Abnormality determination system, abnormality determination method, and program

Abstract

To provide an abnormality determination system that can determine an abnormality in electrical equipment though a temperature sensor is easily installed.SOLUTION: An abnormality determination system (S) comprises a non-contact type first temperature sensor (31) that detects the temperature of electrical equipment (20) in multiple regions, a second temperature sensor (32) that detects the ambient temperature of the electrical equipment (20), and a control unit (C) that determines an abnormality in the electrical equipment (20). The control unit (C) selects the temperature of a predetermined region from the temperatures of multiple regions of the electric equipment (20) detected by the first temperature sensor (31), and determines an abnormality in the electric equipment (20) on the basis of the temperature of the selected predetermined region and the ambient temperature of the electric equipment (20) detected by the second temperature sensor (32).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an abnormality determination system, an abnormality determination method, and a program.

Background Art

[0002] Patent Document 1 discloses a diagnostic device for diagnosing a failure of a bearing. The diagnostic device diagnoses an electric motor which is an electric device. The diagnostic device includes a first temperature sensor that detects the temperature of a first bearing supporting one end of a rotating shaft, and a second temperature sensor that detects the temperature of a second bearing supporting the other end of the rotating shaft. The diagnostic device diagnoses that there is a failure sign of the bearing based on the difference between the detection value of the first temperature sensor and the detection value of the second temperature sensor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an abnormality determination device as described in Patent Document 1, it is necessary to attach a temperature sensor to a target electric device (for example, an electric motor). For this reason, the work of attaching the temperature sensor to the electric device becomes difficult. In particular, when attaching a temperature sensor to an existing electric device, the work of attaching the temperature sensor becomes particularly difficult because it is restricted by the installation state of the electric device.

[0005] The present disclosure provides an abnormality determination system that can determine an abnormality of an electric device while facilitating the installation of a temperature sensor.

Means for Solving the Problems

[0006] The first aspect is directed to an abnormality determination system. The abnormality determination system includes a non-contact first temperature sensor (31) that detects the temperature of an electric device (20) in a plurality of regions, a second temperature sensor (32) that detects the ambient temperature of the electric device (20), and a control unit (C) that determines an abnormality of the electric device (20). The control unit (C) selects the temperature of a predetermined region from the temperatures of the plurality of regions of the electric device (20) detected by the first temperature sensor (31), and determines an abnormality of the electric device (20) based on the temperature of the selected predetermined region and the ambient temperature of the electric device (20) detected by the second temperature sensor (32).

[0007] In the first aspect, the non-contact first temperature sensor (31) detects the temperatures of a plurality of regions of the electric device (20). Here, if the temperatures of these plurality of regions are simply used as they are for specifying the temperature of the electric device (20), there is a possibility that the temperature of the surface of the electric device (20) cannot be accurately detected. Therefore, the control unit (C) selects the temperature of a predetermined region from the temperatures of the plurality of regions. The control unit (C) determines an abnormality of the electric device (20) based on the temperature of the selected predetermined region and the ambient temperature of the electric device (20) detected by the second temperature sensor (32). Since the temperature of the selected predetermined region corresponds to the temperature of the surface of the electric device (20), by using this temperature and the ambient temperature of the electric device (20), the tendency of the heat generation amount of the electric device (20) can be specified. Therefore, the control unit (C) can determine an abnormality of the electric device (20) based on these temperatures.

[0008] Since the first temperature sensor (31) is non-contact, the attachment of the first temperature sensor (31) is easy.

[0009] The second aspect is, in the first aspect, the control unit (C) determines an abnormality of the electric motor (20) as the electric device (20). Here, the electric motor (20) mentioned here includes a rotor and a stator, a rotating shaft to which the rotor is fixed, and a bearing that rotatably supports the rotating shaft.

[0010] In the second aspect, an abnormality associated with an increase in the temperature of the electric motor (20) can be determined.

[0011] In the third aspect, in the second aspect, the control unit (C) determines an abnormality of the electric motor (20) whose rotational speed is adjusted by the inverter device (26). The control unit (C) determines the abnormality of the electric motor (20) based on the temperature of the selected predetermined region, the ambient temperature detected by the second temperature sensor (32), and a parameter related to the rotational speed of the electric motor (20).

[0012] In the third aspect, the control unit (C) uses a parameter related to the rotational speed of the electric motor (20) for determining an abnormality of the electric device (20). This is because the rotational speed of the electric motor (20) affects the heat generation amount of the electric motor (20), and thus the temperature on the surface of the electric motor (20) and the ambient temperature. Therefore, by using the parameter related to the rotational speed of the electric motor (20), the accuracy of determining an abnormality of the electric device (20) is improved by the control unit (C).

[0013] In the fourth aspect, in any one of the first to third aspects, the control unit (C) performs a first determination operation of determining whether an abnormality flag of the electric device (20) is established based on the temperature of the selected predetermined region and the ambient temperature of the electric device (20) detected by the second temperature sensor (32), and a second determination operation of determining the abnormality of the electric device (20) after the abnormality flag of the electric device (20) is established in the first determination operation.

[0014] In the fourth aspect, by the control unit (C) performing the first determination operation and the second determination operation, the accuracy of determining an abnormality of the electric device (20) is improved.

[0015] In the fifth aspect, in the fourth aspect, the control unit (C) determines the confirmation of an abnormality of the electric device (20) based on the detection value of a leakage current sensor (37) that detects a leakage current of the electric device (20) in the second determination operation.

[0016] In the fifth aspect, an abnormality of the electric device (20) associated with a leakage current can be determined.

[0017] In the sixth aspect, in the fourth or fifth aspect, the control unit (C) determines the presence of an abnormality in the motor (20) of the fan (15) serving as the electric device (20) based on the detection value of a flow path resistance detection unit (36) that detects the flow path resistance of the air passage (P) in which the motor (20) of the fan (15) is provided, in the second determination operation.

[0018] In the sixth aspect, it is possible to determine an abnormality in the motor (20) of the fan (15) as the flow path resistance of the air passage (P) increases.

[0019] In the seventh aspect, in any one of the fourth to sixth aspects, the control unit (C) determines the presence of an abnormality in the motor (20) based on the detection value of an axial center position detection unit (38) that detects the axial center position of the rotation shaft (17a) of the motor (20) serving as the electric device (20), in the second determination operation.

