JP7770962B2 - Emergency power storage system - Google Patents

Description

An embodiment of the present invention relates to an emergency power storage system.

In recent years, many railway operators have become increasingly aware of the need to prepare for emergencies such as power outages on overhead lines, and are increasingly putting battery systems equipped with lithium-ion batteries to power railway vehicles.

Traditionally, vehicles equipped with VVVF (Variable Voltage Variable Frequency) inverter devices (hereinafter simply referred to as VVVF), static inverter devices (SIV: Static Inverter), and emergency power storage systems have been separate.

Japanese Patent Application Laid-Open No. 2015-146696

When the VVVF and SIV are installed in separate cars from the emergency energy storage system, the wiring insulation of the crossover wires between the cars can deteriorate due to vibrations, etc., causing ground faults (short circuits), etc. In this case, systems that use contactors and switches have the problem of making it difficult to safely interrupt the circuit.

Furthermore, if the pantograph rises and connects to the overhead lines while connecting the contactor to supply power to the VVVF, there is a risk that the overhead line voltage will flow into the emergency energy storage system, causing the vehicle system to shut down.

This invention was made in light of the above circumstances, and its purpose is to provide technology that safely interrupts the circuit when a specified current (e.g., a current excessive for the VVVF) due to a ground fault (short circuit) or the like occurs between the emergency energy storage system and the VVVF by placing a high-speed circuit breaker in addition to a contactor in the DC circuit section between the emergency energy storage system and the VVVF.

Furthermore, by placing a molded-case circuit breaker in the AC circuit section between the emergency energy storage system and the SIV (or auxiliary equipment), the technology provides a way to safely interrupt the circuit even if a certain current (e.g., a current excessive for the SIV) due to a ground fault or other reason occurs between the SIV (or auxiliary equipment) and the emergency energy storage system.

Furthermore, the objective is to provide technology that enables a control unit located in the emergency energy storage system to control the high-speed circuit breaker and DC contactor to open or close when the pantograph is down.

In one embodiment, the emergency power storage system comprises a VVVF inverter device that converts DC power to AC power to drive a main motor; a pantograph that is provided on the DC side of the VVVF inverter device and supplies power from the overhead line to the VVVF inverter device; a storage battery unit; and a DC circuit unit that has one end connected to the storage battery unit and the other end connected between the VVVF inverter device and the pantograph and supplies DC power from the storage battery unit to the VVVF inverter device. The DC circuit unit has a high-speed circuit breaker that interrupts the circuit when a first predetermined current is generated between the VVVF inverter device and the storage battery unit.

FIG. 1 is a main circuit diagram including a circuit diagram of an emergency power storage device according to this embodiment. FIG. 2 is a control circuit diagram showing an example of a control circuit section of an emergency power storage device. FIG. 3 is a flowchart showing an example of a processing procedure of the control unit 20 shown in FIG.

The energy storage system will be described in detail below with reference to the drawings. Note that in the following embodiments, parts with the same numbers perform similar operations, and redundant explanations will be omitted.

[First embodiment]
(composition)
FIG. 1 is a main circuit diagram including a circuit diagram of an emergency power storage device 1 according to this embodiment.
As shown in Fig. 1, an emergency power storage device 1, which is an emergency power storage system according to this embodiment, includes a storage battery unit 2, an inverter unit 6, a DC circuit unit 101, and an AC circuit unit 102. The emergency power storage device 1 is connected to a VVVF 12 via a VVVF-side high-speed circuit breaker 11. The emergency power storage device 1 is also connected to an SIV 15 and an auxiliary machine 16. The VVVF 12 is further connected to a traction motor 13. The SIV 15 is connected to a pantograph 17 via an SIV-side high-speed circuit breaker 14.

The DC circuit section 101 includes a first DC contactor 3, a high-speed circuit breaker 4, and a second DC contactor 5.

The AC circuit section 102 includes an AC reactor 7, an AC capacitor 8, a three-phase AC contactor 9, and a molded-case circuit breaker 10.

When the pantograph 17 is not connected to the down overhead line, for example in an emergency when the power supply from the overhead line is cut off due to a power outage, the storage battery unit 2 supplies power to the VVVF 12 via the DC circuit unit 101, or to the auxiliary equipment 16 via the AC circuit unit 102. Furthermore, when the pantograph 17 is connected to the up overhead line, the storage battery unit 2 can be charged by receiving power from the SIV 15 via the AC circuit unit 102.

