JP6140085B2 - Vehicle control system - Google Patents

Description

  Embodiments described herein relate generally to a railway vehicle control system.

  Conventionally, there is a case where DC power and AC power exist in the power supplied from the overhead line, and the route extends over the DC power section and the AC power section. Along with this, there are railway vehicles (vehicles for both AC and DC) that can travel in both the DC power section and the AC power section.

In a railway vehicle that travels by receiving DC power supplied from an overhead line, the ground of the power converter is connected to the negative side of the DC circuit. On the other hand, a technology for grounding a neutral point of an intermediate DC circuit of a power converter is known for a railway vehicle that travels by receiving AC power supplied from an overhead wire.

  Here, when realizing the ground circuit of the power conversion device mounted on the AC / DC vehicle, the circuit is configured so that both the DC power section and the AC power section are grounded on the negative side of the intermediate DC circuit of the power conversion apparatus, It is conceivable to switch the grounding between the DC power section and the AC power section.

  In the former case, since it is necessary to set the withstand voltage based on the DC power section, there is a problem that the voltage of the intermediate DC circuit cannot be increased in the AC power section, and the power converter cannot be downsized. . On the other hand, in the latter case, since the ground circuit is made different between the DC power section and the AC power section, the voltage of the intermediate DC circuit can be increased in the AC power section, and accordingly, the current of the intermediate DC circuit is decreased. Therefore, the power converter can be downsized.

JP-A-9-93702

  However, when the ground circuit is switched between the DC power section and the AC power section, a switching circuit is required, and physical switching means such as a contactor is used. When switching means such as contactors are used, excessive voltage or withstand voltage is applied to the components that make up the power converter if the AC power section enters the DC power section or vice versa without switching correctly due to a failure or the like. As a result, there is a possibility of failure of the power conversion device.

  The present invention has been made in view of the above, and is a vehicle control system capable of protecting components constituting a power conversion device or the like even when a switching means such as a contactor fails. The purpose is to provide.

The vehicle control system of the embodiment includes an AC circuit breaker connected to an overhead line via a current collector, a DC circuit breaker connected to the overhead line via the current collector, and the AC circuit breaker. A connected transformer; a converter connected to the transformer; an AC contactor connected between the transformer and the converter; an inverter connected to the converter via an intermediate DC circuit; a DC contactor connected between the DC breaker and the intermediate DC circuit, and the negative side of the intermediate DC circuit and the first current detector which is disposed between the ground, the neutral of the intermediate DC circuit A second current detector disposed between the point and the ground, a switching unit that connects one of the first current detector and the second current detector to the ground, and the power supplied from the overhead wire is a direct current and overhead wire power detector for detecting whether an AC or is, the Based on the detection result of the line power detector, a first control unit for controlling the switching unit to control one of the direct current for the circuit breaker and the AC circuit breaker in the connected state, the first current detector When the switching unit is controlled so as to be connected to ground, when the second current detector detects a current, it is determined that the switching unit has failed and is controlled to be disconnected from the DC contactor. and, wherein the determining that the second current detector said switching unit when said first current detector detects a current when the switching unit is controlled so as to be connected to ground fails And a second control unit that controls the AC contactor to shut off.

FIG. 1 is a diagram illustrating a configuration included in a vehicle according to an embodiment. FIG. 2 is a diagram illustrating a processing flow of the ground switching operation and the protection operation in the embodiment. FIG. 3 is a diagram illustrating a database of determination criteria for ground switching operation according to an embodiment. FIG. 4 is a diagram illustrating a current path when an alternating current is supplied from an overhead line in the embodiment. FIG. 5 is a diagram illustrating a current path when the ground switching circuit becomes abnormal when an alternating current is supplied from an overhead line in an embodiment. FIG. 6 is a diagram illustrating a current path when a direct current is supplied from an overhead line in the embodiment. FIG. 7 is a diagram illustrating a current path when the ground switching circuit becomes abnormal when a direct current is supplied from an overhead line in one embodiment. FIG. 8 is a diagram illustrating a modification of the embodiment.

