POWER CONVERSION DEVICE, INFORMATION PROCESSING DEVICE, AND INFORMATION PROCESSING METHOD

Abstract

To provide an electric power conversion device, an information processing device, and an information processing method capable of distinguishing between abnormalities in cooling performance associated with abnormalities in an air blowing section that blows air to a cooling structure section and abnormalities in cooling performance associated with the presence of a foreign matter.SOLUTION: An electric power conversion device has a power device (semiconductor diode SD and semiconductor switch SW), a cooling structure section 190 for heat dissipation of the power device, a cooling fan that blows air to the cooling structure section 190, and a diagnostic section that diagnoses abnormalities in cooling performance by the cooling structure section 190 and the cooling fan based on the time variation trend of a temperature difference between a temperature Tf of the cooling structure section 190 (cooling fin section 194) and a temperature Ta of air inside the electric power conversion device (housing).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a power conversion device and the like. [Background technology]

[0002] For example, a method has been disclosed for determining cooling abnormalities in a power conversion device due to clogging of a cooling structure such as a fin for dissipating heat from a power device or a failure of a blower that blows air to a cooling structure such as a fan (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-136609 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned Patent Document 1, although it is possible to determine whether or not there is an abnormality in the cooling performance, it is not possible to determine whether the abnormality that has occurred is due to the presence of a foreign object such as a clog in the cooling structure, or due to an abnormality in the air blower. Therefore, for example, even if there is no abnormality in the air blower, the air blower may be replaced, which may lead to an increase in the running costs of the power conversion device.

[0005] Therefore, in consideration of the above problems, an object of the present invention is to provide a technology in a power conversion device that is capable of distinguishing between abnormalities in cooling performance caused by an abnormality in the blower section that blows air to a cooling structure section and abnormalities in cooling performance caused by the presence of a foreign object. [Means for solving the problem]

[0006] In order to achieve the above object, in one embodiment of the present disclosure, Power devices, a cooling structure for dissipating heat from the power device; A blower that blows air to the cooling structure; a diagnosis unit that diagnoses an abnormality in the cooling performance of the cooling structure unit and the blower unit based on a trend of a time change in a temperature difference between a temperature of the cooling structure unit and a temperature of air inside the power conversion device. 、 The diagnostic unit distinguishes between an abnormality in the cooling performance caused by the presence of a foreign object and an abnormality in the cooling performance caused by an abnormality in the air blower unit based on a rate of increase in the temperature difference. R, A power converter is provided.

[0007] In another embodiment of the present disclosure, An information processing device relating to a power conversion device having a power device, a cooling structure for dissipating heat from the power device, and a blower for blowing air to the cooling structure, Based on a trend of a time change in a temperature difference between the temperature of the cooling structure and the temperature of the air inside the power conversion device, a diagnosis is made regarding an abnormality in the cooling performance of the cooling structure and the air blower. Based on the rate of increase in the temperature difference, the abnormality in the cooling performance caused by the presence of a foreign object is distinguished from the abnormality in the cooling performance caused by an abnormality in the blower unit. , An information processing device is provided.

[0008] In still another embodiment of the present disclosure, 1. An information processing method executed by an information processing device for a power conversion device having a power device, a cooling structure for dissipating heat from the power device, and an air blower for blowing air to the cooling structure, comprising: Based on a trend of a time change in a temperature difference between the temperature of the cooling structure and the temperature of the air inside the power conversion device, a diagnosis is made regarding an abnormality in the cooling performance of the cooling structure and the air blower. Based on the rate of increase in the temperature difference, the abnormality in the cooling performance caused by the presence of a foreign object is distinguished from the abnormality in the cooling performance caused by an abnormality in the blower unit. , A method for processing information is provided. Effect of the Invention

[0009] According to the above-described embodiment, in the power conversion device, it is possible to distinguish between an abnormality in cooling performance caused by an abnormality in the blower that blows air to the cooling structure and an abnormality in cooling performance caused by the presence of a foreign object. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 illustrates an example of a configuration of a cooling abnormality diagnosis system. [Diagram 2] FIG. 2 is a schematic diagram illustrating an example of a cooling structure of a power conversion device. [Diagram 3] FIG. 2 is a block diagram showing an example of a hardware configuration of a control device. [Figure 4] FIG. 2 is a block diagram showing an example of a functional configuration of a control device. [Diagram 5] 11 is a diagram showing an example of a change over time in the temperature difference between the fin temperature and the inside air temperature when a cooling abnormality occurs in the power conversion device. FIG. [Figure 6] 1 is a diagram illustrating an example of a method for diagnosing a cooling abnormality in a power conversion device; [Figure 7] 10 is a flowchart illustrating an example of a process for acquiring reference data. [Figure 8] 4 is a flowchart illustrating an example of a process for diagnosing a cooling abnormality in a power conversion device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment will be described with reference to the drawings.

[0012] [Configuration of cooling abnormality diagnosis system] The configuration of a cooling abnormality diagnosis system 1 according to this embodiment will be described with reference to FIG.

[0013] FIG. 1 is a diagram showing an example of the configuration of a cooling abnormality diagnosis system 1 according to this embodiment.

[0014] The cooling anomaly diagnosis system 1 according to this embodiment diagnoses an anomaly in the cooling performance of the power conversion device 100.

[0015] As shown in FIG. 1, a cooling anomaly diagnosis system 1 includes a power conversion device 100, a computing device 200, and a terminal device 300.

[0016] The power conversion device 100 converts three-phase AC power (e.g., R phase, S phase, and T phase) input from a commercial power source PS into three-phase AC power (e.g., U phase, V phase, and W phase) having a predetermined voltage and a predetermined frequency, and drives an electric motor M.

[0017] The electric motor M drives a given machine, such as a winding machine, installed in a spinning factory, based on the three-phase AC power output from the power conversion device 100, for example.

[0018] The power conversion device 100 may generate three-phase AC power for driving the motor M based on three-phase AC power input from a power source other than a commercial power source. The power conversion device 100 may also generate three-phase AC power for driving the motor M based on power input from a DC power source. In this case, the DC power is input to a DC link unit (positive line PL and negative line NL) between a rectifier circuit 110 and an inverter circuit 130 described later.

[0019] The power conversion device 100 includes a rectifier circuit 110, a smoothing circuit 120, an inverter circuit 130, a control device 140, a sensor 150, a display device 160, a communication device 170, and a cooling fan 180.

[0020] The rectifier circuit 110 is configured to be capable of rectifying three-phase AC power of R phase, S phase, and T phase input from a commercial power source PS and outputting DC power. The rectifier circuit 110 has positive and negative output terminals connected to one end of a positive line PL and a negative line NL, respectively, and can output DC power to the smoothing circuit 120 through the positive line PL and the negative line NL. The rectifier circuit 110 is a bridge-type full-wave rectifier circuit including, for example, six semiconductor diodes SD (an example of a power device) (see FIG. 2), and in which three sets of series-connected bodies of two semiconductor diodes SD constituting upper and lower arms are connected in parallel.

[0021] The smoothing circuit 120 suppresses and smoothes pulsations in the DC power output from the rectifier circuit 110 and the DC power regenerated from the inverter circuit 130 .

[0022] The smoothing circuit 120 includes, for example, a smoothing capacitor.

[0023] The smoothing capacitor may be provided in parallel with the rectifier circuit 110 and the inverter circuit 130 in a path connecting the positive line PL and the negative line NL.

