the utilization lower limit value LD (Limit of discharge) is updated based on the management upper limit value S1. The electric power E1 to be secured is the same in FIGS. 7(a) and 7(b). However, if such a management method is adopted, the SOC will be set high from the beginning of operation of the power storage device 9, and the power storage device 9 will be more likely to deteriorate. In order to operate the power storage device 9 which is easily degraded from the initial stage for a long period of time, the storage battery is inevitably required to have a large capacity, resulting in an excessive amount of stored power in the initial stage.

More specifically, secondary batteries such as lithium-ion batteries and nickel-metal hydride batteries generally have the characteristic that the higher the storage rate and the higher the ambient temperature, the more likely the deterioration of the battery progresses. Considering the above, for example, it is often manufactured so that the progress of deterioration is minimized at a storage rate of 50% and an ambient temperature of 25°C. Here, when minimizing the progress of deterioration, for example, in order to maintain the power storage rate at 50%, it is required that the power storage system have a capacity twice as large as the power storage capacity at the power storage rate of 50%.

However, the proposed new management method, that is, based on the management lower limit value S2 at the beginning of use of the storage battery as a reference, sets the use upper limit value LC that can secure the necessary power E1, and gradually sets the use upper limit value LC toward the end of the use of the storage amount. is adjusted toward the control upper limit value S1, a decrease in the capacity retention rate is suppressed, and the storage battery can be operated for a long period of time.

Further, according to this management method, the power storage device 9 can be designed to have a power storage capacity suitable for holding the power E1. As a result, the margin of the power storage capacity can be reduced, and the size of the power storage device 9 can be reduced accordingly, which contributes to the size reduction and weight reduction of on-vehicle equipment of the railway vehicle. In particular, in the case of railcars, since the on-vehicle space is limited, it is desirable that the size of the storage battery is small, and in this respect the proposed management method is useful.

In the example shown in FIGS. 6A and 6B, the management upper limit value S1 and the use upper limit value LC are separate parameters, but they may be treated as the upper limit value for one power storage rate without distinction. . Alternatively, the control lower limit value S2 may be configured to be changed according to the passage of time instead of being fixed.

FIG. 8 shows a schematic configuration of a railway vehicle drive system according to a second embodiment of the present invention. Unlike Embodiment 1, this drive system is a type of electric train that is driven by being supplied with DC power from an overhead wire 4 .

The general configuration is the same as that of the first embodiment, and the vehicles 1a and 1b are vehicles or parts thereof that constitute a train formation. The vehicle 1a and the vehicle 1b are connected by an inter-vehicle coupler 6. As shown in FIG.

The vehicle 1a is supported on a rail surface (not shown) by wheelsets 3a and 3b via a truck 2a and wheelsets 3c and 3d via a truck 2b. The vehicle 1b is supported on a rail surface (not shown) by wheelsets 3e and 3f via a truck 2c and wheelsets 3g and 3h via a truck 2d.

The DC power Pd0 is supplied from the overhead wire 4 to the inverter device 15, the DC converter device 25, and the auxiliary power supply device 10 via the collector device 5. FIG.

The inverter device 15 converts the DC power Pd0 into a voltage-variable, frequency-variable (VVVF) AC power Pa2 to control the torque of the electric motor 17 (not shown). The torque of the electric motor 17 transmits rotational torque to all or any of the wheelsets 3a, 3b, 3c, and 3d, and exerts a tread force between the wheelset and the rail surface, and the tread force accelerates or accelerates the vehicle 1a. slow down.

DC converter device 25 converts voltage Vd0 of DC power Pd0 into DC power Pd1 of voltage Vd1.

The power storage device 9 includes a power storage means such as a lithium ion battery, a power storage circuit breaker that limits charging and discharging (input/output) of stored power, and a power storage controller that monitors the state of the power storage means and controls the power storage circuit breaker. be done. The power storage means is charged/discharged according to the magnitude of voltage Vd1 of DC power Pd1 output from DC converter device 25 and voltage Vbat of power storage device 9 .