  FIG. 1 is a diagram illustrating a configuration included in a vehicle according to an embodiment. As shown in FIG. 1, a vehicle 100 according to the present embodiment is a vehicle (AC / DC vehicle) that can travel by receiving supply of DC power and AC power from an overhead line 1 via a current collector (pantograph), An AC circuit breaker 2, a DC circuit breaker 3, a main transformer 4, a vehicle control device 5, a motor 6, a ground switching circuit 7, a vehicle control unit 8, and a voltage detection sensor 9 are provided.

  The main transformer 4 is connected to the overhead wire 1 via the AC circuit breaker 2 and also connected to the ground (for example, ground via wheels). The voltage of the AC power supplied from the overhead wire 1 is transformed into a voltage corresponding to the ratio between the primary winding 41 and the secondary winding 42 and supplied to the vehicle control device 5.

The vehicle control device 5 includes a converter (CONV) 51 that converts AC power into DC power, an inverter (INV) 52 that converts DC power supplied from the converter into AC power, and a control unit 53.
, A DC current detection circuit 54, an AC section ground current detection circuit 55, voltage detectors (positive side) 56 and (negative side) 57, an AC contactor 58, and a DC contactor 9 having the same configuration. An intermediate DC circuit 60 is formed between the converter 51 and the inverter 52. In FIG. 1, an intermediate DC circuit 60 is shown as an example in which the converter 51 and the inverter 52 are both three-level power converters.

  The control unit 53 of the vehicle control device 5 includes a state of the ground switching circuit 7 controlled by the vehicle control unit 8, a DC current detection circuit 54, an AC section ground current detection circuit 55, and a voltage detector (positive side). When the detection results of 56 and (negative side) 57 do not match, the AC contactor 58 and the DC contactor 59 are opened (blocked), and the vehicle control device 5 is protected.

  The ground switching circuit 7 connects either the neutral point 61 or the negative side 62 of the intermediate DC circuit 60 to the ground in accordance with an instruction from the vehicle control unit 8.

  The vehicle control unit 8 controls the ground switching circuit 7 according to whether the section in which the vehicle 100 is traveling is a DC power section or an AC power section, and one of the DC current detection circuit 54 and the AC section ground current detection circuit 55 is Be connected to ground.

  The voltage detection sensor 9 determines whether the electric power supplied from the overhead line 1 is direct current or alternating current based on the voltage value of the electric power supplied from the overhead line 1 via the current collector, and sends the result to the vehicle control unit 8. Notice.

  Next, the switching operation of the ground switching circuit 7 and the protection operation of the vehicle control device 5 in the vehicle having the above configuration will be described.

  FIG. 2 is a flowchart showing the processing of the switching operation and the protection operation, and illustrates the case of entering the AC power section from the DC power section.

  When the vehicle 100 is traveling in the DC power section, the vehicle control unit 8 receives the determination result that the voltage is detected from the voltage detection sensor 9, and controls the ground switching circuit 7 based on the determination result. The direct current detection circuit 54 is connected to the ground. Further, the vehicle control unit 8 brings the AC circuit breaker 2 into an open state and the DC circuit breaker 3 into a closed state. Thus, the DC power supplied from the overhead wire 1 via the current collector is supplied to the vehicle control device 5 via the DC circuit breaker 3 and converted into AC power of variable voltage and variable frequency by the inverter 52. Thereafter, it is supplied to the motor 6. As a result, the vehicle 100 is driven by the motor 6.

  When the vehicle 100 is traveling, the voltage detection sensor 9 determines whether the supplied power is direct current or alternating current based on the power supplied from the overhead line 1 (step S1). That is, since the vehicle 100 is traveling in the DC power section, a determination result indicating DC is notified from the voltage detection sensor to the vehicle control unit 8.

  The vehicle control unit 8 determines whether the determination result has changed based on the determination result notified from the voltage detection sensor 9 (step S2). As described above, since the vehicle 100 continues to travel in the DC power section, the determination result notified from the voltage detection sensor 9 to the vehicle control unit 8 remains DC (NO in step S2). The control unit 8 does not control the ground switching circuit 7, but only notifies the control unit 53 of the state of the ground switching circuit 7, that is, that the DC current detection circuit 54 is connected to the ground.