[0024] The smoothing capacitor smoothes the DC power output from the rectifier circuit 110 and the DC power output (regenerated) from the inverter circuit 130 while repeatedly charging and discharging as appropriate.

[0025] There may be one smoothing capacitor. Alternatively, a plurality of smoothing capacitors may be disposed, and the plurality of smoothing capacitors may be connected in parallel or in series between the positive line PL and the negative line NL. Alternatively, the plurality of smoothing capacitors may be configured in such a way that a series connection of two or more smoothing capacitors is connected in parallel between the positive line PL and the negative line NL.

[0026] Moreover, the smoothing circuit 120 includes, for example, a reactor.

[0027] The reactor may be provided on the positive line PL between the rectifier circuit 110 and the smoothing capacitor (specifically, the branch point from the path where the smoothing capacitor is disposed).

[0028] The reactor smoothes the DC power output from the rectifier circuit 110 and the DC power output (regenerated) from the inverter circuit 130 while appropriately generating a voltage to prevent a change in the current.

[0029] The inverter circuit 130 has positive and negative input terminals connected to the other terminals of the positive line PL and the negative line NL. The inverter circuit 130 converts the DC power supplied from the smoothing circuit 120 into three-phase AC power (e.g., U phase, V phase, and W phase) having a predetermined frequency and a predetermined voltage by a switching operation of a semiconductor switch SW (an example of a power device) (see FIG. 2), and outputs the converted power to the electric motor M. The semiconductor switch SW may be, for example, an insulated gate bipolar transistor (IGBT) or a metal-oxide-semiconductor field-effect transistor (MOSFET) made of silicon (Si). The semiconductor switch SW may also be, for example, a semiconductor element using a wide band gap semiconductor such as silicon carbide (SiC) or gallium nitride (GaN).

[0030] The inverter circuit 130 includes, for example, six semiconductor switches SW, and is configured to include a bridge circuit in which three sets of series-connected bodies (switch legs) of two semiconductor switches SW constituting upper and lower arms are connected in parallel between a positive line PL and a negative line NL. The inverter circuit 130 may output three-phase AC power through a U-phase wire, a V-phase wire, and a W-phase wire drawn from the connection points of the three sets of upper and lower arms. A free wheel diode may be connected in parallel to each of the six semiconductor switches SW.

[0031] The control device 140 (an example of an information processing device) performs control related to the power conversion device 100. The functions of the control device 140 may be realized by any hardware or any combination of hardware and software.

[0032] Some or all of the functions of the control device 140 may be transferred to an outside of the power conversion device 100, such as to the arithmetic device 200 or the terminal device 300 (both of which are examples of information processing devices).

[0033] The sensor 150 acquires measurement data related to the operating state (operating state) of the power conversion device 100. The sensor 150 is connected to the control device 140, for example, via a one-to-one communication line or the like, and a signal corresponding to the measurement data is input to the control device 140. This allows the control device 140 to control the power conversion device 100 based on the output signal of the sensor 150, and to diagnose cooling abnormalities of the power conversion device 100, as described below.

[0034] The sensor 150 includes, for example, various temperature sensors. The temperature sensor may include, for example, a fin temperature sensor that detects the temperature (hereinafter, "fin temperature") Tf of the cooling fin portion 194. The temperature sensor may also include, for example, an inside air temperature sensor that detects the temperature (hereinafter, "inside air temperature") Ta of the air inside the housing of the power conversion device 100.

[0035] Moreover, the sensor 150 includes, for example, various current sensors, voltage sensors, etc. The current sensor may include, for example, a load current sensor that detects a load current output to the electric motor M.

[0036] The display device 160 is provided, for example, on the outer surface of the housing of the power conversion device 100. The display device 160 displays information relating to the operating state (operating state) of the power conversion device 100 under the control of the control device 140.

[0037] The display device 160 may be provided outside the housing of the power conversion device 100, for example, on the surface (outer surface) of the housing of a predetermined machine electrically driven by the electric motor M.

[0038] The communication device 170 communicates with devices external to the power conversion device 100, such as the arithmetic device 200 and the terminal device 300, through a predetermined communication line.

[0039] The predetermined communication line may be, for example, a one-to-one communication line. The predetermined communication line may include, for example, a local network (LAN) such as a field network constructed in a facility (factory) where a predetermined machine electrically driven by the electric motor M is installed. The local network may be constructed as a wired network, may be constructed as a wireless network, or may include both. The predetermined communication line may include, for example, a wide area network (WAN) outside the facility (factory) where a predetermined machine electrically driven by the electric motor M is installed. The wide area network may include, for example, a mobile communication network with a base station as an end, a satellite communication network using a communication satellite, an Internet network, and the like. The predetermined communication line may also include, for example, a short-distance communication line according to a predetermined wireless communication standard such as Bluetooth (registered trademark) or WiFi.

[0040] The functions of the communication device 170 may be incorporated into the control device 140 (interface 144).

[0041] The cooling fan 180 (an example of an air blower) blows air to a cooling structure 190 (specifically, a cooling fin portion 194) described below, and promotes heat dissipation by the cooling structure 190.

[0042] The housing of the power conversion device 100 is provided with an intake port (intake port) for outside air and an exhaust port (exhaust port) for inside air, and the cooling fan 180 may be provided upstream of the cooling structure 190 in the path of the air flow from the intake port to the exhaust port. In this case, the cooling fan 180 draws in outside air from the intake port and sends it out toward the cooling structure 190, thereby blowing the relatively low-temperature outside air onto the cooling structure 190 and discharging the air heated by heat exchange with the cooling structure 190 from the exhaust port. The cooling fan 180 may also be provided downstream of the cooling structure 190 in the path of the air flow from the intake port to the exhaust port. In this case, the cooling fan 180 draws in air around the cooling structure 190 and creates an air flow from the upstream intake port toward the cooling structure 190, thereby blowing the relatively low-temperature outside air onto the cooling structure 190.

[0043] The arithmetic device 200 is provided outside the power conversion device 100 and performs various types of arithmetic processing.

[0044] The arithmetic device 200 may be communicatively connected to the power conversion device 100 via a predetermined communication line, for example, and may perform arithmetic processing related to the control of the power conversion device 100 in response to a command from the control device 140. Specifically, the arithmetic device 200 may perform a part or all of arithmetic processing related to the determination of a cooling anomaly, which will be described later, in response to a command from the control device 140.

[0045] The arithmetic device 200 may be, for example, a programmable logic controller (PLC) or an edge controller for controlling a predetermined machine electrically driven by an electric motor M. The arithmetic device 200 may also be, for example, a computer terminal such as a personal computer (PC).

[0046] The arithmetic device 200 may also be, for example, a server device. The server device may be a cloud server or an on-premise server installed outside a facility (factory) where a specific machine electrically driven by the electric motor M is installed. The server device may also be, for example, an edge server installed inside the facility (factory) where a specific machine electrically driven by the electric motor M is installed, or in a communication facility (for example, a base station or station building) near the facility.

[0047] The terminal device 300 is provided outside the power conversion device 100 and is used by a user of the power conversion device 100 (cooling abnormality diagnosis system 1). The terminal device 300 provides various information to the user through a display unit 310, for example, and receives various inputs from the user and transmits them to the power conversion device 100.

[0048] The terminal device 300 may include, for example, a stationary terminal device such as a desktop computer terminal, or a portable terminal device (mobile terminal) such as a smartphone, a tablet terminal, or a laptop computer terminal.

[0049] [Cooling structure for power conversion equipment] Next, the cooling structure 190 of the power conversion device 100 will be described with reference to FIG.