[0020] In the seventh aspect, it is possible to determine an abnormality in the motor (20) as the axial center position of the rotation shaft (17a) of the motor (20) shifts.

[0021] In the eighth aspect, in any one of the fourth to seventh aspects, the control unit (C) performs a protection operation to protect the motor (20) after an abnormality flag of the motor (20) serving as the electric device is set in the first determination operation.

[0022] In the eighth aspect, by performing the protection operation after the abnormality flag of the motor (20) is set, it is possible to extend the period until the motor (20) fails.

[0023] The ninth aspect is directed to an abnormality determination method. The abnormality determination method includes a step of selecting the temperature of a predetermined region from the temperatures of a plurality of regions of the electric device (20) detected by a non-contact first temperature sensor (31), and determining an abnormality in the electric device (20) based on the temperature of the selected predetermined region and the ambient temperature of the electric device (20) detected by a second temperature sensor (32).

[0024] Aspect 10 targets a program. The program causes a computer to execute steps of selecting the temperature of a predetermined area from the temperatures of a plurality of areas of the electrical device (20) detected by a non-contact first temperature sensor (31), and determining an abnormality of the electrical device (20) based on the temperature of the selected predetermined area and the ambient temperature of the electrical device (20) detected by the second temperature sensor (32).

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

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Figure 10

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Figure 13

Embodiments for Carrying Out the Invention

[0026] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below, and various modifications are possible without departing from the technical idea of the present disclosure. Since each drawing is for conceptually explaining the present disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for easy understanding.

[0027] (1) Overview This embodiment is an abnormality determination system (S). The abnormality determination system (S) in this example is used to determine the abnormality of an electric motor (20), which is an electrical device. The abnormality determination system (S) in this example is applied to an air conditioner (10) having an electric motor (20). The abnormality determination system (S) includes a terminal unit (30) which is an abnormality determination device and a plurality of sensors, the details of which will be described later. The terminal unit (30) has a control unit (C) for determining the abnormality of the electric motor (20).

[0028] (2) Air conditioner The air conditioner (10) in this example is a so-called air handling unit. The air conditioner (10) is installed in a building such as a building and constitutes a part of the air conditioning system.

[0029] As shown in FIG. 1, the air treatment device (10) includes a casing (11) and a plurality of elements housed in the casing (11). The plurality of elements include a filter (12), a heat exchanger (13), a humidifying unit (14), and a fan (15).

[0030] The casing (11) is formed in a hollow rectangular parallelepiped shape. An inlet (11a) and an outlet (11b) are formed in the casing (11). In this example, the inlet (11a) is formed on a side surface of the casing (11), and the outlet (11b) is formed on an upper surface of the casing (11). An air passage (P) is formed inside the casing (11) from the inlet (11a) to the outlet (11b). In the air passage (P), a filter (12), a heat exchanger (13), a humidifying section (14), and a fan (15) are arranged in order from the upstream side to the downstream side in the air flow direction.

[0031] The filter (12) collects dust in the air. The heat exchanger (13) exchanges heat between a heat medium (water in this example) supplied from a heat source device (not shown) and the air flowing through the air passage (P). The humidifying section (14) humidifies the air by imparting water to the air. The humidifying section (14) in this example is a humidifying element that humidifies the air by vaporizing the supplied water.

[0032] A drain pan (17) is provided below the heat exchanger (13) and the humidifying section (14). The drain pan (17) is a tray that receives condensed water generated in the vicinity of the heat exchanger (13) and water that has fallen from the humidifying section (14).

[0033] The fan (15) is, for example, a sirocco fan. The fan (15) has an impeller (16) and an electric motor (20) as an electric device that rotationally drives the impeller (16). The electric motor (20) is supported from below by a support base (18).

[0034] As shown in FIG. 2, the electric motor (20) includes a housing (21), a stator (22) and a rotor (23) disposed inside the housing (21), a rotating shaft (24) fixed to the rotor (23), and a bearing (25) that rotatably supports the rotating shaft (24). The bearing (25) is constituted by, for example, a rolling bearing. The rotating shaft (24) extends from inside the housing (21) toward the impeller (16) and is connected to the central portion of the impeller (16). The electric motor (1) is configured such that the rotational speed of the rotating shaft is variable by being controlled by an inverter device (26). In other words, the fan (15) is of a variable air volume type.

[0035] During the operation of the air conditioner (10), the fan (15) is in an operating state. Air is sucked from the inlet (11a) into the air passage (11c) and passes through the filter (12) and the heat exchanger (13) in sequence. The filter (12) collects dust in the air. The heat exchanger (13) cools or heats the air by a heat medium flowing inside it. The humidifying unit (14) humidifies the air whose temperature has been adjusted by the heat exchanger (13). The air humidified by the humidifying unit (14) is supplied from the outlet (11b) to a predetermined target space.

[0036] As shown in FIG. 3, the air conditioner (10) has an air conditioning controller (27). The air conditioning controller (27) controls each device of the air conditioner (10). The air conditioning controller (27) controls the inverter device (26) based on an operation command. Specifically, the air conditioning controller (27) controls the operating frequency, that is, the rotational speed, of the electric motor (20) by switching the ON / OFF of a plurality of switching elements of the inverter device (26). Thereby, the air volume of the fan (15) is adjusted.

[0037] (3) Configuration of the abnormality determination system The abnormality determination system (S) includes a terminal unit (30), a plurality of sensors, a camera (38), and a communication terminal (70).

[0038] (3-1) Terminal unit As shown in FIG. 3, the terminal unit (30) includes a control unit (C), a storage device (M), an I / F device (30a), and a communication device (30b).

[0039] The control unit (C) includes a microprocessor, an electric circuit, and an electronic circuit. The microprocessor includes a CPU (Central Processing Unit). The CPU (Central Processing Unit) is an arithmetic device that executes various programs.

[0040] The storage device (M) stores various programs for execution by the CPU and data used by the programs. The storage device (M) includes a non-volatile memory and a volatile memory. The non-volatile memory includes an HDD (Hard Disk Drive), an SSD (Solid State Drive), a flash memory, a ROM (Read Only Memory), etc. The volatile memory includes a DRAM (Dynamic Random Access Memory), an SRAM (Solid State Drive), etc.

