JP6752368B2 - Rotating machine diagnostic equipment, diagnostic methods and rotating machine system - Google Patents

Description

The present invention is a diagnostic device for a rotating machine used in a drive system in which one power conversion device drives a plurality of rotating machines, and a drive for driving a plurality of rotating machines with one power conversion device. It relates to a method of diagnosing a rotating machine of a system.

When a rotating machine such as a motor or a generator stops due to a sudden failure, great damage occurs. In particular, a stoppage due to a sudden failure of a motor used in factory equipment has a large impact, such as a decrease in the operating rate of production equipment and a need to review the production plan. Therefore, there is an increasing need to realize highly accurate state diagnosis in the operating state and prevent sudden failure of the motor.

In response to such needs, Japanese Patent Application Laid-Open No. 7-194186 (Patent Document 1) detects the load current of each of two motors having the same drive conditions with a current sensor, and the difference between the detected currents is a reference. A technique for determining an abnormality when the value is exceeded is disclosed.

Further, in Japanese Patent Application Laid-Open No. 2017-32567 (Patent Document 2), a distribution showing a correlation between a plurality of motors is calculated, an abnormality is determined based on the distribution, and which motor is responsible for the abnormality is determined. Motor monitoring devices are disclosed.

Japanese Patent Application Laid-Open No. 7-194186 JP-A-2017-32567

In the techniques of Patent Documents 1 and 2, since it is necessary to install a current sensor for each motor, there are problems that the cost of the sensor and the trouble of installing the sensor are required.

The present invention has been made to solve the problems of the prior art as described above.

The method for diagnosing a rotating machine of the present invention that solves the above problems measures the total load current of a plurality of rotating machines, and identifies information derived from the load current of a desired rotating machine from an increase or decrease in the total load current. , The purpose is to compare the specified load current with the load current in the normal state and judge whether the rotating machine is normal or abnormal.

Further, the rotary machine diagnostic device of the present invention that solves the above problems includes a current data acquisition unit that acquires the sum of the load currents of a plurality of rotary machines, and a diagnostic unit that diagnoses the state of each rotary machine based on the current data. , An output unit that outputs the diagnosis result is provided, and the diagnosis unit identifies the load current of each rotating machine from the data of the period during which the total load current increases or decreases, and performs a state diagnosis for each rotating machine. ..

Further, the rotary machine system of the present invention that solves the above problems measures the sum of the load currents of the plurality of rotary machines, the power converter connected to the plurality of rotary machines and supplying power, and the plurality of rotary machines. A current sensor is provided, a diagnostic unit that diagnoses each state of each rotating machine based on information from the current sensor, and a display unit that displays the result of the diagnosis by the diagnostic unit.

Then, the increase in the load current of each rotating machine is extracted from the increase / decrease in the total load current measured during the period when the number of the rotating machines to which the load is applied increases / decreases at a substantially constant speed. Then, the abnormality is detected by the difference from the normal state of the increase in the load current of each of the extracted rotary machines.

More specifically, when the number of rotating machines to which the load of the object is applied increases or decreases with the movement of the object, such as a rotating machine system for transporting the object, the tip of the object moves over the plurality of rotating machines. The sum of the load currents is measured during the period of passage, the period of time when the rear end of the object passes over the plurality of rotating machines, or both.

Further, in the present invention, any one or more of the phase currents of the rotating machine can be used. Specifically, a current sensor that measures the total load current of the rotating machine is installed on the feeder line of at least one phase. Alternatively, install each on at least two phases of feeders. Alternatively, it is installed on the feeder lines of all phases.

Further, the diagnostic apparatus of the present invention detects an abnormality by using the absolute amplitude value of the increase in the load current of each rotating machine. Alternatively, the increase in the load current of each rotating machine is extracted for each frequency, and an abnormality is detected using the peak value of a specific frequency component. Alternatively, anomalies are detected using the level of the spectrum around the fundamental frequency.

Further, the diagnostic apparatus of the present invention extracts the increase in the load current of each of the rotating machines for two phases, and detects an abnormality by using a Lissajous figure drawn on a plane around them. Alternatively, the increase in the load current of each rotating machine is extracted for all phases, and an abnormality is detected using a locus drawn in a multidimensional space centered on them.