[0050] FIG. 2 is a schematic diagram showing an example of a cooling structure 190 of the power converter 100. As shown in FIG.

[0051] The cooling structure 190 corresponds to, for example, a heat sink, and includes a fin base 192 and a cooling fin portion 194 .

[0052] Fin base 192 has a flat plate shape with a predetermined thickness. Cooling fin section 194 is provided on one surface (the lower surface in the figure) of the flat plate shape of fin base 192, and circuit boards 110A, 130A corresponding to rectifier circuit 110 and inverter circuit 130, respectively, are placed on the other surface (the upper surface in the figure).

[0053] Fin base 192 is made of a material with relatively high thermal conductivity. This makes it easier for thermal energy generated by losses when current is passed through the semiconductor diode SD or the semiconductor switch SW to escape to fin base 192. Fin base 192 may be made of a metal such as aluminum, iron, or copper. The same may be true for cooling fin portion 194 below.

[0054] As described above, the cooling fin portion 194 is provided on one surface of the flat plate-shaped fin base 192. The cooling fin portion 194 includes a plurality of fins 194A provided so as to protrude in a direction away from the surface of the fin base 192 (in the negative Z-axis direction in the figure).

[0055] The multiple fins 194A each have a very thin flat plate shape, and are arranged on one surface of the fin base 192 at approximately equal intervals along a predetermined direction (the X-axis direction in the figure).

[0056] Each of the fins 194A is made of a material having relatively high thermal conductivity. This allows thermal energy generated due to losses when the semiconductor diode SD or the semiconductor switch SW is energized to be easily released from the fin base 192 to the fins 194A. The fins 194A also have a relatively large surface area. This allows the contact area between the fins 194A and the air to be relatively large, making it easier to dissipate thermal energy into the surrounding air. This makes it easier to dissipate thermal energy generated due to losses when the semiconductor diode SD or the semiconductor switch SW is energized to the air, improving the cooling performance of the power conversion device 100.

[0057] Moreover, the cooling fan 180 causes the cooling air CA to flow in a direction (Y-axis direction in the figure) perpendicular to the direction (X-axis direction) in which the fins 194A are arranged. This allows the cooling air CA to pass between the fins 194A, and the temperature of the air around the fins 194A is maintained relatively low. This relatively increases the temperature difference between the fins 194A and the surrounding air, making it easier to dissipate the thermal energy of the fins 194A to the surrounding air. This makes it easier to dissipate the thermal energy generated by losses when the semiconductor diode SD and the semiconductor switch SW are energized to the air, further improving the cooling performance of the power conversion device 100, thereby ensuring the cooling performance required for the power conversion device 100.

[0058] On the other hand, depending on the environment in which the power conversion device 100 is installed, a foreign object may be stuck between the fins 194A. Depending on the size of the foreign object, the foreign object may be stuck in the intake port of the housing of the power conversion device 100. For example, in a spinning factory, not only dust but also cotton may be contained in the air, and the cotton or the like may be stuck between the fins 194A or in the intake port of the housing of the power conversion device 100. Then, the cooling air CA may not hit the fin 194A corresponding to the part where the foreign object is stuck, or the amount of outside air sucked in from the intake port may be reduced, and the temperature of the air supplied to the cooling fin unit 194 may become high. Therefore, the cooling performance of the semiconductor diode SD and the semiconductor switch SW by the cooling structure unit 190 and the cooling fan 180 may deteriorate. As a result, an abnormality in the cooling performance of the power conversion device 100 (semiconductor diode SD and semiconductor switch SW) by the cooling structure unit 190 and the cooling fan 180 (hereinafter, "cooling abnormality") may occur.

[0059] Furthermore, if an abnormality occurs in the cooling fan 180, causing the number of revolutions of the cooling fan 180 to decrease or the cooling fan 180 to stop, the temperature of the air around the cooling fin portion 194 (fins 194A) becomes relatively high. This deteriorates the cooling performance of the cooling structure portion 190 and the cooling fan 180 for the semiconductor diode SD and the semiconductor switch SW. As a result, there is a possibility that an abnormality in the cooling of the power conversion device 100 (the semiconductor diode SD and the semiconductor switch SW) by the cooling structure portion 190 and the cooling fan 180 occurs.

[0060] Depending on the degree of the cooling abnormality, the fin temperature Tf may reach the overheating temperature Tferr, which may result in the need to forcibly shut down the power conversion device 100, potentially affecting the operation of a factory in which a specific machine electrically driven by the electric motor M is installed.

[0061] The cooling structure 190 may have any shape as long as it can promote the dissipation of heat energy generated by losses when the semiconductor diode SD or the semiconductor switch SW is energized to the surrounding air. For example, the fin 194A may be one instead of multiple. Moreover, the fin base 192 may be provided with one or multiple rod-shaped or needle-shaped protrusions made of a material with relatively high thermal conductivity instead of the fin 194A.

[0062] [Control device configuration] Next, the configuration of the control device 140 will be described with reference to FIG. 3 and FIG.

[0063] 3 and 4 are diagrams showing an example of the configuration of the control device 140 in the cooling abnormality diagnosis system 1 according to this embodiment. Specifically, Fig. 3 is a block diagram showing an example of the hardware configuration of the control device 140, and Fig. 4 is a block diagram showing an example of the functional configuration of the control device 140.

[0064] 3, the control device 140 includes, for example, a central processing unit (CPU) 141, a memory device 142 such as a random access memory (RAM), an auxiliary storage device 143 such as a read only memory (ROM), and an interface 144, all of which are connected to one another via a bus B. The control device 140 performs various controls by loading a program installed in the auxiliary storage device 143 into the memory device 142 and having the CPU 141 execute the program. The control device 140 also receives external signals and outputs (transmits) signals to the outside through the interface 144.

[0065] 4, the control device 140 includes, as functional units, a drive control unit 1401, a recording unit 1402, a storage unit 1403, a maintenance judgment unit 1404, and a diagnosis unit 1405. The functions of the drive control unit 1401, the recording unit 1402, the maintenance judgment unit 1404, and the diagnosis unit 1405 are realized, for example, by a program installed in the auxiliary storage device 143 being loaded into the memory device 142 and executed on the CPU 141. The function of the storage unit 1403 is realized, for example, by a storage area defined in the auxiliary storage device 143.

[0066] The drive control unit 1401 controls the drive of the electric motor M through the inverter circuit 130. Specifically, the drive control unit 1401 outputs a drive signal to the inverter circuit 130 (specifically, to the gates of the respective semiconductor switches SW) and drives the electric motor M using the inverter circuit 130 so as to satisfy predetermined operating conditions. In other words, the drive control unit 1401 generates a control signal for driving the electric motor M in accordance with the predetermined operating conditions and outputs the control signal to the inverter circuit 130.

[0067] Furthermore, when the fin temperature Tf reaches an overheat temperature Tferr that indicates an overheated state of the cooling fin section 194, the drive control section 1401 activates a protection function of the power conversion device 100, and forcibly stops the operation of the power conversion device 100.

[0068] The recording unit 1402 records in chronological order the predetermined measurement data acquired from the sensor 150 in the storage unit 1403. The details of the recording unit 1402 will be described later (see FIG. 7).

[0069] The storage unit 1403 stores the predetermined measurement data recorded in chronological order through the recording unit 1402. For example, the storage unit 1403 may accumulate record data including the predetermined measurement data and time data when the measurement data was acquired.

