Deterioration diagnosing device, learning device, power supply device, and deterioration diagnosing system

Abstract

A deterioration diagnosing device (2) for a transformer (4) provided at the output of an auxiliary power supply device (3) having a power converting circuit (33) comprises: a current acquiring unit (21) that acquires current values flowing through the primary side and the secondary side of the transformer (4); a voltage acquiring unit (22) that acquires the primary-side and secondary-side voltage values of the transformer (4); an input power calculating unit (23) that calculates an input power, which is the primary-side power of the transformer (4); an output power calculating unit (24) that calculates an output power, which is the secondary-side power of the transformer (4); a power loss calculating unit (25) that calculates the power loss of the transformer (4) on the basis of the input power and the output power; and a deterioration determining unit (26) that determines whether or not the transformer (4) has deteriorated, depending on whether or not a deviation between the power loss calculated by the power loss calculating unit (25) and a normal power loss is greater than or equal to a threshold value, on the basis of a determination criterion indicating a relationship between the secondary-side current of the transformer (4) and the normal power loss of the transformer (4).

Description

Degradation diagnosis device, learning device, power supply device, and degradation diagnosis system

[0001] The present disclosure relates to a deterioration diagnosis device for a transformer mounted on a railway vehicle.

[0002] Railway vehicles are equipped with auxiliary power supplies as power sources for auxiliary loads other than the main motor, such as interior lighting devices, air conditioning devices, or compressors. Patent Document 1 listed below discloses an auxiliary power supply configured to convert high-voltage DC power input from a current collector into AC power using a three-phase inverter, and to supply the AC power output from the three-phase inverter to a transformer via an AC reactor, which then converts the AC power into desired low-voltage AC power. The transformer has an insulating member for insulating the high-voltage input side, which is the three-phase inverter side, from the low-voltage output side, which is the auxiliary load side.

[0003] The transformers of auxiliary power supplies for railway vehicles are installed in open areas of the vehicle for cooling purposes. This means that there is a risk of the transformers deteriorating due to factors such as rainwater, dust, and temperature changes. Deterioration of the transformer can lead to problems such as short circuits inside the transformer or ground faults outside the transformer, so it is advisable to periodically monitor the degree of deterioration of the transformer.

[0004] JP 2011-211777 A

[0005] However, to determine the degree of deterioration of the transformers installed in the auxiliary power supply units of railway vehicles, workers must remove the transformers from the vehicles and inspect them. The transformers installed in railway vehicles are large, and a wide variety of control devices are densely located around the transformers, making transformer maintenance work complicated. This makes it difficult to frequently monitor the presence or absence of transformer deterioration.

[0006] The present disclosure has been made in consideration of the above circumstances, and aims to provide a degradation diagnosis device that can determine whether or not a transformer has deteriorated while the transformer is mounted on a vehicle.

[0007] In order to solve the above-mentioned problems and achieve the object, a degradation diagnosis device according to the present disclosure is a degradation diagnosis device for a transformer provided at the output of an auxiliary power supply device having a power conversion circuit, and includes a current acquisition unit that acquires a first current that is a current value flowing between the power conversion circuit and the transformer, and a second current that is a current value flowing between the transformer and a load in a railway vehicle, a voltage acquisition unit that acquires a first voltage that is a voltage value input from the power conversion circuit to the transformer, and a second voltage that is a voltage value output from the transformer to the load, and an input power calculation unit that calculates input power that is power input to the transformer based on the first current and the first voltage. an output power calculation unit that calculates the output power, which is the power output from the transformer, based on the second current and the second voltage; a power loss calculation unit that calculates the power loss of the transformer based on the difference between the input power calculated by the input power calculation unit and the output power calculated by the output power calculation unit; and a degradation determination unit that determines the normal power loss corresponding to the second current acquired by the current acquisition unit based on a determination criterion that is data indicating the relationship between the normal power loss of the transformer and the second current, and determines whether or not the transformer has deteriorated based on whether the difference between the power loss calculated by the power loss calculation unit and the normal power loss deviates by more than a threshold value.

[0008] The degradation diagnosis device according to the present disclosure calculates the power loss in the transformer based on the current and voltage values ​​input to the transformer and the current and voltage values ​​output from the transformer, and determines whether the transformer is degraded based on whether the difference between the normal power loss of the transformer, which is the determination criterion, and the actual power loss of the transformer deviates by more than a threshold value. This makes it possible to determine whether the transformer is degraded while it is installed in a vehicle.

[0009] A block diagram showing the configuration of a degradation diagnosis system according to embodiment 1. A diagram showing an example of the hardware configuration of a degradation diagnosis device according to embodiment 1. A flowchart showing an example of the operation of a degradation determination process performed by the degradation diagnosis device according to embodiment 1. A block diagram showing the configuration of a degradation diagnosis system according to embodiment 2. A block diagram showing the configuration of a degradation diagnosis system according to embodiment 3. A flowchart showing an example of the operation of a criteria determination process performed by the degradation diagnosis device according to embodiment 3. A block diagram showing the configuration of a degradation diagnosis system according to embodiment 4. A block diagram showing the configuration of a power supply device including a degradation diagnosis device according to an embodiment. A diagram showing a modified example of the hardware configuration of a degradation diagnosis device according to an embodiment.

[0010] A degradation diagnosis device, a learning device, a power supply device, and a degradation diagnosis system according to embodiments of the present disclosure will be described in detail below with reference to the drawings. In the drawings, the same or equivalent parts are designated by the same reference numerals.