Further, the diagnostic apparatus of the present invention makes a diagnosis by using information on the weight of the object in addition to the increase in the load current of each rotating machine. Alternatively, the diagnosis is made using the temperature information of the environment in which each of the rotating machines is installed.

In the diagnostic method of the present invention, the number of the rotating machines to which the load of the object is applied to the drive system including a plurality of rotating machines that convey the object and a power conversion device that collectively supplies power to the rotating machines is approximately the same. A step of measuring the total load current during a period of increasing or decreasing at a constant speed, and a step of extracting an increase in the load current of each rotating machine during transportation of the object from the increase or decrease of the total load current were extracted. The step includes a step of detecting an abnormality by the difference from the normal state of the increase in the load current of each rotating machine.

More specifically, during the period in which the front end portion of the object passes over the plurality of rotating machines, the rear end portion of the object passes over the plurality of rotating machines, or both. The total load current is measured, and the increase in load current of each rotating machine during transportation is extracted.

Further, the diagnostic method of the present invention detects an abnormality by using the absolute amplitude value of the increase in the load current of each rotating machine. Alternatively, the increase in the load current of each rotating machine is extracted for each frequency, and an abnormality is detected using the peak value of a specific frequency component. Alternatively, anomalies are detected using the level of the spectrum around the fundamental frequency.

Further, in the diagnostic method of the present invention, the increase in the load current of each rotating machine is extracted for two phases, and an abnormality is detected by using a Lissajous figure drawn on a plane centered on them. Alternatively, the increase in the load current of each rotating machine is extracted for all phases, and an abnormality is detected using a locus drawn in a multidimensional space centered on them.

Further, the diagnostic method of the present invention makes a diagnosis using information on the weight of the object in addition to the increase in the load current of each rotating machine. Alternatively, the diagnosis is made using the temperature information of the environment in which each of the rotating machines is installed.

According to the above configuration, in a drive system in which a plurality of rotating machines are driven by one power converter, an abnormality of each rotating machine can be separated and detected from the total current of the plurality of rotating machines. Therefore, it is possible to realize the diagnosis of the rotating machine at low cost and without the trouble of installation.

The basic block diagram of Examples 1 and 2 of the diagnostic apparatus of a rotating machine. Schematic diagram of an increase in the total load current during the period in which the tip of an object passes in a diagnostic device for a rotating machine. The schematic diagram of the waveform of the sum total load current in a part of the period through which the tip of an object passes in the diagnostic apparatus of a rotating machine. Flowchart in the diagnostic equipment of the rotating machine Part 1. Schematic diagram of the increase in the total load current during the period when the rear end of the object passes in the diagnostic device of the rotating machine. The schematic diagram of the waveform of the sum total load current in a part of the period through which the rear end of an object passes in the diagnostic apparatus of a rotating machine. Flowchart in the diagnostic equipment of the rotating machine Part 2. The basic configuration diagram of the third embodiment of the diagnostic device for the rotating machine and the current data displayed on a plane centered on the two phases. FIG. 3 is a basic configuration diagram of a fourth embodiment of a rotary machine diagnostic device.

The object of the present invention is a diagnostic method of a rotary machine system (drive system) including a plurality of rotary machines and a power conversion device that collectively supplies power to the plurality of rotary machines, a diagnostic device, and a rotary machine system incorporating the diagnostic device. Is.

The diagnostic device includes a data acquisition unit that acquires current sensor information, a diagnostic unit that analyzes data and diagnoses the state of each rotating machine, and an output unit that outputs the diagnostic result of each rotating machine or the entire rotating machine system. Be prepared.

The inventors of the present application have studied to detect an abnormality of each motor separately from the sum of the currents of the plurality of motors when a plurality of motors are driven by one inverter. In a rotating machine system including a plurality of rotating machines, the load applied to each rotating machine may vary or the load applied to the rotating machines may not be uniform, such as when transporting an object. Therefore, the load current for each rotating machine can be specified by measuring the total load current and extracting the load fluctuation of the desired rotating machine. Therefore, each rotating machine can be diagnosed based on the current sensor information that measures the total load current of the plurality of rotating machines. As a result, it is not necessary to install a current sensor for each rotating machine.