The high-speed circuit breaker 4, first DC contactor 3, and second DC contactor 5 are installed in the circuit between the storage battery unit 2 and the VVVF 12. For example, the high-speed circuit breaker 4 and first DC contactor 3 are installed on the positive wiring, and the second DC contactor 5 is installed on the negative wiring. When the pantograph 17 is not connected to the overhead line and power is to be supplied from the storage battery unit 2 to the VVVF 12, the high-speed circuit breaker 4, first DC contactor 3, and second DC contactor 5 are closed, electrically connecting the storage battery unit 2 and the VVVF 12 and enabling power from the storage battery unit 2 to be sent to the VVVF 12. Furthermore, if a ground fault occurs in the wiring between the emergency power storage device 1 and the VVVF 12 and a large current flows, the high-speed circuit breaker 4 can shut off the circuit using its self-tripping function. The high-speed circuit breaker 4 can also shut off the circuit in response to instructions from the control unit, etc.

Furthermore, the first DC contactor 3 and the second DC contactor 5 interrupt the circuit in response to instructions from the control unit, etc., after the high-speed circuit breaker 4 performs its interruption operation. This makes it possible to reliably interrupt the circuit between the storage battery unit 2 and the VVVF 12 using multiple devices. For example, when the high-speed circuit breaker 4 detects an overcurrent and performs an interruption operation, even if it cannot be opened due to sticking or welding, the circuit can be interrupted by opening the first DC contactor 3 and the second DC contactor 5.

The AC reactor 7 and AC capacitor 8 arranged in the AC circuit unit 102 are installed between the storage battery unit 2 and the auxiliary equipment 16 or SIV 15 via the inverter unit 6. The inverter unit 6 converts the DC current output from the storage battery unit 2 into three-phase AC current. The AC reactor 7 and AC capacitor 8 smooth the input current and voltage, respectively.

When a predetermined current (e.g., a current excessive for the auxiliary equipment 16 or SIV 15) flows in the wiring between the auxiliary equipment 16 or SIV 15 and the inverter unit 6, the three-phase AC contactor 9 cuts off the circuit to prevent the predetermined current from being supplied to the wiring.

The molded case circuit breaker 10 is installed between the auxiliary equipment 16 or SIV 15 and the storage battery unit 2, and is installed on the wiring output from the inverter unit 6. When the storage battery unit 2 is charged using power from the SIV 15, a ground fault may occur in the wiring between the SIV 15 and the inverter unit 6. When a predetermined current (e.g., a current excessive for the SIV 15) caused by this ground fault occurs between the SIV 15 and the inverter unit 6, the molded case circuit breaker 10 uses its self-tripping function to shut off the circuit so that the predetermined current does not flow to the inverter unit 6. Also, when power is supplied from the storage battery unit 2 to the auxiliary equipment 16 via the inverter unit 6, a ground fault may occur in the wiring between the inverter unit 6 and the auxiliary equipment 16. The molded case circuit breaker 10 uses its self-tripping function to shut off the circuit so that the predetermined current (e.g., a current excessive for the auxiliary equipment 16) caused by this ground fault does not flow to the auxiliary equipment 16.

The VVVF-side high-speed circuit breaker 11 is installed on the DC side of the VVVF 12, which will be described later. The VVVF-side high-speed circuit breaker 11 breaks the circuit when a predetermined current (e.g., a current excessive for the VVVF 12) flows in the wiring between the VVVF 12 and the pantograph 17.

VVVF 12 is a power conversion device that converts DC power supplied from the pantograph 17 or the battery unit 2 into AC power. VVVF 12 can also change the voltage and current supplied to the main motor 13, which will be described later.

The main motor 13 drives the vehicle using the power supplied from the VVVF 12.

The SIV-side high-speed circuit breaker 14 is installed between the SIV 15 and the pantograph 17. The SIV-side high-speed circuit breaker 14 breaks the circuit when a predetermined current (e.g., a current excessive for the SIV 15) is supplied from the pantograph 17 to the SIV 15.

