Rail vehicles

Abstract

To provide a railroad vehicle that facilitates measurement of insulation resistance of an electric circuit.SOLUTION: In a non-energization time when a pantograph 17 is lowered so that supply of electric power to a power source wire 18 is cut off, an electromagnetic switch 44a opens, so that the power source wire 18 at an input side of a VVVF inverter 20 and a grounding-side electric wire 42 are cut off from a grounding wire 40. In this state, a contact-type monitoring device 70g applies a voltage to a space between the grounding wire 40 and the power source wire 18 to measure insulation resistance of the power source wire 18. Thus, mounting the contact-type monitoring device 70g on a railroad vehicle 110 can make measurement of insulation resistance of the power source wire 18 easier than conventional methods for measuring insulation resistance.SELECTED DRAWING: Figure 15

Description

[Technical field]

[0001] The present invention relates to a railway vehicle that allows easy measurement of insulation resistance of an electric circuit. [Background technology]

[0002] In railway vehicles, for example, power supplied from an overhead line via a pantograph is converted by a converter such as a VVVF inverter or SIV, and the output power is used to operate various electric devices such as electric motors. Conventionally, in order to evaluate the soundness of electric circuits such as a power line connecting the pantograph and the converter, and an output electric wire connecting the converter and multiple electric devices, the insulation resistance of the electric circuits has been measured in periodic inspections, for example, every 90 days.

[0003] During regular inspections, the pantograph is lowered to cut off the power supply from the overhead lines to the railway vehicle, and multiple switches are manually operated to disconnect the electrical circuit to be measured from the ground, after which an insulation resistance meter is connected to the measurement target to measure its insulation resistance. After the measurement, the insulation resistance meter must be removed, the measurement target must be grounded again, power must be supplied, and the device must be confirmed to be operating normally. Performing these measurement and confirmation tasks individually for each railway vehicle requires a lot of effort and time.

[0004] Patent Document 1 discloses that the insulation resistance (leakage current) of a part of the main circuit (power line) from the pantograph to the converter among the electric circuits of the railway vehicle is measured by a test circuit mounted on the railway vehicle. Specifically, Patent Document 1 describes a method in which the insulation resistance of the main circuit is measured by applying a voltage between the main circuit on the pantograph side of the high-speed circuit breaker and the ground (car body) with the test circuit disconnecting the pantograph, which is separated from the overhead line, and the converter with a high-speed circuit breaker and disconnecting the converter from the ground with a contactor (switch). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-223020 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the conventional technology, before measuring the insulation resistance of an electric circuit, it is necessary to open a switch that separates the electric circuit to be measured from the ground. This results in problems such as the measurement of the insulation resistance of an electric circuit taking time and requiring many work steps.

[0007] The present invention has been made to solve the above-mentioned problems, and has an object to provide a railway vehicle that allows easy measurement of the insulation resistance of an electric circuit. [Means for solving the problem]

[0008] In order to achieve this objective, the railway vehicle of the present invention is equipped with a conversion device that converts and outputs input power, or sends power to another vehicle equipped with the conversion device, and runs on rails and is equipped with a grounding part connected to the rail, a ground side electric wire that connects the input side of the conversion device to the grounding part, a power line to which power input to the conversion device is supplied and which is connected to the ground side electric wire via the conversion device, an electromagnetic contactor that opens in response to a cut-off in the supply of power to the power line to separate the ground side electric wire from the grounding part, and a power supply monitoring device that applies a voltage between the grounding part and at least one of the power line and the ground side electric wire when the electromagnetic contactor is open, and measures the insulation resistance of at least one of them.

[0009] The conversion device may be an inverter that converts DC power to AC power, a converter that converts AC power to DC power, or a transformer that transforms voltage. A combination of a plurality of these inverters, converters, and transformers may also be used as the conversion device. Effect of the Invention

[0010] According to the railway vehicle described in claim 1, when the power supply to the power line is cut off and the power is not energized, the electromagnetic switch opens, the ground side electric wire on the input side of the conversion device is disconnected from the ground, and the power line connected to the ground side electric wire via the conversion device is also disconnected from the ground. In this state, the power supply monitoring device applies a voltage between the ground and at least one of the power line and the ground side electric wire to measure the insulation resistance of at least one of the power line and the ground side electric wire. In this way, by installing the power supply monitoring device on the railway vehicle, it is possible to easily measure the insulation resistance of the power line and the ground side electric wire, compared to the conventional insulation resistance measurement method in which various operations such as cutting off the power supply, disconnecting the measurement target from the ground and connecting a measuring instrument to the measurement target were performed individually for each railway vehicle. In particular, since the measurement target is disconnected from the ground by the electromagnetic switch in response to the power supply being cut off, the operation of manually disconnecting the measurement target from the ground is unnecessary, and the insulation resistance of the measurement target can be more easily measured.

[0011] According to the railway vehicle of claim 2, in addition to the effect of the railway vehicle of claim 1, the following effect is achieved. The coil of the electric motor is connected to the output side of the conversion device and connected to the ground part via the ground side electric wire. Therefore, when the electromagnetic switch is opened during non-energization and the ground side electric wire is disconnected from the ground part, the connection between the coil and the ground part is cut. In this state, the electric motor monitoring device applies a voltage between the coil and the ground part to measure the insulation resistance between the housing constituting a part of the ground part and the coil, i.e., the insulation resistance of the electric motor. In this way, by mounting the electric motor monitoring device on the railway vehicle, it is possible to easily measure the insulation resistance of the electric motor compared to the conventional method of measuring the insulation resistance, which was performed individually for each railway vehicle. In particular, since the coil of the electric motor is disconnected from the ground part by the electromagnetic switch in response to the interruption of the power supply, the work of manually disconnecting the coil from the ground part is unnecessary, and the insulation resistance of the electric motor can be measured more easily.

[0012] According to the railway vehicle of claim 3, in addition to the effects of the railway vehicle of claim 1 or 2, the following effects are achieved. When the AC output device as a conversion device and the grounding part are connected via the grounding side electric wire by the closed electromagnetic switch and power is supplied to the power supply line, AC power is output from the AC output device to a set of multiple AC circuits. When this current is applied, a zero-phase current transformer through which the set of AC circuits passes detects leakage current generated in an AC device connected downstream of the AC circuit (the side farther from the AC output device) than the passing position. The AC monitoring device measures the insulation resistance of the AC device based on the detection value of the zero-phase current transformer when this current is applied. As a result, by mounting the AC monitoring device on the railway vehicle, it is possible to measure the insulation resistance of the AC device actually in operation, and it is possible to eliminate the need for disconnecting the AC device from the grounding part, which is required when measuring the insulation resistance by applying a voltage.

[0013] In addition, when an AC monitoring device measures the insulation resistance of an object to be measured, this does not only mean measuring the value of the insulation resistance itself that occurs in the object to be measured, but also means measuring the component of leakage current that is caused by the insulation resistance.

[0014] According to the railway vehicle of claim 4, in addition to the effect of the railway vehicle of claim 3, the following effect is achieved. The AC monitoring device periodically measures the insulation resistance while the railway vehicle is running, with the grounded electric wire and the grounding part being connected by the closed electromagnetic switch to supply power to the power line. This allows the AC monitoring device to measure insulation resistance in a state that cannot be grasped while the train is stopped, such as the insulation resistance of equipment that is subjected to a load associated with running.

[0015] According to the railway vehicle of claim 5, in addition to the effect of the railway vehicle of claim 4, the following effect is achieved. Since the measurement results measured by the AC monitoring device while the railway vehicle is running are transmitted to the outside of the railway vehicle by the transmitting unit, for example, the measurement results while the railway vehicle is running can be monitored externally. As a result, if an abnormality is discovered during monitoring, the timing of maintenance of the railway vehicle can be planned early.

[0016] According to the railway vehicle described in claim 6, 3In addition to the effects of the railway vehicle described above, the present invention provides the following effects. A set of main electric wires extends from an AC output device, and multiple sets of branch electric wires branching off from the main electric wire are each connected to multiple AC devices. The AC monitoring device includes a main monitoring device, and the main electric wire that is closer to the AC output device than the multiple sets of branch electric wires passes through a zero-phase current transformer of the main monitoring device. This allows the main monitoring device to measure the total insulation resistance of the AC devices connected to the multiple sets of branch electric wires.

[0017] According to the railway vehicle described in claim 7, 3 In addition to the effects of the railway vehicle described above, the present invention provides the following effects: A set of main electric wires extends from an AC output device, and a plurality of sets of branch electric wires branching off from the main electric wires are respectively connected to a plurality of AC devices. The AC monitoring device includes a branch monitoring device, and a set of branch electric wires passes through a zero-phase current transformer of the branch monitoring device, so that the branch monitoring device can measure the insulation resistance of the AC device connected to the set of branch electric wires without being affected by the insulation resistance of AC devices connected to other branch electric wires.

[0018] According to the railway vehicle of claim 8, 3 In addition to the effects of the railway vehicle described above, the following effects are achieved. A set of main wires extends from an AC output device, and multiple sets of branch wires branch off from the main wires and are each connected to multiple AC devices. A rectifier connected to the main wires converts AC power into DC power, and the DC devices connected to the rectifier operate on the DC power. Because the DC devices are connected to the main wires via the rectifier, leakage current generated by the DC devices flows into the main wires.

[0019] The AC monitoring device includes a trunk monitoring device and a branch monitoring device. The trunk electric wire that is closer to the AC output device than the rectifier and the multiple sets of branch electric wires passes through the zero-phase current transformer of the trunk monitoring device, so the trunk monitoring device can measure the sum of the insulation resistance of the DC device connected to the rectifier and the insulation resistance of the AC device connected to the multiple sets of branch electric wires. In addition, the multiple sets of branch electric wires branched from the trunk electric wire that passes through the zero-phase current transformer of the trunk monitoring device each pass through multiple zero-phase current transformers of the branch monitoring device, so the branch monitoring device can measure the insulation resistance of the AC device connected to those branch electric wires. As a result, for example, when the measurement result of the trunk monitoring device indicates deterioration of the insulation resistance but the measurement result of the branch monitoring device does not indicate deterioration of the insulation resistance, it can be inferred that the insulation resistance of the DC device, not the AC device connected to the branch electric wire, has deteriorated.

[0020] The railway vehicle according to claim 9 is 3 In a train configuration in which the railway vehicle described above is an AC output device-equipped car, the railway vehicle receives AC power from the AC output device-equipped car. This railway vehicle is coupled to the AC output device-equipped car by a coupling section, either directly or via another vehicle. A set of multiple own vehicle AC circuits is connected to the AC circuit of the AC output device owner via the coupling section, and the own vehicle AC equipment connected to the own vehicle AC circuit is operated by the AC power supplied from the AC circuit.

[0021] During this energization, a zero-phase-sequence current transformer through which one set of the vehicle's own AC circuit passes detects leakage current generated in the vehicle's own AC equipment connected downstream of the vehicle's own AC circuit from the position of passage. The vehicle's own AC monitoring device measures the insulation resistance of the vehicle's own AC equipment based on the detection value of the zero-phase-sequence current transformer during energization. As a result, by installing the vehicle's own AC monitoring device on a railway vehicle, it is possible to measure the insulation resistance of the vehicle's own AC equipment that is actually in operation, and it is also possible to eliminate the need to disconnect the vehicle's own AC equipment from the ground, which is necessary when measuring insulation resistance by applying a voltage.

[0022] The railway vehicle according to claim 10 comprises: or 2The train runs on rails in a train configuration in which the railway vehicle described in the above is an electromagnetic switch-equipped car. This railway vehicle is coupled to the electromagnetic switch-equipped car by a coupling part, either directly or via another car. The vehicle's own power supply line is connected to the power supply line of the electromagnetic switch-equipped car via the coupling part, and the vehicle's own ground side electric wire is connected to the ground part connected to the rail via the coupling part and the ground side electric wire of the electromagnetic switch-equipped car.

[0023] When the supply of power to the vehicle power line is cut off and the connection by the coupling part is released during a de-energized state, the vehicle power line and the vehicle ground side electric wire are disconnected from the ground part. In this state, the vehicle power supply monitoring device applies a voltage between the ground part and at least one of the vehicle power line and the vehicle ground side electric wire, and measures the insulation resistance of at least one of the vehicle power line and the vehicle ground side electric wire. This allows the vehicle power supply monitoring device to individually measure the insulation resistance of at least one of the vehicle power line and the vehicle ground side electric wire without being affected by the insulation resistance of the power line and the ground side electric wire of other vehicles in the train set. [Brief description of the drawings]

[0024] [Figure 1] FIG. 2 is a circuit diagram showing a schematic diagram of an electric circuit of the railway vehicle in the first embodiment. [Diagram 2] FIG. 2 is a schematic circuit diagram showing the electrical circuit of the railway vehicle upstream of the SIV. [Diagram 3] FIG. 2 is a circuit diagram showing a schematic diagram of the electrical circuit of the railway vehicle downstream of the SIV. [Figure 4] FIG. 2 is a block diagram showing the electrical configuration of the railway vehicle. [Diagram 5] FIG. 2 is a block diagram showing the electrical configuration of the contact monitoring device. [Figure 6] FIG. 4 is a diagram showing the contents of each measurement result memory. [Figure 7] 4 is a flowchart of a main process executed by a CPU of the contact-type monitoring device. [Figure 8] 13 is a flowchart of a resistance measurement process. [Figure 9] 13 is a flowchart of post-measurement processing. [Figure 10] 4 is a flowchart of a self-diagnosis process. [Figure 11] 4 is a flowchart of main processing executed by a CPU of the control device for railway vehicles. [Figure 12] 1 is a graph showing changes over time in insulation resistance measurement results and predictions for the future. [Figure 13] FIG. 11 is a circuit diagram showing a schematic diagram of an electric circuit of a railway vehicle upstream of an SIV in a second embodiment. [Figure 14] FIG. 11 is a circuit diagram showing a schematic diagram of an electric circuit of a railway vehicle downstream of an SIV in a second embodiment. [Figure 15] FIG. 11 is a circuit diagram showing a schematic diagram of an electric circuit of a railway vehicle in a third embodiment. [Figure 16] FIG. 2 is a block diagram showing the electrical configuration of the AC monitoring device. [Figure 17] 4 is a flowchart of main processing executed by a CPU of the AC monitoring device. [Figure 18] FIG. 11 is a circuit diagram showing a schematic diagram of an electric circuit of a railway vehicle in a fourth embodiment. [Figure 19] 13 is a flowchart of a warning display process. [Figure 20] FIG. 13 is a circuit diagram showing a schematic diagram of an electric circuit of a railway vehicle in a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, preferred embodiments will be described with reference to the accompanying drawings. First, an overview of a railway vehicle 10 in a first embodiment will be described with reference to Fig. 1. Fig. 1 is a circuit diagram showing a schematic diagram of an electric circuit of railway vehicles 10, 11.

[0026] Both railway cars 10, 11 are DC electric trains and mainly comprise a metal car body 12, a number of wheels 13 that support the car body 12 and roll on the rails 2, coupling parts 14 provided on both ends of the car body 12 in the rail direction (front-to-rear direction), and a number of electrical devices such as air conditioning equipment 15 and lighting 16. The coupling parts 14 include couplers that mechanically couple the railway cars 10, 11 to transmit tensile and compressive forces between the cars, and electrical couplers that electrically couple the railway cars 10, 11 to each other.

[0027] A vehicle formation is formed by coupling the coupling parts 14 of the railway cars 10, 11. The railway car 10 is a powered car that has multiple electric motors 22 as a power source and runs on the rails 2 by rotating the wheels 13 with the electric motors 22. On the other hand, the railway car 11 is a trailer car that does not have a power source and runs accompanying the railway car 10.

