WO2021261370A1 - Analyzing device, analysis method, and program - Google Patents

Abstract

This analyzing device is provided with: a current data reading unit for reading three-phase current data, which are data obtained by sampling a three-phase current being supplied to an electric motor; a periodic unit dividing unit which divides the three-phase current data into three-phase alternating current periodic units; a three-phase/two-phase converting unit which converts the three-phase current data into two-phase current data; an error calculating unit which calculates the error, from reference data, of a vector in which the phases of the two-phase current data are used as the horizontal component and the vertical component, and outputs the same as error data; and a processing/output unit which processes the error data in periodic units and for a plurality of periodic units, and outputs the processing results.

Description

Analytical equipment, analytical methods and programs

The present disclosure relates to analyzers, analytical methods and programs.
The present application claims priority based on Japanese Patent Application No. 2020-109490 filed on June 25, 2020, the contents of which are incorporated herein by reference.

As an abnormality diagnosis technique using a motor current, a method of comparing the amplitude probability density of a current waveform (ideally a sine wave) with an ideal current (sine wave) and an actually measured current as described in Patent Document 1 and Patent Document 2 As described in the above, there is a technique for monitoring the current effective value and performing abnormality diagnosis by comparing the thresholds.

Japanese Unexamined Patent Publication No. 2011-257362 Japanese Unexamined Patent Publication No. 2013-05294

However, in the abnormality diagnosis technique described in Patent Document 1 and Patent Document 2, the influence of the abnormality of the motor or auxiliary equipment on the current appears only as numerical values such as the amplitude probability density and the current effective value. Therefore, for example, the presence or absence of the abnormality. There is a problem that the analysis may be inappropriate, such as making it difficult to visually understand.

The present disclosure is made to solve the above-mentioned problems, and provides an analyzer, an analysis method and a program capable of appropriately analyzing the influence of an abnormality of a motor or an accessory on an electric current. The purpose.

In order to solve the above problems, the analyzer according to the present disclosure includes a current data reading unit that reads three-phase current data, which is data obtained by sampling three-phase current supplied to an electric motor, and a three-phase current data. A periodic unit dividing unit that divides in AC periodic units, a three-phase two-phase conversion unit that converts the three-phase current data into two-phase current data, and a vector having each phase of the two-phase current data as a horizontal component and a vertical component. An error calculation unit that calculates an error from the reference data and outputs it as error data, and a processing output unit that processes the error data in the cycle unit and for a plurality of the cycle units and outputs the processing result. Be prepared.

The analysis method according to the present disclosure includes a step of reading the three-phase current data, which is data obtained by sampling the three-phase current supplied to the electric motor, a step of separating the three-phase current data into three-phase AC periodic units, and the above three steps. A step of converting phase current data into two-phase current data, a step of calculating an error from reference data of a vector having each phase of the two-phase current data as a horizontal component and a vertical component, and outputting it as error data. The step includes processing the error data in the cycle unit and for the plurality of cycle units, and outputting the processing result.

The program according to the present disclosure includes a step of reading three-phase current data, which is data obtained by sampling three-phase current supplied to an electric motor, a step of separating the three-phase current data into three-phase AC periodic units, and the three-phase. A step of converting current data into two-phase current data, a step of calculating an error from reference data of a vector having each phase of the two-phase current data as a horizontal component and a vertical component, and outputting it as error data. The computer is made to perform a step of processing the error data in the cycle unit and for the plurality of cycle units and outputting the processing result.

According to the analyzer, analysis method and program of the present disclosure, it is possible to appropriately analyze the influence of an abnormality of an electric motor (motor) or auxiliary equipment on an electric current.

It is a block diagram which shows the structural example of the analyzer which concerns on embodiment of this disclosure. It is a flowchart which shows the operation example of the analyzer which concerns on embodiment of this disclosure. It is a waveform diagram for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a waveform diagram for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a waveform diagram for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a waveform diagram for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a waveform diagram for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a waveform diagram for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a waveform diagram for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a waveform diagram for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a waveform diagram for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a phase plane for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a phase plane for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a phase plane for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a phase plane for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a phase plane for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a phase plane for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a phase plane for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a phase plane for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a waveform diagram for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a phase plane for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a waveform diagram for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a phase plane for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a waveform diagram for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a schematic diagram for demonstrating the operation example of the analyzer which concerns on embodiment of this disclosure. It is a schematic block diagram which shows the structure of the computer which concerns on at least one Embodiment.

(Configuration of analyzer)
Hereinafter, the analyzer, the analysis method, and the program according to the embodiment of the present disclosure will be described with reference to FIGS. 1 to 25. FIG. 1 is a block diagram showing a configuration example of the analyzer according to the embodiment of the present disclosure. FIG. 2 is a flowchart showing an operation example of the analyzer according to the embodiment of the present disclosure. 3 to 11, FIGS. 20, 22, and 24 are waveform diagrams for explaining an operation example of the analyzer according to the embodiment of the present disclosure. 12 to 19, 21 and 23 are phase planes for explaining an operation example of the analyzer according to the embodiment of the present disclosure. FIG. 25 is a schematic diagram for explaining an operation example of the analyzer according to the embodiment of the present disclosure. In each figure, the same reference numerals are used for the same or corresponding configurations, and the description thereof will be omitted as appropriate.

