Rotary machine abnormality diagnosis device and abnormality diagnosis method

Abstract

To provide an abnormality diagnosis device capable of detecting an abnormality due to contamination or deterioration of an insulation coating sheet under an environment where an electrostatic capacitance changes by moisture absorption and moisture releasing of the insulation coating sheet.SOLUTION: An abnormality diagnosis device includes: an electrostatic capacitance calculation section for calculating a wiring electrostatic capacitance being the electrostatic capacitance of wiring based on a wiring current flowing through the wiring of a rotary machine; an environment information acquisition section for acquiring environment information of an area with the rotary machine provided therein; a rotary machine information storage section for storing a characteristic change of the wiring electrostatic capacitance with respect to the change of the environment information; a wiring state estimation section for acquiring the environment information when the rotary machine is actuated from the environment information acquisition section, acquiring the characteristic change from the rotary machine information storage section when the environment information changes, and estimating an estimated wiring electrostatic capacitance corresponding to the changed environment information; and a diagnosis section for acquiring the wiring electrostatic capacitance after the change of the environment information from the electrostatic capacitance calculation section, and comparing the wiring electrostatic capacitance with the estimated wiring electrostatic capacitance, thereby to diagnose the abnormality in the rotary machine.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an abnormality diagnosis apparatus and an abnormality diagnosis method for a rotating machine such as a motor or a generator.

Background Art

[0002] When a motor or a generator stops, a large damage occurs. In particular, the stop due to a sudden failure of a motor used in an electric aircraft has a great impact on ensuring the safety of the system and passengers. Therefore, there is an increasing need to perform a high-precision fault prediction diagnosis while the motor is in use in the actual environment to prevent a sudden failure of the motor.

[0003] In response to such needs, Patent Document 1 below describes a technique for diagnosing an abnormality of a rotating machine. Specifically, Patent Document 1 shows a method of measuring the capacitance of an insulating member and detecting deterioration of an insulating material with high sensitivity. However, this technique has a problem that there is a risk of misdiagnosis when the film of the insulating material absorbs moisture due to changes in atmospheric pressure, temperature, and humidity, and the capacitance changes due to a change in the relative dielectric constant.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When the humidity around the rotating machine increases, the temperature decreases, or the atmospheric pressure rises, the relative permittivity of the insulating film contained in the winding in the rotating machine increases due to moisture absorption of the insulating film, resulting in an increase in capacitance. On the other hand, when the humidity decreases, the temperature rises, or the atmospheric pressure drops, the relative permittivity of the insulating film decreases due to moisture release of the insulating film, resulting in a decrease in capacitance. Thus, the change in capacitance due to moisture absorption and release of the insulating film is reversible. On the other hand, when the insulating film is contaminated or deteriorated due to changes in atmospheric pressure, humidity, temperature, or the external environment, the relative permittivity of the insulating film increases and the winding capacitance increases. The change in capacitance due to such contamination or deterioration of the insulating film is irreversible.

[0006] As described above, there is a method of monitoring the capacitance of an insulating member when diagnosing an abnormality of a rotating machine. However, in the conventional technology, when the capacitance changes, it is impossible to determine whether it is reversible or irreversible.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an abnormality diagnosis device capable of detecting an abnormality due to contamination or deterioration of an insulating film in an environment where the capacitance changes due to moisture absorption and release of the insulating film.

Means for Solving the Problems

[0008] In order to solve the above problems, an abnormality diagnosis device for a rotating machine according to the present invention includes a capacitance calculation unit that calculates a winding capacitance, which is the capacitance of a winding, based on a winding current flowing through the winding of the rotating machine, an environment information acquisition unit that acquires environment information of an area where the rotating machine is installed, a rotating machine information storage unit that stores characteristic changes of the winding capacitance with respect to changes in the environment information, a winding state estimation unit that acquires the environment information when the rotating machine is operating from the environment information acquisition unit, acquires the characteristic changes from the rotating machine information storage unit when the environment information changes, and estimates an estimated winding capacitance corresponding to the changed environment information, and a diagnosis unit that acquires the winding capacitance after the environment information has changed from the capacitance calculation unit and diagnoses an abnormality of the rotating machine by comparing the winding capacitance with the estimated winding capacitance.