[0028] An overhead wire 4 is suspended above the rails 2. A high-voltage (1500 V in this embodiment) direct current flows through this overhead wire 4 by generating an electromotive force at a substation 6 with respect to the grounded rail 2. By raising a pantograph 17 provided on the top of the body 12 of the railway vehicle 10 and bringing it into contact with the overhead wire 4, direct current is supplied from the overhead wire 4 via the pantograph 17 to a power line 18 of the railway vehicle 10.

[0029] This power supply line 18 is connected to a VVVF inverter 20 and an SIV (static inverter) 30 mounted on the railway vehicle 10. Both the VVVF inverter 20 and the SIV 30 are conversion devices that convert and adjust DC power input from the power supply line 18 into AC power and output it.

[0030] The output side of the VVVF inverter 20 is connected to each of a plurality of electric motors 22 via electric motor wires 24, and the electric motors 22 are operated by AC power output from the VVVF inverter 20. The VVVF inverter 20 is configured to be able to variably control the voltage and frequency of the AC power it outputs. In response to control of the voltage and frequency of this AC power, the rotation speed and torque of the electric motors 22 are controlled, and the traveling speed of the railway vehicle 10 is controlled.

[0031] The SIV 30 outputs AC power of a fixed voltage (440 V in this embodiment) and a fixed frequency. A first low-voltage AC circuit 32 is connected to the output side of the SIV 30. This first low-voltage AC circuit 32 is laid between the coupling parts 14 at both ends of the railway vehicle 10. The first low-voltage AC circuit 32 is also laid between the coupling parts 14 of the railway vehicle 11, and the first low-voltage AC circuits 32 of the railway vehicles 10, 11 are connected to each other via the coupling parts 14. In each of the railway vehicles 10, 11, air conditioning equipment 15 is connected to the first low-voltage AC circuit 32, and the air conditioning equipment 15 is operated by the AC power supplied from the first low-voltage AC circuit 32.

[0032] Further, a second low-voltage AC circuit 36 ​​is connected to the first low-voltage AC circuit 32 via an isolation transformer 34. The isolation transformer 34 has a primary winding (not shown) connected to the first low-voltage AC circuit 32 and a secondary winding (not shown) connected to the second low-voltage AC circuit 36 ​​wound around the same iron core, and the primary winding and secondary winding are insulated from each other. The isolation transformer 34 transforms the voltage of the AC power input from the first low-voltage AC circuit 32 to 100 V in this embodiment and outputs it to the second low-voltage AC circuit 36.

[0033] The second low-voltage AC circuit 36, like the first low-voltage AC circuit 32, is laid between the coupling parts 14 at both ends of the railway cars 10, 11. The second low-voltage AC circuits 36 of the railway cars 10, 11 are connected to each other via the coupling parts 14. In each of the railway cars 10, 11, a plurality of electrical devices such as lighting 16 are connected to the second low-voltage AC circuit 36, and the plurality of electrical devices are operated by power supplied from the second low-voltage AC circuit 36.

[0034] Next, the electrical circuit of the railway vehicle 10 will be described in more detail with reference to Figures 2 and 3. Figure 2 is a circuit diagram that shows a schematic diagram of the electrical circuit of the railway vehicle 10 upstream of the SIV 30 (pantograph 17 side). Figure 3 is a circuit diagram that shows a schematic diagram of the electrical circuit of the railway vehicle 10 downstream of the SIV 30 (electrical equipment side such as air conditioner 15).

[0035] As shown in Fig. 2, the car body 12 (part of the grounding portion) is grounded by being connected to the rail 2 via the wheels 13. The railway vehicle 10 is also provided with a ground wire 40 (part of the grounding portion) that is routed between the coupling parts 14 (see Fig. 1) at both ends. This ground wire 40 is grounded by being connected to the rail 2 via the car body 12 and the wheels 13.

[0036] The input sides of the VVVF inverter 20 and the SIV 30 are respectively provided with a positive terminal to which the power line 18 is connected and a negative terminal to which a grounding wire 42 is connected. When the grounding wire 42 is connected to the grounding wire 40 and the pantograph 17 comes into contact with the overhead line 4, a closed circuit is formed between the VVVF inverter 20 and the SIV 30 and the substation 6 via the overhead line 4 and the rails 2. This brings the railway vehicle 10 into a power-on state.

[0037] Between the ground-side electric wire 42 and the ground wire 40, there are provided two electromagnetic switches (MS) 44a arranged in parallel, and a manual switch (S) 46a connected in series to the ground wire 40 side of the electromagnetic switches 44a. The electromagnetic switches 44a are latch-type switches that open and close with an electric signal, and open the electric circuit in response to the lowering of the pantograph 17, and close the electric circuit in response to the rising of the pantograph 17. In other words, the electromagnetic switches 44a are closed when the railway vehicle 10 is energized (when it is running). The manual switch 46a is a switch that opens and closes the electric circuit in response to manual operation.

[0038] By closing at least one of the two electromagnetic switches 44a and the manual switch 46a, the ground-side electric wire 42 and the ground wire 40 are connected. By opening both of the electromagnetic switches 44a and at least one of the manual switch 46a, the ground-side electric wire 42 is disconnected from the ground wire 40.

[0039] The electromagnetic switches 44b to 44i described later are configured in the same manner as the electromagnetic switch 44a except for their different arrangements. In each drawing except for FIG. 2, only one of the two electromagnetic switches 44a to 44i arranged in parallel is shown, and the other is not shown. Hereinafter, when the electromagnetic switches 44a to 44i are described without distinction, they are referred to as the electromagnetic switch 44. Furthermore, the manual switches 46b to 46i described later are configured in the same manner as the manual switch 46a except for their different arrangements. Hereinafter, when the manual switches 46a to 46i are described without distinction, they are referred to as the manual switch 46.

[0040] Conventionally, in a periodic inspection for measuring the insulation resistance of each part of a railway vehicle 10, first, the pantograph 17 is lowered and separated from the overhead line 4, and the supply of power from the overhead line 4 to the power line 18 is interrupted. Next, the manual switch 46a is manually opened to disconnect the ground side electric wire 42 from the ground line 40, and also to disconnect the ground line 40 and the power line 18 via the VVVF inverter 20 and the SIV 30. Thereafter, an insulation resistance measuring instrument (not shown) connected to the power line 18 and the ground line 40 detects a leakage current generated in the power line 18 when a voltage is applied to the ground part such as the ground line 40 or the car body 12, and measures the insulation resistance of the power line 18 with respect to the ground part. Similarly, an insulation resistance measuring instrument connected to the ground side electric wire 42 and the ground line 40 measures the insulation resistance of the ground side electric wire 42.

[0041] In contrast, the railway vehicle 10 of this embodiment is equipped with a contact-type monitoring device 70a that automatically measures the insulation resistance of the power line 18 or the ground-side electric wire 42 with respect to the ground at a predetermined timing. The contact-type monitoring device 70a has a terminal V connected to the ground wire 40 via an electric wire AV, a terminal a connected to the power line 18 via an electric wire Aa, and a terminal b connected to the ground-side electric wire 42 via an electric wire Ab.

[0042] The contact-type monitoring devices 70b to 70g described below are configured substantially the same as the contact-type monitoring device 70a, except for their arrangement, the voltage value applied, and the number of terminals. In the following description, when the contact-type monitoring devices 70a to 70g are not to be distinguished from one another, they will be referred to as the contact-type monitoring device 70.

[0043] The timing for measuring the insulation resistance by the contact-type monitoring device 70 is when the pantograph 17 is lowered and the power supply to the power line 18 of the railway vehicle 10 is cut off. Note that even when the railway vehicle 10 is not energized (when the power supply from the overhead wires 4 to the railway vehicle 10 is cut off), the contact-type monitoring device 70 operates using the storage battery 82 (see FIG. 3).

[0044] In response to the interruption of the power supply to the railway vehicle 10, the electromagnetic switch 44a opens, and the power line 18 and the ground wire 42 are disconnected from the ground wire 40. In this state, the contact-type monitoring device 70a applies a voltage between terminals V and a to measure the insulation resistance of the power line 18 connected to terminal a. In a similar state, by applying a voltage between terminals V and b instead of between terminals V and a, the insulation resistance of the ground wire 42 connected to terminal b can be measured.

[0045] The voltage applied by the contact-type monitoring device 70a is set to be equal to or lower than the voltage (DC 1500V) of the power supplied from the overhead line 4 to the power line 18. This makes it possible to prevent the VVVF inverter 20 and the like connected to the power line 18 from being broken down due to the voltage applied by the contact-type monitoring device 70a.

[0046] Since the contact-type monitoring device 70a as described above is installed on the railway vehicle 10, it is possible to easily measure the insulation resistance of the power line 18 and the ground side wire 42, compared to the conventional method of measuring insulation resistance during regular inspection, in which various tasks such as cutting off the power supply, disconnecting the object to be measured from the ground wire 40 (ground portion), and connecting a measuring instrument to the object to be measured were performed individually for each railway vehicle 10.

[0047] In addition, the lowering of the pantograph 17 is used as a trigger to automatically perform measurement by the contact-type monitoring device 70, so that it is possible to more easily measure the insulation resistance of the object to be measured (the power line 18 and the ground-side electric wire 42 in the case of the contact-type monitoring device 70a) compared to conventional measurement methods in which insulation resistance is measured manually. Furthermore, the object to be measured is disconnected from the ground wire 40 by the electromagnetic switch 44 in response to the lowering of the pantograph 17, so that it is possible to eliminate the need to manually disconnect the object to be measured from the ground wire 40, making it easier to measure the insulation resistance of the object to be measured.

[0048] Since the manual switch 46 is connected in series to the electromagnetic switch 44, the insulation resistance of each part of the railway vehicle 10 can be measured by a conventional periodic inspection that is performed by opening the manual switch 46. This makes it possible to measure the insulation resistance of each part of the railway vehicle 10 in detail by a periodic inspection when deterioration of the insulation resistance of the measurement target is suspected by the contact-type monitoring device 70.

[0049] Furthermore, because two electromagnetic switches 44 are provided in parallel, even if one of the two parallel electromagnetic switches 44 fails to close due to a malfunction in response to the rise of the pantograph 17, the measurement target (for example, the ground side electric wire 42) can be connected to the ground wire 40 as long as the other closes, allowing the railway vehicle 10 to run normally. In other words, even if the electromagnetic switch 44 is provided for measuring the insulation resistance with the contact-type monitoring device 70, the railway vehicle 10 can run normally as long as the two parallel electromagnetic switches 44 do not fail simultaneously.

[0050] The VVVF inverter 20 outputs three-phase AC power to the electric motor wires 24. Therefore, the electric motor wires 24 are configured as a set of three electric wires 24u, 24v, and 24w. Each of the electric wires 24u, 24v, and 24w branches out and is connected to a plurality of electric motors 22.

[0051] The motor 22 is a three-phase induction motor that operates with three-phase AC power and includes a coil 22a to which electric wires 24u, 24v, and 24w are respectively connected, and a housing 22b that surrounds the coil 22a. The housing 22b is connected to a ground wire 40 via a housing ground wire 22c, and constitutes a part of the ground section.

[0052] The railway vehicle 10 is equipped with a contact-type monitoring device 70b that automatically measures, at a predetermined timing, the insulation resistance of the coil 22a and the electric wires 24u, 24v, 24w with respect to the grounding parts of the casing 22b and the car body 12. The contact-type monitoring device 70b includes a terminal V connected to the grounding wire 40 via the electric wire BV, and a terminal a connected to the electric wire 24w via the electric wire Ba. The electric wire Ba may be connected to the electric wire 24u or the electric wire 24v.

[0053] When the electromagnetic switch 44a opens in response to the lowering of the pantograph 17 (cutting off the power supply to the power line 18) and the ground wire 42 is disconnected from the ground wire 40, the connection between the electric motor wire 24 and the coil 22a and the ground wire 40 via the ground wire 42 and the VVVF inverter 20 is cut. In this state, the contact type monitoring device 70b applies a voltage between terminal V and terminal a.

[0054] In this way, the contact-type monitoring device 70b measures the insulation resistance of the electric wire 24w connected to the terminal a, the coil 22a connected to the electric wire 24w, and the electric wires 24u, 24v connected to the coil 22a. As a result, by mounting the contact-type monitoring device 70b on the railway vehicle 10, similar to the contact-type monitoring device 70a, it is possible to more easily measure the insulation resistance of the electric motor 22 and the electric motor wire 24 compared to conventional methods of measuring insulation resistance.

[0055] The voltage applied by the contact-type monitoring device 70b is set to be equal to or lower than the withstand voltage standard (for example, 250 to 500 V) on the output side of the VVVF inverter 20. This makes it possible to prevent dielectric breakdown inside the VVVF inverter 20 due to the voltage applied by the contact-type monitoring device 70b.

[0056] 3, the first low-voltage AC circuit 32 connected to the output side of the SIV 30 is configured with a set of three electric wires 32u, 32v, and 32w. The first low-voltage AC circuit 32 passes through the inside of the SIV 30 and is connected to a ground wire 40 via an electromagnetic switch 44b and a manual switch 46b. Therefore, when the railway vehicle 10 is energized (when power is supplied from the overhead line 4 to the railway vehicle 10), the first low-voltage AC circuit 32 is grounded.

[0057] The SIV 30 outputs three-phase AC power to the electric wires 32u, 32v, and 32w to operate the air conditioner 15 connected to the electric wires 32u, 32v, and 32w. In addition, the electric wires 32u, 32v, and 32w are connected to each other by a primary winding of an insulating transformer .

[0058] The second low-voltage AC circuit 36 ​​connected to the secondary winding of the isolation transformer 34 is configured with a set of three electric wires 36r, 36n, and 36t. The electric wires 36r, 36n, and 36t are connected to one another by the secondary winding of the isolation transformer 34. The electric wire 36n is connected to a ground wire 40 via an electromagnetic switch 44c and a manual switch 46c. Therefore, when the railway vehicle 10 is energized, the electric wire 36n is grounded, and the ground wire 40 also functions as the electric wire 36n (part of the second low-voltage AC circuit 36).

[0059] The isolation transformer 34 outputs single-phase AC power so that the potential difference between the electric wire 36r and the electric wire 36n and the potential difference between the electric wire 36t and the electric wire 36n are each 100 V. The light 16 is connected to the electric wire 36r, and the isolation transformer 86 of the charger 84 is connected to the electric wire 36t. Although not shown, in addition to the light 16 and the isolation transformer 86 of the charger 84, a plurality of AC devices that operate on AC power are connected to the electric wires 36r and 36t.

[0060] A plurality of AC devices including the lighting 16 and the isolation transformer 86 are connected to the ground line 40 via the electromagnetic switch 44d and the manual switch 46d. Therefore, when the railway vehicle 10 is energized and the electromagnetic switch 44d is closed, the plurality of AC devices are operated by AC power.

[0061] The charger 84 is a device for charging the storage battery 82 of the contact-type monitoring device 70. The charger 84 and the storage battery 82 are insulated from the second low-voltage AC circuit 36 ​​by the isolation transformer 86, so that the output voltage of the contact-type monitoring device 70 can be stabilized, malfunction of the contact-type monitoring device 70 can be suppressed, and safety against electric shock can be ensured.

[0062] In addition to the multiple AC devices, the brake 19, the control device 60, and multiple other DC devices (not shown) are connected to the electric wires 36r, 36t via a rectifier 38. The rectifier 38 is a device that converts AC power from the second low-voltage AC circuit 36 ​​into DC power and outputs it.