[0070] The maintenance determination unit 1404 determines whether or not maintenance has been performed on the cooling structure unit 190. Maintenance on the cooling structure unit 190 means maintaining the function of the cooling structure unit 190, i.e., the cooling function of the cooling structure unit 190 for the power conversion device 100, in a normal state. Maintenance on the cooling structure unit 190 includes, for example, cleaning of the cooling structure unit 190 (cooling fin unit 194) and the air intake of the housing of the power conversion device 100.

[0071] For example, when a predetermined input indicating that maintenance on the cooling structure unit 190 has been performed is received from a user, the maintenance determination unit 1404 may determine that maintenance of the cooling structure unit 190 has been performed. The predetermined input from the user is received, for example, through an input unit installed in the power conversion device 100 or a predetermined machine on which the power conversion device 100 is mounted. In addition, the predetermined input from the user is received, for example, when a signal indicating a predetermined user input to an input unit installed in the arithmetic device 200 or the terminal device 300 is transmitted from the arithmetic device 200 or the terminal device 300 and received by the communication device 170.

[0072] Also, for example, the maintenance determination unit 1404 may determine whether or not maintenance of the cooling structure unit 190 has been performed by comparing measurement data of the sensor 150 during the previous and current operation of the power conversion device 100. Specifically, the maintenance determination unit 1404 may compare measurement data of the temperature (fin temperature Tf) of the cooling fin unit 194 during the previous and current operation of the power conversion device 100 or its change over time to determine whether or not maintenance of the cooling structure unit 190 has been performed. This is because when maintenance (cleaning) of the cooling structure unit 190 is performed, the heat dissipation efficiency of the cooling structure unit 190 is improved, and a difference may occur in the fin temperature Tf or its change over time compared to the previous operation of the power conversion device 100. Also, the maintenance determination unit 1404 may compare measurement data of the temperature of the air inside the housing of the power conversion device 100 during the previous and current operation of the power conversion device 100 or its change over time to determine whether or not maintenance of the cooling structure unit 190 has been performed. When the maintenance of the cooling structure 190 is performed, as described above, the heat dissipation efficiency of the cooling structure 190 improves, and a difference may occur in the temperature of the air (inside air temperature Ta) to which the thermal energy of the cooling structure 190 is transferred and its change over time, compared to the previous operation of the power conversion device 100. The maintenance determination unit 1404 may compare the measurement data of the temperature difference Y between the fin temperature Tf and the inside air temperature Ta during the previous and current operation of the power conversion device 100, or the change over time, to determine whether or not the maintenance of the cooling structure 190 has been performed. When the maintenance of the cooling structure 190 is performed, as described above, the heat dissipation efficiency of the cooling structure 190 improves, and a difference may occur in the temperature difference Y between the fin temperature Tf and the inside air temperature Ta and its change over time, compared to the previous operation of the power conversion device 100.

[0073] The diagnosing unit 1405 diagnoses abnormalities in the cooling performance of the power conversion device 100. Specifically, the diagnosing unit 1405 diagnoses abnormalities in the cooling performance of the cooling structure 190 for dissipating heat generated by losses when a current is applied to a semiconductor diode SD and a semiconductor switch SW, which will be described later, and the cooling fan 180 for blowing cooling air to the cooling structure 190. Details will be described later (see FIGS. 6 and 8).

[0074] [Outline of cooling abnormality diagnosis method] Next, an overview of a method for diagnosing cooling abnormality in the power conversion device 100 by the control device 140 (diagnostic unit 1405) will be described with reference to Figs.

[0075] Fig. 5 is a diagram showing an example of a change over time in temperature difference Y between fin temperature Tf and inside air temperature Ta when a cooling abnormality occurs. Specifically, Fig. 5 is a diagram showing an example (graph 501) of a change over time in temperature difference Y when a cooling abnormality occurs due to the presence of a foreign object, and an example (graph 502) of a change over time in temperature difference Y when a cooling abnormality occurs due to an abnormality (failure) of cooling fan 180. Fig. 6 is a diagram showing a schematic diagram of an example of a method for diagnosing a cooling abnormality in power conversion device 100.

[0076] 5, when a cooling abnormality occurs, the temperature difference Y between the fin temperature Tf and the inside air temperature Ta increases as time passes. This is because, as the amount of heat dissipated from the cooling structure 190 to the air decreases, the rate at which the fin temperature Tf increases over time becomes relatively large, while the rate at which the inside air temperature Ta increases over time becomes relatively small. Therefore, the diagnosis unit 1405 can determine whether or not a cooling abnormality has occurred based on the magnitude of the measurement data of the temperature difference Y and the tendency of the change over time.

[0077] Furthermore, the rate of increase in temperature difference Y when a cooling abnormality occurs due to the presence of a foreign object is relatively small (gentle), whereas the rate of increase in temperature difference Y when a cooling abnormality occurs due to an abnormality in cooling fan 180 is relatively large. Therefore, diagnosis unit 1405 can distinguish between an abnormality in cooling performance due to the presence of a foreign object and an abnormality in cooling performance due to an abnormality in cooling fan 180, based on the rate of increase in temperature difference Y.

[0078] For example, as shown in FIG. 6, the diagnosis unit 1405 uses reference data 600 that indicates the tendency of time-dependent change in temperature difference Y when an abnormality in cooling performance occurs due to the presence of a foreign object, and determines whether or not there is a cooling abnormality while distinguishing between a cooling abnormality due to the presence of a foreign object and a cooling abnormality due to an abnormality in the cooling fan 180.

[0079] The reference data 600 represents a change over time in the temperature difference Y with the lapse of the accumulated operating time OTa of the power conversion device 100 from a state in which the cooling structure 190 has been maintained when an abnormality in the cooling performance occurs due to the presence of a foreign object. The accumulated operating time OTa of the power conversion device 100 from a state in which the cooling structure 190 has been maintained is the accumulated operating time of the power conversion device 100 starting from a state in which the maintenance on the cooling structure 190 has been performed. The control device 140 can calculate the accumulated operating time OTa by subtracting the accumulated operating time OT from the accumulated operating time OT from the start of use after shipment from the factory until just before the maintenance on the cooling structure 190 is performed.

[0080] The diagnosis unit 1405 may determine that there is an abnormality in the cooling performance due to the presence of a foreign object when the deviation of the measurement data of the temperature difference Y from the reference data 600 is relatively small. Specifically, the diagnosis unit 1405 may determine that there is an abnormality in the cooling performance due to the presence of a foreign object when the coordinates defined by the measurement data of the temperature difference Y and the cumulative operation time OTa from the maintenance-completed state when the measurement data is acquired are in the region 601 including the reference data 600. More specifically, the diagnosis unit 1405 may determine that there is an abnormality in the cooling performance due to the presence of a foreign object when the difference between the measurement data of the temperature difference Y and the reference value Ycr at the same timing starting from the maintenance-completed state regarding the cooling structure 190 is smaller than a threshold value ΔYth (>0). For example, the region 601 is set to a range of ±30% of the value of the reference data 600 (hereinafter, "reference value") Ycr. In this case, the threshold value ΔYth corresponds to 30% of the reference value Ycr at the same timing as when the measurement data of the temperature difference Y is acquired, starting from the state where the cooling structure 190 has been maintained.