Effects of the Invention

[0009] According to the present invention, it is possible to provide an abnormality diagnosis device capable of detecting an abnormality due to contamination or deterioration of an insulating film in an environment where the capacitance changes due to moisture absorption and desorption of the insulating film. Further features related to the present invention will become apparent from the description of this specification and the accompanying drawings. In addition, problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

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Figure 7

Modes for Carrying Out the Invention

[0011] [Example 1] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments are examples for explaining the present invention, and for the sake of clarity of explanation, appropriate omissions and simplifications are made. Also, not all of the elements and their combinations described in the embodiments are essential for the solution means of the invention. When there are a plurality of components having the same or similar functions, they may be described with the same reference numeral and different subscripts. Also, when it is not necessary to distinguish these plurality of components, the subscripts may be omitted in the description.

[0012] FIG. 1 is a diagram showing an example of the configuration of the rotating machine system 100 according to the first embodiment. As shown in FIG. 1, the rotating machine system 100 includes a battery 1, an inverter 2, a rotating machine 3, a current sensor 4, a control device 5, an abnormality diagnosis device 30, a temperature sensor 6, a humidity sensor 7, and an atmospheric pressure sensor 8. The inverter 2 converts the DC voltage input from the battery 1 into an AC voltage. The rotating machine 3 is rotationally driven based on the AC voltage input from the inverter 2. The control device 5 supplies current to the winding to control the driving of the rotating machine, and uses, for example, the detection value of the current sensor 4 for control. The temperature sensor 6, the humidity sensor 7, and the atmospheric pressure sensor 8 measure the temperature, humidity, and atmospheric pressure around the rotating machine 3, respectively, and output them to the control device 5. The abnormality diagnosis device 30 includes a capacitance calculation unit 301, an environment information acquisition unit 302, a rotating machine information storage unit 303, a winding state estimation unit 304, and a diagnosis unit 305.

[0013] [Abnormality Diagnosis Device 30] FIG. 2 is a functional block diagram showing an example of the configuration of the abnormality diagnosis device 30. In FIG. 2, in the capacitance calculation unit 301, data related to the ringing of the current with respect to the application of the voltage pulse is acquired from the current sensor 4 by, for example, the method shown in Patent Document 1, and the winding capacitance proportional to the relative permittivity of the sensor insulating member is calculated.

[0014] In the environmental information acquisition unit 302, environmental information (temperature, humidity, air pressure) around the rotating machine 3 is acquired from various sensors (temperature sensor 6, humidity sensor 7, air pressure sensor 8), and the environmental information is output to the rotating machine information storage unit 303 and the winding state estimation unit 304. In the rotating machine information storage unit 303, environmental information at a plurality of time points is acquired and stored from the environmental information acquisition unit 302, and winding capacitance environmental information at a plurality of time points is acquired and stored from the capacitance calculation unit 301. Based on these data at a plurality of time points, characteristic changes in the winding capacitance with respect to changes in the environmental information are generated and stored, and output to the winding state estimation unit 304. Note that in this embodiment, the characteristic changes in the winding capacitance with respect to changes in the environmental information refer to, but are not limited to, the winding capacitance change delay indicating the delay in the change of the winding capacitance and / or the winding capacitance change speed indicating the change speed of the winding capacitance. Also, regarding the winding capacitance change delay information and the winding capacitance change speed information, both of these information may be used, or only one of them may be used. The same applies to other functional units.

[0015] In the winding state estimation unit 304, winding capacitance change delay information and / or winding capacitance change speed information is acquired from the environmental information acquisition unit 302, and an estimated winding capacitance, which is the winding capacitance, is estimated based on these data. Note that in order to distinguish it from the "winding capacitance" calculated by the capacitance calculation unit 301, the winding capacitance estimated by the winding state estimation unit 304 is defined as the "estimated winding capacitance". In the diagnosis unit 305, the "winding capacitance" calculated by the capacitance calculation unit 301 is compared with the "estimated winding capacitance" estimated by the winding state estimation unit 304 to diagnose an abnormality of the rotating machine.

[0016] [Flow of the abnormality diagnosis device 30] FIG. 3 is a diagram showing an example of a flowchart showing the processing executed by the abnormality diagnosis device 30.

[0017] In step S101, when the rotating machine is normal, the winding capacitance is calculated by the capacitance calculation unit 301, and the process proceeds to step S102.