[0063] A plurality of DC devices including the brake 19 and the control device 60 are connected to the ground line 40 via the electromagnetic switch 44e and the manual switch 46e. Therefore, when the railway vehicle 10 is energized and the electromagnetic switch 44e is closed, the plurality of DC devices are operated by DC power.

[0064] Brake 19 is a device for decelerating traveling railcar 10. Control device 60 is a device for controlling the acceleration / deceleration of railcar 10 and the operation of a plurality of electrical devices (AC devices and DC devices).

[0065] For example, the control device 60 controls the operation of a switch circuit 20a built into the VVVF inverter 20. The switch circuit 20a is a circuit for controlling the voltage and frequency of the power output from the VVVF inverter 20 by switching the timing for turning on and off a plurality of switching elements.

[0066] The control device 60 and the switch circuit 20a are connected by a plurality of control lines 201, 202, and 203. The control device 60 is provided with relays 201a, 202a, and 203a that switch between supplying and cutting off power to the control lines 201 to 203. Note that in FIG. 3, the relays 201a to 203a are arranged outside the control device 60 for convenience of illustration.

[0067] When relay 201a is closed and power is supplied to control line 201 from second low-voltage AC circuit 36 ​​via control device 60, switch circuit 20a is controlled to output power of a voltage and frequency corresponding to control line 201 from VVVF inverter 20. Similarly, when relays 202a, 203a are closed, switch circuit 20a is controlled to output power of a voltage and frequency corresponding to control lines 202, 203, respectively, from VVVF inverter 20. When railway vehicle 10 is not energized, all relays 201a-203a are opened and control lines 201-203 are not connected to second low-voltage AC circuit 36.

[0068] The railway vehicle 10 is equipped with a contact-type monitoring device 70c that automatically measures the insulation resistance of the first low-voltage AC circuit 32, the second low-voltage AC circuit 36, and the control lines 201-203 relative to the grounding parts such as the grounding wire 40 and the car body 12 at a predetermined timing.

[0069] The contact type monitoring device 70c includes a terminal V connected to the ground wire 40 via the electric wire CV, a terminal a connected to the electric wire 32v via the electric wire Ca, a terminal b connected between a plurality of AC devices (such as the lighting 16 and the insulating transformer 86) and the electromagnetic switch 44d via the electric wire Cb, a terminal c connected to the control line 201 via the electric wire Cc, a terminal d connected to the control line 202 via the electric wire Cd, a terminal e connected to the control line 203 via the electric wire Ce, and a terminal f connected between a plurality of DC devices (such as the brake 19 and the control device 60) and the electromagnetic switch 44e via the electric wire Cf. The electric wire Ca may be connected to the electric wire 32u or the electric wire 32w.

[0070] When all the electromagnetic switches 44b to 44e are opened in response to the descent of the pantograph 17 (see FIG. 2), the first low-voltage AC circuit 32 and the second low-voltage AC circuit 36 ​​are disconnected from the ground wire 40, and the connection between the ground wire 40 and the multiple electrical devices (air conditioners 15 and lights 16) via the first low-voltage AC circuit 32 and the second low-voltage AC circuit 36 ​​is cut. In this state, the contact-type monitoring device 70c applies a voltage between the terminal V and any one of the terminals a to f.

[0071] When a voltage is applied between terminal V and terminal a, the contact-type monitoring device 70c measures the insulation resistance between the electric wire 32v connected to terminal a, the primary winding of the isolation transformer 34 connected to the electric wire 32v, and the electric wires 32u, 32w connected to the primary winding.

[0072] Furthermore, since the first low-voltage AC circuit 32 (electric wires 32u, 32v, 32w) of the railway vehicle 10 is connected to the first low-voltage AC circuit 32 of the railway vehicle 11 via the connecting portion 14, the contact-type monitoring device 70c can measure the insulation resistance of the first low-voltage AC circuits 32 of both railway vehicles 10, 11 when a voltage is applied between terminals V and a.

[0073] Furthermore, when a voltage is applied between terminal V and terminal b, the contact-type monitoring device 70c measures the insulation resistance of the wires between the electromagnetic switch 44d and the multiple AC devices (such as the lighting 16 and the isolation transformer 86) connected to terminal b, the wires 36r, 36t connected to the AC devices, the secondary winding of the isolation transformer 34 connected to the wires 36r, 36t, and the wire 36n connected to the secondary winding. In this case, similar to when a voltage is applied between terminal V and terminal a, when a voltage is applied between terminal V and terminal b, the contact-type monitoring device 70c can measure the insulation resistance of not only the second low-voltage AC circuit 36 ​​(wires 36r, 36n, 36t) of the railway vehicle 10 but also the second low-voltage AC circuit 36 ​​of the railway vehicle 11.

[0074] In addition, when a voltage is applied between the terminal V and any one of the terminals c to e, the contact-type monitoring device 70c measures the insulation resistance of any one of the control wires 201 to 203 connected to the terminal c to e to which the voltage is applied. In this way, the control wires 201 to 203 that are not connected to the second low-voltage AC circuit 36 ​​when the railway vehicle 10 is not energized can also be measured by the contact-type monitoring device 70c.

[0075] Furthermore, when a voltage is applied between terminals V and f, the contact-type monitoring device 70c measures the insulation resistance between the electric wires between the electromagnetic contactor 44e and multiple DC devices (such as the brake 19 and the control device 60) connected to terminal f, the rectifier 38 connected to the DC devices, the electric wires 36r, 36t connected to the rectifier 38, the secondary winding of the isolation transformer 34 connected to the electric wires 36r, 36t, and the electric wire 36n connected to the secondary winding.

[0076] As a result, by installing the contact-type monitoring device 70c on the railway vehicle 10, like the contact-type monitoring devices 70a, 70b, it is possible to easily measure the insulation resistance of each part of the first low-voltage AC circuit 32 and the second low-voltage AC circuit 36 ​​compared to conventional methods of measuring insulation resistance.

[0077] When the contact-type monitoring device 70c applies a voltage between terminals V and a, the voltage is set to be equal to or lower than the voltage (440V AC) output from the SIV 30 to the first low-voltage AC circuit 32. When the contact-type monitoring device 70c applies a voltage between terminals V and terminals b-f, the voltage is set to be equal to or lower than the voltage (100V AC) output from the insulating transformer 34 to the second low-voltage AC circuit 36. As a result, it is possible to prevent dielectric breakdown of each electrical device connected to the first low-voltage AC circuit 32 and the second low-voltage AC circuit 36 ​​due to the applied voltage of the contact-type monitoring device 70c.

[0078] It is also preferable that the voltage applied between terminals V and a by the contact-type monitoring device 70c is 100V or less, and the voltage applied by the contact-type monitoring device 70c is constant to avoid erroneous application of voltage. This makes it possible to prevent the voltage intended for the first low-voltage AC circuit 32 from being applied to the second low-voltage AC circuit 36, and reduces fluctuations in the insulation resistance measured by the contact-type monitoring device 70c due to erroneous application of voltage.

[0079] In addition, since the contact-type monitoring devices 70a, 70b, and 70c are provided separately, the electric wires Aa and Ab connected to the contact-type monitoring device 70a, the electric wire Ba connected to the contact-type monitoring device 70b, and the electric wires Ca to Cf connected to the contact-type monitoring device 70c can be prevented from concentrating in one place. This makes it possible to prevent short circuits between the electric wires Aa to Cf, and also to prevent noise caused by consolidating the electric wires Aa to Cf.

[0080] Furthermore, since the insulation resistance can be measured simultaneously using the contact-type monitoring devices 70a, 70b, and 70c, the time required to measure the insulation resistance can be reduced by providing the contact-type monitoring devices 70a, 70b, and 70c separately compared to combining the contact-type monitoring devices 70a, 70b, and 70c together.

[0081] In addition, since the voltage applied to the measurement target for each of the contact-type monitoring devices 70a, 70b, and 70c is different, erroneous application of voltage to each measurement target can be suppressed compared to the case where the contact-type monitoring devices 70a, 70b, and 70c are grouped together. This makes it possible to reduce fluctuations in the insulation resistance measurement values ​​by the contact-type monitoring devices 70a, 70b, and 70c caused by erroneous application of voltage.

[0082] Next, the control of each part of the railway vehicle 10 equipped with the contact-type monitoring devices 70a-70c will be described in more detail with reference to Figs. 4-12. Fig. 4 is a block diagram showing the electrical configuration of the railway vehicle 10. Fig. 5 is a block diagram showing the electrical configuration of the contact-type monitoring device 70. Fig. 4 shows in schematic form that the contact-type monitoring devices 70 (70a-70c) receive power from a storage battery 82.

[0083] As shown in FIG. 4, the control device 60 of the railway vehicle 10 has a CPU 61, a hard disk drive (HDD) 62, and a RAM 63 which is a memory for rewritably storing various work data, flags, etc. when the CPU 61 executes a program, and these are each connected to an input / output port 65 via a bus line 64.

[0084] Further connected to the input / output port 65 are a pantograph 17, electromagnetic contacts 44 (44a to 44e), a power supply switch 66, a VVVF inverter 20, an SIV 30, air conditioning equipment 15, lighting 16, brakes 19, contact-type monitoring devices 70a to 70c, and a wireless communication device 68 that transmits and receives information to and from an external server 90 via the Internet, etc.

[0085] The CPU 61 is a calculation device that controls each part connected by a bus line 64. The HDD 62 is a rewritable non-volatile memory that stores programs executed by the CPU 61, various data, etc., and includes a control program 62a, a vehicle information memory 62b, and each measurement result memory 62c. When the control program 62a is executed by the CPU 61, the main process of FIG. 11 is executed.

[0086] The vehicle information memory 62b is a memory that stores vehicle information such as the vehicle number and formation information of the railway vehicle 10. Each measurement result memory 62c is a memory that temporarily stores the measurement results of the insulation resistance in the contact monitoring devices 70a to 70c until they are transmitted to the external server 90.

[0087] The contents of each measurement result memory 62c will be described with reference to Fig. 6. Each measurement result memory 62c is provided with a date and time memory and a measurement result memory for each contact monitoring device 70a-70c and for each measurement target (one of measurement targets a-f, or a reference resistance). The date and time memory and the measurement result memory store the measurement dates and times and measurement results by the contact monitoring devices 70a-70c mounted on the railway vehicle 10 in sequential order.

[0088] If an error occurs during measurement by the contact-type monitoring devices 70a-70c, the date and time memory of the measurement target stores "error" instead of the date and time, and the corresponding measurement result memory stores information indicating the content of the error instead of the measurement result. For example, if an error occurs during measurement of the measurement target b by the contact-type monitoring device 70a, "error" is stored in the date and time memory corresponding to the measurement target b of the contact-type monitoring device 70a among the measurement result memories 62c, and "SW22" is stored in the measurement result memory. "SW22" indicates that the second switch SW2-2 has welded and cannot be opened.

[0089] The power supply switch 66 is a switch for controlling the raising and lowering of the pantograph 17 and the opening and closing of the electromagnetic switches 44. When the power supply switch 66 is turned off, the pantograph 17 descends, and then all of the electromagnetic switches 44 open so that the insulation resistance can be measured by the contact-type monitoring device 70. When the power supply switch 66 is turned on, all of the electromagnetic switches 44 close, and then the pantograph 17 ascends. In this way, by closing the electromagnetic switches 44 before the pantograph 17 comes into contact with the overhead wires 4, welding of the electromagnetic switches 44 can be prevented. A storage battery 67 is provided to operate the electromagnetic switches 44 and the like when the railway vehicle 10 is not energized.

[0090] 5, the contact-type monitoring device 70 has a CPU 71, a flash ROM 72, and a RAM 73 which is a memory for rewritably storing various work data, flags, etc. when the CPU 71 executes a program, and these are each connected to an input / output port 75 via a bus line 74. The input / output port 75 is further connected to an interface (I / F) 76 which is connected to the input / output port 65 of the railway vehicle 10, a measuring unit 77, a voltage application unit 78, and a switching unit 79.

[0091] The CPU 71 is a calculation device that controls each part connected by a bus line 74. The flash ROM 72 is a rewritable non-volatile memory that stores programs executed by the CPU 71, fixed value data, etc., and includes a contact monitoring program 72a, a unique number memory 72b, and a contact type measurement memory 72c. When the contact monitoring program 72a is executed by the CPU 71, the main process of FIG. 7 is executed.

[0092] The unique number memory 72b is a memory that stores the unique number of the contact-type monitoring device 70. This unique number is part of the information that indicates the object of insulation resistance measurement by the contact-type monitoring device 70. The contact-type measurement memory 72c is a memory for storing the results of insulation resistance measurement by the contact-type monitoring device 70 while the railway vehicle 10 is not energized.

[0093] The contact-type measurement memory 72c has substantially the same configuration as the portion of the contents of each measurement result memory 62c described using Fig. 6 that corresponds to the contact-type monitoring device 70 having this contact-type measurement memory 72c itself. For example, the contact-type measurement memory 72c of the contact-type monitoring device 70a of the railway vehicle 10 has a reduced storage capacity of the portion of each measurement result memory 62c that corresponds to the contact-type monitoring device 70a.

[0094] Voltage application unit 78 is a device that applies a positive DC voltage from terminal V to ground wire 40. Measurement unit 77 is a device that calculates (measures) the value of the insulation resistance of the measurement object. Specifically, for example, measurement unit 77 may be a device that divides the voltage applied by voltage application unit 78 between an internal resistance provided inside measurement unit 77 and the insulation resistance of the measurement object, and calculates the value of the insulation resistance from the voltage applied to the internal resistance.

[0095] The measuring unit 77 is not limited to a device that calculates the insulation resistance value, but may be a device that detects the value of leakage current flowing through an object of insulation resistance measurement. In this case, the CPU 71 calculates the insulation resistance value of the object of measurement based on the voltage applied by the voltage application unit 78 and the value of leakage current detected by the measuring unit 77.

[0096] The switching unit 79 is a circuit for connecting one electric wire from among the electric wires connected to the terminals a to f to the measuring unit 77, and for measuring the insulation resistance of the electric wire connected to the measuring unit 77. Hereinafter, the electric wire to be measured that is connected to the terminal a will be referred to as the measurement object a, and similarly, the electric wires to be measured that are connected to the terminals b to f will be referred to as the measurement objects b to f.

[0097] A first switch SW1-n (n: integer) and a second switch SW2-n are connected in series between each of the terminals a-f and the measurement unit 77, in that order from the terminals a-f side. A voltage detection unit VDn is connected between the first switch SW1-n and the second switch SW2-n. Terminal a (measurement object a) corresponds to n=1, terminal b to n=2, terminal c to n=3, terminal d to n=4, terminal e to n=5, and terminal f to n=6.

[0098] The first switch SW1-n and the second switch SW2-n are switches that open and close an electric circuit in response to an instruction from the CPU 71, and maintain an open state when not energized. Closing the first switch SW1-n connects the corresponding measurement objects a to f to the voltage detection unit VDn. As a result, the voltage detection unit VDn detects the voltage applied to the measurement objects a to f.

[0099] By closing the first switch SW1-n and then closing the second switch SW2-n connected in series thereto, the corresponding measurement objects a-f are connected to the measurement unit 77. As a result, a measurement circuit that measures the insulation resistance of the measurement objects a-f is formed between the voltage application unit 78 and the measurement unit 77.