The auxiliary power supply device 10 converts the AC power Pd1 of the main converter 8 into constant voltage, constant frequency (CVCF) AC power Pa3, which is used by vehicle auxiliary equipment (air conditioning, lighting, air compressor, etc.) (not shown). supply to

Based on the voltage Vbat of the power storage device 9, the overall control device 11 sets a voltage command Vbd that is higher than Vbat by ΔVbat when charging the power storage device 9, and a voltage lower than Vbat by ΔVbat when discharging the power storage device 9. Calculate the command Vbd. The magnitude of the charge/discharge current generated with respect to ΔVbat is determined by the internal resistance value of power storage device 9 .

DC converter device 25 performs constant voltage adjustment so that DC voltage Vd1 follows voltage command Vdb, and manages the amount of stored electricity SOC to match the target value of stored electricity SOC(t).

The charged amount target value SOC(t) is managed in the same manner as in the first embodiment. That is, based on the elapsed time from the start of use of the power storage device 9 and the storage battery temperature Tb of the power storage device 9, the storage battery capacity retention rate prediction means is referred to and determined. The elapsed time from the start of use of the power storage device 9 can be obtained by accumulating the time from the start of use of the power storage device 9 by the time measuring means provided in the integrated control unit 23. You may manually enter an elapsed time value such as The storage battery temperature Tb of the power storage device 9 can be detected as state information from the power storage device 9, but the average temperature in the environment in which the power storage device 9 is used may be stored in advance. In particular, since railway vehicles are operated on a limited number of routes, it is also possible to use temperature information in the area around the operating route based on past weather data published on the Internet or the like.

Also, in the present embodiment, a two-car formation of vehicles 1a and 1b is shown, but the number of cars in the formation is not limited. The railway vehicle drive system of the present invention does not need to be centrally installed in one vehicle, and may be installed separately in any one of the vehicles in the train (including a one-car train with both cabs).

FIG. 9 is a diagram showing a configuration for realizing the stored electricity amount management method in the second embodiment of the present invention.

The DC power Pd0 is supplied to the reactor 24 from the overhead wire 4 (not shown) via the current collector 5 . Reactor 24 forms a filter circuit together with capacitor 16 to remove harmonics of DC power Pd0, and supplies the output to inverter device 15, DC converter device 25, and auxiliary power supply device .

The inverter device 15 converts the DC power Pd0 into a voltage-variable, frequency-variable (VVVF) AC power Pa2 to control the torque of the electric motor 17 (not shown). The torque of the electric motor 17 transmits rotational torque to all or any of the wheelsets 3a, 3b, 3c, and 3d, and exerts a tread force between the wheelset and the rail surface, and the tread force accelerates or accelerates the vehicle 1a. slow down.

DC converter device 25 converts voltage Vd0 of DC power Pd0 into DC power Pd1 of voltage Vd1. The power storage device 9 includes a power storage means such as a lithium ion battery, a power storage circuit breaker that limits charging and discharging (input/output) of stored power, and a power storage controller that monitors the state of the power storage means and controls the power storage circuit breaker. be done. The power storage means is charged/discharged according to the magnitude of voltage Vd1 of DC power Pd1 output from DC converter device 25 and voltage Vbat of power storage device 9 .

The auxiliary power supply device 10 converts the AC power Pd1 of the main converter 8 into constant voltage, constant frequency (CVCF) AC power Pa3, which is used by vehicle auxiliary equipment (air conditioning, lighting, air compressor, etc.) (not shown). supply to

The integrated control device 11 includes a converter control unit 21 , an inverter control unit 22 , a storage battery control unit 23 and an integrated control unit 20 .

Converter control unit 21 performs constant voltage control in which DC voltage Vd1 detected by DC voltage detector 51 follows voltage command Vdb according to a command from integrated control unit 20, and generates a DC current based on the output. Constant current control is performed so that the DC current Id1 detected by the DC current detector 52 follows the command.

The inverter control unit 22 generates a torque current command for generating drive torque of the electric motor 17 for accelerating or decelerating the vehicles 1a and 1b in accordance with the command from the overall control unit 20, and detects the electric motor by the alternating current detector 18. Constant current control is performed to make the torque current calculated based on the currents Imu, Imv, and Imw follow the torque current command, and based on the output, a PWM pulse is generated to operate the switching circuit of the inverter device 15, and the inverter device 15 input.