[0018] In step S102, when the rotating machine is normal, environmental information (atmospheric pressure, humidity, temperature) is acquired by the environmental information acquisition unit 302. Steps S101 and S102 are performed at multiple times and stored in the rotating machine information storage unit 303 in association with the time information. After repeating the above steps S101 and S102 a predetermined number of times, the process proceeds to step S103.

[0019] In step S103, using the time-series data of environmental information (atmospheric pressure, humidity, temperature) and the time-series data of winding capacitance when the rotating machine is normal, the relationship between the delay of the change in winding capacitance and the change rate with respect to the change in environmental information is modeled and stored in the rotating machine information storage unit 303. Here, steps S101 to S103 are performed when the rotating machine is normal. For example, in the case of an electric aircraft, pre-tests may be conducted under conditions where the humidity and temperature are changed before operation (immediately after the manufacture of the rotating machine) when the rotating machine is normal, or modeling may be performed based on data when the rotating machine is normal during operation between the Nth regular inspection and the (N + 1)th regular inspection (N is a natural number) and stored in the rotating machine information storage unit 303.

[0020] Note that it is also possible to store data obtained in advance by simulation or the like for the environmental information, but as in this embodiment, it is preferable to directly obtain it by operating the actual rotating machine when it is normal. This is because, as described above, when the rotating machine is used in an electric aircraft, the aircraft flies in the sky where the environmental information changes rapidly, so it is possible to respond to such rapidly changing environmental information by acquiring and updating the environmental information in real time.

[0021] In step S104, the winding state estimation unit 304 constructs a winding state estimation unit 304 that can estimate the estimated winding capacitance without using the data of the capacitance calculation unit 301 based on the information stored in the rotating machine information storage unit 303 and the environmental information acquired by the environmental information acquisition unit 302. In step S105, when the rotating machine 3 operates, the capacitance calculation unit 301 calculates the winding capacitance, and the winding state estimation unit 304 estimates the estimated winding capacitance and outputs it to the diagnosis unit 305.

[0022] In step S106, the diagnosis unit 305 compares the winding capacitance calculated by the capacitance calculation unit 301 with the estimated winding capacitance estimated by the winding state estimation unit 304, and determines whether there is an abnormality in the rotating electrical machine 3. If the degree of abnormality is large (the degree of coincidence is small), the process proceeds to step S108. If the degree of abnormality is small (the degree of coincidence is large), the process proceeds to step S107.

[0023] In step S107, it is determined that the rotating electrical machine 3 is normal, and the process ends. It may be displayed on a display (not shown in FIG. 1) that the rotating electrical machine 3 is normal. In step S108, abnormality information is issued and the process ends. The abnormality information may be displayed on the display as described above. Alternatively, the abnormality information may be output to the control device 5 to suppress the output of the rotating electrical machine 3 so that the abnormality of the rotating electrical machine 3 does not progress.

[0024] [Details of the rotating electrical machine information storage unit and the winding state estimation unit] The details of the rotating electrical machine information storage unit 303 and the winding state estimation unit 304 will be described with reference to FIGS. 4 and 5. FIG. 4 is a diagram showing an example of the time change of the winding capacitance with respect to the time change of the environmental information. The environmental information is, for example, the temperature, humidity, or atmospheric pressure around the winding. The environmental information is estimated using, for example, the temperature of the peripheral part of the rotating electrical machine 3 detected by a temperature sensor, the humidity of the peripheral part of the rotating electrical machine 3 detected by a humidity sensor, and the atmospheric pressure of the peripheral part of the rotating electrical machine 3 detected by an atmospheric pressure sensor.

[0025] Further, when the temperature sensor is arranged in the peripheral part of the rotating electrical machine 3 and the temperature around the winding cannot be directly measured, the heat generation of the winding due to the Joule loss of the winding current, the temperature detected by the temperature sensor, and the physical model based on the motor structure using the positional relationship between the winding and the temperature sensor are further used to estimate the winding temperature, so that the environmental information of the winding can be detected more accurately. Also, when the humidity sensor cannot directly detect the humidity around the winding, the humidity around the winding can be estimated by using the humidity detected by the humidity sensor and the physical model based on the motor structure or material using the positional relationship between the winding and the humidity sensor, so that the environmental information of the winding can be detected more accurately.