[0100] When the railway vehicle 10 is traveling, all of the first switches SW1-n and second switches SW2-n are opened, thereby isolating each part of the contact-type monitoring device 70 that is unrelated to the traveling of the railway vehicle 10 from circuits related to the traveling, such as the power supply line 18 and the electric motor wires 24. Furthermore, even if one of the first switch SW1-n and the second switch SW2-n connected in series melts, it is possible to prevent each part of the contact-type monitoring device 70 from being connected to the circuits related to the traveling, as long as the other one is open. In other words, deterioration in the reliability of the existing circuits of the railway vehicle 10 can be suppressed.

[0101] The existing circuit refers to the electrical circuit of the railway vehicle 10 excluding the contact-type monitoring device 70 and the electric wires Aa-CV for connecting the contact-type monitoring device 70 to each part of the railway vehicle 10. In other words, the existing circuit refers to the equipment and circuits that were placed on the railway vehicle 10 before the contact-type monitoring device 70 was installed, and includes the power supply line 18, the VVVF inverter 20, the SIV 30, the electric motor wires 24, etc.

[0102] Furthermore, the measurement objects a-f can be connected to each other via the switching unit 79 only when two or more pairs of the first switch SW1-n and the second switch SW2-n connected in series are closed at the same time. That is, by connecting the first switch SW1-n and the second switch SW2-n in series, it becomes difficult for the measurement objects a-f to be connected to each other via the switching unit 79. This makes it possible to prevent failure of each electrical device of the measurement objects a-f caused by being connected to each other via the switching unit 79.

[0103] In addition, the switching unit 79 includes a reference resistor 81 connected to an electric wire branching off from between the terminal V and the voltage application unit 78, and a third switch SW3 that opens and closes the reference resistor 81 and the measurement unit 77. The reference resistor 81 is a load having a predetermined resistance value that serves as a reference. The third switch SW3 may be provided between the reference resistor 81 and the electric wire branching off from between the terminal V and the voltage application unit 78.

[0104] Closing the third switch SW3 connects the voltage application unit 78 and the measurement unit 77 via the reference resistor 81. In this case, when the voltage application unit 78 applies a voltage, the measurement unit 77 calculates the resistance value of the reference resistor 81 instead of the insulation resistance value. This calculated resistance value is compared with a predetermined resistance value of the reference resistor 81, and if the two are almost the same, it can be determined that the contact-type monitoring device 70 is operating normally. In addition, the contact-type monitoring device 70 can be calibrated so that the resistance value of the reference resistor 81 measured (calculated) by the contact-type monitoring device 70 approaches the predetermined resistance value of the reference resistor 81.

[0105] Next, the main processing executed by the CPU 71 of the contact-type monitoring device 70 will be described with reference to Figs. 7 to 10. Fig. 7 is a flowchart of the main processing of the contact-type monitoring device 70. Fig. 8 is a flowchart of the resistance measurement processing S33 carried out during the main processing. Fig. 9 is a flowchart of the post-measurement processing S49 carried out during the resistance measurement processing S33. Fig. 10 is a flowchart of the self-diagnosis processing S53 carried out during the resistance measurement processing S33. The main processing of the contact-type monitoring device 70 is executed when the power of the contact-type monitoring device 70 is turned on.

[0106] 7, the main process first checks whether the pantograph 17, which was in the raised state, has lowered (S31). This check may be based on a signal from a sensor that is turned on when the pantograph 17 is lowered, or may be based on a signal from the control device 60 of the railway vehicle 10 indicating that the power supply switch 66 has been turned off.

[0107] When the pantograph 17 is lowered and the power supply from the overhead line 4 to the power line 18 is cut off, all the electromagnetic switches 44 are opened as described above, and the insulation resistance can be measured by the contact type monitoring device 70. Immediately after the process of S31, a process may be performed to check whether all the electromagnetic switches 44 are open using a sensor or the like.

[0108] In the process of S31, if the pantograph 17 has been lowered (S31: Yes), a check is made to see if a predetermined time has passed since the pantograph 17 was lowered (S32) in order to release any remaining power in each part of the electrical circuit of the railway vehicle 10. This is because if power remains in the measurement target of the contact-type monitoring device 70, an overvoltage may be applied to the contact-type monitoring device 70, which may damage the contact-type monitoring device 70. There is also a concern that the measurement results of the insulation resistance of the measurement target may affect the remaining power. The predetermined time is set to be at least longer than the discharge time of the residual power in a capacitor (not shown) arranged inside the railway vehicle 10.

[0109] In the process of S32, if the predetermined time has not elapsed (S32: No), since there is a high possibility that residual power will affect the insulation resistance measurement result, the process of S32 is looped to wait for the predetermined time to elapse.

[0110] If the predetermined time has elapsed (S32: Yes), the possibility that residual power will affect the insulation resistance measurement result has become sufficiently low, so a resistance measurement process S33 is executed to measure the insulation resistance of the measurement target, and the process proceeds to S34. Note that if the pantograph 17 is raised in the process of S31, or if the pantograph 17 has already lowered (S31: No), the processes of S32 and S33 are skipped and the process proceeds to S34.

[0111] The resistance measurement process S33 will now be described with reference to Fig. 8. In the resistance measurement process S33, first, n=1 is set to measure the insulation resistance of the measurement object a (S41). Next, the first switch SW1-n is closed to connect the electric wire to be measured to the voltage detection unit VDn (S42). In the first process of S42 after the process of S41, the first switch SW1-1 is closed to connect the measurement object a to the voltage detection unit VD1.

[0112] After the process of S42, it is confirmed whether the voltage detected by the voltage detection unit VDn has become equal to or lower than the threshold value (S43). Note that this threshold value is set to a value smaller than the voltage applied by the voltage application unit 78 to the electric wire to be measured. In the process of S43, if the detected voltage is higher than the threshold value (S43: No), the residual voltage of the measurement object when not energized is high, so the process waits until the residual voltage is discharged. Note that, although not shown, if the detected voltage does not become equal to or lower than the threshold value even after waiting for a certain period of time, the measurement object is energized and is not in a state where the insulation resistance can be measured, so the resistance measurement process S33 is terminated without measuring the insulation resistance.

[0113] In the process of S43, if the detected voltage becomes equal to or lower than the threshold value (S43: Yes), the voltage that affects the measurement of the insulation resistance has become low, so the second switch SW2-n (SW2-1 in the first process after S41) is closed (S44). As a result, a measurement circuit that measures the insulation resistance of the measurement object is formed, so the voltage application unit 78 applies a voltage to the measurement object (S45).

[0114] In this way, when an excessive voltage is applied to the measurement target by the processes of S43 and S44, the second switch SW2-n is not closed, so that the electric circuits of the measurement unit 77 of the contact-type monitoring device 70 and the like can be protected from the excessive voltage. Therefore, the voltage detection unit VDn and the second switch SW2-n can ensure the durability of the contact-type monitoring device 70 and improve the detection accuracy of the insulation resistance of the measurement target. Furthermore, the opening and closing between the measurement target and the measurement unit 77 is multiplexed by the first switch SW1-n and the second switch SW2-n to provide redundancy, thereby improving safety. As a result, it is no longer necessary to provide the contact-type monitoring device 70 with durability (voltage resistance) greater than necessary, and it is expected that the cost and size of the contact-type monitoring device 70 can be reduced.

[0115] After the process of S45, it is checked whether a predetermined time has passed since the application of voltage (S46). If the predetermined time has not passed (S46: No), the measured insulation resistance value is not stable, so the process of S46 is looped.

[0116] On the other hand, if the predetermined time has passed since the application of the voltage (S46: Yes), the measurement unit 77 measures the insulation resistance of the measurement object (S47). Next, the measurement result, the measurement object (measurement object a in the first process after S41), and the date and time of measurement are stored in the contact measurement memory 72c (S48), and a post-measurement process S49 is executed.

[0117] 9, in the post-measurement process S49, first, the second switch SW2-n that was closed in the process of S44 is opened (S61). Next, it is confirmed whether the insulation resistance of the measurement target is still being detected by the measurement unit 77 (S62).

[0118] If insulation resistance is detected in the process of S62 (S62: Yes), it can be determined that the second switch SW2-n instructed to be opened in the process of S61 did not actually open due to welding, etc. In this case, error information that the second switch SW2-n did not open is stored in the contact measurement memory 72c (S63), and the process of S64 is executed.

[0119] On the other hand, if no insulation resistance is detected in the process of S62 (S62: No), the second switch SW2-n that was instructed to be opened in the process of S61 was opened without any problems, so the process of S63 is skipped and the process of S64 is executed.

[0120] In the process of S64, the first switch SW1-n that was closed in the process of S42 is opened. After the process of S64, it is confirmed whether a voltage is detected by the voltage detection unit VDn to which the first switch SW1-n that should have been opened is connected (S65). If the first switch SW1-n that was instructed to be opened in the process of S64 is not actually opened due to welding or the like, a voltage is detected in the process of S65 (S65: Yes). In this case, error information that the first switch SW1-n was not opened is stored in the contact measurement memory 72c (S66), the application of voltage by the voltage application unit 78 is terminated (S67), and the post-measurement process S49 is terminated.

[0121] On the other hand, if no voltage is detected in the process of S65 (S65: No), the first switch SW1-n that was instructed to be opened in the process of S64 was opened without any problems, so the process of S66 is skipped and the process of S67 is executed, and the post-measurement process S49 is terminated.

[0122] In this way, in the post-measurement process S49, the first switch SW1-n and the second switch SW2-n are opened stepwise while their normal operation can be confirmed. Therefore, in the contact-type monitoring device 70, the operation check of the first switch SW1-n and the second switch SW2-n can be automated.

[0123] Returning to Fig. 8, the following description will be given. After the post-measurement process S49, it is checked whether or not there was an error in this process (S50). If there is an error (S50: No), the resistance measurement process S33 ends without measuring the insulation resistance of other measurement targets.

[0124] For example, if the first switch SW1-1 and the second switch SW2-1 are both welded together and cannot be opened, causing an error, and the first switch SW1-2 and the second switch SW2-2 are closed to measure the insulation resistance of the measurement object b, the measurement objects a and b will be connected. If a voltage is applied by the voltage application unit 78 in this state, the contact-type monitoring device 70 and the electrical equipment of the measurement objects a and b may break down due to the unintended voltage.

[0125] In contrast, by terminating the resistance measurement process S33 when an error occurs in the post-measurement process S49 (S50: No), it is possible to prevent a plurality of measurement targets from being connected to each other via the switching unit 79. As a result, it is possible to reduce the possibility that the contact-type monitoring device 70 or each electrical device of the measurement target will break down due to an unintended voltage.

[0126] In the process of S50, if there is no error in the post-measurement process S49 (S50: Yes), n=n+1 is set to measure the insulation resistance of the measurement target that has not yet been measured (S51). Next, it is confirmed whether n≧7 (S52), and if n<7 (S52: No), there is still a measurement target that has not yet been measured, so the process from S42 onwards is executed again.

[0127] On the other hand, if n≧7 (S52: Yes), measurement of the insulation resistance of all measurement objects has been completed, so a self-diagnosis process S53 is executed and the resistance measurement process S33 is terminated. In the process of S52, an upper limit is set according to the number of connections of terminals a-f of the contact-type monitoring device 70. For example, in the case of the contact-type monitoring device 70a where only terminals a and b are connected to the measurement object, the process of S52 checks whether n≧3. In the case of the contact-type monitoring device 70b where only terminal a is connected to the measurement object, the process of S52 checks whether n≧2.

[0128] 10, in the self-diagnosis process S53, first, the third switch SW3 is closed (S71) to connect the voltage application unit 78 and the measurement unit 77 via the reference resistor 81. Next, a voltage is applied by the voltage application unit 78 (S72), and it is confirmed (S73) whether a predetermined time has passed since the application of the voltage so that the value of the current passing through the reference resistor 81 becomes stable. If the predetermined time has not passed since the application of the voltage (S73: No), the process of S73 is looped.

[0129] On the other hand, if the predetermined time has passed since the application of the voltage (S73: Yes), the measurement value by the measurement unit 77 has stabilized, so the measurement unit 77 measures the resistance value of the reference resistor 81 (S74). Next, the measurement result of this resistance value, the measurement target (reference resistor 81), and the date and time of the measurement are stored in the contact measurement memory 72c (S75).

[0130] The external server 90 or the like that has acquired the resistance measurement result compares the resistance measurement result of the reference resistor 81 with a predetermined resistance value of the reference resistor 81, and if the two values ​​are almost identical, it can be confirmed that the contact-type monitoring device 70 is operating normally. On the other hand, if there is a large discrepancy between the resistance measurement result and the predetermined resistance value, the normal operation of the contact-type monitoring device 70 is suspected, and therefore, a notice can be sent to the administrator of the external server 90 or the like to require maintenance of the contact-type monitoring device 70.

[0131] After the process of S75, the third switch SW3 that was closed in the process of S71 is opened (S76), and the connection between the voltage application unit 78 and the measurement unit 77 via the reference resistor 81 is cut off. In this state, it is confirmed whether the resistance value of the reference resistor 81 is still detected by the measurement unit 77 (S77).

[0132] If the third switch SW3 instructed to be opened in the process of S76 does not actually open due to welding or the like, the resistance value is detected in the process of S77 (S77: Yes). In this case, error information that the third switch SW3 did not open is stored in the contact measurement memory 72c (S78), the application of voltage by the voltage application unit 78 is terminated (S79), the self-diagnosis process S53 is terminated, and the resistance measurement process S33 in FIG. 8 is terminated.

[0133] On the other hand, if no resistance value is detected in the process of S77 (S77: No), the third switch SW3 that was instructed to be opened in the process of S76 was opened without any problem, so the process of S78 is skipped and the process of S79 is executed, the self-diagnosis process S53 is ended, and the resistance measurement process S33 in Fig. 8 is ended. In this way, in the contact-type monitoring device 70, the operation check of the third switch SW3 can be automated, similar to the first switch SW1-1 and the second switch SW2-1.

[0134] Returning to Fig. 7, the explanation will be given below. After the resistance measurement process S33, it is confirmed whether a measurement result has been requested from the control device 60 of the railway vehicle 10 (S34), and if a request has been received (S34: Yes), the unsent measurement result (or error information) stored in association with the contact-type measurement memory 72c, the measurement target, date and time, and the unique number of the contact-type monitoring device 70 stored in the unique number memory 72b are transmitted to the control device 60 (S35).

[0135] Next, other processes are executed (S36), and the processes from S31 onwards are repeatedly executed. Note that in the process of S36, for example, charging control of the storage battery 82 and confirmation of the presence or absence of connection of the measurement targets a-f to the terminals a-f are performed.

[0136] Next, main processing executed by the CPU 61 of the control device 60 of the railway vehicle 10 will be described with reference to Fig. 11. Fig. 11 is a flowchart of the main processing of the control device 60. The main processing of the control device 60 is executed when the pantograph 17 rises, power is supplied to the railway vehicle 10 from the overhead line 4, and the control device 60 is powered on.

[0137] 11, the main process begins with a request for measurement results from each of the contact-type monitoring devices 70 (S81), since the contact-type monitoring devices 70 are measuring insulation resistance while the control device 60 is not powered on. As described above, unsent measurement results and the like are transmitted from the contact-type monitoring devices 70 to the control device 60 by the processes of S34 and S35 in FIG. 7 in response to this request.