In accordance with a command from the integrated control unit 20, the storage battery control unit 23 restricts charging/discharging (input/output) of the storage means by closing/releasing the storage power circuit breaker, and provides state information (storage amount, storage battery temperature, etc.) are aggregated and transmitted to the integrated control unit 20 .

With the above configuration, by adjusting the charge/discharge power Pbat of the power storage device 9, the SOC is managed so as to match the SOC(t).

SOC(t) is determined based on the elapsed time from the start of use of the power storage device 9 and the storage battery temperature Tb of the power storage device 9 with reference to the storage battery capacity maintenance rate prediction means. The elapsed time from the start of use of the power storage device 9 can be obtained by accumulating the time from the start of use of the power storage device 9 by the time measuring means provided in the integrated control unit 23. You can also enter the elapsed time value manually. The storage battery temperature Tb of the power storage device 9 can be detected as state information from the power storage device 9, but the average temperature in the environment in which the power storage device 9 is used may be stored in advance.

Further, in each of the above-described embodiments, the integrated control device 11 is illustrated as including individual control units such as the integrated control unit 20, the converter control unit 21, the inverter control unit 22, and the storage battery control unit 23. , this division is for convenience and the controls may be implemented by a single control unit or a combination of control units. Moreover, the content of control in each control unit is not limited to the embodiment, and any mounting form can be adopted. For example, assume that the overall control unit 20 collectively generates the control commands generated by the respective control units in the embodiment, and each of the other control units sends the state of the controlled object to the overall control unit 20. You may specialize in the function of notifying you.

In addition, as a basic function, the integrated control device 11 controls the operation of the main converter 8 based on a train control command, and in addition, executes switching between the first drive mode and the second drive mode. Note that the switching function between the first drive mode and the second drive mode may be implemented based on command information output from the command device to the integrated control device 11 by providing a command device in the driver's cab. good.

Furthermore, each of the above-described embodiments shows the case where the on-vehicle power storage device is managed by the proposed management method, but this management method can also be applied to the power storage device provided in the power supply facility on the ground side. is.

DESCRIPTION OF SYMBOLS 1a, 1b... vehicle, 2a, 2b, 2c, 2d... bogie 3a, 3b... wheelset, 4... overhead line, 5... current collector, 6... inter-vehicle coupler, 7... transformer, 8... main converter, 9... Power storage device 9a Storage battery 10 Auxiliary power supply 11 Integrated control device 12 AC voltage detector 13 AC current detector 14 Converter device 15 Inverter device 16 Capacitor 17 Electric motor , 18... AC current detector, 19... Vehicle auxiliary equipment, 20... Integrated control unit, 20a... Arithmetic device, 20b... Timer, 20c... Memory, 21... Converter control unit, 22... Inverter control unit, 23... Storage battery control DESCRIPTION OF SYMBOLS Unit 23a... Electricity storage controller, 23b... Thermometer, 23c... Electricity storage power breaker, 24... Reactor, 25... DC converter apparatus, 51... DC voltage detector, 52... DC current detector.

Claims (4)

a main converter;
an electric motor connected to the main converter;
a secondary battery type power storage device connectable to the main converter;
In a railway vehicle comprising at least
A control device that controls the power storage rate of the power storage device,
The control device has a memory in which a target power storage rate that increases as time elapses from the start of use or manufacture of the power storage device is recorded for each inquiry reference time,
The target value of the charge rate at the reference reference time that matches or is close to the current time is read from the memory , and the charge control or natural control of the power storage device is performed according to the difference between the read target value of charge rate and the charge rate at the current time. A railway vehicle characterized by executing discharge control including discharge. In the railway vehicle according to claim 1,
Having a measuring means for measuring the temperature of the power storage device,
The railway vehicle, wherein the control device corrects the read target value of the storage rate according to the current temperature. In the railway vehicle according to claim 1 or claim 2,
setting a management lower limit value for the power storage rate based on the amount of discharged power required for traveling in a predetermined section;
The control device sets a usage upper limit value, which is a storage rate for securing the discharged power amount, based on the management lower limit value, and controls the storage rate based on the usage upper limit value. rail car. In the railway vehicle according to any one of claims 1 to 3,
a current collector that supplies power from overhead lines to the main converter;
a command device that outputs a control command for switching between a first drive mode operated using power from the current collector and a second drive mode operated using power from the power storage device; Characteristic railway vehicle.

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