[0026] In FIG. 4, as an example, the change in humidity among the environmental information will be used for explanation. Even when there are changes in a plurality of elements among the environmental information, the contribution degree of the change in each element to the change in the winding capacitance can be calculated by, for example, machine learning, and the same function can be realized.

[0027] FIG. 4(a) shows an example of the time change of the winding capacitance with respect to the increase in humidity, and FIG. 4(b) shows an example of the time change of the winding capacitance with respect to the decrease in humidity. This is because there is a delay in the change of physical phenomena such as moisture absorption and desorption with respect to the time change of the environmental information, and there is a delay in the time change of the winding capacitance with respect to the time change of the environmental information.

[0028] When the rotating machine 3 is normal, the winding state estimation unit 304 models the moisture absorption and desorption phenomena of the winding with respect to the change in environmental information and the change in the winding capacitance accompanying the moisture absorption and desorption phenomena. This modeling corresponds to the "construction of the winding state estimation unit" shown in step S104 of FIG. 3. If an abnormality is observed in the rotating machine 3 at this time, the modeling is aborted, and measures such as replacing or repairing the rotating machine 3 are taken.

[0029] FIG. 5 is a diagram showing an example of the time change of the winding capacitance and the estimated winding capacitance with respect to the time change of the environmental information. The winding state estimation unit 304 and the rotating machine information storage unit 303 model based on the physical phenomena related to the moisture absorption or desorption of the winding so that the winding state estimation unit 304 can estimate the estimated winding capacitance without using the information of the winding capacitance calculated by the capacitance calculation unit 301. Then, parameters related to the delay and the change rate are calculated from the winding capacitance calculated by the capacitance calculation unit 301 and the actual data. The data in the rotating machine information storage unit 303 is learned to construct a winding state model using the data including the time change of the winding capacitance when the rotating machine 3 is normal and calculate the estimated winding capacitance without using the winding capacitance. Finally, as shown in FIGS. 5(a) and 5(b), the parameters of the winding state estimation unit 304 are adjusted so that the estimated winding capacitance coincides with the winding capacitance.

[0030] In this embodiment, as described above, the moisture absorption and desorption phenomena of the winding with respect to changes in environmental information during the normal operation of the rotating machine 3 and the change in the winding capacitance accompanying the moisture absorption and desorption phenomena are modeled. That is, the created model includes the reversible change in the winding capacitance accompanying the moisture absorption and desorption phenomena of the winding. Therefore, when the capacitance actually measured during the operation of the rotating machine 3 greatly deviates from the estimated value based on this model, it can be determined that the deviation is an irreversible change in the capacitance due to contamination and deterioration of the winding.

[0031] FIG. 6 is a diagram for explaining an example of the operations of the winding state estimation unit 304, the capacitance calculation unit 301, and the diagnosis unit 305 during the operation of the rotating machine 3 in an environment where environmental information changes with time. The capacitance calculation unit 301 calculates the capacitance of the winding based on the ringing of the current. The winding state estimation unit 304 estimates the estimated winding capacitance based on the environmental information and the data in the rotating machine information storage unit 303. When the rotating machine 3 operates in an environment where environmental information changes with time, the winding capacitance and the estimated winding capacitance change with time as shown in FIG. 6(a). The diagnosis unit 305 compares the winding capacitance and the estimated winding capacitance and diagnoses the abnormality of the winding. When the two match or the degree of deviation is small, it can be said that the winding is normal. On the other hand, when the degree of agreement between the two is low and the winding capacitance is larger than the estimated winding capacitance, it is determined that an increase in capacitance has occurred due to a winding abnormality (such as thermal deterioration of the winding) different from moisture absorption and desorption, and winding abnormality information is output at the time (Time≧t1) when the degree of abnormality (the difference between the winding capacitance and the estimated winding capacitance) exceeds the reference value Th, as shown in FIG. 6(b).

[0032] [Computer] FIG. 7 is a block diagram of the computer 980. Each of the control device 5 and the abnormality diagnosis device 30 shown in FIG. 1 includes one or more of the computers 980 shown in FIG. 7.

