JP2001260718A - Dc power supply facility for electric railroad - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem with the use of a storage battery as an energy storage device that it cannot be quickly charged and discharged and the problem with the use of an electric double-layer capacitor that it cannot be charged and discharged by a large capacity. SOLUTION: A storage battery 11 and an electric double-layer capacitor 12 are provided as power storage devices. A controller 13 is capable of individually controlling the charge and discharge of the storage battery and the capacitor by means of switch circuits 13A and 13B and capable of paralleling them off, and controls charge and discharge between each of the storage battery and the capacitor and a feeder by means of a step-up/ step-down chopper 13C. In another embodiment, the storage battery and the capacitor are provided with respective individual controllers to individually control the charge and discharge thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC power supply system for railways provided with an energy storage device, and more particularly to a power storage device of an energy storage device.

[0002]

2. Description of the Related Art Electric power supply facilities for electric railways are mainly electric vehicles, and therefore are required to have a specific power supply capability relative to other general distribution system loads.

(1) Capable of following a sudden load change. That is, the electric trains, which are loads of the electric railway, have a plurality of randomly changing operating states such as acceleration, constant speed, deceleration, and stop, and can supply electric power with a high response to a rapidly changing load. Equipment is required.

(2) A stable power supply is possible for a long time. That is, electric vehicles include those that operate non-stop over long distances, such as limited express trains, and require a stable power supply capability over the operation time.

(3) It is desired to level the load. That is, a sudden load change involves a sudden change in the load as viewed from the substation. In addition, the number of electric vehicles to be driven is large during the morning and evening rush hours, and is reduced during the off hours during the day. For these load changes, load leveling is required from the substation side in order to improve power conversion efficiency and the like.

[0006] In order to meet these requirements,
A method for providing an energy storage device has been proposed. For example, a test using a storage battery facility as an energy storage device has been performed at Nakajima Station on the JR Kabe Line for five years since 1979, and a report has been published.

As another method, in a DC feeding system, a system has been proposed in which regenerative power from an electric vehicle is regenerated as DC power in an energy storage device provided on the feeder line side (for example, Japanese Patent Application Laid-Open No. 11-91415). No.). This energy storage device is configured as shown in FIG. In supplying DC power from the rectifier 1 to the feeder line, energy consisting of a current control circuit (step-up / step-down chopper) 2 and a DC power storage device (secondary battery, power capacitor, electric double layer capacitor) 3 is provided on the DC side of the rectifier 1. A DC power storage device 3 is charged through the current control circuit 2 when the electric vehicle is in a regenerative state, and discharged from the DC power storage device 3 through the current control circuit 2 when the electric vehicle is in the power running state. Let it.

[0008]

In a conventional energy storage device, a storage battery or an electric double layer capacitor is used as power storage means.

When power is stored by a storage battery, the storage battery is a large-capacity power storage device excellent in long-term energy storage and storage amount, but is inferior in quick charge / discharge characteristics and has a delay in charging regenerative power or the like having a fast rise. This causes a delay in the discharge following a sudden change in load at the time of starting or accelerating the electric vehicle, leading to a sudden change in the feeder line voltage or regenerative lapse.

When electric power is stored by the electric double-layer capacitor, the electric double-layer capacitor becomes a high-speed power storage device having an excellent rapid charge / discharge performance, and can absorb energy from a regenerative vehicle or the like and respond to a sudden load change. However, the electric double layer capacitor is inferior to the storage battery in energy storage amount and has a large spontaneous discharge amount, and is not suitable for long-term power storage.

It is an object of the present invention to provide a DC power supply facility for railways which is excellent in rapid charge / discharge performance, long-time power storage and power storage amount.

[0012]

SUMMARY OF THE INVENTION The present invention relates to a high-speed power storage device having a rapid charge / discharge capability such as an electric double layer capacitor, and a power storage device capable of storing power for a long time such as a storage battery (secondary battery). An energy storage device with a large-capacity power storage device that has a large power supply is charged and discharged quickly by the high-speed power storage device at the beginning of charging and discharging, and is charged and discharged by the large-capacity power storage device for long-time charging and discharging. And is characterized by the following configuration.