[0041] The I / F device (30a) is a device for connecting to an external device and performing signal exchange and control with the external device. The external device includes various sensors described later. The communication device (30b) is a device for communicating with an external device via a network (N). The communication device (30b) in this example is connected to a communication terminal (70) via the network (N). A server device (80) is connected to the network (N).

[0042] (3-2) Sensor As shown in FIGS. 1 and 3, the abnormality determination system (S) includes an infrared temperature sensor (31) which is a first temperature sensor and a surrounding temperature sensor (32) which is a second temperature sensor. The abnormality determination system (S) further includes an inflow temperature sensor (33), an inflow humidity sensor (34), an outflow humidity sensor (35), and a differential pressure sensor (36). In this example, the inflow temperature sensor (33) and the inflow humidity sensor (34) are integrated to form a first temperature and humidity sensor unit (U1). In this example, the surrounding temperature sensor (32) and the outflow humidity sensor (35) are integrated to form a second temperature and humidity sensor unit (U2).

[0043] The inflow temperature sensor (33) is arranged near the inlet (11a). The inflow temperature sensor (33) detects the temperature of the air before passing through the heat exchanger (13) in the air passage (P). The inflow humidity sensor (34) is arranged near the inlet (11a). The inflow humidity sensor (34) detects the humidity (strictly speaking, relative humidity) of the air before passing through the heat exchanger (13) in the air passage (P).

[0044] The outflow humidity sensor (35) is arranged near the outlet (11b). The outflow humidity sensor (35) detects the humidity (strictly speaking, relative humidity) of the air after passing through the heat exchanger (13) in the air passage (P).

[0045] The surrounding temperature sensor (32) is arranged near the motor (20). The surrounding temperature sensor (32) detects the temperature of the air around the motor (20). The surrounding temperature sensor (32) detects the temperature of the air after passing through the heat exchanger (13) in the air passage (P). The surrounding temperature sensor (32) is fixed to the casing (11) via a support member (not shown). The surrounding temperature sensor (32) does not contact the motor (20). The surrounding temperature sensor (32) is an electric temperature sensor and is composed of, for example, a thermistor.

[0046] The infrared temperature sensor (31) is arranged near the electric motor (20). The infrared temperature sensor (31) is a non-contact type temperature sensor. The infrared temperature sensor (31) takes the electric motor (20) as the measurement object and is used to detect the surface temperature of the electric motor (20). The infrared temperature sensor (31) is of a multi-element type having a plurality of detection elements (cells). As shown in FIG. 3, the infrared temperature sensor (31) measures the temperature distribution of the measurement space including the electric motor (20). Specifically, the measurement space is divided into a plurality of regions. In this example, the measurement space is divided into 16 regions. A part of the electric motor (20) is located within the respective range of each region. The infrared temperature sensor (31) detects the temperature of each of these plurality of regions respectively.

[0047] The differential pressure sensor (36) detects the differential pressure between the upstream side and the downstream side of the filter (12). Specifically, the differential pressure sensor (36) has a first pressure sensor (36a) located on the upstream side of the filter (12) and a second pressure sensor (36b) located on the downstream side of the filter (12). The differential pressure sensor (36) detects the difference between the detected pressure of the first pressure sensor (36a) and the detected pressure of the second pressure sensor (36b) as the differential pressure of the filter (12).

[0048] As shown in FIGS. 1 and 3, the abnormality determination system (S) has a leakage sensor (37). The leakage sensor (37) is connected between the electric motor (20) and the power supply (5) that supplies power to the electric motor (20), specifically, between the inverter device (26) and the power supply (5). The leakage sensor (37) is composed of a ZCT (Zero-phase Current Transformer). The leakage sensor (37) detects the leakage of the electric motor (20), specifically, the leakage current of the electric motor (20).

[0049] (3-3) Camera The camera (38) is disposed near the electric motor (20). As shown in FIG. 5, the camera (38) images the rotation axis (24) of the electric motor (20). The camera (38) constitutes an axial center position detection unit that detects the axial center position of the rotation axis (24). The camera (38) is disposed so as to face the axial end of the rotation axis (24). In other words, the imaging surface of the camera (38) is orthogonal to the axial center of the rotation axis (24). The camera (38) images the axial end of the rotation axis (24) at, for example, fine time intervals.

[0050] (3-4) Communication terminal The communication terminal (70) is used by a user. The user includes a maintenance worker, a management worker, and an owner. The communication terminal (70) includes a display device (71), an operation device (72), and a user-side communication device (73).

[0051] The display device (71) is composed of a display or the like and allows the user to visually recognize information. The operation device (72) is composed of a touch panel or the like and receives an input associated with the user's operation. The user-side communication device (73) is a communication device for communicating with external devices via the network (N). The user-side communication device (73) is connected to the communication terminal (70) via the network (N).

[0052] (4) Control regarding determination of abnormality The control unit (C) performs a plurality of operations for determining an abnormality of the electric motor (20). The abnormality determination system (S) performs a selection operation, a first determination operation, a second determination operation, and a protection operation.

[0053] (4-1) Selection operation of measurement target area The infrared temperature sensor (31) is used to measure the surface temperature of the electric motor (20). On the other hand, when the infrared temperature sensor (31) measures the temperatures of a plurality of regions, it may not be able to accurately measure the surface temperature of the electric motor (20) in all of those regions. For example, in a certain region, if the proportion of the space occupied is larger than that of the electric motor (20), the temperature of the air in this space will have a great influence on the detected temperature. Therefore, the control unit (C) performs selection control to select the region to be measured so that the surface temperature of the electric motor (20) can be accurately detected.

[0054] As shown in FIG. 6, in step ST11, the infrared temperature sensor (31) detects the temperatures of all regions while the electric motor (20) is stopped. In step ST12, the control unit (C) obtains the average value A and the standard deviation σ of the temperatures detected in each region. In step ST13, the control unit (C) determines whether all the detected temperatures in each region are within the range of A±σ. In step ST13, if some of the detected temperatures in each region are not within the range of A±σ, the process proceeds to step ST14. In step ST14, the control unit (C) excludes the region corresponding to the detected temperature outside the A±σ range from the measurement target. In step ST13, if all the detected temperatures are within the range of A±σ, the process proceeds to step ST15.