[0081] On the other hand, when the deviation of the measurement data of the temperature difference Y from the reference data 600 is relatively large in the direction in which the temperature difference Y increases, the diagnosis unit 1405 determines that there is an abnormality in the cooling performance due to an abnormality in the cooling fan 180. Specifically, the diagnosis unit 1405 may determine that there is an abnormality in the cooling performance due to an abnormality in the cooling fan 180 when the coordinates defined by the measurement data of the temperature difference Y and the cumulative operation time OTa from the maintenance-completed state when the measurement data is acquired are in the region 602. The region 602 is an area adjacent to the side where the temperature difference Y is larger than the region 601. More specifically, the diagnosis unit 1405 may determine that there is an abnormality in the cooling performance due to an abnormality in the cooling fan 180 when the value obtained by subtracting the reference value Ycr at the same timing starting from the maintenance-completed state of the cooling structure unit 190 from the measurement data of the temperature difference Y is equal to or larger than the threshold value ΔYth.

[0082] Incidentally, when there is a cooling abnormality due to an abnormality in the cooling fan 180, this may include a case where there is a cooling abnormality due to the presence of a foreign object in addition to an abnormality in the cooling fan 180.

[0083] Furthermore, the diagnosis unit 1405 may determine that there is no cooling abnormality when the deviation of the measurement data of the temperature difference Y from the reference data 600 is relatively large in the direction in which the temperature difference Y becomes smaller. Specifically, the diagnosis unit 1405 may determine that there is no cooling abnormality when the coordinates defined by the measurement data of the temperature difference Y and the accumulated operation time OTa from the maintained state when the measurement data is acquired are in the region 603. The region 603 is an area adjacent to the side where the temperature difference Y is smaller than the region 601. More specifically, the diagnosis unit 1405 may determine that there is no cooling abnormality when the value obtained by subtracting the measurement data of the temperature difference Y from the reference value Ycr at the same timing starting from the maintained state of the cooling structure 190 is equal to or greater than the threshold value ΔYth.

[0084] In this manner, in this example, the control device 140 determines whether or not an abnormality exists in the power conversion device 100 by using the reference data 600 that indicates the time change in the temperature difference Y when a cooling abnormality occurs due to the presence of a foreign object.

[0085] This allows the control device 140 to determine whether or not a cooling abnormality exists, while distinguishing between cooling abnormalities due to the presence of foreign matter and cooling abnormalities due to an abnormality in the cooling fan 180, depending on the degree of deviation of the measurement data of the temperature difference Y from the reference data 600.

[0086] [Reference data acquisition process] Next, the process of acquiring reference data by the control device 140 will be described with reference to FIG.

[0087] 7 is a flowchart outlining an example of a process for acquiring reference data by the control device 140. This flowchart is repeatedly executed at predetermined intervals during operation of the power conversion device 100 from power-on to power-off, for example.

[0088] In this example, a flag F1 is used which indicates whether acquisition of the reference data has been completed. The flag F1 is stored in the auxiliary storage device 143, for example, and is set to "0" as an initial value at the time of shipping the power conversion device 100 from the factory, which indicates that the reference data has not been acquired. The flag F1 may be read from the auxiliary storage device 143 to the memory device 142 when the power conversion device 100 is powered on, and used or updated, and the latest state of the flag F1 may be stored in the auxiliary storage device 143 when the power conversion device 100 is powered off.

[0089] 7, in step S102, the recording unit 1402 determines whether the flag F1 is "0", that is, whether the state indicates that the reference data has not been acquired. If the flag F1 is "0", the recording unit 1402 proceeds to step S104, and if the flag F1 is not "0", that is, if the flag F1 is "1", indicating that the reference data has been acquired, the recording unit 1402 ends this flow chart.

[0090] In step S104, the recording unit 1402 determines whether or not the measurement data of the temperature difference Y between the latest fin temperature Tf and the inside air temperature Ta is larger than the maximum temperature difference Ymax.

[0091] The maximum temperature difference Ymax represents the maximum value among the measurement data of the temperature difference Y already recorded in the memory unit 1403. The maximum temperature difference Ymax is set to a predetermined initial value at the time of shipping from the factory. The initial value of the maximum temperature difference Ymax functions as a lower limit value of the temperature difference Y when recording the temperature difference Y as reference data.

[0092] If the latest measurement data of the temperature difference Y is greater than the maximum temperature difference Ymax, the recording unit 1402 proceeds to step S106, otherwise the recording unit 1402 ends the processing of this flowchart.

[0093] In step S106, the recording unit 1402 associates the latest measurement data of the temperature difference Y with the accumulated operation time OT of the power conversion device 100 from the start of use after shipment from the factory when the measurement data was acquired, and records them in the storage unit 1403. Specifically, the recording unit 1402 creates record data including the latest measurement data of the temperature difference Y and the accumulated operation time OT when the measurement data was acquired, and saves it in the storage unit 1403.

[0094] When the process of step S106 is completed, the control device 140 proceeds to step S108.

[0095] In step S108, the recording unit 1402 determines whether or not a condition for ending the recording of the measurement data in time series of the temperature difference Y corresponding to the reference data is met.

[0096] The end condition may be, for example, that the fin temperature Tf reaches a temperature corresponding to the end condition (hereinafter, "recording end temperature") Tfover. The recording end temperature Tfover is set to a temperature somewhat smaller (lower) than the overheating temperature Tferr. The end condition may also be, for example, that the number of times that the measurement data is recorded reaches a predetermined number.

[0097] If the end condition for the recording of the reference data is met, the recording unit 1402 proceeds to step S110, and if the end condition is not met, the recording unit 1402 ends this flow chart.

[0098] In step S110, the recording unit 1402 sets the flag F1 to "1."

[0099] When the process of step S110 is completed, the control device 140 ends the process of this flowchart.

[0100] In this way, in this example, the control device 140 acquires time-series measurement data that indicates an upward trend in the change in temperature difference Y over time with the lapse of the accumulated operating time OT, starting from the state in which the power conversion device 100 starts to be used after being shipped from the factory, which corresponds to a state in which the power conversion device 100 has been maintained. This allows the control device 140 to acquire reference data based on the acquired time-series measurement data. This is because the possibility of an abnormality occurring in the cooling fan 180 at an early stage after the start of use of the power conversion device 100 after being shipped from the factory is extremely low, and the increase in the temperature difference Y at this time point is considered to be caused by the presence of a foreign object.

[0101] At this time, the control device 140 (diagnosis unit 1405) may use the record group of the measurement data stored in the memory unit 1403 as the reference data as is, or may generate an approximation formula or table data equivalent to the reference data based on the record group of the measurement data.

[0102] [Diagnosis process for cooling abnormalities] Next, a process of diagnosing a cooling abnormality in the power conversion device 100 by the control device 140 will be described with reference to FIG.

[0103] 8 is a flowchart outlining an example of a diagnosis process for a cooling abnormality of the power conversion device 100 by the control device 140. This flowchart is repeatedly executed at predetermined intervals during operation of the power conversion device 100 from power-on to power-off, for example.

[0104] In this example, a flag F2 is used which indicates whether or not maintenance on the cooling structure 190 has been performed immediately before the current operation start (power on) of the power conversion device 100. The flag F2 is set to "1" which indicates that maintenance on the cooling structure 190 has been performed as an initial value at the time of the first start of use (power on) after shipment from the factory, for example, and is held in the memory device 142 from power on to power off of the power conversion device 100. The flag F2 may be set according to the determination result of the maintenance determination unit 1404 at the second or subsequent power on of the power conversion device 100 after shipment from the factory, and may be maintained in that state until the power is turned off. Specifically, when the maintenance determination unit 1404 determines that maintenance on the cooling structure 190 has been performed, the flag F2 may be set to "1", and the state may be maintained until the power of the power conversion device 100 is turned off. On the other hand, if the maintenance judgment unit 1404 determines that no maintenance has been performed on the cooling structure unit 190, the flag F2 is set to "0", which indicates that no maintenance has been performed on the cooling structure unit 190, and this state may be maintained until the power conversion device 100 is turned off.