[0033] In FIG. 7, computer 980 includes a CPU 981, a storage unit 982, a communication I / F (interface) 983, an input / output I / F 984, and a media I / F 985. Here, the storage unit 982 includes a RAM 982a, a ROM 982b, and an HDD 982c. The communication I / F 983 is connected to a communication circuit 986. The input / output I / F 984 is connected to an input / output device 987. The media I / F 985 reads and writes data from and to a recording medium 988.

[0034] The ROM 982b stores an IPL (Initial Program Loader) or the like executed by the CPU. The HDD 982c stores a control program, various data, and the like. The CPU 981 realizes various functions by executing a control program or the like read from the HDD 982c into the RAM 982a. The interior of the abnormality diagnosis device 30 or the like shown in FIG. 2 above is shown with functions realized by a control program or the like as blocks.

[0035] As described above, according to the present invention, even in an environment where environmental information changes with time, when a change in capacitance due to moisture absorption and desorption of the insulating film occurs, an abnormality due to contamination or deterioration of the insulating film can be correctly detected without being detected as an abnormality or false detection.

[0036] [Modification Example] The present invention is not limited to the above-described embodiments, and various modifications are possible. The above-described embodiments are exemplified for easy understanding and explanation of the present invention, and are not necessarily limited to those having all the configurations described. Also, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, part of the configuration of each embodiment can be deleted, or other configurations can be added or replaced. Also, the control lines and information lines shown in the figures indicate those considered necessary for explanation, and do not necessarily show all the control lines and information lines required on the product. In fact, it may be considered that almost all the configurations are interconnected. Possible modifications to the above embodiments are, for example, as follows.

[0037] (1) Since the hardware of the abnormality determiner in the above embodiment can be realized by a general computer, a program for executing the processing corresponding to each of the above block diagrams, each flowchart, and other various processes described above, etc. may be stored in a storage medium (a computer-readable recording medium on which the program is recorded), or distributed via a transmission path.

[0038] (2) The processing corresponding to each of the above block diagrams, each flowchart, and other various processes described above, etc. were described as software processing using a program in the above embodiment, but part or all of it may be replaced with hardware processing using an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array), etc.

[0039] (3) The various processes executed in the above embodiment may be executed by a server computer via a network not shown, and the various data stored in the above embodiment may also be stored in the server computer.

[0040] According to the embodiments of the present invention described above, the following operational effects can be obtained.

[0041] (1) The abnormality diagnosis apparatus according to the present invention includes a capacitance calculation unit that calculates a winding capacitance, which is the capacitance of a winding, based on a winding current flowing through the winding of a rotating machine; an environment information acquisition unit that acquires environment information of an area where the rotating machine is installed; a rotating machine information storage unit that stores characteristic changes of the winding capacitance with respect to changes in the environment information; a winding state estimation unit that acquires the environment information when the rotating machine is operating from the environment information acquisition unit, acquires the characteristic changes from the rotating machine information storage unit when the environment information changes, and estimates an estimated winding capacitance corresponding to the changed environment information; and a diagnosis unit that acquires the winding capacitance after the environment information has changed from the capacitance calculation unit, and diagnoses an abnormality of the rotating machine by comparing the winding capacitance with the estimated winding capacitance.

[0042] With the above configuration, even in an environment where the environment information changes over time, when a change in capacitance occurs due to moisture absorption and desorption of the insulating film, an abnormality due to fouling or deterioration of the insulating film can be correctly detected without misdetecting it as an abnormality.

[0043] (2) The environment information is any one of the temperature, humidity, or atmospheric pressure around the winding. It is necessary to consider these factors that affect the change in the capacitance of the insulating member.

[0044] (3) The rotating machine information storage unit estimates the humidity around the winding using the humidity detection value around the winding and information regarding the structure or material of the rotating machine. Alternatively, the rotating machine information storage unit estimates the temperature around the winding using the temperature detection value around the winding, the winding current flowing through the winding of the rotating machine, and information regarding the structure or material of the rotating machine. Even when the humidity or temperature around the winding cannot be directly measured, it is possible to acquire the necessary data by indirectly measuring in this way.

[0045] (4) The rotating machine information storage unit calculates a physical phenomenon related to moisture absorption or desorption of the winding using the environment information. Thereby, it becomes possible to construct a winding state estimation unit that can estimate the estimated winding capacitance.