SIV 15 is installed between auxiliary equipment 16 and pantograph 17. SIV 15 converts DC power supplied from pantograph 17 into AC power, and also steps down the voltage supplied from pantograph 17 (e.g., 1500V to 1800V) to a voltage at which auxiliary equipment 16 can operate.

Auxiliary equipment 16 includes lighting equipment, air conditioning equipment, etc.

The pantograph 17 draws power from the overhead line. If an abnormality occurs, the pantograph 17 is lowered to disconnect from the overhead line, and power is supplied from the battery unit 2 to the VVVF 12 and auxiliary equipment 16.

(operation)
Next, the operation of the emergency power storage device 1 configured as above will be described.
First, the operation of the DC circuit section 101 will be described.

First, let's assume that the pantograph 17 is down and power is being supplied from the battery unit 2 to the VVVF 12, i.e., an emergency situation. In this case, if a ground fault or other problem occurs in the wiring between the battery unit 2 and the VVVF 12, causing a predetermined current (e.g., a current excessive for the VVVF 12) to flow between the battery unit 2 and the VVVF 12, the high-speed circuit breaker 4 will shut off the circuit using its self-trip function. This shuts off the circuit in the DC circuit unit 101, and the VVVF 12 is no longer affected by the excessive current. As a result, the VVVF 12 will not be destroyed by the excessive current.

Furthermore, if the pantograph 17 accidentally connects to the overhead line while the storage battery unit 2 is supplying power to the VVVF 12, the voltage supplied by the storage battery unit 2 will be lower than the voltage supplied by the pantograph 17, causing excessive current to flow from the pantograph 17 to the storage battery unit 2. In such a case, the high-speed circuit breaker 4 will shut off the circuit using its self-tripping function. This will shut off the circuit in the DC circuit unit 101, preventing the storage battery unit 2 from being destroyed by excessive current from the pantograph 17.

Next, we will explain the operation of the AC circuit unit 102.

Let's assume that the storage battery unit 2 is charged from the SIV 15 through the inverter unit 6. In this case, if a ground fault or other problem occurs between the SIV 15 and the inverter unit 6, a certain current (e.g., a current that is excessive for the storage battery unit 2) may flow from the SIV 15 to the inverter unit 6. In such a case, the molded case circuit breaker 10 will shut off the circuit using its self-tripping function. This will shut off the circuit in the AC circuit unit 102. Therefore, even if an excessive current occurs due to a ground fault or other problem while the storage battery unit 2 is being charged, the molded case circuit breaker 10 will shut off the circuit. Therefore, the storage battery unit 2, the inverter unit 6, and the SIV 15 will not be destroyed by the excessive current.

Furthermore, if the SIV 15 fails or the pantograph 17 is not connected to the down overhead line, the storage battery unit 2 supplies power to the auxiliary equipment 16 via the inverter unit 6. In such a case, if a ground fault or other problem occurs in the wiring between the auxiliary equipment 16 and the inverter unit 6, a certain current (e.g., a current excessive for the auxiliary equipment 16) may flow from the inverter unit 6 to the auxiliary equipment 16. In such a case, the molded case circuit breaker 10 cuts off the circuit using its self-tripping function. This cuts off the circuit in the AC circuit unit 102, preventing the storage battery unit 2, inverter unit 6, and auxiliary equipment 16 from being destroyed by the excessive current.

(Operation and effect of the first embodiment)
According to the first embodiment described above, even if a ground fault or the like occurs in the wiring from the emergency storage device 1 to the VVVF 12 and excessive current flows, the circuit can be safely interrupted by the high-speed circuit breaker 4.

Furthermore, when power is supplied from the storage battery unit 2 to the auxiliary equipment 16 via the inverter unit 6, or when the storage battery unit 2 is charged from the SIV 15 via the inverter unit 6, even if an excessive current flows in the wiring between these units due to a ground fault or the like, the circuit can be safely interrupted by the molded case circuit breaker 10.

Second Embodiment
(composition)
The circuit diagram of the emergency power storage device 1 in the second embodiment is the same as that shown in FIG. 1 of the first embodiment, and therefore the description of the emergency power storage device 1 will be omitted.