[0055] In step ST15, while the electric motor (20) is stopped, it is determined whether all the detected temperatures are within the allowable error range. In step ST15, if some of the detected temperatures in each region are outside the allowable error range, the process proceeds to step ST16. In step ST16, the control unit (C) excludes the region corresponding to the detected temperature outside the allowable error range from the measurement target. In step ST16, if all the detected temperatures are within the allowable error range, the process proceeds to step ST17.

[0056] While the electric motor (20) is stopped, it is not affected by the temperature rise caused by the heat generation of the electric motor (20). Therefore, it becomes easier to accurately select the region to be excluded from the measurement target.

[0057] In step ST17, the infrared temperature sensor (31) detects the temperature of the areas not excluded in steps S14 and S16 during the operation of the electric motor (20). In step ST18, the control unit (C) determines whether all the detected temperatures are within the allowable error during the operation of the electric motor (20). If, in step ST18, some of the detected temperatures in each area are outside the allowable error range, the process proceeds to step ST19. In step ST19, the control unit (C) excludes the area corresponding to the detected temperature outside the allowable error range from the measurement target. If, in step ST18, all the detected temperatures are within the allowable error range, the process proceeds to step ST20 and the selection of the measurement target is completed.

[0058] The abnormal selection control may be automatically executed at predetermined time intervals or manually executed based on the user's operation.

[0059] (4-2) First determination operation The first determination operation is an operation for determining an abnormality of the electric motor (20). Here, the abnormality of the electric motor (20) is an abnormality caused by heat generation of the electric motor (20). In the first determination operation, the control unit (C) determines not only the abnormality of the electric motor (20) but also whether attention is required for the electric motor (20).

[0060] When the first determination operation starts, in step ST21, the infrared temperature sensor (31) detects the temperature T1 of each area. In step ST22, the temperature T1 of the area specified in the above-described selection operation is extracted. For example, in the selection operation, if the first area (E1) and the fourth area (E4) in FIG. 4 are excluded from the measurement target, the control unit (C) extracts the temperature T1 of the remaining areas (E2, E3, E5 to E16) respectively. In step ST23, the control unit (C) obtains the average value of the temperature T1 of the selected area as the surface temperature Tm. In step ST24, the ambient temperature sensor (32) detects the ambient temperature T2 of the electric motor (20).

[0061] In step ST25, the control unit (C) obtains the difference ΔT between the surface temperature Tm and the ambient temperature T2 shown in FIG. 8. The control unit (C) appropriately obtains ΔT as the elapsed time, at least during the operation of the motor (20).

[0062] In step ST26, the control unit (C) obtains the average value of ΔT in a predetermined first period as ΔTave. In step ST27, the control unit (C) obtains the maximum value of ΔT in the first period as ΔTpk. The first period is the operation period of the motor (20) in a day. The first period is preferably the operation period when the rotational speed of the motor (20) reaches a constant speed and is in a steady operation. In step ST28, the crest factor C1 in the first period is obtained. The crest factor C1 is the value obtained by dividing ΔTpk by ΔTave.

[0063] In step ST29, the control unit (C) determines whether the crest factor C1 is greater than a predetermined determination value (for example, 1.2). When the crest factor C1 is smaller than the predetermined determination value, the control unit (C) determines in step ST35 that there is no abnormality in the motor (20). When the crest factor C1 is greater than the predetermined determination value, the control unit (C) sets the caution flag 1 in step ST30. The caution flag 1 is a flag indicating that the temperature of the motor (20) may rise due to some factor during the daily operation period and that caution is required. The caution flag 1 is included in the abnormality flag of the motor (20).

[0064] In step ST31, the control unit (C) determines whether the difference between the ΔTave obtained during the first period of the current day and the ΔTave obtained during the first period of the previous day is greater than a predetermined value (for example, 1°C). When the condition of step ST31 is satisfied, the control unit (C) sets the caution flag 2. The caution flag 2 is a flag indicating that the degree of heat generation of the electric motor (20) has increased when comparing the current day with the previous day. The caution flag 2 has a higher degree of caution than the caution flag 1. For example, when the sliding resistance increases due to a defect in the bearing (25), the lubricant of the bearing (25) deteriorates. As a result, the sliding resistance further increases or electric discharge occurs in the bearing (25), so the degree of heat generation of the electric motor (20) also increases day by day. It can be said that the caution flag 2 is a flag indicating such a state. The caution flag 2 is included in the abnormality flag of the electric motor (20). When the condition of step ST31 is not satisfied, the control unit (C) determines in step ST35 that there is no abnormality in the electric motor (20).

[0065] In step ST33, the control unit (C) determines whether the condition indicating that the difference between the ΔTave obtained during the first period of the current day and the ΔTave obtained during the first period of the previous day is greater than a predetermined value (for example, 1°C) has been continuously satisfied for a predetermined number of days. When the condition of step ST33 is satisfied, the control unit (C) determines in step T34 that the electric motor (20) is abnormal. This is because when ΔTave continuously rises for a predetermined number of days in a row, it can be determined that an abnormality has occurred in the electric motor (20). When the condition of step ST35 is not satisfied, the control unit (C) determines in step ST35 that there is no abnormality in the electric motor (20).

[0066] In the first determination operation, when the caution flag 1 is set, it is preferable for the control unit (C) to output a signal regarding the caution flag 1 to the communication terminal (70). The communication terminal (70) that receives this signal displays information regarding the caution flag 1 on the display device (71). Thereby, the user can know that caution is required for the electric motor (20).

[0067] In the first determination operation, when the caution flag 2 is set, it is preferable that the control unit (C) outputs a signal regarding the caution flag 2 to the communication terminal (70). The communication terminal (70) that has received this signal displays information regarding the caution flag 2 on the display device (71). Thereby, the user can know that the degree of caution for the electric motor (20) is high.

[0068] In the first determination operation, when it is determined that there is an abnormality in the electric motor (20), it is preferable that the control unit (C) outputs a signal regarding the abnormality of the electric motor (20) to the communication terminal (70). The communication terminal (70) that has received this signal displays information regarding the abnormality of the electric motor (20) on the display device (71). Thereby, the user can know that the electric motor (20) is abnormal.

[0069] (4-3) Second determination operation The second determination operation is an operation for determining the abnormality of the electric motor (20).