[0011] Embodiment 1. Using as an example a transformer provided in an auxiliary power supply that is mounted on a railway vehicle and supplies power to a load within the railway vehicle, a degradation diagnosis device that determines degradation of the transformer and a degradation diagnosis system that includes the degradation diagnosis device will be described in Embodiment 1. Figure 1 is a block diagram showing the configuration of the degradation diagnosis system 1 according to Embodiment 1. The degradation diagnosis device 2 provided in the degradation diagnosis system 1 shown in Figure 1 determines whether or not a transformer 4 provided in an auxiliary power supply 3 has deteriorated. The auxiliary power supply 3 is connected to a load 91. After describing the configurations of the load 91 and the auxiliary power supply 3, the degradation diagnosis device 2 and the degradation diagnosis system 1 will be described.

[0012] The auxiliary power supply 3 that supplies power to the load 91 is, for example, a DC-AC converter that is mounted on a DC-fed railway vehicle and converts DC power supplied from a power source (not shown) into three-phase AC power and supplies it to the load 91. To avoid complicating the diagram, one load 91 is shown in FIG. 1, but the number of loads 91 to which the auxiliary power supply 3 supplies power is arbitrary. Also, in this disclosure, the AC power supplied to the load 91 is three-phase AC power as an example, but is not limited to this. Single-phase AC power, for example, may also be used.

[0013] An example of the load 91 is an auxiliary load. The auxiliary load is a term used to refer to loads installed on a railway vehicle other than the main motor. Examples of the auxiliary load include an interior lighting device, a door opening / closing device, an air conditioning device, safety equipment, a compressor, a battery, and a control power supply.

[0014] The auxiliary power supply 3 includes an input terminal 3a connected to a power supply and an input terminal 3b connected to ground. The auxiliary power supply 3 further includes a power conversion circuit 33 that converts DC power supplied from the power supply into three-phase AC power and outputs the converted three-phase AC power. The auxiliary power supply 3 further includes a control unit 38 that controls multiple switching elements of the power conversion circuit 33. The auxiliary power supply 3 further includes a transformer 4 and an AC filter capacitor 39. The transformer 4 steps down the AC power converted by the power conversion circuit 33 to a voltage that can be supplied to the load 91 and smooths the current using leakage inductance before outputting it. The auxiliary power supply 3 further includes a capacitor 31 connected in series between the input terminals 3a and 3b. The capacitor 31 is provided with a voltage sensor 32 that measures the voltage of the capacitor 31.

[0015] The auxiliary power supply 3 is provided with a current detection unit 34 that detects a current value ia flowing between the power conversion circuit 33 and the transformer 4, and a current detection unit 35 that detects a current value ib flowing between the transformer 4 and the load 91. The auxiliary power supply 3 is also provided with a voltage detection unit 36 ​​that detects a voltage value output from the power conversion circuit 33, in other words, a voltage value Va input to the transformer 4, and a voltage detection unit 37 that detects a voltage value Vb output from the transformer 4. The voltage detection unit 36 ​​in this embodiment detects the voltage value Va output from the power conversion circuit 33 based on the voltage value of the capacitor 31 acquired by the voltage sensor 32 and a gate pulse command, which is a control command output by the control unit 38 to the power conversion circuit 33.

[0016] The input terminal 3a is electrically connected to a power source, specifically, a current collector that acquires power supplied from a substation via a power supply line, via a contactor, circuit breaker, etc. (not shown). For example, the current collector may be a pantograph that acquires power via an overhead line, which is an example of a power supply line, or a current collector shoe that acquires power via a third rail, which is an example of a power supply line. The input terminal 3b is grounded via a ground ring, ground brush, wheel, etc. (not shown).

[0017] One end of capacitor 31 is connected to input terminal 3b. The other end of capacitor 31 is connected to input terminal 3a and to a connection point between a reactor (not shown) and a primary terminal of power conversion circuit 33. The reactor and capacitor 31 form an LC filter that attenuates harmonic components generated by the switching operation of power conversion circuit 33. A voltage sensor 32 is provided on capacitor 31 and detects the voltage value of capacitor 31.

[0018] The power conversion circuit 33 is, for example, an inverter that outputs AC power with a constant effective voltage and frequency. The power conversion circuit 33 has a plurality of switching elements. Each switching element is, for example, an insulated gate bipolar transistor (IGBT), a gate turn-off thyristor (GTO), or a metal-oxide-semiconductor field-effect transistor (MOSFET).

[0019] The current detection unit 34 detects the value of the current flowing between the power conversion circuit 33 and the transformer 4, in other words, the current value ia input to the transformer 4. The current detection unit 35 detects the value of the current flowing between the transformer 4 and the load 91, in other words, the current value ib output from the transformer 4. The current detection units 34 and 35 send the detected current values ​​ia and ib to the control unit 38. In the following description, the current value ia will be referred to as the "first current" and the current value ib as the "second current."