[0046] (5) The winding state estimation unit estimates the estimated winding capacitance based on a model including a reversible change in the winding capacitance associated with the moisture absorption and desorption phenomena of the winding. Thereby, when the actually measured capacitance greatly deviates from the estimated value, it becomes possible to determine that this is due to an irreversible change in the capacitance.

[0047] (6) The characteristic change is winding capacitance change delay information indicating a delay in the change of the winding capacitance and / or winding capacitance change speed information indicating the change speed of the winding capacitance. By using these data of the winding capacitance, it becomes possible to estimate the winding capacitance in detail.

[0048] (7) Further, the abnormality diagnosis method according to the present invention also has the same effect as the above-described abnormality diagnosis device.

Explanation of symbols

[0049] 3 Rotating machine, 6 Temperature sensor, 7 Humidity sensor, 8 Atmospheric pressure sensor 30 Abnormality diagnosis device, 301 Capacitance calculation unit, 302 Environment information acquisition unit, 303 Rotating machine information storage unit, 304 Winding state estimation unit, 305 Diagnosis unit

Claims

1. A capacitance calculation unit that calculates the winding capacitance, which is the capacitance of the winding, based on the winding current flowing through the winding of the rotating machine winding, An environmental information acquisition unit that acquires environmental information of the area in which the rotating machine is installed, A rotating machine information storage unit that stores the characteristic changes of the winding capacitance in response to the changes in the environmental information, A winding state estimation unit acquires the environmental information from the environmental information acquisition unit when the rotating machine is in operation, acquires the characteristic change from the rotating machine information storage unit when the environmental information changes, and estimates the estimated winding capacitance corresponding to the changed environmental information. A diagnostic unit that obtains the winding capacitance after the environmental information has changed from the capacitance calculation unit and diagnoses an abnormality in the rotating machine by comparing the winding capacitance with the estimated winding capacitance, Equipped with, A device for diagnosing abnormalities in rotating machinery, characterized by the following features.

2. An abnormality diagnosis device for a rotating machine according to claim 1, The aforementioned environmental information is either the temperature, humidity, or atmospheric pressure around the winding. A device for diagnosing abnormalities in rotating machinery, characterized by the following features.

3. An abnormality diagnosis device for a rotating machine according to claim 2, The rotating machine information storage unit estimates the humidity around the winding using the detected humidity value around the winding and information about the structure or materials of the rotating machine. A device for diagnosing abnormalities in rotating machinery, characterized by the following features.

4. An abnormality diagnosis device for a rotating machine according to claim 2, The rotating machine information storage unit estimates the temperature around the winding using the temperature detection value around the winding, the winding current flowing through the winding of the rotating machine, and information about the structure or materials of the rotating machine. A device for diagnosing abnormalities in rotating machinery, characterized by the following features.

5. An abnormality diagnosis device for a rotating machine according to claim 2, The rotating machine information storage unit uses the environmental information to calculate the physical phenomena related to moisture absorption or release of the winding. A device for diagnosing abnormalities in rotating machinery, characterized by the following features.

6. An abnormality diagnosis device for a rotating machine according to claim 2, The winding state estimation unit estimates the estimated winding capacitance based on a model that includes a reversible change in the winding capacitance due to the moisture absorption and release phenomenon of the winding. A device for diagnosing abnormalities in rotating machinery, characterized by the following features.

7. An abnormality diagnosis device for a rotating machine according to claim 2, The characteristic change is winding capacitance change delay information indicating the delay in the change of the winding capacitance and / or winding capacitance change rate information indicating the rate of change of the winding capacitance. A device for diagnosing abnormalities in rotating machinery, characterized by the following features.

8. The winding capacitance, which is the capacitance of the winding, is calculated based on the winding current flowing through the winding of the rotating machine. The environmental information of the area where the rotating machine is installed is acquired, The characteristic change of the winding capacitance in response to the change in the environmental information is stored. The system acquires the environmental information while the rotating machine is in operation, acquires the characteristic change when the environmental information changes, and estimates the winding capacitance corresponding to the changed environmental information. The winding capacitance after the environmental information has changed is obtained, and the abnormality of the rotating machine is diagnosed by comparing the winding capacitance with the estimated winding capacitance. A method for diagnosing abnormalities in a rotating machine, characterized by the following features.

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