[0070] As shown in FIG. 9, in step ST41, the above-described first determination operation is executed. Then, when an abnormality of the electric motor (20) is determined (YES in step ST42), the process proceeds to step ST43. In step ST43, the control unit (C) checks data regarding the history of the rotational speed of the electric motor (20) during the first period in the first determination operation. The storage device (M) of the present embodiment appropriately stores parameters regarding the rotational speed of the electric motor (20) in the first determination operation. Specifically, the storage device (M) stores the control signal of the inverter device (26) during the operation of the electric motor (20). This control signal includes the operating frequency or the rotational speed of the electric motor (20). The control unit (C) reads the data regarding the rotational speed stored in the storage device (M).

[0071] In step ST44, when the rotational speed of the electric motor (20) changes by a predetermined value or more, in step ST52, the control unit (C) determines that there is an abnormality in the electric motor (20). When the rotational speed of the electric motor (20) changes, the temperature of the electric motor (20) changes. For this reason, in the first determination operation, when the rotational speed of the electric motor (20) changes, the crest factor C1 and ΔTave change. Therefore, in the first determination operation, there is a possibility of misjudging the abnormality of the electric motor (20) due to the change in the rotational speed of the electric motor (20). Thus, in the second determination operation, when the rotational speed of the electric motor (20) does not change in the first determination operation, the control unit (C) determines that there is an abnormality in the electric motor (20). In step ST44, when the rotational speed of the electric motor (20) changes by a predetermined value or more, the process proceeds to step ST45.

[0072] In step ST45, the camera (38) images the rotation shaft (24) of the electric motor (20). In step ST46, the control unit (C) determines whether there is an axial misalignment of the rotation shaft (24) based on the image data captured by the camera (38). Specifically, in a plurality of image data captured by the camera (38), when the degree of variation (for example, standard deviation) of the X and Y coordinate positions of the axis center of the rotation shaft (24) is greater than a predetermined value, the control unit (C) determines that there is an axial misalignment of the rotation shaft (24). When there is an axial misalignment of the rotation shaft (24), it can be estimated that the sliding resistance of the bearing (25) increases and, as a result, the electric motor (20) is generating heat. For this reason, in step ST46, when it is determined that there is an axial misalignment of the rotation shaft (24), in step ST52, the control unit (C) determines that there is an abnormality in the electric motor (20). In step ST46, when it is determined that there is no axial misalignment of the rotation shaft (24), the process proceeds to step ST47. Note that the axial misalignment of the rotation shaft (24) occurs, for example, due to deterioration of the vibration isolation rubber of the support base or deflection of the rotation shaft (24).

[0073] In step ST47, the leakage current sensor (37) detects the leakage current of the electric motor (20). In step ST48, the control unit (C) determines whether the leakage current detected by the leakage current sensor (37) is equal to or greater than a predetermined value. When heat is generated in the electric motor (20), discharge may occur in the windings of the stator (22). Specifically, the insulation resistance between two adjacent portions of the windings may become low, and discharge may occur between these portions. In this case, the leakage current of the leakage current sensor (37) increases. Also, for example, when condensation occurs in the air flowing around the electric motor (20), the condensed water may enter the interior of the electric motor (20), resulting in leakage current. Therefore, in step ST48, if the leakage current is equal to or greater than the predetermined value, in step ST52, the control unit (C) determines that there is an abnormality in the electric motor (20). In step ST48, if the leakage current is less than the predetermined value, the process proceeds to step ST49.

[0074] In step ST49, the differential pressure sensor (36) detects the differential pressure of the filter (12). In other words, the differential pressure sensor (36), which is a flow path resistance detection unit, detects the flow path resistance of the air passage (P). In step ST50, the control unit (C) determines whether the differential pressure of the filter (12) is equal to or greater than a predetermined value. When the filter (12) is in a clogged state, the load on the electric motor (20) increases, and the electric motor (20) generates heat. Such a situation means that the electric motor (20) is not being used in its normal state. Therefore, in step ST50, if the differential pressure of the filter (12) is equal to or greater than the predetermined value, in step ST52, the control unit (C) determines that there is an abnormality in the electric motor (20). In step ST50, if the differential pressure of the filter (12) is less than the predetermined value, the process proceeds to step ST51, and the control unit (C) determines that there is no abnormality in the electric motor (20).

[0075] In the second determination operation, when it is determined that an abnormality in the electric motor (20) has been confirmed, the control unit (C) preferably outputs a signal regarding the confirmed abnormality in the electric motor (20) to the communication terminal (70). The communication terminal (70) that has received this signal displays an image regarding the confirmed abnormality in the electric motor (20) on the display device (71). As a result, the user can know that an abnormality in the electric motor (20) has been confirmed.

[0076] When an abnormality in the electric motor (20) has been confirmed, the control unit (C) preferably outputs a signal regarding the cause of the abnormality in the electric motor (20) to the communication terminal (70). The communication terminal (70) that has received this signal displays information regarding the cause of the abnormality in the electric motor (20) on the display device (71). As a result, the user can know the cause of the abnormality in the electric motor (20). The causes of the abnormality include the axial misalignment of the rotating shaft (24) determined in step ST46, the increase in leakage current determined in step ST48, and the increase in differential pressure of the filter (12) determined in step ST50. As a result, the user can take countermeasures according to the cause of the abnormality.

[0077] Note that in the second determination operation of FIG. 9, all or part of the processes of steps S45 to T50 may be omitted.

[0078] (4-4) Protection operation The control unit (C) performs a protection operation in conjunction with the first determination operation. The protection operation is an operation that is executed when an abnormality flag (in this example, caution flag 2) of the electric motor (20) is established, and is an operation for protecting the electric motor (20). By performing the protection operation when the abnormality flag of the electric motor (20) is established, it is possible to prevent a failure of the electric motor (20) and further a failure of the fan (15). As shown in FIG. 10, in the protection operation, in step ST61, when the caution flag 2 of the electric motor (20) is established, the first protection operation in step ST70, the second protection operation in step ST90, and the third protection operation in step ST100 are executed.