FIG. 2 is a control circuit diagram showing an example of the control circuit section 100 of the emergency power storage device 1. As shown in FIG.
The control circuit unit 100 includes a control unit 20, a high-speed circuit breaker closing relay contact 21, a high-speed circuit breaker control coil 22, a first DC contactor closing relay contact 23, a first DC contactor control coil 24, a second DC contactor closing relay contact 25, and a second DC contactor control coil 26. Also shown in Fig. 2 are a control battery group 18 and a pantograph rising detection relay contact 19, which are installed outside the control circuit unit 100.

The control battery group 18 is a group of batteries that supply power (e.g., 100 V) to the control circuit unit 100 when the pantograph 17 is not connected to the overhead line.

The pantograph rise detection relay contact 19 is not closed when the pantograph 17 is connected to the overhead line. Therefore, power is not supplied to the control circuit unit 100 from the control battery group 18. On the other hand, when the pantograph 17 is lowered and not connected to the overhead line, the pantograph rise detection relay contact 19 is closed. Power is then supplied to the control circuit unit 100 from the control battery group 18.

The control unit 20 controls whether to open or close the high-speed circuit breaker closing relay contact 21, the first DC contactor closing relay contact 23, and the second DC contactor closing relay contact 25. For example, when power is supplied from the control battery group 18, i.e., when the pantograph 17 is not connected to the overhead line, the storage battery unit 2 supplies power to the VVVF 12. In this case, the control unit 20 closes the high-speed circuit breaker closing relay contact 21, the first DC contactor closing relay contact 23, and the second DC contactor closing relay contact 25 to supply power from the storage battery unit 2 to the VVVF 12. At this time, if a ground fault occurs and a predetermined current (e.g., a current excessive for VVVF 12) flows between the storage battery unit 2 and VVVF 12, the control unit 20 closes each contact, thereby opening the high-speed circuit breaker closing relay contact 21, the first DC contactor closing relay contact 23, and the second DC contactor closing relay contact 25, thereby interrupting the circuit. In other words, the control unit 20 controls so that excessive current does not flow to the storage battery unit 2 or VVVF 12.

The control unit 20 also has a CPU, memory, an interface, etc. The CPU is a processor that executes programs to realize various processing functions. The memory includes various types of memory, such as non-volatile memory that stores the programs executed by the CPU, volatile memory that temporarily holds data, and rewritable non-volatile memory that saves setting data, etc. In other words, the control unit 20 performs various processes by having the CPU execute programs stored in the memory.

The high-speed circuit breaker closing relay contact 21, the first DC contactor closing relay contact 23, and the second DC contactor closing relay contact 25 are controlled by the control unit 20 to open or close. For example, when the high-speed circuit breaker closing relay contact 21 is closed, the high-speed circuit breaker control coil 22 causes the high-speed circuit breaker 4 to connect the circuit, and when the high-speed circuit breaker closing relay contact 21 is opened, the high-speed circuit breaker 4 breaks the circuit. Furthermore, when the first DC contactor making relay contact 23 and the second DC contactor making relay contact 25 are respectively closed, the first DC contactor control coil 24 and the second DC contactor control coil 26 connect the first DC contactor 3 and the second DC contactor 5 to the circuit, and when the first DC contactor making relay contact 23 and the second DC contactor making relay contact 25 are respectively opened, the first DC contactor control coil 24 and the second DC contactor control coil 26 cause the first DC contactor 3 and the second DC contactor 5 to break the circuit.

(operation)
Next, the operation of the emergency power storage device 1 configured as above will be described.
FIG. 3 is a flowchart showing an example of a processing procedure of the control unit 20 shown in FIG.

The operation of this flowchart is realized by reading out a program stored in the control unit 20 and memory located within the control unit 20.

This flowchart begins when the pantograph 17 is lowered and disconnected from the overhead lines.

The control unit 20 detects that the pantograph rise detection relay contact 19 has been closed (step ST101). The pantograph 17 is lowered and disconnected from the overhead line, causing the pantograph rise detection relay contact 19 to be closed. The control unit 20 receives power from the control battery group 18 as a result of the pantograph rise detection relay contact 19 being closed. This allows the control unit 20 to detect that the pantograph rise detection relay contact 19 has been closed.