[0020] The voltage detection unit 36 ​​detects the voltage value Va input to the transformer 4. The voltage detection unit 37 detects the voltage value Vb output from the transformer 4. In the present disclosure, an example is shown in which the voltage detection unit 36 ​​detects the voltage Va output from the power conversion circuit 33 by performing a calculation based on the voltage value of the capacitor 31, i.e., the input voltage value of the power conversion circuit 33, and a gate pulse command output by the control unit 38 to the power conversion circuit 33. However, the voltage value Va may also be detected by providing a voltage detection unit similar to the voltage detection unit 37 between the power conversion circuit 33 and the transformer 4. The voltage detection units 36 and 37 send the detected voltage values ​​Va and Vb to the control unit 38. In the following description, the voltage value Va will be referred to as the "first voltage" and the voltage value Vb will be referred to as the "second voltage."

[0021] It should be noted that the current detection units 34, 35, voltage detection units 36, 37, and voltage sensor 32 according to the present disclosure are sensors provided for controlling the power conversion circuit 33, and are not sensors newly provided for the degradation diagnosis device 2 and degradation diagnosis system 1 according to the present disclosure. The degradation diagnosis device 2 and degradation diagnosis system 1 according to the present disclosure perform the control and calculations described below using the detection information of these sensors provided for control purposes.

[0022] The AC filter capacitor 39 is a circuit in which three capacitors are delta-connected. The AC filter capacitor 39 is connected between the secondary side of the transformer 4 and the load 91, and the transformer 4 and the AC filter capacitor 39 form an LC filter circuit. The LC filter circuit formed by the leakage inductance of the transformer 4 and the AC filter capacitor 39 reduces harmonics contained in the output voltage of the power conversion circuit 33. As a result, the load 91 is supplied with a sinusoidal AC voltage with reduced harmonics compared to when there is no LC filter circuit.

[0023] The control unit 38 outputs a gate pulse command to the power conversion circuit 33 to control the switching operation of each switching element of the power conversion circuit 33. The control unit 38 also sends the gate pulse command to the power conversion circuit 33 to the voltage detection unit 36. The control unit 38 further acquires the first current ia and the second current ib detected by the current detection units 34 and 35, and acquires the first voltage Va and the second voltage Vb detected by the voltage detection units 36 and 37. The control unit 38 controls the power conversion circuit 33 based on the acquired information on the first current ia, the second current ib, the first voltage Va, and the second voltage Vb. The control unit 38 then sends the acquired first current ia, the second current ib, the first voltage Va, and the second voltage Vb to the degradation diagnosis system 1.

[0024] The degradation diagnosis system 1 determines whether or not there is degradation in the transformer 4. The degradation diagnosis system 1 includes a degradation diagnosis device 2 that determines whether or not there is degradation in the transformer 4, and an output device 5 that outputs the determination result acquired from the degradation diagnosis device 2.

[0025] Degradation diagnosis device 2 includes a current acquisition unit 21, a voltage acquisition unit 22, an input power calculation unit 23, an output power calculation unit 24, a power loss calculation unit 25, and a degradation determination unit 26. Degradation diagnosis device 2 determines whether or not transformer 4 has deteriorated based on a first current ia, a second current ib, a first voltage Va, and a second voltage Vb acquired from auxiliary power supply 3.

[0026] The current acquiring unit 21 acquires, from the control unit 38, a first current ia, which is the value of a current flowing between the power conversion circuit 33 and the transformer 4, and a second current ib, which is the value of a current flowing between the transformer 4 and the load 91. The current acquiring unit 21 sends the first current ia input to the transformer 4 to the input power calculation unit 23, and sends the second current ib output from the transformer 4 to the output power calculation unit 24. The current acquiring unit 21 also sends the second current ib output from the transformer 4 to the deterioration determining unit 26.

[0027] The voltage acquiring unit 22 acquires, from the control unit 38, a first voltage Va, which is a voltage value input to the transformer 4, and a second voltage Vb, which is a voltage value output from the transformer 4. The voltage acquiring unit 22 sends the first voltage Va, which is input to the transformer 4, to the input power calculation unit 23, and sends the second voltage Vb, which is output from the transformer 4, to the output power calculation unit 24.

[0028] The input power calculation unit 23 calculates input power Pa, which is power input from the power conversion circuit 33 to the transformer 4, based on the first current ia and the first voltage Va input to the transformer 4. The input power calculation unit 23 sends the calculated input power Pa to the power loss calculation unit 25.

[0029] The output power calculation unit 24 calculates the output power Pb, which is the power output from the transformer 4 to the load 91, based on the second current ib and the second voltage Vb output from the transformer 4. The output power calculation unit 24 sends the calculated output power Pb to the power loss calculation unit 25.

[0030] The power loss calculation unit 25 subtracts the output power Pb calculated by the output power calculation unit 24 from the input power Pa calculated by the input power calculation unit 23 to calculate the power loss PL, which is the actual power loss of the transformer 4. The power loss calculation unit 25 sends the calculated actual power loss PL of the transformer 4 to the deterioration determination unit 26.

[0031] In the first embodiment, the degradation determiner 26 includes a storage unit (not shown), which stores a determination criterion used to determine whether the transformer 4 is degraded. The determination criterion is normal power loss data indicating the relationship between the normal power loss of the transformer 4 and the second current Vb. The degradation determiner 26 determines a normal power loss PLref corresponding to the second current ib flowing through the secondary side of the transformer 4, acquired by the current acquirer 21, based on the stored normal power loss data serving as the determination criterion for degradation of the transformer 4. The normal power loss PLref is a loss that occurs regardless of whether the transformer 4 is degraded, such as iron loss and copper loss of the transformer 4. Because iron loss and copper loss occur even when the transformer 4 is in a normal state, excluding the iron loss and copper loss from the actual power loss PL as the normal power loss PLref allows the degradation diagnosis device 2 to improve the accuracy of determining degradation of the transformer 4. The normal power loss data may be created from measurement data obtained through tests, for example, at a factory.