When the tip portion passes through a plurality of rotating machines, the number of loaded rotating machines increases, and when the rear end portion passes through a plurality of rotating machines, the number of loaded rotating machines decreases. The plot of the total load current during the period when the number of rotating machines to which the load is applied increases or decreases may be a straight line / curve or a stepped shape depending on the transport speed and the measurement frequency.

The plurality of rotating machines are connected to one power conversion device for controlling them, and the sensor is installed at a position where the total load current of the plurality of rotating machines can be measured.

The current sensor that measures the total load current is installed at a location where the currents of a plurality of rotating machines of the rotating machine system flow. It may be incorporated in the power conversion device and installed in the power conversion device, or may be installed between the power conversion device and the rotating machine. For example, in the case of a three-phase motor, the current sensor may be installed on one of the three-phase currents fed to the rotating machine, or on the two-phase and three-phase feeders, respectively.

Further, the diagnostic sensor may be used in combination with the current sensor for rotating machine control. In that case, it is possible to use the data with large fluctuations for diagnosis, the data with no fluctuations for control, etc. separately for each data, and temporarily store it in the memory and use the same data. You can also. For example, the current sensor already installed in the inverter can measure the total load current of all motors. Depending on the performance, a diagnostic device using only the current sensor installed in the inverter can be realized.

The diagnostic unit identifies the load current information during the period when the number of rotating machines to which the load is applied increases or decreases, specifies the amount of increase or decrease in the load current of each rotating machine, and the extracted fluctuation of the load current of each rotating machine is normal. Compare with the state and judge whether it is normal or abnormal. From the abnormal value of the load current, it is possible to judge the deterioration of the insulation of the rotating machine, the deterioration of the bearing, and the like.

For example, in a machine that is connected to a rotating machine and conveys an object by arranging a plurality of rotating rollers and conveyors and passing them over the machine, the load applied to each rotating machine changes as the object moves. The load current of each rotating machine increases when the tip of the object reaches, and the load of the next rotating machine starts to increase when the tip of the object passes through. Further, the decrease starts when the rear end portion of the object reaches each rotating machine, and the load disappears after the rear end portion of the object passes.

Therefore, the amount of change associated with each rotating machine can be extracted from the amount of change (increase / decrease) in the total load current and used for diagnosing the state of each rotating machine. The extracted load current value is judged to be normal or abnormal by comparing both the increase when the tip passes and the decrease when the rear end passes, or on the other hand, the normal state specified in advance. ..

For comparison, the absolute value of the swing width of the increase in the load current and the peak value of a specific frequency component when the increase / decrease is classified by frequency can be used. In particular, it is preferable to detect using the level of the spectrum around the fundamental frequency. When lubrication becomes insufficient due to deterioration or shortage of grease in bearings, the frictional force fluctuates irregularly, causing fluctuations in the fundamental frequency of the load current, and the spectrum at the hem on both sides of the peak rises relatively. Can be seen. By measuring the swelling, it is possible to detect an abnormality in the bearing.

Since the load current data of each rotating machine can be acquired in a plurality of phases, it is possible to diagnose the state and detect an abnormality using the current data of two or three phases. The accuracy of judgment can be improved by displaying the current data extracted for a plurality of phases on two or three dimensions centered on them and using the drawn loci.

The output unit outputs, for example, at least one of normal or abnormal as a result of determination by the diagnostic unit. The result may be displayed as an image, or an abnormality may be notified by an alarm or the like.

According to the system as described above, the state of each rotating machine can be diagnosed without installing sensors in each of a plurality of rotating machines.

For example, when used in a harsh environment of high temperature and humidity, the motor tends to fail in a shorter period than the general life of the motor, and it is difficult to completely prevent a sudden failure by regular maintenance. Further, in a system using a large number of motors (for example, several hundreds), it is troublesome to monitor all the devices individually, and there is a possibility that a sudden failure cannot be detected by partial extraction. In the present invention, since a plurality of rotating machines are diagnosed from one sensor data, it seems to be effective in such a case.

It can also be attached to a rotating machine system that is already in operation. Further, a control sensor installed in the power conversion device may be used, and a part of the obtained data may be utilized.