When the pantograph rise detection relay contact 19 is closed, the control unit 20 closes the high-speed circuit breaker closing relay contact 21, the first DC contactor closing relay contact 23, and the second DC contactor closing relay contact 25, respectively, connecting the circuit from the VVVF 12 to the emergency storage battery 1 via the high-speed circuit breaker 4, the first DC contactor 3, and the second DC contactor 5. Furthermore, when the pantograph 17 rises and the pantograph rise detection relay contact 19 is opened, the high-speed circuit breaker closing relay contact 21, the first DC contactor closing relay contact 23, and the second DC contactor closing relay contact 25 are forcibly opened, respectively, and the high-speed circuit breaker 4, the first DC contactor 3, and the second DC contactor 5 interrupt the circuit from the VVVF 12 to the emergency storage battery 1 (step ST102).

The control unit 20 determines whether a predetermined condition for interrupting the circuit of the DC circuit unit 101 is met (step ST103). Here, the predetermined condition may be a condition in which a predetermined current (e.g., a current excessive for the VVVF 12) is flowing in the wiring between the VVVF 12 and the emergency power storage device 1 due to a ground fault or the like. Alternatively, the predetermined condition may be an instruction from an administrator to interrupt the circuit of the DC circuit unit 101. In other words, the predetermined condition may be any condition that interrupts the circuit of the DC circuit unit 101.

If it is determined that the predetermined conditions are not met, processing may return to step ST102. On the other hand, if it is determined that the predetermined conditions are met, processing proceeds to step ST104.

The control unit 20 opens the high-speed circuit breaker closing relay contact 21 (step ST104). By having the control unit 20 open the high-speed circuit breaker closing relay contact 21 and the second DC contactor closing relay contact 25, the high-speed circuit breaker 4 breaks the circuit.

The control unit 20 opens the first DC contactor closing relay contact 23 and the second DC contactor closing relay contact 25 (step ST105). By having the control unit 20 open the first DC contactor closing relay contact 23 and the second DC contactor closing relay contact 25, the first DC contactor 3 and the second DC contactor 5 will interrupt the circuit. For example, even if the high-speed circuit breaker 4 is unable to interrupt the circuit due to sticking, welding, etc., the first DC contactor 3 and the second DC contactor 5 can interrupt the circuit. This makes it possible to interrupt the circuit more reliably and safely.

(Operation and effect of the second embodiment)
According to the second embodiment described above, the control unit 20 can detect that the pantograph 17 is lowered by closing the pantograph-up detection relay contact 19. Therefore, it is possible to provide an interlock that allows the control unit 20 to close or open the circuits of the high-speed circuit breaker 4, the first DC contactor 3, and the second DC contactor 5 only when the pantograph 17 is lowered. In other words, when the pantograph 17 is raised and the pantograph-up detection relay contact 19 is open, the circuits of the high-speed circuit breaker 4, the first DC contactor 3, and the second DC contactor 5 are opened, and the pantograph 17, which is connected to the overhead line via the DC circuit unit 101, and the storage battery unit 2 are not electrically connected.

In addition, even if a ground fault or other problem occurs in the wiring from the emergency power storage device 1 to the VVVF 12, causing excessive current to flow, the control unit 20 can safely interrupt the circuit using the high-speed circuit breaker 4, first DC contactor 3, and second DC contactor 5. Furthermore, by controlling the circuit interruption using the control unit 20, it is possible to interrupt the circuit using the high-speed circuit breaker 4, first DC contactor 3, and second DC contactor 5 under any conditions.

Other Embodiments
The present invention is not limited to the above-described embodiment. For example, the first and second embodiments may be combined. That is, when an excessive current is generated in the wiring between the VVVF 12 and the emergency power storage device 1 while the pantograph 17 is down, the high-speed circuit breaker 4 may break the circuit by its self-tripping function, and the control unit 20 may control the high-speed circuit breaker 4, the first DC contactor 3, and the second DC contactor 5 to break the circuit.

The control unit 20 may also control the molded case circuit breaker 10 and the three-phase AC contactor 9 to interrupt the circuit.

In short, this invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the various embodiments may be implemented in combination as appropriate as possible, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining the multiple disclosed constituent elements.