[0032] The deterioration determination unit 26 determines whether deterioration has occurred based on the difference between the actual power loss PL of the transformer 4 calculated by the power loss calculation unit 25 and a normal power loss PLref, which is a determination criterion determined according to the second current ib output from the transformer 4. The deterioration determination unit 26 can determine that deterioration has occurred in the transformer 4 when the difference between the actual power loss PL and the normal power loss PLref determined according to the second current ib is equal to or greater than a predetermined threshold.

[0033] When the output device 5 receives a determination result indicating that there is deterioration from the deterioration determination unit 26 included in the deterioration diagnosis device 2, the output device 5 outputs the determination result indicating that there is deterioration in the transformer 4 by, for example, displaying on a screen or outputting audio. The output device 5 is provided, for example, in the driver's cab or in wayside equipment. The output device 5 provided in the driver's cab is a display device connected to the deterioration diagnosis device 2 via an in-vehicle network, and displays on a screen the determination result acquired from the deterioration determination unit 26. The output device 5 provided in a control center, which is an example of wayside equipment, is connected to the deterioration diagnosis device 2 via the in-vehicle network and the Internet. The output device 5 displays the determination result acquired from the deterioration determination unit 26 on a screen, or transmits it to another device provided in the control center, for example, a condition monitoring and maintenance device that estimates signs of failure in on-board equipment.

[0034] 2 is a diagram showing an example of the hardware configuration of the degradation diagnosis device 2 having the above-described configuration. The degradation diagnosis device 2 includes a processor 81, a memory 82, and an interface 83. The processor 81, the memory 82, and the interface 83 are connected to one another via a bus 80. The functions of each unit of the degradation diagnosis device 2 are realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in the memory 82. The processor 81 reads and executes the programs stored in the memory 82, thereby realizing the functions of each unit described above. That is, the memory 82 stores programs for executing the processing of each unit of the degradation diagnosis device 2.

[0035] The memory 82 includes, for example, non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read-Only Memory), flash memory, EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable and Programmable Read-Only Memory), magnetic disk, flexible disk, optical disk, compact disk, mini disk, DVD (Digital Versatile Disc), etc.

[0036] The degradation diagnosis device 2 is connected to the auxiliary power supply 3, the output device 5, etc. via an interface 83. The interface 83 has an interface module that complies with one or more standards depending on the connected device.

[0037] 2, the core part that performs the processing of each part of the degradation diagnosis device 2 does not need to be a dedicated system, but can be realized by using an ordinary computer system. For example, a computer program for executing the processing of each part of the degradation diagnosis device 2 may be stored and distributed on a computer-readable recording medium (such as a flexible disk, a CD-ROM (Compact Disc-Read Only Memory), or a DVD-ROM (Digital Versatile Disc-Read Only Memory)), and the degradation diagnosis device 2 that performs the above-mentioned processing may be realized by installing the computer program on a computer. Alternatively, the degradation diagnosis device 2 may be realized by storing the computer program in a storage device of a server device on a communication network and downloading it to an ordinary computer system.

[0038] Furthermore, when the functions of the degradation diagnosis device 2 are realized by sharing the functions of an OS (Operating System) and an application program, or by collaboration between the OS and an application program, only the application program portion may be stored on a recording medium, storage device, etc.

[0039] The operation of the above-described degradation diagnosis device 2 will be described with reference to Fig. 3. When the degradation diagnosis device 2 is started up, it starts the processing of Fig. 3. The current acquisition unit 21 included in the degradation diagnosis device 2 acquires the first current ia input to the transformer 4 and the second current ib output from the transformer 4 from the control unit 38 of the auxiliary power supply 3 (step S11).

[0040] The voltage acquisition unit 22 acquires the first voltage Va input to the transformer 4 and the second voltage Vb output from the transformer 4 from the control unit 38 of the auxiliary power supply 3 (step S12).

[0041] The input power calculation unit 23 calculates the input power Pa, which is the power input to the transformer 4, based on the first current ia and the first voltage Va acquired by the current acquisition unit 21 and the voltage acquisition unit 22 (step S13).

[0042] The output power calculation unit 24 calculates the output power Pb, which is the power output from the transformer 4, based on the second current ib and second voltage Vb acquired by the current acquisition unit 21 and voltage acquisition unit 22 (step S14).

[0043] The power loss calculation unit 25 calculates the actual power loss PL caused by the transformer 4 based on the input power Pa calculated by the input power calculation unit 23 and the output power Pb calculated by the output power calculation unit 24 (step S15).

[0044] The deterioration determiner 26 determines the normal power loss PLref corresponding to the second current ib acquired by the current acquirer 21 based on the stored normal power loss data of the transformer 4 (step S16). The deterioration determiner 26 determines the presence or absence of deterioration based on whether the difference between the actual power loss PL calculated by the power loss calculator 25 and the normal power loss PLref is equal to or greater than a predetermined threshold value (step S17).