In the case of a large-scale system that uses a plurality of power conversion devices, a sensor may be installed for each power conversion device in order to facilitate comparison with the control signal.

Further, considering that the sensor is more fragile than the rotating machine, a spare sensor may be installed at a position where the total sum of the same load current can be measured.

A sensor mounted at a position where the total load current can be measured extracts the increase or decrease in the load current of the rotating machine. By comparing the increase / decrease of the load current with the load given to each rotating machine, the increase / decrease of the load current is associated with each rotating machine, and normal / abnormal is diagnosed based on the load current increase / decrease extracted for each rotating machine. To do. For example, it is possible to store the increase in load current in the normal state of each rotating machine in advance and detect an abnormality based on the difference from the normal state.

By measuring the load current during the period from the moment when a load is applied to one rotating machine to the time when another rotating machine is loaded, and subtracting the load current value before that, the increase related to each rotating machine is extracted. it can.

Since the rotating machine system operates in the same manner, it may be possible to machine-learn the increased normal pattern and detect an abnormality based on the deviation from the normal pattern. Since the load current value changes depending on the size of the load, environmental factors, etc., it is possible to make a comparison based on the result of additionally considering these conditions in the normal pattern.

In an object transfer device that drives multiple motors with a single inverter, the load current value is measured from the moment the tip of the object rides on one motor until the tip of the object rides on the next motor. By subtracting the value of the load current value in the previous period, the increase in load current due to each motor can be extracted.

Further, the time change of the total load current can be monitored, the abnormality can be detected by the deviation from the normal pattern, and the motor in which the abnormality has occurred can be identified from the location where the abnormality is detected. The normal pattern may be machine learning data based on the result of repeatedly measuring the increase and decrease of the load current. The fluctuation of the total measured load current can be divided for each rotating machine to diagnose the state and detect an abnormality. When an abnormality is detected from the measurement result of the total measured load current, the fluctuation is measured for each rotating machine. It is also possible to identify the rotating machine that has become abnormal by sorting to. In any case, it is possible to identify the rotating machine having an abnormality by evaluating the fluctuation of the total load current by dividing the time zone.

As described above, according to the diagnostic device and the diagnostic method for the rotating machine of the present invention, in the drive system in which one power conversion device drives the plurality of rotating machines, the total currents of the plurality of rotating machines are individually obtained. The abnormality of the rotating machine can be detected separately. Therefore, it is possible to reduce the cost and labor of installing the sensor. In addition, the existing sensor that measures the total load current value can be used to diagnose the rotating machine system.

Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram illustrating a diagnostic device of the rotary machine system of the first embodiment.

The rotary machine system for transporting the object 10 includes N rotary machines 1 to 5 for transporting and driving the object, and a power conversion device 21 for supplying power to all the rotary machines at once. N is an integer greater than or equal to 2 and can be between 40 and 50. In Fig. 1, 5 or more are illustrated. The electric power supplied by the power converter is distributed to the rotating machine via the collective starter panel 20.

Here, a case where a three-phase motor using three feeder lines is used as the rotating machine is shown. The sum of the load currents of the plurality of rotating machines is flowed from the power converter for each phase of the rotating machine.

Instead of one rotating machine system, a plurality of rotating machine systems may be arranged side by side, and an object may be moved from the rotating machine system to the rotating machine system.

Further, in order to diagnose the state of each rotating machine constituting the rotating machine system, a current sensor 11 that measures the phase current of a certain one phase (for example, U phase) and a current data acquisition unit 24 that acquires information from the current sensor 24. A diagnostic unit 22 that diagnoses the rotating machine system, and a display unit 23 that displays the result of the diagnosis by the diagnostic unit are provided.

While the object to be transported is on each rotating machine, the load current of the rotating machine is larger than that in the unloaded state. Therefore, if the total load current during that period is measured and some fluctuation values are specified as the load current of each rotating machine, the load current value increases without measuring the respective load current value of each rotating machine. Minutes can be extracted.

Therefore, if a period in which the number of rotating machines to which the load of the object is applied increases or decreases at a substantially constant speed is selected and the period is limited within that range, each rotating machine at the time of transporting the object is calculated from the increase or decrease in the total load current. The increase in load current can be extracted.