[0079] (4-4-1) First protection operation The first protection operation is an operation for suppressing a failure of the electric motor (20) due to heat generation of the electric motor (20). As shown in FIG. 11, in step S71, it is determined whether or not a condition indicating that the difference between ΔTave obtained in the first period of the current day and ΔTave obtained in the first period of the previous day is greater than a predetermined value (for example, 1°C) has been continuously satisfied for a predetermined number of days. When this condition is satisfied, in step ST72, the control unit (C) estimates the life of the electric motor (20). The life of the electric motor (20) is obtained based on ΔTave of the first period stored in the storage device (M). When the ΔTave of one day is on an upward trend, it is possible to estimate how many more days it will take for the electric motor (20) to reach the heat generation limit. Therefore, the control unit (C) estimates the number of days until the electric motor (20) reaches the heat generation limit as the life of the electric motor (20). In step ST73, the control unit (C) notifies the user of the estimated life of the electric motor (20). Specifically, the control unit (C) transmits a signal regarding the life of the electric motor (20) to the communication terminal (70). The communication terminal (70) that has received this signal causes the display device (71) to display information regarding the life of the electric motor (20). Thereby, the user can know the life of the electric motor (20).

[0080] In step ST74, the control unit (C) obtains the heat generation amount of the electric motor (20) from ΔTave of the first period stored in the storage device (M). When the heat generation amount of the electric motor (20) is greater than 80% of the heat generation limit of the electric motor, in step ST75, the control unit (C) notifies the user of a temperature abnormality alarm. Specifically, the control unit (C) transmits a signal regarding the temperature abnormality alarm of the electric motor (20) to the communication terminal (70). The communication terminal (70) that has received this signal causes the display device (71) to display information regarding the temperature abnormality alarm. Thereby, the user can know that the temperature of the electric motor (20) is close to the heat generation limit and can take a predetermined countermeasure.

[0081] In step ST76, the control unit (C) restricts the rotational speed (operating frequency) of the electric motor (20) to a predetermined value or less. Thereby, heat generation of the electric motor (20) can be suppressed and the electric motor (20) can be protected. In step ST76, the control unit (C) may not only reduce the rotational speed of the electric motor (20), but also reduce the carrier frequency of the inverter device (26).

[0082] In step ST77, when the heat generation amount of the electric motor (20) is greater than 90% of the heat generation limit of the electric motor, in step ST78, the control unit (C) notifies the user of a replacement required alarm. Specifically, the control unit (C) transmits a signal regarding the replacement required alarm of the electric motor (20) to the communication terminal (70). The communication terminal (70) that has received this signal causes the display device (71) to display information regarding the replacement required alarm. Thereby, the user can replace the electric motor (20) before the temperature of the electric motor (20) reaches the heat generation limit.

[0083] In step ST79, when the heat generation amount of the electric motor (20) is greater than 95% of the heat generation limit of the electric motor, in step ST80, the control unit (C) notifies the user of an emergency stop alarm. Specifically, the control unit (C) transmits a signal regarding the emergency stop alarm of the electric motor (20) to the communication terminal (70). The communication terminal (70) that has received this signal causes the display device (71) to display information regarding the emergency stop alarm. Thereby, the user can stop the electric motor (20) before the electric motor (20) malfunctions.

[0084] When the condition of step ST79 is satisfied, the control unit (C) may output a signal for emergency stopping the electric motor (20) to the air conditioner controller (27) or the inverter device (26). Thereby, the electric motor (20) can be automatically stopped.

[0085] (4-4-2) Second protection operation The second protection operation is an operation for suppressing a failure of the motor (20) due to leakage current of the motor (20). As shown in FIG. 12, in step ST91, the leakage current sensor (37) detects the leakage current of the motor (20). In step ST92, the control unit (C) determines whether or not the detected leakage current is greater than 50% of the operating current of the breaker of the power supply (5). When the condition of step ST92 is satisfied, in step ST93, the control unit (C) reduces the carrier frequency of the inverter device (26). Thereby, the leakage current of the motor (20) can be reduced.

[0086] In step ST94, the control unit (C) determines whether or not the detected leakage current is greater than 80% of the operating current of the breaker of the power supply (5). When the condition of step ST94 is satisfied, in step ST95, the control unit (C) notifies the user of an emergency stop alarm. Specifically, the control unit (C) transmits a signal regarding the emergency stop alarm of the motor (20) to the communication terminal (70). The communication terminal (70) that has received this signal causes the display device (71) to display information regarding the emergency stop alarm. Thereby, the user can stop the motor (20) before the motor (20) fails.

[0087] When the condition of step ST94 is satisfied, the control unit (C) may output a signal for emergency stopping the motor (20) to the air conditioner controller (27) and the inverter device (26). Thereby, the motor (20) can be automatically stopped.

[0088] (4-4-3) Third protection operation The third protection operation is an operation for suppressing a failure of the motor (20) due to the axial displacement of the rotating shaft (24). As shown in FIG. 13, in step ST101, the camera (38) images the rotating shaft (24) of the motor (20). In step ST102, the control unit (C) obtains the degree of axial displacement of the rotating shaft (24). The degree of axial displacement of the rotating shaft (24) is obtained, for example, by the standard deviation of the X and Y coordinate positions of the axis center of the rotating shaft (24). When the standard deviation is greater than the first value, in step ST103, the control unit (C) limits the rotational speed of the motor (20) to a predetermined value or less. Thereby, it is possible to suppress an increase in the temperature of the bearing (25) due to the axial misalignment of the motor (20).

[0089] In step ST104, the control unit (C) determines whether the standard deviation of the axial position of the rotating shaft (24) is greater than a second value. The second value is a predetermined value greater than the first value. In step ST104, when the standard deviation is greater than the second value, in step ST105, the control unit (C) notifies the user of an emergency stop alarm. Specifically, the control unit (C) transmits a signal regarding the emergency stop alarm of the motor (20) to the communication terminal (70). The communication terminal (70) that has received this signal causes the display device (71) to display information regarding the emergency stop alarm. Thereby, the user can stop the motor (20) before the motor (20) fails.

[0090] When the condition of step ST104 is satisfied, the control unit (C) may output a signal for emergency stopping the motor (20) to the air conditioner controller (27) or the inverter device (26). Thereby, the motor (20) can be automatically stopped.