An energy storage, which is provided in parallel with a rectifier or a forward converter that supplies DC power to the feeder, stores DC power by charging from the feeder and discharges DC power to the feeder in response to a change in load. In the railway DC power supply equipment provided with the device, the energy storage device, a high-speed power storage device having a rapid charge and discharge capability, a large-capacity power storage device capable of long-term power storage and a large amount of power storage, An initial charge / discharge current for the feeder line is performed by charge / discharge control from the high-speed power storage device, and a long-time or large-current charge / discharge current thereafter is controlled by charge / discharge control from the large-capacity power storage device. It is characterized by having.

[0014] Further, the controller is characterized in that charging and discharging of both devices are collectively controlled via a switch circuit capable of disconnecting between the high-speed power storage device and the large-capacity power storage device. .

Further, the controller is characterized in that the high-speed power storage device and the large-capacity power storage device are individually charged and discharged.

[0016]

FIG. 1 is a diagram showing a main circuit configuration of an energy storage device, which is an electric power supply system according to an embodiment of the present invention.

In the substation, as in the prior art, an AC power supply is converted into DC power having a rated voltage by a rectifier (or a forward converter) 10 and supplied to the electric wire side.

The power storage device includes a storage battery 11 as a large-capacity power storage device and an electric double-layer capacitor 12 as a high-speed power storage device. The storage battery 11 and the electric double layer capacitor 12 are connected through an input / output controller 13 and further through a high-speed circuit breaker 14 and a disconnector 15 and are connected between the electric wire and the rail.

The controller 13 enables the storage battery 11 and the electric double layer capacitor 12 to be installed side by side by a switch circuit 13A provided in series on the storage battery 11 side and a switch circuit 13B provided in series on the electric double layer capacitor 12 side. In order to collectively control the charging and discharging of these devices, a step-up / step-down chopper 13C is provided between the feeder line.

Each of the switch circuits 13A and 13B comprises a semiconductor switch serving as a switch means and a diode connected in anti-parallel to the semiconductor switch. In the switch circuit 13A, the discharge timing from the storage battery 11 can be controlled by a semiconductor switch, and charging can be performed at an arbitrary timing by a diode. In the switch circuit 13B, the charge timing of the electric double layer capacitor 12 can be controlled by a semiconductor switch, and the diode can discharge at an arbitrary timing.

This eliminates the inconvenience of directly connecting the electric double layer capacitor 12 and the storage battery 11 in parallel.

That is, the storage battery 11 exhibits characteristics close to a constant-voltage power supply, and the terminal voltage changes little depending on the amount of charge.
On the other hand, the terminal voltage of the electric double layer capacitor 12 changes depending on the charge amount. Therefore, when both are directly connected in parallel, a charging current flows from the storage battery to the electric double layer capacitor, and the electric double layer capacitor always has the same voltage as the storage battery. At this time, rapid charging and discharging between the feeder line and the electric double layer capacitor is performed only in a high voltage range, and the rapid charging and discharging effect is reduced. Therefore, the switch circuit 13A,
By providing 13B, the rapid charging / discharging effect is enhanced by always keeping the electric double layer capacitor lower than the storage battery voltage.

The electric double layer capacitor has a large amount of spontaneous discharge. If the electric double layer capacitor is connected in parallel with the storage battery, the energy stored in the storage battery is spontaneously discharged through the electric double layer capacitor. Therefore, by providing switch circuits 13A and 13B between the two, natural discharge from the storage battery through the electric double layer capacitor can be prevented.

Next, the step-up / step-down chopper 13C
This is realized by the configuration shown in FIG. Semiconductor switches SW1 and SW2 represented by IGBTs are connected in series, and these switches S
Flywheel diodes D1 and D2 are provided in antiparallel to W1 and SW2 to form upper and lower arms, and a connection point between the upper and lower arms is connected to the electric double layer capacitor 12 and the storage battery 11 via a DC reactor L.