The period during which the number of the rotating machines to which the load of the object is applied increases or decreases at a substantially constant speed includes a period during which the front end portion of the object passes over the plurality of rotating machines and the plurality of rear ends of the object. The period of passing over the rotating machine is conceivable. The number of rotating machines to which the load of the object is applied is linked to the transport speed from the time when the object is transported and the load starts to be applied from the tip until the full load is applied and until the rear end of the object passes and the load disappears. Increase or decrease. In addition, the total load current value also increases or decreases depending on the rotating machine to which the load is applied. In the present invention, the diagnosis may be made using the data of either one period or the data of both periods. When using the data of both periods, the data of both periods may be used for all the rotating machines, which period data is used for each rotating machine, or whether the data of both periods is used. May be selected. In the first embodiment, the period in which the front end portion passes over the plurality of rotating machines is described, and in the second embodiment, the period in which the rear end portion passes over the plurality of rotating machines is described.

In FIG. 2, the period during which the tip of the object passes over the plurality of rotating machines (# 1 to # N) in FIG. 1 (after the idling period Δ, the transportation of the object is started (t ₁ ), and then all A schematic diagram is shown in which the absolute amplitude value of the total load current increases when a load is applied to the rotating machine (until (t _n )). In addition, FIG. 3 shows a schematic diagram of the waveform of the total load current during the same period.

When the period during which the object is not on any of the rotating machines is called the idling period, and the period during which the object is on all the rotating machines is called the full load period, the load of the object is applied from the idling period to the full load period. As the number of the rotating machines added increases, the total load current increases stepwise.

When the object is on the rotating machine # 1 and the tip is not on the rotating machine # 2 (t _{1 to} t ₂ ), only the load current of the rotating machine # 1 increases. Therefore, the increase in the total load current can be identified as being derived from the rotating machine # 1. Similarly, in the state where the object is on the rotating machines # 1 and # 2 and not on the rotating machine # 3 (t _{2 to} t ₃ ), the load current increase of the rotating machine # 1 is removed to remove the rotating machine. The increase in the total load current derived from # 2 can be specified.

In Fig. 2, the absolute amplitude value is used as an index of increase / decrease in the total load current, but the waveform of the total load current itself, the peak value of a specific frequency component, or the spectrum around the fundamental frequency is used for diagnosis. Other data, such as the level of, may be used.

FIG. 4 is a flowchart (No. 1) for explaining a method of diagnosing a rotating machine using an increase in the total load current.

First, from the idling period to the full load period, the total load current for N rotating machines is measured by the current sensor 11 (step S100).

Next, from the measured data, the time t ₁ when the total load current changes from constant to increase and the time t _N when the total load current changes from increase to constant are detected (step S101).

The determination of the increase may be performed on the absolute value of the amplitude, the peak value of a specific frequency component, or the level of the spectrum around the fundamental frequency.

Once the period during which the total load current increases (from t ₁ at the end of the idling period to t _N at the start of the full load period) can be identified, the time (t ₂ ) at which the total load current increases stepwise within that period. ~ T _n-1 ) is detected, and the time t _k (k = 1,2, ..., N) when the load current of each rotating machine increases is set (step S102).

It should be noted that the plot of the absolute amplitude value of the sum of the load currents may be a straight line / curve or a stepped shape depending on the transfer speed and the measurement frequency of the load current values. In this embodiment, it is assumed that the measurement frequency of the current value is sufficient with respect to the moving speed of the object, and stepwise data is acquired as the absolute swing width of the total load current. On the other hand, for reasons such as measurement accuracy of the load current is not sufficient, if not observed stepwise increase pattern, assuming that the number of the rotating machine load of the object is applied is increased at a constant speed, t _k It is estimated that = t ₁ + (k-1) × (t _N -t ₁ ) / (N-1).

Then the extraction of time-series data of the sum of the load current in the idle period and the full-load period (step S103), and the period _{[t k, t k + 1} ] (k = 1,2, ..., N-1) of the load current in By extracting the total time-series data (step S104) and obtaining the difference from the data in the immediately preceding period, the increase in the load current of each rotating machine during the transportation of the object is extracted (step S105). The difference may be obtained with respect to the absolute amplitude value, the peak value of a specific frequency component, or the level of the spectrum around the fundamental frequency.