[0045] If the difference between the actual power loss PL and the normal power loss PLref is equal to or greater than a predetermined threshold (step S17: Yes), the deterioration determiner 26 determines that the transformer 4 is degraded and outputs the determination result to the output device 5 (step S18). If the difference between the actual power loss PL and the normal power loss PLref is less than the predetermined threshold (step S17: No), the deterioration determiner 26 determines that the transformer 4 is not degraded and does not perform the process of step S18. If the difference between the actual power loss PL and the normal power loss PLref is less than the threshold (step S17: No), or when the process of step S18 is completed, the process described above is repeated from step S11. In the present disclosure, if the deviation between the actual power loss PL and the normal power loss PLref is less than a predetermined threshold in step S17 (step S17: No), the processing of step S18 is not performed, but it may be determined that no deterioration has occurred in the transformer 4 and the determination result may be output to the output device 5.

[0046] As described above, the degradation diagnosis device 2 according to the first embodiment calculates the actual power loss PL of the transformer 4, determines the normal power loss PLref corresponding to the second current ib output from the transformer 4 based on the normal power loss data of the transformer 4, and determines whether or not the transformer 4 has deteriorated based on whether or not the deviation between the calculated actual power loss PL and the normal power loss PLref is equal to or greater than a predetermined threshold. This makes it possible to determine whether or not the transformer 4 has deteriorated while the transformer 4 is installed in a vehicle.

[0047] The deterioration diagnosis device 2 can monitor the deviation between the actual power loss PL and the normal power loss PLref even when the transformer 4 is attached to the vehicle and the vehicle is running, making it possible to detect deterioration of the transformer 4 at an early stage. Furthermore, by detecting deterioration of the transformer 4 at an early stage and outputting the determination result to the output device 5, it is possible to urge the user to perform maintenance work on the transformer 4. Maintenance work on the transformer 4 is complicated, but by monitoring the deterioration of the transformer 4 and understanding the deterioration trend, it becomes easier to plan maintenance of the transformer 4 in advance, such as arranging for workers or parts.

[0048] Furthermore, degradation diagnosis device 2 acquires first current ia, second current ib, first voltage Va, and second voltage Vb to perform processing to determine whether or not transformer 4 has deteriorated, but these values ​​are acquired and used in the control of power conversion circuit 33, which supplies power from power conversion circuit 33 to load 91 via transformer 4. Therefore, there is no need to newly provide a special sensor as degradation diagnosis device 2. Furthermore, because degradation diagnosis device 2 does not require complex processing such as extraction and analysis of current or voltage waveforms, degradation diagnosis can be performed by simple processing.

[0049] Second Embodiment The criteria used by the degradation diagnosis device to determine whether or not the transformer 4 has deteriorated are not limited to the above-described examples. The temperature of the transformer 4 rises when the auxiliary power supply operates. As the temperature of the transformer 4 rises, the resistance value of the transformer 4 also increases, and this increase in resistance value leads to an increase in power loss. Therefore, in the second embodiment, a degradation diagnosis device that corrects the output power Pb based on temperature information from a temperature sensor provided in the transformer 4 will be described, focusing on the differences from the first embodiment.

[0050] The degradation diagnosis system 11 according to embodiment 2 shown in FIG. 4 includes a degradation diagnosis device 12 that determines whether or not the transformer 4 provided in the auxiliary power supply 30 has deteriorated, and an output device 5 that outputs the determination result obtained from the degradation diagnosis device 12.

[0051] Auxiliary power supply 30 includes a temperature sensor 41 that acquires the temperature of transformer 4 in addition to the configuration of auxiliary power supply 3 in Fig. 1. Degradation diagnosis device 12 includes a temperature acquisition unit 27 that acquires temperature information of transformer 4 in addition to the configuration of degradation diagnosis device 2 in Fig. 1. The hardware configuration of degradation diagnosis device 12 is similar to the hardware configuration of degradation diagnosis device 2 shown in Fig. 2.

[0052] The temperature acquisition unit 27 acquires temperature information of the transformer 4 from the temperature sensor 41. While Fig. 4 shows an example in which the temperature information is acquired from the temperature sensor 41, the acquisition path is not limited to this and the temperature information may be acquired via the control unit 38 of the auxiliary power supply 30. The temperature acquisition unit 27 sends the acquired temperature information to the output power calculation unit 24.

[0053] The output power calculation unit 24 calculates the output power Pb output from the transformer 4, as in the first embodiment. As the temperature of the transformer 4 rises due to the operation of the auxiliary power supply 30 or the driving of the railway vehicle, the resistance value of the transformer 4 increases. As a result, even if the input power Pa is the same as before the temperature rise of the transformer 4, the output power Pb calculated by the output power calculation unit 24 decreases compared to before the temperature rise of the transformer 4. This decrease in the output power Pb due to the temperature rise of the transformer 4 can be considered not to be due to deterioration of the transformer 4. Therefore, the output power calculation unit 24 corrects the calculated output power Pb according to the temperature based on the temperature information acquired by the temperature acquisition unit 27. For example, the output power calculation unit 24 corrects the output power Pb by increasing it in response to the temperature rise. The output power calculation unit 24 sends the output power Pb' corrected based on the temperature information to the power loss calculation unit 25.

[0054] Power loss calculation unit 25 calculates actual power loss PL caused by transformer 4 based on output power Pb' calculated and corrected by output power calculation unit 24, and sends actual power loss PL to deterioration determination unit 26. Then, as in the first embodiment, deterioration determination unit 26 determines whether or not transformer 4 has deteriorated using normal power loss PLref.