The step-down charging of the electric double layer capacitor 12 and the like by the step-up / step-down chopper 13C is performed by switches SW1 and SW2.
Switch SW1 with respect to the DC voltage applied to both ends of
Is operated as a chopper, and during the ON period, the switch SW1 is turned on.
Supplies the charging current to the electric double layer capacitor 12 and the like through the reactor L, and supplies the charging current to the electric double layer capacitor 12 and the like via the path from the electric double layer capacitor 12 to the diode D2 during the off period. I do.

The step-up discharge from the electric double layer capacitor 12 or the like through the step-up / step-down chopper 13C causes the switch SW2 to operate as a chopper, and a short-circuit current flows from the electric double layer capacitor 12 or the like to the reactor L during the ON period. Current energy is accumulated in the reactor L, and during the off period, the current flows from the reactor L through the diode D1 and is discharged to the electric wire side.

The capacitor C and the reactor DCL provided on the high voltage side of the step-up / step-down chopper 13C suppress harmonics (harmonics due to the chopper operation) included in the charge / discharge current from the electric double layer capacitor 12 and the like through the step-up / step-down chopper 13B. It is for doing. This harmonic suppression prevents a communication failure along a railway, a failure in a railway signaling device, and a failure in an in-car radio or the like.

The energy storage control according to the above configuration is performed by the controller 13, and when it is detected that regenerative electric power from the electric vehicle or the like and the electric wire voltage has become equal to or higher than a certain value (charging start voltage), the step-up / step-down chopper 13C To control charging. At the beginning of this charge control, the switch circuit 13
The switch B is turned on to obtain rapid charging by the electric double layer capacitor 12. When the electric double layer capacitor 12 rises to about the storage battery voltage by this rapid charging, the diode of the switch circuit 13A conducts, and the subsequent large charging current To the storage battery 11 side. At this time, the switch circuit 13
The semiconductor switch B is forcibly turned off.

Conversely, the controller 13 controls the discharge of the step-up / step-down chopper 13C when detecting that the feeder voltage has become equal to or lower than a predetermined value (discharge start voltage). In the initial stage of the discharge control, a rapid discharge is obtained from the electric double layer capacitor 12 through the diode of the switch circuit 13B, and when the electric double layer capacitor 12 falls to a certain voltage by the rapid discharge, the semiconductor switch of the switch circuit 13A is turned off. When turned on, a large discharge current is supplied from the storage battery 11.

Accordingly, charging and discharging of the feeder line by the energy storage device is as shown in FIG. 3, and a high-speed charging / discharging current (hatched portion) by the electric double layer capacitor 12 flows at the beginning of the charging current and the discharging current. The charging and discharging for a long time thereafter is charging and discharging by the storage battery 11.

Thus, even when the electric double layer capacitor 12 and the storage battery 11 are provided side by side, the electric double layer capacitor is set to a voltage lower than that of the storage battery at the time of charging, and rapid charging from this voltage to the storage battery voltage can be performed. Also,
At the time of discharging from the electric double layer capacitor, it is possible to discharge from a voltage about the storage battery voltage to a voltage sufficiently lower than the storage battery voltage. The charge / discharge in such a wide voltage range can enhance the rapid charge / discharge effect.

Further, discharge from the storage battery 11 to the electric double layer capacitor 12 can be blocked by the switch circuits 13A and 13B, and natural discharge from the storage battery 11 to the electric double layer capacitor 12 can be prevented.

FIG. 4 shows another embodiment of the present invention. FIG. 1 shows a case where dedicated controllers 16A and 16B are provided for the storage battery 11 and the electric double layer capacitor 12, respectively. The controllers 16A and 16B include, for example, a step-up / step-down chopper 13C shown in FIG. 2 and a control device therefor.