[0105] 8, in step S202, the diagnosis unit 1405 determines whether the flag F1 is "1", i.e., whether the reference data has been acquired. If the flag F1 is not "1", i.e., if the flag F1 is "0" indicating that the reference data has not been acquired, the diagnosis unit 1405 proceeds to step S204, and if the flag F1 is "1" indicating that the reference data has been acquired, the diagnosis unit 1405 proceeds to step S208.

[0106] In step S204, the diagnosis unit 1405 determines whether or not the measurement data of the temperature difference Y (=Tf-Ta) between the latest fin temperature Tf and the inside air temperature Ta exceeds a predetermined threshold value Yth.

[0107] The threshold value Yth is predefined as a lower limit value of the temperature difference Y for determining that a cooling abnormality occurs in the power conversion device 100. The threshold value Yth is set to a value somewhat smaller than the value of the temperature difference Y corresponding to the timing at which the fin temperature Tf reaches the overheat temperature Tferr. This allows the diagnosing unit 1405 to determine the occurrence of a cooling abnormality in the power conversion device 100 at a timing before the power conversion device 100 is forcibly stopped.

[0108] If the latest measurement data of the temperature difference Y exceeds the threshold value Yth, the diagnosis unit 1405 proceeds to step S206, and if the latest measurement data of the temperature difference Y does not exceed the threshold value Yth, the diagnosis unit 1405 ends this flow chart.

[0109] In step S206, an alert notifying the occurrence of a cooling abnormality in the power conversion device 100 is output to the user.

[0110] The alert may be output to the user in a visual manner, for example, through the display device 160. The alert may be output to the user in a visual manner through the display unit 310 of the terminal device 300, for example, by transmitting a signal corresponding to the alert from the communication device 170 to the terminal device 300. The display device 160 or the display unit 310 may display only the fact of the occurrence of the cooling abnormality, or in addition to that fact, data on the operating state (operating state) of the power conversion device 100 including the fin temperature Tf, the inside air temperature Ta, and the temperature difference Y, or data representing the history of these may be displayed as numerical values. The data representing the history may be, for example, data representing a change in the temperature difference Y. The alert may be output to the user through a sound output device such as a speaker provided in the power conversion device 100, a specific machine on which the power conversion device 100 is mounted, or the terminal device 300. The same may be true for the alerts in steps S212, S216, and S220 described below.

[0111] When the process of step S206 is completed, the control device 140 ends the process of this flowchart.

[0112] On the other hand, in step S208, the diagnosis unit 1405 determines whether the flag F2 is "1", that is, whether or not maintenance was performed on the cooling structure 190 immediately before the current start of operation (power on) of the power conversion device 100. If the flag F2 is not "1", that is, if the flag F2 is "0" indicating that maintenance was not performed on the cooling structure 190, the diagnosis unit 1405 proceeds to step S210, and if the flag F2 is "1" indicating that maintenance was performed on the cooling structure 190, the diagnosis unit 1405 proceeds to step S218.

[0113] In step S208, it may be determined whether or not the cumulative operating time OTa of the power conversion device 100 since the most recent maintenance on the cooling structure 190 is equal to or less than a predetermined time. The predetermined time is set to a value that is somewhat smaller than the lower limit of the time required from the state where the cooling structure 190 has been maintained until a cooling abnormality due to a foreign object occurs in the power conversion device 100. In this case, if the cumulative operating time OTa is not equal to or less than the predetermined time, the diagnosing unit 1405 proceeds to step S210, and if it is equal to or less than the predetermined time, the diagnosing unit 1405 proceeds to step S218.

[0114] In step S210, the diagnosis unit 1405 determines whether the absolute value of the subtraction value ΔY (=Y-Ycr) obtained by subtracting from the measurement data of the latest temperature difference Y the reference data (reference value Ycr) of the same accumulated operating time OTa as when the measurement data was acquired is smaller than the threshold value ΔYth.

[0115] For example, when the reference data is expressed by an approximation formula, the diagnosis unit 1405 can calculate the reference value Ycr corresponding to the cumulative operation time OTa when the measurement data of the temperature difference Y is acquired by the approximation formula. Also, for example, when the reference data is expressed by a discretized data group such as a record group of measurement data or table data, the reference value Ycr of the cumulative operation time OTa that is the same as when the measurement data of the latest temperature difference Y is acquired may or may not exist in the storage unit 1403. When the reference value Ycr of the cumulative operation time OTa that is the same as when the latest temperature difference Y is acquired exists in the storage unit 1403, the diagnosis unit 1405 can use the reference value Ycr as it is. On the other hand, when the reference value Ycr of the cumulative operation time OTa that is the same as when the latest temperature difference Y is acquired does not exist in the storage unit 1403, the reference value Ycr of the target cumulative operation time OTa can be interpolated using the reference value Ycr at the cumulative operation time OTa adjacent to the front and rear of the target cumulative operation time OTa.

[0116] If the absolute value of the subtraction value ΔY is smaller than the threshold value ΔYth, the diagnosis unit 1405 proceeds to step S212, otherwise the diagnosis unit 1405 proceeds to step S214.

[0117] In step S212, diagnosis unit 1405 outputs an alert to the user notifying the occurrence of a cooling abnormality in power conversion device 100 due to the presence of a foreign object (clogging of cooling fin unit 194 or the air intake port with a foreign object).

[0118] When the process of step S212 is completed, the control device 140 ends the process of this flowchart.

[0119] On the other hand, in step S214, the diagnosis unit 1405 judges whether the subtraction value ΔY (=Y-Ycr) is equal to or greater than the threshold ΔYth. If the subtraction value ΔY is equal to or greater than the threshold ΔYth, the diagnosis unit 1405 proceeds to step S216, otherwise it determines that there is no cooling abnormality in the power conversion device 100 and ends the process of this flowchart.

[0120] In step S216, the diagnosis unit 1405 outputs an alert notifying the occurrence of a cooling abnormality in the power conversion device 100 due to an abnormality in the cooling fan 180 to the user.

[0121] When the process of step S216 is completed, the diagnosis unit 1405 ends the process of this flowchart.

[0122] On the other hand, in step S218, the diagnosis unit 1405 judges whether or not a subtraction value ΔY (=Y-Ycr) obtained by subtracting the reference data (reference value Ycr) of the same accumulated operation time OTa as when the measurement data of the latest temperature difference Y was acquired from the measurement data is equal to or greater than a threshold value ΔYth. If the subtraction value ΔY is equal to or greater than the threshold value ΔYth, the diagnosis unit 1405 proceeds to step S220, and otherwise ends the processing of this flowchart. As a result, when the power conversion device 100 is operating immediately after maintenance on the cooling structure unit 190 is performed, the control device 140 can judge only the presence or absence of the latter cooling abnormality between the cooling abnormality due to the presence of a foreign object and the cooling abnormality due to an abnormality in the cooling fan 180.

[0123] In step S220, the diagnosis unit 1405 outputs an alert notifying the occurrence of a cooling abnormality in the power conversion device 100 due to an abnormality in the cooling fan 180 to the user.

[0124] When the process of step S220 is completed, the diagnosis unit 1405 ends the process of this flowchart.