[0138] After the process of S81, the measurement results (or error information), measurement target, date and time received from the contact-type monitoring device 70, and the unique number of the contact-type monitoring device 70 are stored in each measurement result memory 62c in association with each other (S82). By aggregating the measurement results from each contact-type monitoring device 70 in the control device 60, the memory capacity of the contact-type monitoring device 70 can be reduced, and the contact-type monitoring device 70 can be made smaller. This improves the freedom of where the contact-type monitoring device 70 is placed. Furthermore, reducing the memory capacity of the contact-type monitoring device 70 is expected to reduce costs.

[0139] After the process of S82, it is confirmed whether or not unsent measurement results or error information are stored in each measurement result memory 62c from the control device 60 to the external server 90 (S83). If unsent measurement results or error information are stored (S83: Yes), it is confirmed whether or not communication between the railway vehicle 10 and the external server 90 is possible via the wireless communication device 68 in order to transmit them to the external server 90 (S84).

[0140] If communication with the external server 90 is possible (S84: Yes), the unsent measurement results (or error information) stored in each measurement result memory 62c, the measurement target, date and time, and the unique number of the contact-type monitoring device 70, as well as the vehicle information of the railway vehicle 10 stored in the vehicle information memory 62b, are transmitted to the external server 90 (S85).

[0141] Next, other processing is executed (S86), and the processing from S81 onwards is executed repeatedly. Note that the processing of S86 includes various processing for running the railcar 10.

[0142] Furthermore, if there are no unsent measurement results or error information in the process of S83 (S83: No), or if communication with the external server 90 is not possible in the process of S84 (S84: No), the process of S85 is skipped and the process of S86 is executed.

[0143] The external server 90 judges whether or not there is a suspicion of insulation resistance degradation based on the measurement results received from the railway vehicle 10. For example, the external server 90 generates and displays a graph with the vertical axis representing past insulation resistance measurement results and the horizontal axis representing date and time for measurement target a of contact-type monitoring device 70a of the railway vehicle 10, as shown in Fig. 12. In the graph of Fig. 12, the solid line represents the change over time of the past measurement results (actual measured values), and the two-dot chain line represents the change over time of future measurement results (predicted values) that are an extension of a straight line that approximates the actual measured values ​​using the least squares method. The graph of Fig. 12 also shows the threshold value at which insulation resistance degradation is suspected, as a dashed line.

[0144] If the past measurement result is below the threshold value, a notification is sent to the administrator of the external server 90 that degradation of the insulation resistance is suspected. When measuring the insulation resistance in the railway vehicle 10, the temperature and humidity at the time of measurement may also be obtained, and this information may be used to determine the degradation of the insulation resistance.

[0145] The date and time when the future measurement results will be below the threshold value is predicted from the time-dependent change in the future measurement results (predicted values) and the threshold value, and the date and time is displayed in the graph of Fig. 12. Therefore, the administrator of the external server 90 can plan a schedule for maintenance of the railway vehicle 10, etc., based on the date and time when the future measurement results will be below the threshold value, and can also plan ordering of devices and parts that require replacement.

[0146] Next, a second embodiment will be described with reference to Fig. 13 and Fig. 14. In the first embodiment, a case was described in which power is supplied from the pantograph 17 to the power line 18, and the VVVF inverter 20 and the SIV 30 are mounted on one railway vehicle 10. In contrast, in the second embodiment, a case will be described in which, in a train configuration in which railway vehicles 100a, 100b, and 100c are coupled together, power is supplied from a power source 102 consisting of a generator, a storage battery, etc. mounted on the railway vehicle 100a to the power lines 18a to 18c, the VVVF inverter 20 is mounted on the railway vehicle 100c, and the SIV 30 is mounted on the railway vehicle 100b. Note that the same parts as those in the first embodiment are denoted by the same reference numerals, and the following description will be omitted.

[0147] Fig. 13 is a circuit diagram showing the electric circuits of railway vehicles 100a, 100b, and 100c upstream of SIV 30 in the second embodiment. Fig. 14 is a circuit diagram showing the electric circuit of railway vehicle 100b downstream of SIV 30 in the second embodiment.

[0148] As shown in Fig. 13, railway cars 100a to 100c mainly include a car body 12, wheels 13, coupling parts 14, and a plurality of electrical devices. Railway cars 100a to 100c are configured as a train set by coupling parts 14 together. Power line 18a of railway car 100a, power line 18b of railway car 100b, and power line 18c of railway car 100c are connected via coupling parts 14, respectively.

[0149] Similarly, ground side electric wire 42a of railway vehicle 100a, ground side electric wire 42b of railway vehicle 100b, and ground side electric wire 42c of railway vehicle 100c are each connected via coupling portion 14. Also, ground wire 40a of railway vehicle 100a, ground wire 40b of railway vehicle 100b, and ground wire 40c of railway vehicle 100c are each connected via coupling portion 14. Furthermore, ground side electric wires 42a-42c and ground wires 40a-40c of each vehicle are connected via electromagnetic switch 44a and manual switch 46a connected in series to the side of ground wires 40a-40c of electromagnetic switch 44a.

[0150] The railcar 100a is equipped with a power source 102 for running the railcars 100a to 100c. The power source 102 is made up of a generator (including a fuel cell) and a storage battery, and supplies DC power. The positive electrode of the power source 102 is connected to the power line 18a via a power switch 104. The negative electrode of the power source 102 is connected to the ground side electric wire 42a.

[0151] By closing the power supply switch 104, power is supplied from the power supply 102 to the power supply lines 18a to 18c. By opening the power supply switch 104, the power supply from the power supply 102 to the power supply lines 18a to 18c is cut off.

[0152] The railway vehicle 100b is equipped with an SIV 30. The positive terminal on the input side of the SIV 30 is connected to the power supply line 18b, and the negative terminal is connected to the ground side electric wire 42b. The railway vehicle 100c is equipped with a VVVF inverter 20. The positive terminal on the input side of the VVVF inverter 20 is connected to the power supply line 18c, and the negative terminal is connected to the ground side electric wire 42c.

[0153] The railcar 100a is also equipped with a contact-type monitoring device 70a. The contact-type monitoring device 70a has a terminal V connected to the ground wire 40a via an electric wire AV, a terminal a connected to the power supply wire 18a via an electric wire Aa, and a terminal b connected to the ground-side electric wire 42a via an electric wire Ab.

[0154] If the railway cars 100a, 100b, 100c are coupled together, when the power switch 104 is opened to cut off the power supply to the power lines 18a-18c, the electromagnetic switch 44a opens and the power lines 18a-18c and the ground side electric wires 42a-42c are disconnected from the ground lines 40a-40c, as in the first embodiment. In this state, the contact type monitoring device 70a applies a voltage between the terminal V and the terminal a or the terminal b, thereby measuring the total insulation resistance of the power lines 18a-18c connected to the terminal a to which the voltage is applied, or the total insulation resistance of the ground side electric wires 42a-42c connected to the terminal b to which the voltage is applied.

[0155] When the railway vehicle 100a is disconnected from the railway vehicles 100b, 100c, when the railway vehicle 100a is not powered, the contact-type monitoring device 70a can apply a voltage between terminal V and terminal a or terminal b to individually measure the insulation resistance of the power supply line 18a connected to terminal a or the ground side wire 42a connected to terminal b without affecting the insulation resistance of the power supply line 18a or ground side wire 42a of the other railway vehicles 100b, 100c.

[0156] A contact-type monitoring device 70d is mounted on the railway vehicle 100b. The contact-type monitoring device 70d has a terminal V connected to the ground wire 40b via an electric wire DV, a terminal a connected to the power supply wire 18b via an electric wire Da, and a terminal b connected to the ground-side electric wire 42b via an electric wire Db.

[0157] When the railway vehicle 100b is disconnected from the railway vehicles 100a and 100c, the supply of power from the power line 18a to the power line 18b is cut off, and the connection between the ground side electric wire 42b and the ground wire 40b via the ground side electric wire 42a and the ground wire 40a is cut off. Furthermore, in response to the cutoff of the power supply, the electromagnetic switch 44a between the ground side electric wire 42b and the ground wire 40b opens. In this state, the contact-type monitoring device 70d applies a voltage between the terminal V and the terminal a or the terminal b, thereby being able to measure the insulation resistance of the power line 18b connected to the terminal a to which the voltage is applied, or the ground side electric wire 42b connected to the terminal b to which the voltage is applied, separately from the other railway vehicles 100a and 100c.

[0158] A contact-type monitoring device 70e is mounted on the railway vehicle 100c. The contact-type monitoring device 70e has a terminal V connected to the ground wire 40c via an electric wire EV, a terminal a connected to the power supply line 18c via an electric wire Ea, and a terminal b connected to the ground-side electric wire 42c via an electric wire Eb.

[0159] When the railcar 100c is disconnected from the railcars 100a and 100b, the power supply from the power lines 18a and 18b to the power line 18c is cut off, and the connection between the ground side electric wire 42c and the ground wire 40c via the ground side electric wires 42a and 42b and the ground wires 40a and 40b is cut off. Furthermore, in response to the cutoff of the power supply, the electromagnetic switch 44a between the ground side electric wire 42c and the ground wire 40c opens. In this state, the contact type monitoring device 70e applies a voltage between the terminal V and the terminal a or the terminal b, thereby being able to measure the insulation resistance of the power line 18c connected to the applied terminal a or the ground side electric wire 42c connected to the applied terminal b separately from the other railcars 100a and 100c.

[0160] As described above, by installing contact-type monitoring devices 70a, 70d, 70e on each of the railway cars 100a-100c and disconnecting the electric wires that are connected via the connecting portion 14 when power is applied (when the car is running) when power is not applied, the insulation resistance of the power supply lines 18a-18c and the insulation resistance of the ground side electric wires 42a-42c can be measured individually for each of the railway cars 100a-100c.

[0161] The configurations of the first low-voltage AC electric circuit 32 and the second low-voltage AC electric circuit 36 ​​of the railway vehicle 100b will be described with reference to Fig. 14. Note that the first low-voltage AC electric circuit 32 and the second low-voltage AC electric circuit 36 ​​of the railway vehicles 100a, 100c are configured substantially the same as those of the railway vehicle 100b, and therefore some of the description thereof will be omitted.

[0162] When the railcars 100a to 100c are energized, the first low-voltage AC circuit 32 of the railcar 100b is supplied with AC power from the SIV 30, and the second low-voltage AC circuit 36 ​​of the railcar 100b is supplied with AC power from the isolation transformer 34. Meanwhile, the first low-voltage AC circuit 32 of the railcars 100a and 100c is supplied with AC power from the first low-voltage AC circuit 32 of the railcar 100b, and the second low-voltage AC circuit 36 ​​of the railcars 100a and 100c is supplied with AC power from the second low-voltage AC circuit 36 ​​of the railcar 100b.

[0163] In the railway vehicle 100b, an isolation transformer 86 of a charger 84, which is an AC device, is connected to the ground wire 40b via an electromagnetic switch 44f and a manual switch 46f. A light 16, which is an AC device, is connected to the ground wire 40b via an electromagnetic switch 44g and a manual switch 46g. Although not shown, a plurality of AC devices other than the charger 84 and the light 16 are also individually connected to the ground wire 40b via the electromagnetic switch 44 and the manual switch 46.

[0164] Furthermore, the control device 60, which is a DC device, is connected to the ground wire 40b via an electromagnetic switch 44h and a manual switch 46h. The brake 19, which is a DC device, is connected to the ground wire 40b via an electromagnetic switch 44i and a manual switch 46i. Although not shown, a plurality of DC devices other than the control device 60 and the brake 19 are also individually connected to the ground wire 40b via the electromagnetic switch 44 and the manual switch 46.

[0165] A contact-type monitoring device 70f is mounted on the railway vehicle 100b. The contact-type monitoring device 70f has a terminal V connected to the ground wire 40b via an electric wire FV, a terminal a connected to the electric wire 32v of the first low-voltage AC circuit 32 via an electric wire Fa, a terminal b connected between the isolation transformer 86 and the electromagnetic switch 44f via an electric wire Fb, a terminal c connected between the lighting 16 and the electromagnetic switch 44g via an electric wire Fc, a terminal d connected between the control device 60 and the electromagnetic switch 44h via an electric wire Fd, and a terminal e connected between the brake 19 and the electromagnetic switch 44i via an electric wire Fe. Terminals of the contact-type monitoring device 70f are also individually connected between other AC devices and DC devices and the electromagnetic switch 44.

[0166] When the railway vehicle 10 is not powered and all of the electromagnetic switches 44b, 44c, 44f to 44i are open, the contact-type monitoring device 70f applies a voltage between terminal V and any one of terminals a to e, and measures the insulation resistance of the portion where terminals a to e are connected.

[0167] In the first embodiment, the contact-type monitoring device 70c is used to measure the total insulation resistance of a plurality of AC devices and the total insulation resistance of a plurality of DC devices. In contrast, in the second embodiment, a plurality of AC devices and DC devices are individually connected to the ground wire 40b via the electromagnetic switch 44, and a plurality of AC devices and DC devices are individually connected to the terminals b to e of the contact-type monitoring device 70f. Thus, the contact-type monitoring device 70f can individually measure the insulation resistance of a plurality of AC devices and DC devices. This makes it easy to determine which AC device or DC device has deteriorated insulation resistance from the measurement results of the contact-type monitoring device 70f.

[0168] Furthermore, when a voltage is applied between terminal V and terminal a, the contact-type monitoring device 70f measures the insulation resistance of the first low-voltage AC circuit 32 of the railway vehicle 100b connected to terminal a. At this time, when the first low-voltage AC circuit 32 of the railway vehicle 100b and the first low-voltage AC circuits 32 of the railway vehicles 100a and 100c are coupled together, the contact-type monitoring device 70f can measure the total insulation resistance of the first low-voltage AC circuits 32 of the railway vehicles 100a to 100c.

[0169] On the other hand, when the connection between the first low-voltage AC circuit 32 of the railway vehicle 100b and the first low-voltage AC circuit 32 of the railway vehicles 100a and 100c is released, the insulation resistance of the first low-voltage AC circuit 32 of the railway vehicle 100b can be measured separately from the first low-voltage AC circuit 32 of the railway vehicles 100a and 100c.

[0170] After the railway cars 100a-100c change from a non-energized state to an energized state, the insulation resistance measurement results by the contact-type monitoring device 70 of the railway cars 100a-100c are collectively stored in each measurement result memory 62c of the railway car 100b by the processes of S81 and 82 of Fig. 11. Compared to a case in which the measurement results are transmitted from each of the multiple contact-type monitoring devices 70 to the external server 90, the measurement results of the contact-type monitoring device 70 can be transmitted from the railway car 100b to the external server 90 more smoothly.

[0171] Next, a third embodiment will be described with reference to Fig. 15 to Fig. 17. In the first and second embodiments, the insulation resistance of each part of the first low-voltage AC circuit 32 and the second low-voltage AC circuit 36 ​​is measured by a contact-type monitoring device 70. In contrast, in the third embodiment, the insulation resistance of each part of the first low-voltage AC circuit 32 and the second low-voltage AC circuit 36 ​​is measured by an AC monitoring device 120. Note that the same parts as in the first and second embodiments are given the same reference numerals and the following description will be omitted.

[0172] 15 is a circuit diagram showing a schematic diagram of an electric circuit of a railway vehicle 110 in the third embodiment. The railway vehicle 110 mainly includes a car body 12, wheels 13, a coupling portion 14 (see FIG. 1), a plurality of electric devices (such as air conditioners 15 and lights 16), and a contact-type monitoring device 70g.