In this embodiment, since the charge and discharge of the storage battery 11 and the electric double layer capacitor 12 can be individually controlled by the controllers 16A and 16B, spontaneous discharge from the storage battery 11 to the electric double layer capacitor can be prevented, and the rapid charge and discharge function can be achieved. And a long-term charge / discharge function. Furthermore, the voltage of the storage battery 11 and the voltage of the electric double layer capacitor can be controlled independently, and the rapid charging / discharging effect of the electric double layer capacitor can be further enhanced. The switch circuit 13
A, 13B and its control circuit become unnecessary.

In the above embodiments, the case of an electric double layer capacitor is shown as a high-speed power storage device for obtaining rapid charging and discharging, but this can be a power capacitor. Although a storage battery is shown as a large-capacity power storage device for obtaining long-term large-current charging / discharging, this is not limited to a configuration using only a storage battery, and a configuration in which a fuel cell and the like are also provided.

Further, in this embodiment, since the energy storage device is provided, it is needless to say that it is effective as a measure for leveling the load in the feeding system in the off-line section as in the conventional case. That is, the storage battery is charged during the off-hours or at night, and the load is discharged from the storage battery during the rush hour to level the load in the time zone. In addition, the storage battery is charged during the stop time of the express train, and the load time zone is leveled by discharging the storage battery during the operation time of the express train.

[0037]

As described above, according to the present invention, rapid charging and discharging are performed by the high-speed power storage device at the beginning of charging and discharging, and charging and discharging are performed by the large-capacity power storage device during long-time charging and discharging. Charging / discharging can be performed in accordance with a sudden change in load due to starting or regeneration of an electric car, and power can be supplied at a leveled load during an operation of an express train.

Further, even when the storage battery and the electric double layer capacitor are provided in parallel, by providing a controller having a switch circuit or an individual controller, spontaneous discharge by the electric double layer capacitor does not occur.

[Brief description of the drawings]

FIG. 1 is a main circuit configuration diagram showing an embodiment of the present invention.

FIG. 2 is a circuit example of a step-up / step-down chopper according to the embodiment;

FIG. 3 is a waveform diagram of a charge / discharge current in the embodiment.

FIG. 4 is a circuit diagram showing another embodiment.

FIG. 5 is a schematic configuration diagram of an energy storage device.

[Explanation of symbols]

 Reference Signs List 10 rectifier 11 storage battery 12 electric double layer capacitor 13, 16A, 16B controller 13A, 13B switch circuit 13C step-up / step-down chopper

Continued on the front page (72) Inventor Yoshinobu Nakamichi 38-8 Hikaricho, Kokubunji-shi, Tokyo Inside the Railway Technical Research Institute (72) Inventor Shinichi Hase 2-8-8 Hikaricho, Kokubunji-shi, Tokyo Foundation 38 Inside the Railway Technical Research Institute (72) Inventor Tadashi Uemura 2-1-1-17 Osaki, Shinagawa-ku, Tokyo Co., Ltd.Meidensha Corporation (72) Inventor Hideo Watanabe 2-1-1, Osaki, Shinagawa-ku, Tokyo F-term in Meidensha (reference) 5G003 AA01 BA04 CC02 DA07 DA15 FA08

Claims (3)

[Claims] 1. A rectifier or a forward converter for supplying DC power to a feeder, which is provided in parallel to accumulate DC power by charging from the feeder and discharge DC power to the feeder in response to a change in load. In the DC power supply equipment for railways provided with an energy storage device, the energy storage device includes a high-speed power storage device having a rapid charge / discharge capability, and a large-capacity power storage device capable of storing power for a long time and having a large power storage amount. An initial charge / discharge current for the feeder wire is controlled by charge / discharge control from the high-speed power storage device, and a long-time or large current charge / discharge current is controlled by charge / discharge control from the large-capacity power storage device. DC power supply equipment for railways, comprising: 2. The controller according to claim 1, wherein the controller controls the charging and discharging of the two devices via a switch circuit that can be disconnected between the high-speed power storage device and the large-capacity power storage device. A DC power supply system for electric railways according to claim 1. 3. The railway DC power supply system according to claim 1, wherein the controller is configured to control charging and discharging of the high-speed power storage device and the large-capacity power storage device individually.