[0091] (5) Abnormality determination method and program The abnormality determination method of the present disclosure includes a step of selecting the temperature of a predetermined region from the temperatures of a plurality of regions of the motor (20) detected by the infrared temperature sensor (31), and determining the abnormality of the motor (20) based on the temperature of the selected predetermined region and the ambient temperature of the motor (20) detected by the ambient temperature sensor (32).

[0092] The abnormality determination method may include any of the steps included in the above-described selection operation, first determination operation, second determination operation, and protection operation.

[0093] The program of the present disclosure causes a computer to execute a step of selecting the temperature of a predetermined region from the temperatures of a plurality of regions of the electric motor (20) detected by the infrared temperature sensor (31), and determining the abnormality of the electric motor (20) based on the temperature of the selected predetermined region and the ambient temperature of the electric motor (20) detected by the ambient temperature sensor (32).

[0094] The program may cause a computer to execute any of the steps included in the above-described selection operation, first determination operation, second determination operation, and protection operation.

[0095] (6) Effects of the Embodiment (6-1) The abnormality determination system (S) includes a non-contact infrared temperature sensor (31) that detects the temperature of the electric motor (20) in a plurality of regions, an ambient temperature sensor (32) that detects the ambient temperature of the electric motor (20), and a control unit (C) that determines the abnormality of the electric motor (20). The control unit (C) selects the temperature of a predetermined region from the temperatures of a plurality of regions of the electric motor (20) detected by the infrared temperature sensor (31). The control unit (C) determines the abnormality of the electric motor (20) based on the temperature of the selected predetermined region and the ambient temperature of the electric motor (20) detected by the ambient temperature sensor (32).

[0096] Since the infrared temperature sensor (31) is non-contact, the installation of the infrared temperature sensor (31) becomes easy. Since the ambient temperature sensor (32) is not attached to the electric motor (20), the installation of the ambient temperature sensor (32) also becomes easy. For this reason, the abnormality determination system (S) can be easily applied to the electric motor (20) that is already installed.

[0097] The control unit (C) selects the temperature of a predetermined area among the temperatures of a plurality of areas detected by the infrared temperature sensor (31). For this reason, an area that cannot sufficiently reflect the surface temperature of the electric motor (20) can be excluded from the measurement target. For this reason, the temperature of the electric motor (20) can be accurately detected, and the accuracy of determining the abnormality of the electric motor (20) is improved.

[0098] In addition to the temperature of the selected area, the control unit (C) determines the abnormality of the electric motor (20) using the ambient temperature of the electric motor (20). For this reason, since the degree of heat generation of the electric motor (20) can be obtained, the accuracy of determining the abnormality of the electric motor (20) is improved.

[0099] (6-2) The control unit (C) uses a parameter related to the rotational speed of the electric motor (20) to determine the abnormality of the electric motor (20). This is because the rotational speed of the electric motor (20) affects the amount of heat generated by the electric motor (20), and thus the surface temperature and ambient temperature of the electric motor (20). For this reason, by the control unit (C) using a parameter related to the rotational speed of the electric motor (20), the accuracy of determining the abnormality of the electrical equipment (20) is improved.

[0100] (6-3) The control unit (C) performs a first determination operation of determining whether or not an abnormality flag of the electric motor (20) is established based on the temperature of the selected predetermined area and the ambient temperature of the electric equipment (20) detected by the ambient temperature sensor (32). After the abnormality flag of the electric equipment (20) is established in the first determination operation, the control unit (C) performs a second determination operation of determining the abnormality of the electric motor (20). For this reason, the accuracy of determining the abnormality of the electric motor (20) is further improved.

[0101] (6-4) In the second determination operation, the control unit (C) determines the confirmation of the abnormality of the electric motor (20) based on the detection value of the leakage current sensor (37) that detects the leakage current of the electric motor (20). For this reason, for example, an abnormality caused by the leakage current of the electric motor (20) can be determined.

[0102] (6-5) In the second determination operation, the control unit (C) determines the confirmation of an abnormality of the motor (20) of the fan (15) based on the detection value of a differential pressure sensor (36) that detects the differential pressure of the filter (12) in the air passage (P) where the motor (20) of the fan (15) is provided. Therefore, it is possible to determine an abnormality of the motor (20) caused by clogging of the filter (12).

[0103] (6-6) In the second determination operation, the control unit (C) determines the confirmation of an abnormality of the motor (20) of the fan (15) based on the detection value of a differential pressure sensor (36) that detects the differential pressure of the filter (12) in the air passage (P) where the motor (20) of the fan (15) is provided. Therefore, it is possible to determine an abnormality of the motor (20) caused by clogging of the filter (12).

[0104] (6-7) In the second determination operation, the control unit (C) determines the confirmation of an abnormality of the motor (20) based on the detection value (axial center position) of a camera (38) as an axial center position detection unit that detects the axial center position of the rotating shaft (17a) of the motor (20) as an electric device. Therefore, it is possible to determine an abnormality of the motor (20) caused by axial displacement of the rotating shaft (24) of the motor (20).

[0105] (6-8) After the abnormality flag (caution flag 1) of the motor (20) as an electric device is established by the first determination operation, the control unit (C) performs a protection operation to protect the motor (20). Therefore, it is possible to prevent a failure of the motor (20) in advance.

[0106] (7) Other embodiments The electric device to be the target of the abnormality determination may be a control board on which a power module is mounted. In this case, the ambient temperature sensor (32) may be directly attached to the heat sink that dissipates the heat of the control board. Also in this case, since the infrared temperature sensor (31) is non-contact type, the attachment of the infrared temperature sensor (31) is easy.

[0107] The electrical device to be determined for abnormality may be an LED. The LED may be a UVC-LED. The UVC-LED may be used for irradiating an object with ultraviolet rays for sterilization.

[0108] The motor (20) to be determined for abnormality may be a compressor motor. In this case, the air conditioner (10) may be a refrigeration cycle device that performs a refrigeration cycle of compressing a refrigerant with a compressor.

[0109] The first temperature sensor (31) does not have to be an infrared type and may be an ultrasonic type.

[0110] In an embodiment, an outflow temperature sensor may be arranged near the outflow port (11b), and a separate ambient temperature sensor (32) may be arranged near the motor (20).

[0111] The camera (38) may image the inside of the drain pan (17), the pump that discharges the water in the drain pan (17), or the drain outlet of the drain pan (17). The control unit (C) may estimate these dirt based on the captured image data. The control unit (C) may transmit this image data to the communication terminal (70) or the server device (80).