  In the control unit 53, based on the state of the ground switching circuit 7 notified from the vehicle control unit 8, whether or not the switching operation of the ground switching circuit 7 has been performed correctly, and the state of the ground switching circuit 7 becomes abnormal. Judgment is made (step S4). At this time, the determination performed by the control unit 53 is performed by previously registering a determination criterion as shown in FIG. 3 as a database in a memory (not shown), the state of the ground switching circuit 7 notified from the vehicle control unit 8, and the direct current. Based on the values detected by the detection circuit 54, the AC section ground current detection circuit 55, and the voltage detectors 56 and 57, the determination is made by referring to the determination criteria of the database.

  As described above, since the control unit 53 has received a notification from the vehicle control unit 8 that the DC current circuit 54 is connected to the ground, the ground switching circuit is used by using setting information on the negative side of the determination criterion. Determine whether 7 is normal or abnormal.

  Here, when the ground switching circuit 7 is correctly switched to be on the negative current 62 side of the DC current detection circuit 54, that is, the intermediate DC circuit 60, based on the control of the vehicle control unit 8, as shown in FIG. The path through which the current flows to the ground through the DC contactor 59, the voltage detectors 56 and 57, and the DC current detector 54 by the DC power supplied to the vehicle control device 5 through the DC circuit breaker 3. 301 is formed. As a result, this current is detected by the direct current detection circuit 54. Further, when the ground switching circuit 7 is correctly switched, no current is detected by the AC section ground current detection circuit 55, and the voltage values detected by the voltage detectors 56 and 57 are the overhead voltage of the DC power section. When the overhead voltage is DC1500V, for example, the voltage detectors 56 and 57 detect a voltage value of 750V. Therefore, the negative abnormality determination condition is not satisfied, and only the normal determination condition is satisfied. Will do. Since the voltage value detected by the voltage detector may fluctuate to some extent, a width of ± α (arbitrary value) is given to the half value of the overhead line voltage, and if it is within this width range, it is half It may be considered as the value of.

  Therefore, the control unit 53 determines that the ground switching circuit 7 is normal (YES in step S4), and the operation of the vehicle control device 5 is maintained.

  On the other hand, when the vehicle 100 is traveling in the DC power section, if the ground switching circuit 7 is faulty or the like and is switched to the AC section ground current detection circuit 55 side, as shown in FIG. The DC power supplied to the vehicle control device 5 via the machine 3 passes through the DC contactor 59 and is incorporated in any of the converter 51, the inverter 52, and the intermediate DC circuit 60. A path 302 through which a current flows to the ground is formed through a resistor or capacitor (not shown) that is pressed and the AC section ground current detector 55. For this reason, an abnormal condition is established in the setting information on the negative side of the determination criterion that the current cannot be detected by the DC current detection circuit 54 and the current is detected by the AC section ground current detection circuit 55, The controller 53 determines that an abnormality has occurred in the ground switching circuit 7 (NO in step S4).

  When it is determined that an abnormality has occurred in the ground switching circuit 7, the control unit 53 outputs an open instruction signal to the DC contactor 59, and as a result, the DC contactor 59 is opened and the vehicle control is started from the overhead line 1. The power supply to the device 5 is stopped.

  While the vehicle 100 is traveling in the DC power section, the above determination process and the protection process of the vehicle control device 5 are continuously executed.

  After that, when the vehicle 100 enters the AC power section from the DC power section, the voltage detection sensor 9 detects the voltage fluctuation due to the AC power supplied from the overhead line 1 (step S1), and the vehicle control unit 8 receives the AC. The determination result shown is notified.

  The vehicle control unit 8 determines whether the determination result has changed based on the determination result notified from the voltage detection sensor 9 (step S2). As described above, since the determination result notified from the voltage detection sensor 9 has changed from DC to AC, the vehicle control unit 8 detects that the determination result has changed (YES in Step S2), and detects AC section ground current detection. The ground switching circuit 7 is controlled so that the circuit 55 is connected to the ground (step S6). Further, the controller 53 is notified of the state of the ground switching circuit 7, that is, that the AC section ground current detection circuit 55 is connected to the ground.