Then, the state of the rotating machine is diagnosed based on the value of the increase in the load current extracted for each rotating machine. For example, it is determined whether there is a statistically significant difference compared to the value measured in advance or learned in the normal state, or whether there is a difference equal to or greater than a predetermined threshold value, and if there is a difference, it is abnormal. Is diagnosed (step S106).

In the diagnosis, external factors that affect the load current value, such as information on the weight of the object to be transported, or temperature information on the environment in which each rotating machine is installed, may be added. It is possible to suppress variations in diagnostic results due to changes in external factors. In addition, in a rotary machine system that operates in a harsh environment, maintenance management can be optimized by considering environmental factors.

Finally, the above diagnosis result is displayed to complete the diagnosis (step S107). The display method may be a display, a lamp, a buzzer, or the like that appeals to the five human senses, or may be recorded on paper or an electronic file.

In the first embodiment, the case where the tip of the object reaches the rotating machine group and the total load current increases has been described as an example, but the rear end of the object passes and the rotating machines are released in order. Even when the total load current decreases, it is possible to identify the fluctuation of the load current of each rotating machine and diagnose the state in the same manner. In this embodiment, the description will be focused on the parts different from those in the first embodiment.

FIG. 5 shows a schematic diagram of a decrease in the total load current during a period in which the rear end portion of the object passes over the plurality of rotating machines. In addition, FIG. 6 shows a schematic diagram of the waveform of the total load current during the same period.

From the full load period to the idling period, the total load current decreases stepwise as the number of rotating machines to which the load of the object is applied decreases. Although the absolute amplitude value is used as an index of increase / decrease in the total load current in FIG. 5, the peak value of a specific frequency component or the level of the spectrum around the fundamental frequency may be used.

FIG. 7 is a flowchart (No. 2) for explaining a method of diagnosing a rotating machine using a decrease in the total load current.

First, from the full load period to the idling period, the total load current of N rotating machines is measured by the current sensor 11 (step S200). Then, from the measured data, time t the sum of the load current starts to decrease from the predetermined detecting the _{N '1,} and the sum of the load current time t starts to constant from reduced' (step S201). The determination of the decrease may be performed on the absolute value of the amplitude, the peak value of a specific frequency component, or the level of the spectrum around the fundamental frequency.

Once the period during which the total load current decreases can be identified, the time when the total load current decreases stepwise is detected within that period, and the time when the load current of each rotating machine decreases _t'k (k = 1, 2,…, N) (step S202).

When the measurement accuracy of the load current is not observed stepped reduction pattern for reasons such as insufficient, assuming the number of the rotating machine load of the object is applied is reduced at a constant speed, t _'k = t _{'1 + (k-1)} × (t' N -t '1) / (N-1) and estimated.

Then the extraction of time-series data of the sum of the load current in the full-load period and idle period (step S203), and the period _{[t 'k, t' k} + 1] (k = 1,2, ..., N-1) By extracting the time-series data of the total load current in (step S204) and obtaining the difference from the data in the immediately preceding period, the increase in the load current of each rotating machine during the transportation of the object is extracted (step S204). Step S205).

The difference may be obtained with respect to the absolute amplitude value, the peak value of a specific frequency component, or the level of the spectrum around the fundamental frequency. Then, the value of the increase in the load current extracted for each rotating machine has a statistically significant difference compared to the value in the normal state learned in advance, or the difference is greater than or equal to the predetermined threshold value. If there is a difference, it is diagnosed as abnormal (step S206).

In the diagnosis, information on the weight of the object, temperature information on the environment in which each rotating machine is installed, and the like may be added to suppress variations in the diagnosis result due to changes in external factors.

Finally, the above diagnosis result is displayed to complete the diagnosis (step S207). The display method may be a display, a lamp, a buzzer, or the like that appeals to the five human senses, or may be recorded on paper or an electronic file.