[0055] As described above, the degradation diagnosis device 12 according to the second embodiment corrects the output power Pb based on the temperature information of the transformer 4, and uses the corrected output power Pb' to determine whether or not the transformer 4 has deteriorated. This makes it possible to take into account the increase in loss due to the temperature rise of the transformer 4, and to accurately determine whether or not the transformer 4 has deteriorated.

[0056] Third Embodiment The discrimination criteria used to determine whether or not there is deterioration in the transformer 4 may be generated or updated by a deterioration diagnosis device. A deterioration diagnosis device that generates discrimination criteria will be described in a third embodiment, focusing on the differences from the first embodiment.

[0057] The degradation diagnosis system 1 according to embodiment 3 shown in FIG. 5 includes a degradation diagnosis device 13 that determines whether or not the transformer 4 has deteriorated, and an output device 5 that outputs the determination result obtained from the degradation diagnosis device 13.

[0058] Degradation diagnosis device 13 includes a criterion determiner 28 that generates a discrimination criterion in addition to the configuration of degradation diagnosis device 2 in Fig. 1. The discrimination criterion is normal power loss data that indicates the relationship between the current output from transformer 4 and the normal power loss of transformer 4. The hardware configuration of degradation diagnosis device 13 is similar to the hardware configuration of degradation diagnosis device 2 shown in Fig. 2.

[0059] The standard determiner 28 obtains the second current ib output from the transformer 4 from the current acquirer 21, and obtains the actual power loss PL in the transformer 4 from the power loss calculator 25. The standard determiner 28 associates the second current ib with the power loss PL and stores the association data in a storage unit (not shown). The standard determiner 28 generates normal power loss data by associating the second current ib with the power loss PL during a normal period from when the transformer 4 starts operating until the period during which the transformer 4 can be considered normal has elapsed, and determines this data as a discrimination standard. The standard determiner 28 sends the normal power loss data, which is the determined discrimination standard, to the degradation determiner 26.

[0060] When a plurality of transformers 4 are mounted on the same railway vehicle, the criterion determination unit 28 may associate the output current of the transformer 4 with the power loss and store the association for each transformer 4. The criterion determination unit 28 may also determine a common discrimination criterion for a plurality of transformers 4 mounted on the same railway vehicle.

[0061] The deterioration determiner 26 acquires normal power loss data, which is the determination criterion generated and determined by the criterion determiner 28. The deterioration determiner 26 determines the normal power loss PLref corresponding to the second current ib acquired by the current acquirer 21, based on the normal power loss data acquired from the criterion determiner 28. The deterioration determiner 26 then determines whether or not the transformer 4 has deteriorated, based on whether or not the deviation between the actual power loss PL calculated by the power loss calculator 25 and the normal power loss PLref determined according to the second current ib is equal to or greater than a predetermined threshold.

[0062] The criteria determination process performed by degradation diagnosis device 13 having the above configuration will be described with reference to Fig. 6. The processes from step S11 to step S15 are the same as the processes from step S11 to step S15 performed by degradation diagnosis device 2 according to embodiment 1 shown in Fig. 3.

[0063] The standard determination unit 28 determines whether or not the current state is within a normal period, which is the period from when the transformer 4 starts operating until the time when the transformer 4 can be considered normal (step S21). The normal period can be determined by test operation, simulation, etc. of the transformer 4, and is a period during which the transformer 4 can be considered to be operating normally without any failures.

[0064] If it is within the normal period (step S21; Yes), the standard determination unit 28 associates the second current ib acquired by the current acquisition unit 21 with the power loss PL calculated by the power loss calculation unit 25 and stores them in a memory unit not shown (step S22).

[0065] The criterion determination unit 28 determines whether the number of stored data items correlating the second current ib with the power loss PL is sufficient to be used as normal power loss data, which is the discrimination criterion (step S23). If the number of data items is not sufficient (step S23; No), the above-described process is repeated from step S11.

[0066] If the number of data is sufficient (step S23; Yes), the criterion determination unit 28 determines normal power loss data, which is the discrimination criterion, from the stored association between the second current ib and the power loss PL (step S24).

[0067] When the processing of step S24 is completed, or when the period in which the transformer 4 can be considered normal has elapsed since the start of operation of the transformer 4 and the normal period has expired (step S21; No), the deterioration diagnosis device 13 terminates the standard determination processing.

[0068] Upon completion of the reference determination process shown in Fig. 6, the degradation diagnosis device 13 performs the degradation determination process shown in Fig. 3. In the degradation determination process, the degradation determination unit 26 determines a normal power loss PLref corresponding to the second current ib acquired by the current acquisition unit 21, based on the normal power loss data of the transformer 4 generated and determined by the reference determination unit 28. The degradation determination unit 26 determines the presence or absence of degradation based on the deviation between the actual power loss PL calculated by the power loss calculation unit 25 and the normal power loss PLref.

[0069] As described above, the degradation diagnosis device 13 according to the third embodiment stores the second current ib and the power loss PL during the period in which the transformer 4 is considered normal, in association with each other, and determines the stored data as normal power loss data, which is the discrimination criterion, and uses this data as the discrimination criterion for determining whether or not the transformer 4 has deteriorated. This makes it possible to determine whether or not the transformer 4 has deteriorated based on the individual characteristics of the transformer 4 or discrimination criteria according to the environment in which the transformer 4 is installed.