[0173] The contact type monitoring device 70g has a terminal V connected to the ground wire 40 via the electric wire GV, a terminal a connected to the motor electric wire 24 via the electric wire Ga, a terminal b connected to the power supply line 18 via the electric wire Gb, and a terminal c connected to the ground side electric wire 42 via the electric wire Gc. With the electromagnetic switch 44a open in response to the lowering of the pantograph 17, the contact type monitoring device 70g applies a voltage between the terminal V and any one of the terminals a to c, thereby measuring the insulation resistance of the portion connected to the terminal a to c to which the voltage is applied.

[0174] That is, the contact-type monitoring device 70g is a combination of the contact-type monitoring device 70a and the contact-type monitoring device 70b in the first embodiment. This allows the number of contact-type monitoring devices 70 mounted on the railway car 110 to be reduced.

[0175] Although not described in the first embodiment, the first low-voltage AC circuit 32 includes a set of three main electric wires 32u1, 32v1, and 32w1 extending from the output side of the SIV 30 and laid between the front and rear coupling parts 14 of the vehicle, and branch electric wires 32u2, 32v2, and 32w2 branching from the main electric wires 32u1, 32v1, and 32w1, respectively. Although not shown, the first low-voltage AC circuit 32 passes through the inside of the SIV 30 and is connected to the ground wire 40 via the electromagnetic switch 44b and the manual switch 46b. A plurality of sets of the branch electric wires 32u2, 32v2, and 32w2 are provided so as to be connected to a plurality of AC devices such as the air conditioner 15, respectively.

[0176] Similarly, the second low-voltage AC circuit 36 ​​includes main electric wires 36r1, 36t1 extending from the isolation transformer 34 and laid between the front and rear coupling parts 14 of the vehicle, and branch electric wires 36r2, 36t2 branching off from the main electric wires 36r1, 36t1, respectively. In addition, since the main electric wire 36n1 connected to the ground wire 40 extends from the isolation transformer 34, the ground wire 40 also functions as a part of the main electric wire 36n1, and the branch electric wire 36n2 branches off from the ground wire 40.

[0177] The branch electric wire 36r2 and the branch electric wire 36n2 form one set of single-phase two-wire electric circuits, and the branch electric wire 36t2 and the branch electric wire 36n2 form one set of single-phase two-wire electric circuits. A plurality of sets of these electric circuits are provided so as to be connected to a plurality of AC devices such as the lighting 16, respectively.

[0178] The railway vehicle 110 is equipped with an AC monitoring device 120a that automatically and periodically measures the insulation resistance of the first low-voltage AC circuit 32 and electrical equipment connected thereto (e.g., air conditioning equipment 15) when current is applied to the railway vehicle 110, and an AC monitoring device 120b that automatically and periodically measures the insulation resistance of the second low-voltage AC circuit 36 ​​and electrical equipment connected thereto (e.g., lighting 16 and brakes 19) when current is applied.

[0179] The AC monitoring device 120a includes a zero-phase-sequence current transformer 127a through which a set of first low-voltage AC circuits 32 (main electric wires 32u1, 32v1, 32w1) passes, and a reference detection unit 128a that detects a voltage occurring between the main electric wires 32u1, 32w1 of the first low-voltage AC circuit 32. Similarly, the AC monitoring device 120b includes a zero-phase-sequence current transformer 127b through which a set of second low-voltage AC circuits 36 (main electric wires 36r1, 36n1, 36t1) passes, and a reference detection unit 128b that detects a voltage occurring between the main electric wires 36r1, 36t1 of the second low-voltage AC circuit 36. The power to operate the AC monitoring devices 120a, 120b may be supplied from the first low-voltage AC circuit 32 or the second low-voltage AC circuit 36 ​​via an electric wire not shown, or may be supplied from an electric wire other than the first low-voltage AC circuit 32 or the second low-voltage AC circuit 36.

[0180] The AC monitoring device 120a, the AC monitoring device 120b, and the AC monitoring devices 120c to 120h described below are configured substantially the same except for their different layouts (connection positions). Hereinafter, when the AC monitoring devices 120a to 120h are described without distinction, they will be referred to as the AC monitoring device 120. Similarly, when the zero-phase-sequence current transformer 127a and the reference detection unit 128a included in each of the AC monitoring devices 120a to 120h are described without distinction, they will be referred to as the zero-phase-sequence current transformer 127 and the reference detection unit 128, respectively.

[0181] The zero-phase-sequence current transformer 127 is a ring-shaped current transformer through which a set of AC electric circuits to be measured passes, and detects leakage current flowing through the set of AC electric circuits when current is applied to the railway vehicle 110. More specifically, the zero-phase-sequence current transformer 127 through which a set of AC electric circuits passes detects leakage current generated in electric wires downstream of the AC electric circuit from the passing position (the side away from the SIV 30 in the first low-voltage AC circuit 32, and the side away from the isolation transformer 34 in the second low-voltage AC circuit 36) and in each electric device connected to the electric wires.

[0182] The leakage current detected by the zero-phase current transformer 127 includes the leakage current Igc caused by the capacitance to the earth, and the leakage current Igr caused by the insulation resistance to the earth, which is directly related to the insulation resistance. The leakage current Igc not only increases in capacity according to the length of the electric wire to be measured, but also increases in capacity due to harmonic distortion currents caused by inverters, noise filters, etc. used in electrical equipment.

[0183] The reference detection unit 128 is a voltage probe that detects the voltage of one set of AC electric circuits to be measured. When the measurement target is a three-phase three-wire system, for example, when the main electric wire 32v1 and the branch electric wire 32v2 are grounded inside the SIV 30 without a winding, the reference detection unit 128 detects a voltage cross point between the ungrounded U phase (main electric wire 32u1 or branch electric wire 32u2) and W phase (main electric wire 32w1 or branch electric wire 32w2). When the measurement target is a three-phase four-wire system, for example, when the main electric wires 32u1, 32v1, and 32w1 are grounded inside the SIV 30 via a winding and a neutral wire, the reference detection unit 128 detects a voltage cross point between phases other than the ground wire (neutral wire). When the measurement target is a single-phase two-wire system, the reference detection unit 128 detects a cross point of the voltage between the N phase (main electric wire 36n1 or branch electric wire 36n2) and the L phase (main electric wires 36r1, 36t1, or any one of the branch electric wires 36r2, 36t2).

[0184] The AC monitoring device 120 calculates the leakage current Igr of the measurement object from the detection result of the zero-phase current transformer 127 and the detection result of the reference detection unit 128, and calculates the insulation resistance value of the measurement object from the leakage current Igr. The leakage current Igr and insulation resistance may be calculated using a known method, for example, the method disclosed in Japanese Patent No. 4945727.

[0185] Note that the AC monitoring device 120 may calculate the leakage current Igr caused by the insulation resistance of the measurement target as the measurement result, without calculating (measuring) the value of the insulation resistance of the measurement target as the measurement result. In this specification, the AC monitoring device 120 measuring the insulation resistance of the measurement target includes both the calculation of the insulation resistance value itself and the calculation of the leakage current Igr.

[0186] As described above, the AC monitoring device 120 measures the insulation resistance of the AC circuit and electrical equipment downstream of the position where it passes through the zero-phase current transformer 127, based on the detection value of the zero-phase current transformer 127 when the railway vehicle 110 is energized. As a result, by mounting the AC monitoring device 120 on the railway vehicle 110, it is possible to measure the insulation resistance of electrical equipment that is actually in operation, and also to eliminate the need for work such as disconnecting the electrical equipment from the ground wire 40 (ground portion), which is required with the contact-type monitoring device 70 that measures insulation resistance by applying a voltage.

[0187] Furthermore, AC monitoring device 120 periodically measures the insulation resistance while railcar 110 is running. This allows AC monitoring device 120 to measure the insulation resistance of electrical equipment in a state that cannot be grasped while the train is stopped, such as the insulation resistance of electrical equipment that is subjected to a load associated with running.

[0188] Furthermore, since the trunk electric wires 32u1-36t1 pass through each of the zero-phase-sequence current transformers 127a, 127b of the AC monitoring devices 120a, 120b, rather than the branch electric wires 32u2-36t2, the AC monitoring devices 120a, 120b can measure the total insulation resistance of the AC devices connected to the multiple branch electric wires 32u2-36t2 downstream of the zero-phase-sequence current transformers 127a, 127b, respectively.

[0189] In particular, since the main electric wires 32u1-32w1 located upstream of all the branch electric wires 32u2-32w2 pass through the zero-phase-sequence current transformer 127a, the AC monitoring device 120a can measure the total insulation resistance of all the AC devices connected to the first low-voltage AC circuit 32. Moreover, since the main electric wires 36r1-36t1 located upstream of all the branch electric wires 36r2-36t2 pass through the zero-phase-sequence current transformer 127b, the AC monitoring device 120b can measure the total insulation resistance of all the AC devices connected to the second low-voltage AC circuit 36.

[0190] Furthermore, since DC devices such as the brake 19 are connected via the rectifier 38 to the main electric wires 36r1, 36t1 downstream of the zero-phase current transformer 127b, the leakage current of the DC devices can be detected by the zero-phase current transformer 127b, and the AC monitoring device 120b can measure the sum of the insulation resistance of the DC devices and the insulation resistance of the AC devices downstream of the zero-phase current transformer 127b.

[0191] Next, the control of the AC monitoring device 120 will be described with reference to Fig. 16 and Fig. 17. Fig. 16 is a block diagram showing the electrical configuration of the AC monitoring device 120. Fig. 17 is a flowchart of main processing executed by the CPU 121 of the AC monitoring device 120.

[0192] The AC monitoring device 120 has a CPU 121, a flash ROM 122, and a RAM 123 which is a memory for rewritably storing various work data, flags, etc. when the CPU 121 executes a program, and these are each connected to an input / output port 125 via a bus line 124. The input / output port 125 is further connected to an interface (I / F) 126 connected to the input / output port 65 of the railway vehicle 110, the above-mentioned zero-phase current transformer 127, and the above-mentioned reference detection unit 128.

[0193] The CPU 121 is a calculation device that controls each part connected by a bus line 124. The flash ROM 122 is a rewritable non-volatile memory that stores programs executed by the CPU 121, fixed value data, etc., and includes an AC monitoring program 122a, a unique number memory 122b, and an AC measurement memory 122c. When the CPU 121 executes the AC monitoring program 122a, the main process of FIG. 17 is executed.

[0194] The unique number memory 122b is a memory that stores the unique number of the AC monitoring device 120. This unique number indicates the object of insulation resistance measurement by the AC monitoring device 120. The AC measurement memory 122c is a memory for temporarily storing the measurement results of the insulation resistance by the AC monitoring device 120, and is configured substantially the same as the contact measurement memory 72c (see FIG. 6) in the first embodiment.

[0195] 17, a description will be given of main processing executed by the CPU 121 of the AC monitoring device 120. The main processing of the AC monitoring device 120 is executed when the power supply of the AC monitoring device 120 is turned on.

[0196] The main process of the AC monitoring device 120 first checks whether a regular measurement timing for measuring the insulation resistance of the measurement target has arrived (S111). Note that, for example, an example of the regular measurement timing is every hour, but the measurement timing may be changed as appropriate.

[0197] In the processing of S111, when the regular measurement timing arrives (S111: Yes), in order to confirm whether the railway vehicle 110 is energized, it is checked whether the pantograph 17 is in the raised state (S112) and whether all the electromagnetic switches 44 are closed (S113).

[0198] When the pantograph 17 is in the raised state and all the electromagnetic switches 44 are closed (S112: Yes and S113: Yes), the railway vehicle 110 is powered and the insulation resistance of the object to be measured by the AC monitoring device 120 can be measured, so the insulation resistance of the object to be measured is measured by the AC monitoring device 120 (S114).

[0199] In this embodiment, the power supply to the AC monitoring device 120 is turned on only when the railway vehicle 110 is energized with the pantograph 17 raised and all the electromagnetic switches 44 closed, and is not turned on when the railway vehicle 110 is not energized. Therefore, while the main processing of the AC monitoring device 120 is being executed, the pantograph 17 is in the raised state and all the electromagnetic switches 44 are closed (S112: Yes and S113: Yes), so the processing of S112 and S113 may be omitted.

[0200] After the process of S114, the measurement result of the insulation resistance by the AC monitoring device 120 and the date and time of the measurement are stored in the AC measurement memory 122c in association with each other (S115), and the process of S116 is executed.

[0201] In addition, in the process of S111, if the regular measurement timing has not arrived (S111: No), the processes of S112 to S115 for measuring the insulation resistance are skipped, and the process of S116 is executed. Also, if the pantograph 17 is in the lowered state in the process of S112 (S112: No), or if the electromagnetic switch 44 is open in the process of S113 (S113: No), the railway vehicle 110 is not energized, and the AC monitoring device 120 is not able to measure the insulation resistance of the measurement target, so the processes of S114 and S115 are skipped, and the process of S116 is executed.

[0202] In the process of S116, it is confirmed whether or not a measurement result has been requested from the control device 60 of the railway vehicle 110. Note that this request for the measurement result from the control device 60 to the AC monitoring device 120 is executed in the process of S81 in FIG.

[0203] In the process of S116, if the measurement result is requested (S116: Yes), the unsent measurement result, date and time stored in association with the AC measurement memory 122c, and the unique number of the AC monitoring device 120 stored in the unique number memory 122b are transmitted to the control device 60 (S117), and the processes from S111 onwards are repeated. On the other hand, in the process of S116, if the measurement result is not requested (S116: No), the process of S117 is skipped, and the processes from S111 onwards are repeated.

[0204] The measurement result, date and time, and unique number of the AC monitoring device 120 transmitted in the process of S117 are stored in each measurement result memory 62c in correspondence with each other in the process of S82 in Fig. 11 by the control device 60, and are transmitted to the external server 90 in the process of S85 in Fig. 11. The external server 90 that has received this data determines the deterioration of the insulation resistance of the object measured by the AC monitoring device 120 based on the data, and notifies the administrator if deterioration is suspected.

[0205] As described above, the measurement results of the insulation resistance by AC monitoring device 120 are transmitted to external server 90 outside railcar 110, so that the measurement results of AC monitoring device 120 while railcar 110 is running can be monitored by external server 90. As a result, if an abnormality (deterioration of the insulation resistance of the object measured by AC monitoring device 120) is discovered during monitoring, the timing of maintenance of railcar 110, etc. can be planned early.

[0206] Next, a fourth embodiment will be described with reference to Fig. 18 and Fig. 19. In the third embodiment, a case where an AC monitoring device 120 is mounted on one railway car 110 is described. In contrast, in the fourth embodiment, a case where an AC monitoring device 120 is mounted on each part of each railway car 130a, 130b, 130c in a train configuration in which railway cars 130a, 130b, 130c are coupled together is described. Note that the same parts as those in the first to third embodiments are given the same reference numerals and the following description will be omitted.

[0207] Fig. 18 is a circuit diagram showing the electric circuits of the railway vehicles 130a, 130b, and 130c in the fourth embodiment. Fig. 18 shows the electric circuits of the railway vehicles 130a, 130b, and 130c downstream of the SIV 30. The electric circuits of the railway vehicles 130a, 130b, and 130c upstream of the SIV 30 are configured in the same manner as the electric circuits of the railway vehicles 100a, 100b, and 100c in the second embodiment shown in Fig. 13.

[0208] As shown in Fig. 18, each of the railway cars 130a to 130c mainly includes a car body 12, wheels 13, coupling parts 14, and a plurality of electrical devices (such as lights 16 and brakes 19). The railway cars 130a to 130c are configured into a train configuration by coupling parts 14 together.