DESCRIPTION OF SYMBOLS 1... Emergency storage battery device 2... Storage battery section 3... First DC contactor 4... High-speed circuit breaker 5... Second DC contactor 6... Inverter section 7... AC reactor 8... AC capacitor 9... Three-phase AC contactor 10... Molded-case circuit breaker 11... VVVF side high-speed circuit breaker 12... VVVF
DESCRIPTION OF SYMBOLS 13... Main motor 14... SIV side high-speed circuit breaker 16... Auxiliary equipment 17... Pantograph 18... Control battery group 19... Pantograph rise detection relay contact 20... Control unit 21... High-speed circuit breaker closing relay contact 22... High-speed circuit breaker control coil 23... First DC contactor closing relay contact 24... First DC contactor control coil 25... Second DC contactor closing relay contact 26... Second DC contactor control coil 100... Control circuit unit 101... DC circuit unit 102... AC circuit unit

Claims (8)

a VVVF inverter device that converts DC power into AC power to drive a main motor;
a pantograph provided on a DC side of the VVVF inverter device and supplying power from an overhead line to the VVVF inverter device;
A storage battery unit;
a DC circuit section having one end connected to the storage battery section and the other end connected between the VVVF inverter device and the pantograph, for supplying DC power from the storage battery section to the VVVF inverter device;
an inverter unit that converts DC power from the storage battery unit into AC power;
an AC circuit unit connected to a static inverter device for converting DC power into AC power and charging the storage battery unit; and an auxiliary device;
the DC circuit unit has a high-speed circuit breaker, and when a first predetermined current is generated between the VVVF inverter device and the storage battery unit, the high-speed circuit breaker breaks the circuit ;
The AC circuit unit includes a molded case circuit breaker connected to the inverter unit .
Emergency power storage system. the molded case circuit breaker breaks the circuit when a second predetermined current is generated in the wiring between the static inverter device and the inverter unit while the storage battery unit is being charged with power from the static inverter device;
The emergency power storage system according to claim 1. The emergency power storage system of claim 2, wherein the molded case circuit breaker breaks the circuit when a third predetermined current is generated in the wiring between the inverter unit and the auxiliary equipment while power is being supplied from the storage battery unit to the auxiliary equipment via the inverter unit. the DC circuit unit further includes a first DC contactor connected in series to the high-speed circuit breaker, and a second DC contactor installed on a wiring different from the wiring on which the high-speed circuit breaker is arranged,
The emergency power storage system further includes a control unit that controls interruption of the circuits of the high-speed circuit breaker, the first DC contactor, and the second DC contactor,
The emergency energy storage system according to any one of claims 1 to 3, wherein the control unit controls the high-speed circuit breaker, the first DC contactor, and the second DC contactor to interrupt the circuit when a pantograph connected to the emergency energy storage system is not connected to an overhead line. The emergency power storage system of claim 4, wherein the control unit detects that the pantograph is not connected to the overhead line by detecting that a pantograph lift detection relay contact connected to the control unit has been closed. a VVVF inverter device that converts DC power into AC power to drive a main motor;
a pantograph provided on a DC side of the VVVF inverter device and supplying power from an overhead line to the VVVF inverter device;
A storage battery unit;
a DC circuit unit having one end connected to the storage battery unit and the other end connected between the VVVF inverter device and the pantograph, supplying DC power from the storage battery unit to the VVVF inverter device, and including a high-speed circuit breaker, a first DC contactor connected in series to the high-speed circuit breaker, and a second DC contactor installed on a wiring separate from the wiring on which the high-speed circuit breaker is arranged;
a control unit that controls the interruption of the circuits of the high-speed circuit breaker, the first DC contactor, and the second DC contactor;
wherein the DC circuit unit interrupts the circuit by the high-speed circuit breaker when a first predetermined current is generated between the VVVF inverter device and the storage battery unit.
Emergency power storage system. 7. The emergency power storage system according to claim 6, wherein the control unit controls the high-speed circuit breaker, the first DC contactor, and the second DC contactor to interrupt the circuit when a pantograph connected to the emergency power storage system is not connected to an overhead line. 7. The emergency power storage system according to claim 6, wherein the control unit detects that the pantograph is not connected to the overhead line by detecting that a pantograph rise detection relay contact connected to the control unit is closed.