[0112] The flow path resistance detection unit that detects the flow path resistance of the air passage does not detect the differential pressure between the inflow side and the outflow side of the filter (12), and may detect the differential pressure before and after the heat exchanger (13) or the humidifying unit (humidifying element).

[0113] The axial position detection unit that detects the axial position of the rotating shaft (24) may be a non-contact position sensor instead of the camera (38).

[0114] The control unit (C) may determine an abnormality of the electric motor (20) based on a partial temperature rise for each of n regions. Specifically, the control unit (C) obtains the maximum value ΔT1pk for the detected temperature T1 for each region. The control unit (C) obtains the crest factor C2 for each region by dividing each of the maximum values T1pk for each region by the surface temperature Tm (average value of the detected temperatures T1 for all regions). The crest factor C2 serves as an index indicating how much each region is generating heat with respect to the average surface temperature Tm of the electric motor (20). The control unit (C) uses the crest factor C2 to identify local heat generation such as discharge of the winding, for example.

[0115] Instead of the display device (71), another notification device may be employed. The notification device may notify the user of predetermined information by outputting sound or light.

[0116] The abnormality determination system (S) may determine an abnormality of an electrical device such as the electric motor (20) based on the temperature and humidity of the air in the air passage (P). Under conditions where the air in the air passage (P) is likely to condense, the condensed water may enter the interior of the electric motor (20), reducing the insulation resistance of the electric motor (20). Therefore, for example, based on conditions where the air temperature becomes equal to or lower than the dew point temperature, an abnormality of the electric motor (20) can be determined.

[0117] The control unit (C) of the abnormality determination system may be provided in the air conditioner controller (27) or the communication terminal (70), or may be provided in the server device (80) connected to the network (N).

[0118] The storage device (M) of the abnormality determination system (S) may be provided in the air conditioner controller (27) or the communication terminal (70), or may be provided in the server device (80) connected to the network (N).

[0119] The program for performing the abnormality determination may be stored in the air conditioner controller (27) or the communication terminal (70), or may be stored in the server device connected to the network (N).

[0120] Although the embodiments and modifications have been described above, it will be understood that various changes in form and detail can be made without departing from the spirit and scope of the claims. Also, the above embodiments, modifications, and other embodiments may be combined or substituted as appropriate as long as the functions of the subject of the present disclosure are not impaired.

[0121] The above descriptions such as "first", "second", "third",... are used to distinguish the phrases to which these descriptions are given, and do not limit even the number and order of those phrases.

Industrial Applicability

[0122] As described above, the present disclosure is useful for an abnormality determination system, an abnormality determination method, and a program.

Explanation of Signs

[0123] 15 Fan 20 Electric motor (electrical equipment) 26 Inverter device 31 Infrared sensor (first temperature sensor) 32 Ambient temperature sensor (second temperature sensor) 36 Differential pressure sensor (flow path resistance detection unit) 37 Leakage sensor 38 Camera (axial center position detection unit) C Control unit P Air passage S Abnormality determination system

Claims

1. A non-contact first temperature sensor (31) for detecting the temperature of an electrical device (20) in a plurality of regions, a second temperature sensor (32) for detecting the ambient temperature of the electrical device (20), and a control unit (C) for determining an abnormality of the electrical device (20), wherein the control unit (C) selects the temperature of a predetermined region from the temperatures of the plurality of regions of the electrical device (20) detected by the first temperature sensor (31), and determines the abnormality of the electrical device (20) based on the temperature of the selected predetermined region and the ambient temperature of the electrical device (20) detected by the second temperature sensor (32). An abnormality determination system.

2. The control unit (C) determines an abnormality of an electric motor (20) as the electrical device (20). The abnormality determination system according to claim 1.

3. The control unit (C) determines an abnormality of an electric motor (20) whose rotational speed is adjusted by an inverter device (26), and the control unit (C) determines the abnormality of the electric motor (20) based on the temperature of the selected predetermined region, the ambient temperature detected by the second temperature sensor (32), and a parameter related to the rotational speed of the electric motor (20). The abnormality determination system according to claim 2.

4. The control unit (C) performs a first determination operation for determining whether an abnormality flag of the electrical device (20) is established based on the temperature of the selected predetermined region and the ambient temperature of the electrical device (20) detected by the second temperature sensor (32), and in the first determination operation, after the abnormality flag of the electrical device (20) is established, performs a second determination operation for determining the abnormality of the electrical device (20). The abnormality determination system according to any one of claims 1 to 3.

5. In the second determination operation, the control unit (C) determines the confirmation of the abnormality of the electrical device (20) based on the detection value of a leakage current sensor (37) that detects the leakage current of the electrical device (20). The abnormality determination system according to claim 4.

6. In the second determination operation, the control unit (C) determines the confirmation of the abnormality of the electrical device (20) based on the detection value of a flow path resistance detection unit (36) that detects the flow path resistance of an air passage (P) in which an electric motor (20) of a fan as the electrical device (20) is provided. The abnormality determination system according to claim 4.

7. In the second determination operation, the control unit (C) determines the presence or absence of an abnormality in the electric device (20), which is the electric motor (20), based on the detection value of the axial position detection unit (38) that detects the axial position of the rotation shaft (17a) of the electric motor (20) serving as the electric device (20). The abnormality determination system according to claim 4.

8. After the abnormality flag of the electric motor (20) as the electric device is set by the first determination operation, the control unit (C) performs a protection operation to protect the electric motor (20). The abnormality determination system according to claim 4.

9. A step of selecting the temperature of a predetermined region from the temperatures of a plurality of regions of the electric device (20) detected by the non-contact type first temperature sensor (31), and determining the abnormality of the electric device (20) based on the temperature of the selected predetermined region and the ambient temperature of the electric device (20) detected by the second temperature sensor (32). Abnormality determination method.

10. A program for causing a computer to execute a step of selecting the temperature of a predetermined region from the temperatures of a plurality of regions of the electric device (20) detected by the non-contact type first temperature sensor (31), and determining the abnormality of the electric device (20) based on the temperature of the selected predetermined region and the ambient temperature of the electric device (20) detected by the second temperature sensor (32). Program.

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