[0125] In this manner, in this example, the control device 140 uses reference data that indicates the change over time of the temperature difference Y between the fin temperature Tf and the inside air temperature Ta when a cooling abnormality occurs due to the presence of a foreign object.

[0126] This allows the control device 140 to distinguish between a cooling abnormality caused by the presence of a foreign object and a cooling abnormality caused by an abnormality in the cooling fan 180 .

[0127] In addition, in this example, when the cumulative operating time of the power conversion device 100 after maintenance on the cooling structure 190 is relatively short, the control device 140 determines whether or not there is a cooling abnormality due to the presence of a foreign object, or a cooling abnormality due to an abnormality in the cooling fan 180.

[0128] This allows the control device 140 to suppress erroneous determination of a cooling abnormality due to the presence of a foreign object, because the possibility of a cooling abnormality due to the presence of a foreign object occurring is extremely low for a certain period of time after maintenance on the cooling structure 190 is performed.

[0129] Furthermore, in this example, when the control device 140 has not yet acquired the reference data, the control device 140 determines whether or not there is a cooling abnormality in the power conversion device 100 based on the magnitude of the temperature difference Y between the fin temperature Tf and the inside air temperature Ta.

[0130] As a result, although the control device 140 cannot distinguish between cooling abnormalities due to the presence of a foreign object and cooling abnormalities due to an abnormality in the cooling fan 180, it can determine whether or not there is a cooling abnormality in the power conversion device 100 even in a situation where the reference data has not yet been acquired.

[0131] The control device 140 may use reference data prepared in advance in addition to the reference data acquired in a manner suited to the actual use environment of the power conversion device 100. The data prepared in advance may be registered (stored) in advance in the auxiliary storage device 143 during inspection before shipment from the factory, or may be downloaded from an external device (e.g., the arithmetic device 200) after shipment from the factory and stored in the auxiliary storage device 143. In this case, if the reference data has not been acquired (if NO in step S202), instead of the processes in steps S204 and S206, the same processes as steps S208 to S220 may be performed using the reference data prepared in advance. Furthermore, the control device 140 may use the reference data prepared in advance instead of the reference data acquired in a manner suited to the actual use environment of the power conversion device 100. In this case, the process in FIG. 7 is not performed, and the processes in steps S202 to S206 may be omitted. Furthermore, there may be a plurality of types of reference data prepared in advance. For example, a plurality of types of reference data may be prepared in advance in accordance with the usage environment, and may be selectable by a predetermined input received from the user.

[0132] [Effect] Next, the operation of the power conversion device 100 (control device 140) according to this embodiment will be described.

[0133] In this embodiment, the power conversion device 100 includes a power device (for example, a semiconductor diode SD and a semiconductor switch SW), a cooling structure 190, a cooling fan 180, and a diagnosing unit 1405. Specifically, the cooling structure 190 is used to dissipate heat from the power device. The cooling fan 180 blows air to the cooling structure 190. The diagnosing unit 1405 diagnoses an abnormality in the cooling performance (cooling abnormality) of the cooling structure 190 and the cooling fan 180 based on the tendency of the time change in the temperature difference Y between the fin temperature Tf and the inside air temperature Ta.

[0134] This allows the control device 140 to utilize the difference in the tendency of the temperature difference Y to change over time between a cooling abnormality caused by an abnormality in the cooling fan 180 and a cooling abnormality caused by the presence of a foreign object. Therefore, the control device 140 can distinguish between a cooling abnormality caused by an abnormality in the cooling fan 180 and a cooling abnormality caused by the presence of a foreign object.

[0135] Furthermore, in this embodiment, the diagnosis unit 1405 may distinguish between an abnormality in cooling performance due to the presence of a foreign object and an abnormality in cooling performance due to an abnormality in the cooling fan 180, based on the rate of increase in the temperature difference Y.

[0136] Thereby, the control device 140 can use the difference in the rate of increase of the temperature difference Y to specifically distinguish between a cooling abnormality caused by an abnormality in the cooling fan 180 and a cooling abnormality caused by the presence of a foreign object.

[0137] In addition, in this embodiment, the power conversion device 100 includes a storage unit 1403. Specifically, the storage unit 1403 may store reference data that indicates a tendency of a time change in the temperature difference Y when the cooling performance is abnormal due to the presence of a foreign object. The diagnosis unit 1405 may determine that there is an abnormality in the cooling performance due to the presence of a foreign object when the deviation between the measurement data of the temperature difference Y and the reference data corresponding to the same timing as the measurement data is relatively small, and may determine that there is an abnormality in the cooling performance due to an abnormality in the cooling fan 180 when the deviation between the measurement data of the temperature difference Y and the reference data corresponding to the same timing as the measurement data is relatively large in the direction in which the temperature difference Y increases.

[0138] As a result, the control device 140 can utilize reference data that represents the trend of time-dependent change in temperature difference Y when there is an abnormality in cooling performance due to the presence of a foreign object, and specifically distinguish between a cooling abnormality due to an abnormality in the cooling fan 180 and a cooling abnormality due to the presence of a foreign object.

[0139] In addition, in this embodiment, the power conversion device 100 may include a maintenance determination unit 1404. Specifically, the maintenance determination unit 1404 may determine that maintenance on the cooling structure unit 190 has been performed. Furthermore, the reference data may represent a time change in the temperature difference Y when a cooling abnormality occurs due to the presence of a foreign object, starting from a state where the cooling structure unit 190 has been maintained. Then, the diagnosing unit 1405 may diagnose an abnormality in the cooling performance based on a deviation state between the measurement data of the temperature difference Y in a time series and the reference data corresponding to the same timing as the measurement data, starting from a point in time when the maintenance determination unit 1404 determines that the maintenance on the cooling structure unit 190 has been performed.

[0140] This allows the control device 140 to diagnose cooling abnormalities while distinguishing between cooling abnormalities caused by an abnormality in the cooling fan 180 and cooling abnormalities caused by the presence of a foreign object, in accordance with the passage of time from the point in time when the cooling structure 190 has been maintained.

[0141] In addition, in this embodiment, the diagnosis unit 1405 may calculate the difference (subtraction value ΔY) between the measurement data of the temperature difference Y and the reference data (reference value Ycr) corresponding to the same timing as the measurement data, and perform a diagnosis of abnormalities in the cooling performance based on a comparison between the difference and a threshold value ΔYth.

[0142] This allows the control device 140 to perform a diagnosis regarding a cooling abnormality while specifically distinguishing between a cooling abnormality due to an abnormality in the cooling fan 180 and a cooling abnormality due to the presence of a foreign object.

[0143] In the present embodiment, the power conversion device 100 may further include a maintenance determination unit. In a situation where the cumulative operating time of the power conversion device 100 since the maintenance determination unit 1404 determined that maintenance on the cooling structure unit 190 has been performed is relatively short, the diagnosis unit 1405 may determine only the presence or absence of a cooling anomaly associated with an abnormality in the cooling fan 180, out of a cooling anomaly associated with the presence of a foreign object and a cooling anomaly associated with an abnormality in the cooling fan 180.

[0144] This allows the control device 140 to suppress erroneous diagnosis, specifically, erroneous determination of a cooling abnormality due to the presence of a foreign object.

[0145] Furthermore, in this embodiment, the storage unit 1403 may store reference data acquired based on measurement data of the temperature difference Y in time series from the start of initial use of the power conversion device 100 after shipment from the factory to a predetermined timing. Then, after reaching the predetermined timing (specifically, the timing at which the above-mentioned termination condition is satisfied), the diagnosis unit 1405 may diagnose an abnormality in the cooling performance based on the magnitude of deviation between the measurement data of the temperature difference Y and the reference data corresponding to the same timing as the measurement data.