[0209] The first low-voltage AC circuit 32 of the railway vehicle 130b includes a set of three main electric wires 32u1b, 32v1b, and 32w1b extending from the SIV 30 mounted on the railway vehicle 130b and laid between the front and rear coupling parts 14 of the railway vehicle 130b, and branch electric wires 32u2b, 32v2b, and 32w2b branching from the main electric wires 32u1b, 32v1b, and 32w1b, respectively. Although not shown, the first low-voltage AC circuit 32 passes through the inside of the SIV 30 and is connected to the ground wire 40 via the electromagnetic switch 44b and the manual switch 46b. A plurality of sets of the branch electric wires 32u2b, 32v2b, and 32w2b are provided so as to be connected to a plurality of AC devices such as the air conditioner 15, respectively.

[0210] The railway vehicle 130a includes trunk electric wires 32u1a, 32v1a, and 32w1a connected to trunk electric wires 32u1b, 32v1b, and 32w1b, respectively, via coupling parts 14, and branch electric wires 32u2a, 32v2a, and 32w2a branching off from the trunk electric wires 32u1a, 32v1a, and 32w1a, respectively. A plurality of sets of the branch electric wires 32u2a, 32v2a, and 32w2a are provided so as to be connected to a plurality of AC devices such as air conditioners 15, respectively.

[0211] The railway car 130c includes trunk electric wires 32u1c, 32v1c, and 32w1c that are connected to the trunk electric wires 32u1b, 32v1b, and 32w1b, respectively, via the coupling portion 14, and branch electric wires 32u2c, 32v2c, and 32w2c that branch off from the trunk electric wires 32u1c, 32v1c, and 32w1c, respectively. A plurality of sets of the branch electric wires 32u2c, 32v2c, and 32w2c are provided so as to be connected to a plurality of AC devices such as air conditioners 15, respectively.

[0212] The railcars 130a to 130c are equipped with AC monitoring devices 120c, 120d, and 120e, one for each pair of branch electric wires 32u2a to 32w2c. The pair of branch electric wires 32u2a to 32w2a passes through a zero-phase-sequence current transformer 127c of the AC monitoring device 120c, and a reference detection unit 128c of the AC monitoring device 120c is connected to the main electric wires 32u1a and 32w1a.

[0213] A set of branch electric wires 32u2b-32w2b passes through a zero-phase-sequence current transformer 127d of the AC monitoring device 120d, and a reference detection unit 128d of the AC monitoring device 120d is connected to the main electric wires 32u1b, 32w1b. A set of branch electric wires 32u2c-32w2c passes through a zero-phase-sequence current transformer 127e of the AC monitoring device 120e, and a reference detection unit 128e of the AC monitoring device 120e is connected to the main electric wires 32u1c, 32w1c.

[0214] Therefore, each of the AC monitoring devices 120c to 120e can measure the insulation resistance of an AC device (such as air conditioner 15) to which one set of branch electric wires 32u2a to 32w2c is connected, without being affected by the insulation resistance of AC devices connected to the other branch electric wires 32u2a to 32w2c.

[0215] The second low-voltage AC circuit 36 ​​of the railway vehicle 130b includes main electric wires 36r1b, 36t1b extending from an insulating transformer 34 mounted on the railway vehicle 130b and laid between the front and rear coupling parts 14 of the railway vehicle 130b, and branch electric wires 36r2b (not shown) and 36t2b branching off from the main electric wires 36r1b, 36t1b, respectively. In addition, since a main electric wire 36n1b connected to a ground wire 40b extends from the insulating transformer 34, the ground wire 40b also functions as a part of the main electric wire 36n1b, and a branch electric wire 36n2b branches off from the ground wire 40b.

[0216] The railway car 130a includes trunk electric wires 36r1a, 36t1a connected to trunk electric wires 36r1b, 36t1b, respectively, via the coupling portion 14, and branch electric wires 36r2a (not shown), 36t2a branching off from the trunk electric wires 36r1a, 36t1a, respectively. In addition, a ground wire 40a connected to a ground wire 40b functions as a part of the trunk electric wire, and a branch electric wire 36n2a branches off from the ground wire 40a.

[0217] The railway car 130c includes trunk electric wires 36r1c, 36t1c connected to the trunk electric wires 36r1b, 36t1b, respectively, via the coupling portion 14, and branch electric wires 36r2c, 36t2c (not shown) branching off from the trunk electric wires 36r1c, 36t1c, respectively. In addition, a ground wire 40c connected to a ground wire 40b functions as a part of the trunk electric wire, and a branch electric wire 36n2c branches off from the ground wire 40c.

[0218] Rectifiers 38 are connected to the main electric lines 36r1a, 36t1a, main electric lines 36r1b, 36t1b, and main electric lines 36r1c, 36t1c, respectively, and DC devices such as brakes 19 are connected between the rectifiers 38 and the main electric lines 36n1a, 36n1b, 36n1c, respectively.

[0219] The branch electric wires 36r2a and 36n2a form one set of single-phase two-wire electric circuits, and similarly, the branch electric wires 36t2a and 36n2a, the branch electric wires 36r2b and 36n2b, the branch electric wires 36t2b and 36n2b, the branch electric wires 36r2c and 36n2c, and the branch electric wires 36t2c and 36n2c form one set of single-phase two-wire electric circuits. A plurality of sets of electric circuits made of the branch electric wires 36r2a to 36t2c are provided so as to be connected to a plurality of AC devices such as the lighting 16.

[0220] An AC monitoring device 120b is mounted on the railway vehicle 130b. The main electric wires 36r1b-36t1b at the most upstream side (upstream of all the branch electric wires 36r2b-36t2b) pass through a zero-phase current transformer 127b of the AC monitoring device 120b. This enables the AC monitoring device 120b to measure the total insulation resistance of a plurality of electric devices (AC devices such as lighting 16 and DC devices such as brakes 19) connected to the main electric wires 36r1b-36t1b via the main electric wires 36r1a-36t1a, 36r1c-36t1c, the branch electric wires 36r2a-36t2c, and the rectifier 38.

[0221] The railcars 130a to 130c are equipped with AC monitoring devices 120f, 120g, and 120h, one for each set of electric paths formed by the branch electric wires 36r2a to 36t2c. A set of electric paths formed by the branch electric wires 36r2a to 36t2a passes through a zero-phase-sequence current transformer 127f of the AC monitoring device 120f, and a reference detection unit 128f of the AC monitoring device 120f is connected to the main electric wire 36t1a and the ground wire 40a.

[0222] A set of electric paths formed by the branch electric wires 36r2b-36t2b passes through a zero-phase-sequence current transformer 127g of the AC monitoring device 120g, and a reference detection unit 128g of the AC monitoring device 120g is connected to the main electric wire 36t1b and the ground wire 40b. A set of electric paths formed by the branch electric wires 36r2c-36t2c passes through a zero-phase-sequence current transformer 127h of the AC monitoring device 120h, and a reference detection unit 128h of the AC monitoring device 120h is connected to the main electric wire 36r1c and the ground wire 40c.

[0223] As a result, each of the AC monitoring devices 120f to 120h can measure the insulation resistance of an AC device (lighting 16) connected to a set of electric circuits formed by the branch electric wires 36r2a to 36t2c without being affected by the insulation resistance of AC devices connected to the other branch electric wires 36r2a to 36t2c.

[0224] Furthermore, by comparing the measurement results by the AC monitoring devices 120f, 120g, and 120h with the measurement results by the AC monitoring device 120b, it is possible to determine the deterioration of the insulation resistance of DC devices such as the brake 19. This will be described with reference to Fig. 19. Fig. 19 is a flowchart of a warning display process executed by the external server 90.

[0225] As shown in FIG. 19, in the warning display process, first, it is confirmed whether the measurement results of the AC monitoring devices 120b in the main electric cables 36r1a to 36t1c of the second low-voltage AC circuit 36 ​​are equal to or lower than the threshold value (S121).

[0226] If the measurement result of the AC monitoring device 120b is equal to or lower than the threshold value (S121: Yes), deterioration of the insulation resistance of at least one of the multiple AC devices and DC devices connected to the second low-voltage AC circuit 36 ​​of the railway cars 130a-130c is suspected. In this case, therefore, in order to determine (predict) which device's insulation resistance has deteriorated, it is confirmed whether any of the measurement results of the AC monitoring devices 120f-120g in the branch electric wires 36r2a-36t2c of the second low-voltage AC circuit 36 ​​has become equal to or lower than the threshold value (S122).

[0227] If any of the measurement results of the AC monitoring devices 120f-120g falls below the threshold (S122: Yes), it can be inferred that the reason the measurement result of the AC monitoring device 120b falls below the threshold is due to deterioration of the insulation resistance of the object of measurement of the AC monitoring devices 120f-120g (AC equipment connected to a set of electric circuits formed by the branch electric wires 36r2a-36t2c).

[0228] In this case, a warning is displayed for the AC devices that are the measurement targets of the AC monitoring devices 120f-120g whose measurement results are below the threshold (S123), and the warning display process is terminated. In this warning display, the measurement targets that are suspected of having deteriorated insulation resistance are displayed on the display device of the external server 90, and the administrator of the external server 90 is notified of the suspected deterioration.

[0229] On the other hand, if none of the measurement results of the AC monitoring devices 120f-120g are below the threshold in the process of S122 (S122: No), it can be assumed that the reason why the measurement result of the AC monitoring device 120b is below the threshold is not the AC device that is the measurement target of the AC monitoring devices 120f-120g, but the deterioration of the insulation resistance of the DC device. Therefore, in this case, a warning is displayed for the DC device (S124), and the warning display process is terminated.

[0230] Furthermore, in the process of S121, if the measurement result of AC monitoring device 120b is not below the threshold value (S121: No), specifically, for example, if the measurement result of AC monitoring device 120c or the measurement result of contact-type monitoring device 70d is merely below the threshold value, a warning is displayed for the measurement target of AC monitoring device 120c or contact-type monitoring device 70d that is below the threshold value (S125), and the warning display process is terminated.

[0231] Next, a fifth embodiment will be described with reference to Fig. 20. In the first to fourth embodiments, a case where the contact-type monitoring device 70 and the AC monitoring device 120 are mounted on railway cars 10, 100a-100c, 110, 130a-130c, which are DC electric trains, has been described. In contrast, in the fifth embodiment, a case where the contact-type monitoring device 70 and the AC monitoring device 120 are mounted on railway car 150, which is an AC electric train, will be described. Note that the same parts as those in the first to fourth embodiments are given the same reference numerals, and the following description will be omitted.

[0232] 20 is a circuit diagram showing a schematic diagram of an electric circuit of a railway vehicle 150 in the fifth embodiment. The railway vehicle 150 is an AC electric train, and mainly includes a car body 12, wheels 13, a coupling portion 14, and a plurality of electric devices (such as air conditioners 15 and lights 16).

[0233] A high-voltage (25,000 V in this embodiment) single-phase AC current flows through the overhead wire 140 that is suspended above the rail 2 by generating an electromotive force at a substation 141 with respect to the grounded rail 2. By raising the pantograph 17 to contact the overhead wire 140, AC power is supplied from the overhead wire 140 via the pantograph 17 to the power line 18 of the railway vehicle 150.

[0234] The power line 18 and the ground side electric wire 42 are connected by the primary winding of the main transformer 151. The main transformer 151 is an insulating transformer that transforms and outputs an input voltage and insulates the input side from the output side, and has a secondary winding and a tertiary winding on the output side relative to the primary winding on the input side.

[0235] An AC / DC converter 152 that converts AC power output from the main transformer 151 into DC power is connected to the secondary winding of the main transformer 151. The VVVF inverter 20 is connected to the output side of this AC / DC converter 152. AC power is supplied from the VVVF inverter 20 to the electric motor 22 via the electric motor wire 24.

[0236] A single-phase two-wire first low-voltage AC circuit 154 is connected to the tertiary winding of the main transformer 151. Similar to the first low-voltage AC circuit 32 of the first to fourth embodiments, single-phase AC power of a fixed voltage (e.g., 440 V) and a fixed frequency is supplied to the first low-voltage AC circuit 154 from the main transformer 151.

[0237] The first low-voltage AC circuit 154 includes a pair of main electric wires 154L1, 154N1 extending from the main transformer 151 and laid between the coupling parts 14 at both ends of the railway vehicle 150, and branch electric wires 154L2, 154N2 branching off from the main electric wires 154L1, 154N1, respectively. Although not shown, the main electric wire 154N1 is connected to the ground wire 40. A plurality of sets of the branch electric wires 154L2, 154N2 are provided so as to be connected to a plurality of AC devices such as the air conditioners 15, respectively.

[0238] A primary winding of an isolation transformer 155 is connected to the main electric wires 154L1, 154N1 of the first low-voltage AC circuit 154. A single-phase two-wire second low-voltage AC circuit 156 is connected to a secondary winding of the isolation transformer 155. The isolation transformer 155 transforms the voltage of the AC power input from the first low-voltage AC circuit 154 to 100 V in this embodiment and outputs it to the second low-voltage AC circuit 156, and also insulates the first low-voltage AC circuit 154 from the second low-voltage AC circuit 156.

[0239] The second low-voltage AC circuit 156 includes a main electric line 156L1 extending from the insulating transformer 155 and laid between the coupling parts 14 at both ends of the railway vehicle 150, and a branch electric line 156L2 branching off from the main electric line 156L1. Since a main electric line 156N1 connected to the grounding line 40 extends from the insulating transformer 155, the grounding line 40 also functions as a part of the main electric line 156N1, and the branch electric line 156N2 branches off from the grounding line 40.

[0240] A plurality of sets of branch electric wires 156L2, 156N2 are provided so as to be connected to a plurality of AC devices such as lights 16. A rectifier 38 is connected to the main electric wire 156L1, and DC devices such as brakes 19 are connected between the rectifier 38 and a ground wire 40 (main electric wire 156N1).

[0241] Such a railway vehicle 150 is equipped with a contact type monitoring device 70a and AC monitoring devices 120a, 120b, and 120i for measuring the insulation resistance of each part.

[0242] The contact-type monitoring device 70a has a terminal V connected to the ground wire 40 via an electric wire AV, and a terminal a connected to the power line 18 via an electric wire Aa. When the railway vehicle 150 is not energized (with the pantograph 17 lowered and the electromagnetic switch 44a open), a voltage is applied between the terminals V and a, thereby making it possible to measure the total insulation resistance of the power line 18, the primary winding of the main transformer 151, and the ground-side electric wire 42, which are all connected to each other.

[0243] The AC monitoring devices 120a and 120b include zero-phase current transformers 127a and 127b through which the most upstream of one set of main electric cables 154L1 and 154N1 or one set of main electric cables 156L1 and 156N1 passes, and reference detection units 128a and 128b that detect the voltage between the set of main electric cables 154L1 to 156N1. Based on the detection value of the zero-phase current transformer 127a and the detection value of the reference detection unit 128a, the AC monitoring device 120a measures the total insulation resistance of the first low-voltage AC circuit 154 and the multiple current devices connected thereto. Based on the detection value of the zero-phase current transformer 127b and the detection value of the reference detection unit 128b, the AC monitoring device 120b measures the total insulation resistance of the second low-voltage AC circuit 156 and the multiple current devices connected thereto.

[0244] The AC monitoring device 120i includes a zero-phase current transformer 127i through which the set of three electric wires 24u, 24v, 24w of the electric motor wires 24 passes, and a reference detection unit 128i that detects the voltage between the ungrounded electric wires 24u, 24w. The AC monitoring device 120i can measure the insulation resistance of the electric motor wires 24 and the electric motor 22 based on the detection value of the zero-phase current transformer 127i and the detection value of the reference detection unit 128i.