Based on the above, according to Examples 1 and 2, in a drive system in which a plurality of rotating machines are driven by one power converter, an abnormality of each rotating machine is separated from the total current of the plurality of rotating machines. It is possible to realize a diagnostic device that can be detected. Example 1 is a diagnosis when the total load current increases, and Example 2 is a diagnosis when the total load current decreases. However, either one of these may be used in combination, or both may be used in combination. ..

FIG. 8A is a basic configuration diagram of a third embodiment of a rotary machine diagnostic device. The difference from Examples 1 and 2 is that a current sensor for measuring the total load current of the rotating machine is installed on the feeder lines of two phases (for example, U phase and W phase). With such a configuration, the load current of each rotating machine is extracted using the data obtained from each sensor.

By correlating the data of the two phases, it is possible to detect weaker signs of anomalies and increase the probability of detecting anomalies that appear only in a specific phase. For example, by accumulating the data on a plane centered on the data of the two phases as shown in FIG. 8B, it is possible to easily convolve the data in units of one cycle even if the repetition frequency is unknown. By superimposing data belonging to different periods, the sampling rate of measurement can be substantially increased.

FIG. 9 is a basic configuration diagram of a fourth embodiment of a rotary machine diagnostic device. The difference from Examples 1 to 3 is that current sensors for measuring the total load current of the rotating machine are installed on the feeder lines of all phases. With such a configuration, the load current of each rotating machine is extracted using the data obtained from each sensor.

By correlating the data of three phases, it is possible to detect weaker abnormal signs and increase the probability of detecting abnormalities that appear only in a specific phase. For example, by accumulating data in a form of drawing a locus in a multidimensional space centered on data of a plurality of phases, the sampling speed of measurement can be substantially increased. Alternatively, it is also possible to select data of any two phases and accumulate the data in the form of drawing a Lissajous figure as in the third embodiment.

Although the embodiments for carrying out the present invention have been described above with reference to examples, the present invention is not limited to these examples. For example, in Examples 1 to 4, the case of a three-phase motor using three feeder lines is shown as the rotating machine, but rotating machines having different numbers of phases may be used. Further, as an object, a rotary machine system for transporting an object is taken as an example, but the present invention is not limited to the object transport, and can be applied to a rotary machine system in which a rotary machine under a load changes with time. Needless to say, it can be carried out in various forms without departing from the gist of the present invention.

1 Rotating machine # 1
2 Rotating machine # 2
3 Rotating machine # 3
4 rotating machine # 4
5 Rotating machine #N
10 Objects to be transported
11,12,13 Current sensor
20 Collective starter panel
21 Power converter
22 Diagnostic Department
23 Display
24 Current data acquisition unit

Claims (22)