[0070] Fourth Embodiment The discrimination criteria used to determine whether or not the transformer 4 is deteriorated may be generated by a learning device using machine learning, statistical processing, AI (Artificial Intelligence), etc. A deterioration discrimination system including a learning device will be described in a fourth embodiment, focusing on the differences from the first embodiment.

[0071] The deterioration diagnosis system 15 shown in Figure 7 includes a deterioration diagnosis device 2 that determines whether or not the transformer 4 has deteriorated, an output device 5 that outputs the determination result obtained from the deterioration diagnosis device 2, and a learning device 71 that generates determination criteria used by the deterioration diagnosis device 2 to determine whether or not the transformer 4 has deteriorated.

[0072] The hardware configuration of the degradation diagnosis device 2 according to the fourth embodiment is similar to the hardware configuration of the degradation diagnosis device 2 according to the first embodiment shown in FIG.

[0073] The learning device 71 includes a learning unit 72 that learns the correspondence between the second current ib and the power loss PL, and a model generation unit 73 that generates a deterioration discrimination model from the correspondence between the second current ib and the power loss PL learned by the learning unit 72.

[0074] The learning unit 72 acquires the second current ib output from the transformer 4 from the current acquisition unit 21 included in the degradation diagnosis device 2. The learning unit 72 acquires the power loss PL caused by the transformer 4 from the power loss calculation unit 25 included in the degradation diagnosis device 2. The learning unit 72 learns the correspondence between the second current ib acquired as described above and the power loss PL during a normal period from when the transformer 4 starts operating until the period during which the transformer 4 can be considered normal has elapsed.

[0075] The model generation unit 73 receives the second current ib and the power loss PL as inputs and generates a deterioration determination model, which is a neural network model that outputs the presence or absence of deterioration of the transformer 4, from the correspondence between the second current ib and the power loss PL learned by the learning unit 72. The model generation unit 73 sends the generated deterioration determination model to the deterioration determination unit 26 included in the deterioration diagnosis device 2.

[0076] In detail, the model generation unit 73 uses the second current ib and the power loss PL as input values ​​and the presence or absence of degradation as output values ​​to generate a neural network model having an input layer, an intermediate layer, and an output layer. The correspondence between the second current ib and the power loss PL during a normal period learned by the learning unit 72 becomes the input value when the output value indicates no degradation of the transformer 4. The model generation unit 73 adjusts the weights between the input layer and the intermediate layer, the weights between the intermediate layers, and the weights between the intermediate layer and the output layer based on the learning data consisting of the second current ib and the power loss PL.

[0077] The deterioration determination unit 26 included in the deterioration diagnosis device 2 determines whether or not the transformer 4 has deteriorated by applying the second current ib and the power loss PL to the deterioration determination model acquired from the learning device 71.

[0078] As described above, the degradation diagnosis system 15 according to the fourth embodiment uses the learning device 71 to generate a degradation determination model that serves as a determination criterion for determining degradation of the transformer 4. This makes it possible to determine whether or not the transformer 4 has deteriorated based on a determination criterion according to the individual characteristics of the transformer 4 or the environment in which the transformer 4 is installed.

[0079] In the present disclosure, the normal power loss data serving as the discrimination criterion corresponds to the second current ib and the power loss PL. However, the operating state of the load 91 to which the transformer 4 is connected may also be associated as a parameter. Examples of parameters include the equipment type of the load 91, whether the load 91 is operating, and the power factor of the load 91. The parameters can be acquired from a train information management device (not shown) that manages the load 91 or the state of the load 91. The degradation diagnosis device 2 acquires the parameters from the train information management device, determines a normal power loss PLref corresponding to the second current ib based on the normal power loss data of the transformer 4 associated with the above-mentioned parameters, and determines whether the transformer 4 is degraded. This allows the presence or absence of degradation of the transformer 4 to be determined based on discrimination criteria corresponding to the state of the parameters, thereby enabling the presence or absence of degradation corresponding to the individual environment of the transformer 4 to be determined.

[0080] 8, auxiliary power supply device 3 and degradation diagnosis device 2 may be embodied together as a power supply device 74. The same applies to degradation diagnosis devices 12 and 13.

[0081] The auxiliary power supply 3 is not limited to being mounted on a DC-fed railway vehicle, but can be mounted on any vehicle, such as an AC-fed railway vehicle or a railway vehicle equipped with an internal combustion engine. When the auxiliary power supply 3 is mounted on an AC-fed railway vehicle, it is sufficient to provide a transformer that steps down the voltage of the AC power supplied from the current collector and a converter that converts the AC power stepped down by the transformer into DC power. The auxiliary power supply 3 converts the DC power supplied from the converter into AC power and supplies the converted AC power to the load 91 via the transformer 4.

[0082] The deterioration diagnosis devices 2, 12, and 13 may be implemented as one function of a train information management system. Alternatively, the deterioration diagnosis devices 2, 12, and 13 may be provided in ground facilities such as a train operation control center on the ground, rather than being mounted on a railway vehicle.

[0083] FIG. 9 is a diagram showing a modified example of the hardware configuration of the degradation diagnosis devices 2, 12, and 13 according to the embodiment. As shown in FIG. 9 , the degradation diagnosis devices 2, 12, and 13 may be realized by a processing circuit 84. The processing circuit 84 is connected to the auxiliary power supply devices 3 and 30, the output device 5, and the like via an interface circuit 85. When the processing circuit 84 is dedicated hardware, the processing circuit 84 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. Each unit of the degradation diagnosis devices 2, 12, and 13 may be realized by a separate processing circuit 84, or each unit of the degradation diagnosis devices 2, 12, and 13 may be realized by a common processing circuit 84.