[0245] Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-mentioned embodiments, and it can be easily assumed that various improvements and modifications are possible within the scope of the present invention. For example, the voltage of the overhead line 4, the value of the output voltage from the SIV 30, and the number of railway cars 10, 11, 100a-100c, 110, 130a-130c, and 150 coupled to each other may be appropriately changed. In addition, the detailed electric circuits of each part of the railway cars 10, 11, 100a-100c, 110, 130a-130c, and 150 may be appropriately changed.

[0246] In the above embodiment, the railcars 10, 11, 100a to 100c, 110, 130a to 130c, and 150 run on rails 2, but the present invention is not limited to this. For example, the present invention may be applied to a railcar suspended from a rail.

[0247] In the above embodiment, the case where power is supplied from the overhead line 4, 140 (pantograph 17) or the power source 102 to the power source line 18 has been described, but the present invention is not limited to this. For example, the supply from the overhead line 4, 140 to the power source line 18 and the supply from the power source 102 to the power source line 18 may be switchable.

[0248] In the above embodiment, as the conversion device that converts and outputs the voltage input from the power line 18, the combination of the VVVF inverter 20, the SIV 30, the combination of the SIV 30 and the isolation transformer 34, the combination of the main transformer 151, the AC / DC converter 152 and the VVVF inverter 20, and the combination of the main transformer 151 and the isolation transformer 155 have been exemplified, but are not limited to these. For example, a device that reduces the voltage of the DC power from the power line 18 by voltage division and outputs the reduced voltage may be used as the conversion device.

[0249] In the above embodiment, the case where either the contact-type monitoring device 70 or the AC monitoring device 120 is provided for the measurement target of one AC electric circuit (the electric wire 24 for the motor, the first low-voltage AC electric circuit 32, or the second low-voltage AC electric circuit 36) has been described, but this is not limited thereto. Both the contact-type monitoring device 70 and the AC monitoring device 120 may be provided for the measurement target of one AC electric circuit.

[0250] In the above embodiment, the electromagnetic switches 44 are opened and closed by the storage battery 67, but the present invention is not limited to this. For example, the electromagnetic switches 44 may be opened and closed by the storage battery 82 of the contact-type monitoring device 70. In this case, in the main processing of the CPU 71 of the contact-type monitoring device 70 in Fig. 7, when the pantograph 17 is lowered (S31: Yes), the CPU 71 may send a signal to open all the electromagnetic switches 44, and then the processing of S32 and S33 may be shifted to, and after the processing of S33, the CPU 71 may send a signal to close all the electromagnetic switches 44.

[0251] Also, although the electromagnetic switch 44 has been described as a latch-type switch that opens and closes with an electric signal, it may be configured such that the open state is maintained by an electromagnet when current is applied to the electromagnetic switch 44, and the closed state is maintained by a spring when current is not applied to the electromagnetic switch 44. In this case, even if the power supply circuit to the electromagnetic switch 44 breaks down, the electromagnetic switch 44 can maintain the closed state when the railway cars 10, 11, 100a-100c, 110, 130a-130c, 150 are running (when current is applied), and the cars can run normally.

[0252] In the above embodiment, the case where all the electromagnetic switches 44 are arranged in parallel in pairs has been described, but one switch or three or more switches may be arranged in parallel. Also, depending on the circuit in which the electromagnetic switches 44 are provided, a portion in which multiple switches are arranged in parallel and a portion in which only one switch is arranged may be combined.

[0253] In the above embodiment, the contact-type monitoring device 70c is used to measure the control lines 201-203 that are not connected to the second low-voltage AC circuit 36, the power line 18, the first low-voltage AC circuit 32, etc., when the railcar 10 is not energized. When the railcar 10 is energized, only one of the control lines 201-203 is selectively connected to the second low-voltage AC circuit 36 ​​via the control device 60, so it is difficult for the AC monitoring device 120 to measure the insulation resistance of the control lines 201-203 in the second low-voltage AC circuit 36. In contrast, the contact-type monitoring device 70 can easily measure the insulation resistance of the control lines 201-203. In addition to the control lines 201-203, the contact-type monitoring device 70 may also measure the insulation resistance of various control lines that are not connected to the second low-voltage AC circuit 36, the power line 18, the first low-voltage AC circuit 32, etc., when the railcar 10 is not energized.

[0254] In the above embodiment, a case has been described in which normal operation of the contact-type monitoring device 70 is confirmed by measuring the resistance value of the reference resistor 81 with the contact-type monitoring device 70. For purposes other than this confirmation of normal operation, the third switch SW3 may be closed to connect the measuring unit 77 and the switching unit 79 to the ground line 40 via the reference resistor 81. In this case, residual voltage and electrostatic capacitance parasitic in the contact-type monitoring device 70 can be discharged using the reference resistor 81.

[0255] In the above embodiment, the contact-type monitoring devices 70c and 70f are used to measure the insulation resistance of each part of the first low-voltage AC circuit 32 and the second low-voltage AC circuit 36, but the present invention is not limited to this. For example, a contact-type monitoring device 70 for measuring the insulation resistance of the first low-voltage AC circuit 32 and a contact-type monitoring device 70 for measuring the insulation resistance of each part of the second low-voltage AC circuit 36 ​​may be provided separately. In this case, since the first low-voltage AC circuit 32 and the second low-voltage AC circuit 36 ​​have different voltages, the insulation resistance of each circuit can be measured with high accuracy by providing a dedicated contact-type monitoring device 70 for each circuit. Furthermore, the application of a voltage intended for the first low-voltage AC circuit 32 to the second low-voltage AC circuit 36 ​​can be suppressed.

[0256] Furthermore, the applied voltage during measurement by the contact-type monitoring device 70 is set to be lower than the voltage flowing through each electrical circuit being measured when current is applied to the railway vehicles 10, 100a-100c, 110, 130a-130c, and 150, so measurements can be made using the contact-type monitoring device 70 while electrical equipment for which conventional insulation resistance tests that apply excessive voltages are prohibited is left connected to each electrical circuit.

[0257] Furthermore, a contact-type monitoring device 70 may be provided for each of one or more measurement objects, regardless of the value of the voltage applied between terminal V and terminals a-f. Furthermore, the number of terminals a-f of the contact-type monitoring device 70 may be increased so that the insulation resistance of each part of one railway car 10, 100a-100c, 110, 130a-130c, 150 is measured by a single contact-type monitoring device 70.

[0258] In the above embodiment, the AC monitoring device 120 calculates the insulation resistance of the measurement object from the detection result of the zero-phase-sequence current transformer 127 and the detection result of the reference detection unit 128, but this is not limited to the above. For example, the reference detection unit 128 may be omitted. However, by calculating the insulation resistance of the measurement object from the detection result of the zero-phase-sequence current transformer 127 and the detection result of the reference detection unit 128, the detection accuracy of the insulation resistance measurement result by the AC monitoring device 120 can be improved.

[0259] In the above embodiment, the brake 19 and the control device 60 are connected to the second low-voltage AC circuit 36, 156 via the rectifier 38, but this is not limiting. For example, the brake 19 and the control device 60 may be connected to the battery via an electric wire different from the second low-voltage AC circuit 36, 156 and the first low-voltage AC circuit 32, 154. This allows the brake 19 and the control device 60 to be operated even if the power supply from the overhead line 4, 140 is cut off.

[0260] In the above embodiment, the case where the air conditioner 15 is connected to the first low-voltage AC circuit 32, 154 has been described as an example, but the present invention is not limited to this. Examples of AC equipment that may be connected to the first low-voltage AC circuit 32, 154 include, in addition to the air conditioner 15, an electric air compressor, a ventilator, and various cooling fans. [Explanation of symbols]

[0261] 2 Rail 10, 100b, 100c, 110, 130a, 130c, 150 Railway vehicles 100a Railway vehicles (vehicles with electromagnetic switches) 130b Railway vehicles (vehicles with AC output devices) 12 Vehicle body (part of the ground contact area) 14 Connection part 15 Air conditioning equipment (AC equipment, vehicle AC equipment) 16 Lighting (AC equipment, vehicle AC equipment) 18,18a power line 18b, 18c Power line (vehicle power line) 19 Brake (DC equipment) 20 VVVF inverter (conversion device (AC output device) or part of a conversion device) 22 Electric motor (AC equipment) 22a Coil 22b Housing (part of the grounding part) 24 Electric wire for electric motor (AC line) 30 SIV (conversion device (AC output device) or part of a conversion device) 32,154 1st low voltage AC line (AC wire) 32u1~32w1,32u1b~32w1b,154L1,154N1 Main power line 32u2~32w2, 32u2b~32w2b, 154L2, 154N2 Branch wire 32u1a~32w1a,32u1c~32w1c Main power line (part of own vehicle AC line) 32u2a~32w2a, 32u2c~32w2c Branch wires (part of the vehicle's AC circuit) 34,155 Isolation transformer (part of conversion device (AC output device)) 36,156 2nd low voltage AC line (AC power line) 36r1~36t1,36r1b~36t1b,156L1,156N1 Main power line 36r2~36t2,36r2b~36t2b,156L2,156N2 Branch wire 36r1a~36t1a,36r1c~36t1c Main power line (part of own vehicle AC line) 36r2a~36t2a, 36r2c~36t2c Branch wires (part of the vehicle's AC circuit) 38 Rectifier 40, 40a~40c Ground wire (part of the grounding section) 42,42a Ground side wire 42b, 42c Ground side wire (own vehicle ground side wire) 44a Electromagnetic switch 60 Control equipment (DC equipment) 68 Wireless communication device (transmitter) 70a Contact monitoring device (power monitoring device) 70b Contact monitoring device (motor monitoring device) 70d, 70e Contact type monitoring device (vehicle power supply monitoring device) 70g Contact type monitoring device (power supply monitoring device and motor monitoring device) 86 Isolation transformer (AC equipment) 120,120i AC monitoring device 120a,120b AC monitoring device (main monitoring device) 120d, 120g AC monitoring device (branch monitoring device) 120c, 120e, 127f, 127h AC monitoring device (own vehicle AC monitoring device) 127,127a~127i Zero phase current transformer 151 Main transformer (converter or part of a converter) 152 AC / DC converter (part of the conversion device)

Claims

1. A railway vehicle equipped with a conversion device that converts input power and outputs the converted power, or a railway vehicle that transmits power to another vehicle equipped with the conversion device, the railway vehicle running on rails, A ground portion connected to the rail; A ground side electric wire that connects the input side of the converter to the ground part; a power supply line to which power input to the conversion device is supplied and which is connected to the ground side electric wire via the conversion device; an electromagnetic switch that opens in response to a cutoff of the supply of power to the power line to thereby separate the ground side electric wire from the ground portion; a power supply monitoring device that applies a voltage between the grounding part and at least one of the power supply line and the grounding side electric wire while the electromagnetic switch is open, and measures an insulation resistance of at least one of the power supply line and the grounding side electric wire; A railway vehicle comprising:

2. an electric motor for running the railway vehicle, the electric motor having a coil connected to an output side of the conversion device and a housing surrounding the coil and constituting a part of the grounding portion; a motor monitoring device that applies a voltage between the coil and the ground while the electromagnetic switch is open, and measures an insulation resistance of the motor; 2. The railway vehicle according to claim 1, further comprising:

3. As the conversion device, an AC output device that outputs AC power; a set of multiple AC circuits to which AC power is supplied from the AC output device; At least one AC device connected to the AC circuit and operated by AC power; an AC monitoring device that has a zero-phase current transformer through which the set of AC current circuits pass, and measures the insulation resistance of the AC device based on a detection value of the zero-phase current transformer in a state in which the ground side electric wire and the ground part are connected by the closed electromagnetic switch and power is supplied to the power supply line; 3. The railway vehicle according to claim 1, further comprising:

4. 4. The railway vehicle according to claim 3, characterized in that the AC monitoring device connects the grounded electric wire and the grounding portion by the closed electromagnetic contactor to supply power to the power supply line, and periodically measures the insulation resistance while the railway vehicle is running.

5. 5. The railway vehicle according to claim 4, further comprising a transmitting section that transmits the insulation resistance measurement results measured by the AC monitoring device while the railway vehicle is running to an outside of the railway vehicle.

6. The AC circuit is a set of mains wires extending from the AC output device; A plurality of sets of branch electric wires each branching off from the trunk electric wire, The AC device is provided in plurality and connected to each of the sets of branch electric wires, The AC monitoring device is 4. A railway vehicle according to claim 3, further comprising a main monitoring device which has a zero-phase current transformer through which the main wire passes on the AC output device side of the plurality of sets of branch wires and which measures the total insulation resistance of AC devices connected to the plurality of sets of branch wires.

7. The AC circuit is a set of mains wires extending from the AC output device; A plurality of sets of branch electric wires each branching off from the trunk electric wire, The AC device is provided in plurality and connected to each of the sets of branch electric wires, The AC monitoring device is 4. A railway vehicle according to claim 3, further comprising a branch monitoring device which has the zero-phase current transformer through which a set of the branch electric wires pass and which measures the insulation resistance of an AC device connected to the set of the branch electric wires.

8. The AC circuit is a set of mains wires extending from the AC output device; A plurality of sets of branch electric wires each branching off from the trunk electric wire, The AC device is provided in plurality and connected to each of the sets of branch electric wires, The railway vehicle includes: a rectifier connected to the mains power line to convert AC power into DC power; a DC device connected to the rectifier and operated by DC power, The AC monitoring device is a trunk monitoring device having the zero-phase current transformer through which the trunk line passes on the AC output device side of the rectifier and the plurality of sets of branch electric wires, and measuring the sum of the insulation resistance of the DC equipment connected to the rectifier and the insulation resistance of the AC equipment connected to the plurality of sets of branch electric wires; a branch monitoring device having a plurality of zero-phase current transformers through which a plurality of sets of branch electric wires branched from a main electric wire passing through a zero-phase current transformer of the main monitoring device pass, and measuring the insulation resistance of each of the AC devices connected to the branch electric wires; 4. The railway vehicle according to claim 3, further comprising:

9. A railway vehicle that receives AC power from the AC output device-equipped car in a train configuration that includes the railway vehicle according to claim 3, A coupling part that is coupled to the AC output device-equipped vehicle directly or via another vehicle; a set of multiple AC electric circuits of the vehicle connected to the AC electric circuit of the vehicle having the AC output device via the connecting portion; a vehicle's own AC device that is connected to the vehicle's own AC circuit and operates using AC power; a host vehicle AC monitoring device having a zero-phase-sequence current transformer through which the set of host vehicle AC electric circuits pass, the device measuring an insulation resistance of the host vehicle AC equipment based on a detection value of the zero-phase-sequence current transformer in a state in which AC power is supplied from the AC electric circuits to the host vehicle AC electric circuits; A railway vehicle comprising:

10. A railway vehicle running on a rail in a train configuration including the railway vehicle according to claim 1 or 2 as an electromagnetic switch-equipped car, A ground portion connected to the rail; A coupling section that is coupled to the electromagnetic switch-equipped vehicle directly or via another vehicle; a vehicle power supply line that is connected to the power supply line of the vehicle having the electromagnetic switch via the connecting portion and receives power; a vehicle ground side electric wire connected to the ground part via the coupling part and the ground side electric wire of the electromagnetic switch-equipped vehicle; a vehicle power supply monitoring device that applies a voltage between the grounding part and at least one of the vehicle power supply line and the vehicle ground side electric wire when the supply of power to the vehicle power supply line is cut off and the connection by the connecting part is released, and measures an insulation resistance of at least one of the vehicle power supply line and the vehicle ground side electric wire; A railway vehicle comprising:

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