  When the vehicle control unit 8 detects that the DC power section has moved to the AC power section based on the notification from the voltage detection sensor 9, the AC circuit breaker 2 is closed and the DC circuit breaker 3 is turned on. Switch to the open state. Thereby, the AC power supplied from the overhead wire 1 via the current collector is sent to the vehicle control device 5 via the AC circuit breaker 2 and the main transformer 4. In the vehicle control device 5, the AC power supplied by the converter 51 is converted into DC power and supplied to the intermediate DC circuit 60. Thereafter, as in the case where the vehicle 100 is traveling in the DC power section, the inverter 52 converts the AC power into AC power having a variable voltage and variable frequency and supplies the AC power to the motor 6.

  In the control unit 53, based on the state of the ground switching circuit 7 notified from the vehicle control unit 8, whether or not the switching operation of the ground switching circuit 7 has been performed correctly, and the state of the ground switching circuit 7 becomes abnormal. Judgment is made (step S4).

  Since the control unit 53 has received notification from the vehicle control unit 8 that the AC section ground current detection circuit 55 is connected to the ground, the neutral point side of the criterion registered in the database shown in FIG. Is used to determine whether the ground switching circuit 7 is normal or abnormal.

  Here, when the ground switching circuit 7 is correctly switched to the neutral point 61 side of the AC section ground current detection circuit 55, that is, the intermediate DC circuit 60, based on the control of the vehicle control unit 8, FIG. As shown, a leakage current path 401 is formed from the ground side to the neutral point 61 via the AC section ground current detection circuit 55.

  As a result, this leakage current is detected by the AC section ground current detection circuit 55. Furthermore, when the ground switching circuit 7 is correctly switched, no current is detected by the DC current detection circuit 54, so that only a normal determination condition is satisfied.

  Therefore, the control unit 53 determines that the ground switching circuit 7 is normal (YES in step S4), and the operation of the vehicle control device 5 is maintained.

  On the other hand, when the ground switching circuit 7 does not operate correctly with respect to the control from the vehicle control unit 8 and remains connected to the DC current detection circuit 54 side, or after the switching to the AC section ground current detection circuit 55 is correctly performed, If the switching circuit 7 is switched to the DC current detection circuit 54 due to a failure or the like, as shown in FIG. 7, the ground side changes to the negative side 62 of the intermediate DC circuit 60 via the DC current detection circuit 54. A flowing leakage current path 402 is formed. For this reason, an abnormal condition is established in the setting information on the neutral point side of the determination criterion that the current cannot be detected by the AC section ground current detection circuit 55 and the current is detected by the DC current detection circuit 54. Thus, the control unit 53 determines that an abnormality has occurred in the ground switching circuit 7 (NO in step S4).

  When it is determined that an abnormality has occurred in the ground switching circuit 7, the control unit 53 outputs an opening instruction signal to the AC contactor 58, and as a result, the AC contactor 58 is opened and the vehicle control is started from the overhead wire 1. The power supply to the device 5 is stopped.

  As described above, by switching the ground point between the DC power section and the AC power section, the voltage of the intermediate DC circuit 60 in the AC power section can be doubled that of the DC power section. As a result, since the voltage applied to the intermediate DC circuit 60 can be increased in the AC power section, the current flowing through the intermediate DC circuit 60 can be reduced, and the vehicle control device 5 can be downsized. Further, by providing a function of stopping the power supplied to the vehicle control device 5 when the ground switching circuit 7 fails, the ground switching circuit 7 that has emerged due to the provision of the ground switching circuit 7 is accompanied by a failure. The risk of destruction of the parts constituting the vehicle control device 5 is greatly reduced.

  In the above description, the DC power section and the AC power section are detected by the voltage detection sensor 9. However, the present invention is not limited to this, and a direct current and alternating current switching signal is received from the ground equipment by radio or the like. In addition, the vehicle control unit 8 may control the ground switching circuit 7 according to the switching signal, and may notify the control unit 53 of the control state of the ground switching circuit 7.