[0084] A part of the functions of the degradation diagnosis devices 2, 12, 13 may be realized by dedicated hardware, and the other parts may be realized by software or firmware. For example, the current acquisition unit 21 and the voltage acquisition unit 22 provided in the degradation diagnosis device 2 may be realized by a processing circuit 84 shown in Fig. 9, and the input power calculation unit 23, the output power calculation unit 24, the power loss calculation unit 25, and the degradation determination unit 26 may be realized by a processor 81 shown in Fig. 2 reading and executing programs stored in a memory 82.

[0085] The present disclosure allows various embodiments and modifications without departing from the broad spirit and scope of the present disclosure. Furthermore, the above-described embodiments are intended to illustrate the present disclosure and do not limit the scope of the present disclosure. That is, the scope of the present disclosure is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and the meaning of equivalent disclosures are considered to be within the scope of the present disclosure.

[0086] 1, 11, 15 Deterioration diagnosis system, 2, 12, 13 Deterioration diagnosis device, 3, 30 Auxiliary power supply device, 3a, 3b Terminal, 4 Transformer, 5 Output device, 21 Current acquisition unit, 22 Voltage acquisition unit, 23 Input power calculation unit, 24 Output power calculation unit, 25 Power loss calculation unit, 26 Deterioration determination unit, 27 Temperature acquisition unit, 28 Reference determination unit, 31 Capacitor, 32 Voltage sensor, 33 Power conversion circuit, 34, 35 Current detection unit, 36, 37 Voltage detection unit, 38 Control unit, 39 AC filter capacitor, 41 Temperature sensor, 71 Learning device, 72 Learning unit, 73 Model generation unit, 74 Power supply device, 81 Processor, 82 Memory, 83 Interface, 84 Processing circuit, 85 Interface circuit.

Claims

1. A deterioration diagnosis device for a transformer provided at the output of an auxiliary power supply device having a power conversion circuit, comprising: a current acquisition unit that acquires a first current, which is the value of a current flowing between the power conversion circuit and the transformer, and a second current, which is the value of a current flowing between the transformer and a load in a railway vehicle; a voltage acquisition unit that acquires a first voltage, which is the value of a voltage input from the power conversion circuit to the transformer, and a second voltage, which is the value of a voltage output from the transformer to the load; an input power calculation unit that calculates input power, which is the power input to the transformer, based on the first current and the first voltage; an output power calculation unit that calculates output power, which is the power output from the transformer, based on the second current and the second voltage; and a power loss calculation unit that calculates power loss of the transformer based on the difference between the input power calculated by the input power calculation unit and the output power calculated by the output power calculation unit. a degradation determination unit that determines the normal power loss corresponding to the second current acquired by the current acquisition unit based on a determination criterion that is data indicating a relationship between the second current and the normal power loss of the transformer, and determines whether or not the transformer is degraded based on whether or not a difference between the power loss calculated by the power loss calculation unit and the normal power loss deviates by a threshold value or more.

2. The degradation diagnosis device according to claim 1, further comprising a temperature acquisition unit that acquires temperature information of the transformer, wherein the output power calculation unit corrects the calculated output power based on the temperature information acquired by the temperature acquisition unit, and calculates the corrected output power.

3. A degradation diagnosis device as described in claim 1 or 2, further comprising a criterion determination unit that generates and determines the discrimination criterion according to the second current from the second current acquired by the current acquisition unit and the power loss of the transformer calculated by the power loss calculation unit during a normal period from the start of operation of the transformer until the period during which the transformer can be considered normal has elapsed.

4. A learning device that generates a degradation discrimination model that determines whether or not a transformer provided at the output of an auxiliary power supply device having a power conversion circuit has deteriorated, comprising: a learning unit that learns a correspondence between a second current, which is a current value flowing between the transformer and a load in a railway vehicle, and a power loss of the transformer during a normal period from when the transformer begins operation until a period during which the transformer can be considered normal has elapsed; and a model generation unit that generates a degradation discrimination model that uses the second current and the power loss as inputs and outputs whether or not the transformer has deteriorated, based on the correspondence between the second current and the power loss of the transformer learned by the learning unit.

5. A power supply device comprising: the degradation diagnosis device according to any one of claims 1 to 3; the power conversion circuit that converts power supplied from a power source into power to be supplied to the load and supplies the converted power to the load via the transformer; and the auxiliary power supply device having a first current detection unit that detects the first current, a second current detection unit that detects the second current, a first voltage detection unit that detects the first voltage, a second voltage detection unit that detects the second voltage, and a control unit that controls the switching operation of a switching element in the power conversion circuit.

6. A degradation diagnosis system comprising: a degradation diagnosis device according to any one of claims 1 to 3; and an output device that acquires the determination result of the degradation determination section provided in said degradation diagnosis device and outputs said determination result.

7. A degradation diagnosis system comprising: a degradation diagnosis device according to any one of claims 1 to 3; and a learning device according to claim 4, wherein the degradation determination unit included in the degradation diagnosis device applies the second current acquired by the current acquisition unit and the power loss of the transformer calculated by the power loss calculation unit to the degradation determination model generated by the model generation unit included in the learning device, thereby determining whether or not the transformer has deteriorated.

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