[0146] This allows the control device 140 to use reference data suited to the usage environment, etc., of the power conversion device 100. Therefore, the control device 140 can improve the accuracy of diagnosing cooling abnormalities, such as the accuracy of determining whether or not there is a cooling abnormality and the accuracy of distinguishing between a cooling abnormality due to the presence of a foreign object and a cooling abnormality due to an abnormality in the cooling fan 180.

[0147] In addition, in this embodiment, the memory unit 1403 may store reference data obtained based on measurement data of the temperature difference Y in a time series from the point at which the temperature difference Y exceeds a predetermined value to a predetermined timing after the power conversion device 100 is first used after being shipped from the factory.

[0148] This allows the control device 140 to obtain the reference data based on the measurement data in a state where the influence of the presence of foreign matter such as the cooling fin section 194 or the clogging of the intake port is relatively large. Therefore, in a state where the influence of the presence of foreign matter such as the clogging of the cooling fin section 194 or the intake port is relatively small, the control device 140 does not need to record the measurement data, and the processing load for obtaining the reference data can be reduced.

[0149] In the present embodiment, the storage unit 1403 may store the measurement data of the temperature difference Y in association with the accumulated operating time from the start of use of the power conversion device 100 when the measurement data was acquired.

[0150] This allows the control device 140 to use, for example, the record data of a combination of the measurement data of the temperature difference Y and the accumulated operating time from the start of use of the power conversion device 100 at the time the measurement data was acquired, as reference data as is.

[0151] Furthermore, in this embodiment, the diagnosing unit 1405 may diagnose the cooling abnormality of the power conversion device 100 based on the magnitude of the temperature difference Y before a predetermined timing is reached.

[0152] This allows the control device 140 to diagnose the cooling abnormality of the power conversion device 100 even before reference data suited to the usage environment of the power conversion device 100 is acquired.

[0153] Although the embodiments have been described in detail above, the present disclosure is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist described in the claims. [Explanation of symbols]

[0154] 1 Cooling abnormality diagnosis system 100 Power conversion device 110 Rectifier circuit 110A Circuit Board 120 Smoothing circuit 130 Inverter circuit 130A Circuit Board 140 Control device (information processing device) 141 CPU 142 Memory Device 143 Auxiliary storage device 144 Interface 150 Sensors 160 Display device 170 Communication Equipment 180 Cooling Fan 190 Cooling structure 192 Fin Base 194 Cooling fin section 194A Fin 200 Calculation device (information processing device) 300 Terminal device (information processing device) 310 Display section 1401 Drive control unit 1402 Recording Department 1403 Storage section 1404 Maintenance judgment section 1405 Diagnostics Department M electric motor NL Negative Line PL positive line PS commercial power supply SD Semiconductor diode (power device) SW Semiconductor switch (power device)

Claims

1. Power devices, a cooling structure for dissipating heat from the power device; A blower that blows air to the cooling structure; a diagnosis unit that diagnoses an abnormality in the cooling performance of the cooling structure unit and the blower unit based on a trend of a time change in a temperature difference between a temperature of the cooling structure unit and a temperature of air inside the power conversion device, The diagnostic unit distinguishes between an abnormality in the cooling performance caused by the presence of a foreign object and an abnormality in the cooling performance caused by an abnormality in the blower unit, based on a rate of increase in the temperature difference. Power conversion equipment.

2. a storage unit that stores reference data that indicates a tendency of a time change in the temperature difference when the cooling performance is abnormal due to the presence of a foreign object, The diagnosis unit determines that there is an abnormality in the cooling performance due to the presence of a foreign object when the deviation between the measurement data of the temperature difference and the reference data corresponding to the same timing as the measurement data is relatively small, and determines that there is an abnormality in the cooling performance due to an abnormality in the air blower when the deviation between the measurement data of the temperature difference and the reference data corresponding to the same timing as the measurement data is relatively large in a direction in which the temperature difference increases. The power conversion device according to claim 1 .

3. a maintenance determination unit that determines whether maintenance has been performed on the cooling structure, the reference data represents a time change in the temperature difference when an abnormality in the cooling performance occurs due to the presence of a foreign object, starting from a state in which the cooling structure has been maintained; the diagnosing unit diagnoses an abnormality in the cooling performance based on a deviation state between the measurement data of the temperature difference in time series and the reference data corresponding to the same timing as the measurement data, starting from a point in time when it is determined by the maintenance determining unit that maintenance has been performed on the cooling structure unit. The power conversion device according to claim 2 .

4. the diagnosing unit calculates a difference between the measurement data of the temperature difference and the reference data corresponding to the same timing as the measurement data, and performs a diagnosis regarding an abnormality in the cooling performance based on a comparison between the difference and a predetermined threshold value. The power conversion device according to claim 2 or 3.

5. a maintenance determination unit that determines whether maintenance has been performed on the cooling structure, the diagnosis unit, in a situation where a cumulative operating time of the power conversion device since the maintenance determination unit determined that maintenance on the cooling structure unit was performed is relatively short, determines only the presence or absence of an abnormality in the cooling performance associated with an abnormality in the air blower unit among an abnormality in the cooling performance associated with the presence of a foreign object and an abnormality in the cooling performance associated with an abnormality in the air blower unit. The power conversion device according to any one of claims 1 to 4.

6. the storage unit stores the reference data acquired based on measurement data of the temperature difference in a time series from a first start of use of the power conversion device after shipment from a factory to a predetermined timing; the diagnosing unit diagnoses an abnormality in the cooling performance based on a magnitude of deviation between the measurement data of the temperature difference and the reference data corresponding to the same timing as the measurement data after the predetermined timing is reached. The power conversion device according to any one of claims 2 to 4.

7. The storage unit stores the reference data, the reference data being acquired based on measurement data of the temperature difference in a time series from a time point at which the temperature difference exceeds a predetermined value to the predetermined timing after the power conversion device is first used after being shipped from a factory. The power converter according to claim 6.

8. The storage unit stores the measurement data of the temperature difference in association with a cumulative operation time from the start of use of the power conversion device when the measurement data is acquired. The power converter according to claim 7.

9. the diagnosing unit diagnoses an abnormality in the cooling performance based on the magnitude of the temperature difference before the predetermined timing is reached. The power converter according to any one of claims 6 to 8.

10. An information processing device relating to a power conversion device having a power device, a cooling structure for dissipating heat from the power device, and a blower for blowing air to the cooling structure, A diagnosis is made regarding an abnormality in the cooling performance of the cooling structure and the air blower based on a trend of a time change in a temperature difference between the temperature of the cooling structure and the temperature of the air inside the power conversion device, and a distinction is made between an abnormality in the cooling performance due to the presence of a foreign object and an abnormality in the cooling performance due to an abnormality in the air blower based on a rate of increase in the temperature difference. Information processing device.

11. 1. An information processing method executed by an information processing device for a power conversion device having a power device, a cooling structure for dissipating heat from the power device, and an air blower for blowing air to the cooling structure, comprising: A diagnosis is made regarding an abnormality in the cooling performance of the cooling structure and the air blower based on a trend of a time change in a temperature difference between the temperature of the cooling structure and the temperature of the air inside the power conversion device, and a distinction is made between an abnormality in the cooling performance due to the presence of a foreign object and an abnormality in the cooling performance due to an abnormality in the air blower based on a rate of increase in the temperature difference. Information processing methods.

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