  The control unit 53 receives a notification from the vehicle control unit 8 indicating which of the DC current detection circuit 54 and the AC section ground current detection circuit 55 is connected to the ground. Instead, the voltage detection sensor 9 is used to input the determination result of DC or AC, or separately provided, and a DC overhead wire voltage detector that detects that the power supplied from the overhead wire is DC and an AC overhead wire voltage detector that detects that the power is AC ( A detection signal may be input from each of the voltage detectors (not shown), and the state of the ground switching circuit 7 may be determined based on this input.

(Modification)
The DC intermediate circuit 60 shown in FIG. 1 has a circuit configuration when both the converter 51 and the inverter 52 are three-level power converters, but both or one of them can be a two-level power converter. It is. FIG. 8 shows a circuit configuration of an intermediate DC circuit 60a in the case of a two-level converter 51a and a two-level inverter 52a. That is, in order to form the neutral point 61a, two capacitors C1 and C2 having the same capacity are connected in series between the positive side and the negative side, and a voltage is applied to the capacitors C1 and C2 connected in series. Detectors 56 and 57 are connected. Further, the AC section ground current detection circuit 55 is connected through a wiring connecting the intermediate point between the capacitors C1 and C2 and the intermediate point between the voltage detectors 56 and 57.

  By using such an intermediate DC circuit 61, the same effect can be obtained even when both the two-level converter 51a and the inverter 52a are used.

  If one is at the 2nd level and the other is at the 3rd level, for example, the wiring on the 3rd level side of the neutral point 61a in FIG. 8 is passed to the power converter (converter 51 or inverter 52), and the intermediate DC A circuit will be formed. Of course, even when such a circuit configuration is adopted, the same effect can be obtained.

  DESCRIPTION OF SYMBOLS 1 ... Overhead wire, 2 ... AC circuit breaker, 3 ... DC circuit breaker, 4 ... Main transformer, 5 ... Control device for vehicles, 6 ... Motor, 7 ... Ground switching circuit, 8 ... Vehicle control part, 9 ... Voltage detection Sensor, 41 ... primary winding, 42 ... secondary winding, 51 ... converter, 52 ... inverter, 53 ... control unit, 54 ... DC current detection circuit, 55 ... AC section ground current detection circuit, 56, 57 ... voltage detection 58 ... AC contactor, 59 ... DC contactor, 60 ... intermediate DC circuit, 100 ... vehicle

Claims (3)

In a vehicle control system for driving a motor mounted on a vehicle based on electric power supplied from an overhead line,
An AC circuit breaker connected to the overhead wire via a current collector;
A DC circuit breaker connected to the overhead wire via the current collector;
A transformer connected to the AC circuit breaker;
A converter connected to the transformer;
An AC contactor connected between the transformer and the converter;
An inverter connected to the converter via an intermediate DC circuit;
A DC contactor connected between the DC circuit breaker and the intermediate DC circuit;
A first current detector disposed between the negative side of the intermediate DC circuit and ground;
A second current detector disposed between a neutral point of the intermediate DC circuit and ground;
A switching unit for connecting one of the first current detector and the second current detector to ground;
An overhead line power detector for detecting whether the power supplied from the overhead line is direct current or alternating current;
Based on the detection result of the overhead line power detector, a first control unit for controlling the switching unit to control one of the direct current for the circuit breaker and the AC circuit breaker in the connected state,
When the switching unit is controlled so that the first current detector is connected to the ground, it is determined that the switching unit has failed when the second current detector detects a current , and the DC contact The switching unit when the first current detector detects a current when the switching unit is controlled so that the second current detector is connected to ground. A second control unit that determines that the AC contactor has failed and controls the AC contactor to shut off;
A vehicle control system comprising:   A first voltage detector provided between the positive side and the neutral point of the intermediate DC circuit and a second voltage detector provided between the neutral point and the negative side; The vehicle control according to claim 1, wherein the second control unit detects that a failure has occurred in the switching unit based on voltage values detected by the first voltage detector and the second voltage detector. system.   The overhead wire power detector determines whether the power supplied from the overhead wire is direct current or alternating current based on the power applied between the current collector in contact with the overhead wire and the DC breaker and the alternating current breaker. The vehicle control system according to claim 1.

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