Diagnose the rotating machine based on information from a plurality of rotating machines, a power converter that supplies power to the plurality of rotating machines at once, a current sensor that measures the total load current of the plurality of rotating machines, and information from the current sensor. A diagnostic unit and a display unit that displays the result of diagnosis by the diagnostic unit are provided.
The diagnostic unit extracts the fluctuation of the total load current from the information on the total load current of the plurality of rotating machines, and extracts the increase or decrease of the load current derived from any of the rotating machines.
A rotating machine system characterized in that a rotating machine is diagnosed based on one or both of an increase or a decrease in a load current of the rotating machine. The rotation according to claim 1, wherein the rotating machine system is a rotating machine system that conveys an object, and the total load current fluctuates as the number of rotating machines to which the load of the object is applied increases or decreases. Machine system. The diagnostic unit includes data on an increase or decrease in the load current of the rotating machine in a normal state measured in advance, an increase or decrease in the load current of the extracted rotating machine, and data on the normal state. The rotary machine system according to claim 1, wherein the normality or abnormality of the rotary machine is diagnosed based on the difference between the two. The rotary machine system according to claim 1, wherein the diagnostic unit uses an absolute amplitude value of an increase or decrease in the load current of the rotary machine. The rotary machine system according to claim 1, wherein the diagnostic unit makes a diagnosis using the peak value of a specific frequency component among the increase or decrease of the load current of the rotary machine. The rotary machine system according to claim 1, wherein the diagnostic unit extracts an increase or decrease in the load current of the rotary machine for each frequency and diagnoses using the level of the spectrum around the fundamental frequency. The diagnostic unit displays the increase or decrease of the load current of two or more phases of the rotating machine on a plane or a multidimensional space centered on the data of each phase, and diagnoses using the obtained locus. The rotary machine system according to claim 1. The rotary machine system according to claim 1, wherein the diagnostic unit makes a diagnosis using at least one of information on the weight of an object as a load and information on the temperature of the environment in which the rotary machine is installed. The rotary machine according to claim 1, wherein the diagnostic unit extracts a load current derived from any of the rotary machines from an increase curve or a decrease curve of the total load current as an increase amount or a decrease amount. system. The rotary machine system according to claim 1, wherein the current sensor for measuring the total load current of the rotary machine is installed on a feeder line of at least one phase connected to the rotary machine. The rotary machine system according to claim 1, wherein the current sensor for measuring the total load current of the rotary machine is installed on each of the feeder lines of at least two phases connected to the rotary machine. The rotary machine system according to claim 1, wherein the current sensor for measuring the total load current of the rotary machine is installed on each of a plurality of phase feeder lines connected to the rotary machine. It is a rotary machine diagnostic device that diagnoses multiple rotary machines.
A current data acquisition unit that acquires the total load current supplied to the plurality of rotating machines, and
From the current data, the fluctuation of the total load current is extracted, the increase or decrease of the load current derived from any of the rotating machines is extracted, and one of the increase or decrease of the load current of the rotating machine is extracted. A rotary machine diagnostic device including a diagnostic unit that diagnoses a rotary machine based on both of them and an output unit that outputs a diagnosis result. The diagnostic unit includes data on an increase or decrease in the load current of the rotating machine in a normal state measured in advance, an increase or decrease in the load current of the extracted rotating machine, and data on the normal state. The rotary machine diagnostic device according to claim 13, wherein the normality or abnormality of the rotary machine is detected by the difference between the two. The rotary machine diagnosis according to claim 13, wherein the diagnostic unit uses one or both of the absolute amplitude value of the increase or decrease of the load current of the rotary machine and the peak value of a specific frequency component. apparatus. The rotary machine diagnostic apparatus according to claim 13, wherein the diagnostic unit extracts an increase or decrease in the load current of the rotary machine for each frequency and diagnoses using the level of the spectrum around the fundamental frequency. .. The diagnostic unit displays the increase or decrease of the load current of two or more phases of the rotating machine on a plane or a multidimensional space centered on the data of each phase, and diagnoses using the obtained locus. 13. The rotary machine diagnostic apparatus according to claim 13. It is a rotary machine diagnostic method that diagnoses multiple rotary machines.
The total load current supplied to the plurality of rotating machines is measured, and
The fluctuation of the total load current is extracted from the measured total load current information.
Information on the increase or decrease in the load current derived from any of the rotating machines is extracted and used as the load current information on the rotating machine.
By comparing the load current information of the rotating machine with the load current data of the rotating machine in the normal state, the normality or abnormality of the rotating machine is diagnosed.
A rotary machine diagnostic method characterized by outputting a diagnostic result. In the plurality of rotating machines, the number of rotating machines to which a load is applied increases or decreases at a substantially constant speed during a predetermined period.
The rotary machine diagnostic method according to claim 18, wherein the diagnosis is performed based on the sum of the load currents in the predetermined period. The plurality of rotary machines are rotary machines that carry objects.
The measurement of the total load current is performed during a period in which the front end portion of the object passes over the plurality of rotating machines or a period in which the rear end portion of the object passes over the plurality of rotating machines.
Information on the increase or decrease in the load current derived from the rotating machine is extracted by extracting information on the period during which the front end or the rear end of the object passes over the rotating machine.
18. The rotary machine diagnostic method according to claim 18. The rotary machine diagnosis according to claim 18, wherein the diagnosis of the rotary machine is performed by at least one or a plurality of an absolute amplitude value of the load current of the rotary machine and a load current of a specific frequency of the rotary machine. Method. The total load current is measured for two or more phases.
Information on the load currents of two or more phases of the rotating machine is displayed on a plane or a multidimensional space about each of them.
The rotary machine diagnostic method according to claim 18, wherein the diagnostic of the rotary machine is performed using the display result.

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