The analyzer 1 according to the embodiment of the present disclosure shown in FIG. 1 is composed of, for example, a computer such as a personal computer, peripheral devices of the computer, and the like, hardware such as a computer and peripheral devices, and a program executed by the computer. As a functional configuration composed of a combination with such software, a processing unit 11, a storage unit 12, and a display unit 13 are provided. Here, the storage unit 12 stores data and the like used by the processing unit 11. Further, the display unit 13 displays characters and figures instructed by the processing unit 11 on a predetermined display screen.

The analyzer 1 shown in FIG. 1 uses the measured values of the three-phase currents Iu, Iv, and Iw supplied from the power supply panel 5 to the electric motor 3, and analyzes the abnormalities of the electric motor 3 and the auxiliary machine 4 which is a rotating machine such as a pump. And make an abnormality diagnosis. In the example shown in FIG. 1, the electric motor 3 is supplied with three-phase currents Iu, Iv, and Iw from a power source 51 such as a commercial power source included in the power supply panel 5 via a switch 52 and a three-phase power supply line 53. The motor 3 is a three-phase AC motor such as a three-phase induction motor, which is connected to the auxiliary machine 4 via a drive shaft 31 and rotationally drives the auxiliary machine 4. Further, the measuring device 2 measures the three-phase currents Iu, Iv, and Iw flowing through the three-phase power supply line 53 using the current sensor 21, samples them at a predetermined cycle, generates three-phase current data, and generates the three-phase current data. Output to. The measuring device 2 may generate three-phase current data from the measured values of the three-phase currents Iu, Iv, and Iw for two phases and the remaining values calculated from the relational expression of Iu + Iv + Iw = 0. .. The electric motor 3 may be directly driven by a three-phase power supply supplied from the three-phase power supply line 53, or may be driven via an inverter, a converter, or the like. Further, the transfer of the three-phase current data from the measuring device 2 to the analyzer 1 may be a real-time process or a batch process.

In the analyzer 1, the processing unit 11 includes a current data reading unit 111, a data interpolation unit 112, a periodic unit dividing unit 113, a phase axis normalizing unit 114, a current amplitude normalizing unit 115, a three-phase two-phase conversion unit 116, and a phase plane. The error radius calculation unit 117 and the processing output unit 118 are included. Further, the processing output unit 118 includes a phase plane error radius expansion unit 1181, an error expansion phase plane drawing unit 1182, a shape strain evaluation value calculation unit 1183, a radius variation evaluation value calculation unit 1184, and a phase plane abnormality degree calculation unit 1185. ..

The current data reading unit 111 reads the three-phase current data, which is the sampled data of the three-phase currents Iu, Iv, and Iw supplied to the motor 3, into the main memory or the like. The current data reading unit 111 may read the three-phase current data from the measuring device 2 or may read the three-phase current data previously stored in the storage unit 12. An example of the three-phase currents Iu, Iv and Iw is shown in FIG. FIG. 3 shows the time variation of the three-phase currents Iu, Iv, and Iw with the horizontal axis representing the time and the vertical axis representing the current value.

Next, the data interpolation unit 112 interpolates the three-phase current data read by the current data reading unit 111 to increase the number of samples of the three-phase current data. Further, the periodic unit dividing unit 113 divides the three-phase current data into three-phase alternating current periodic units. That is, the cycle unit dividing unit 113 performs a process of separating the current waveform for each cycle. Separation of each period can be performed, for example, by searching for a current zero crossing point of a one-phase current (for example, current Iu) and separating all three-phase currents with the same sampling number (or sampling time). .. In the present embodiment, "separation" means to specify the sampling data at the start or end of each cycle, and "cutting out" means to separate and extract the sampling data for each cycle based on the result of the separation processing. Used as.

At the time of separation, if the current data sampling (storage cycle) is rough, the separation position may not be aligned with the current zero crossing point. In such a case, the periodic unit dividing unit 113 can interpolate the three-phase current data into finer sampling by the data interpolation unit 112 and then perform the division. However, the data interpolation process by the data interpolation unit 112 may be omitted. Further, in the data interpolation by the data interpolation unit 112, if continuous smooth interpolation such as linear interpolation or spline interpolation is performed, the distortion of the current in the original data may be smoothed, so that the shape is maintained. It is desirable to use a method such as piecewise tertiary interpolation. FIG. 4 shows the result of dividing the current Iu with the horizontal axis as the time and the vertical axis as the current value. The raw data represents the unprocessed three-phase current data, the broken line represents the three-phase current data in the first cycle after interpolation, and the chain line represents the three-phase current data in the second cycle after interpolation. Further, FIGS. 5 and 6 show an example of interpolation of the current Iu with the horizontal axis as the time and the vertical axis as the current value. Further, FIG. 7 shows an example (an example of overwriting for 60 cycles) in which the waveform obtained by cutting out the current Iu is overwritten with the horizontal axis as the time and the vertical axis as the current value. The AC frequency in the waveform diagram used in the description of this embodiment is 60 Hz.

Next, the phase axis normalization unit 114 normalizes the three-phase current data so that the number of samples for one cycle becomes a constant value. The time axis of the cut out current data includes the original current cycle variation and a slight error in zero cross detection. In addition, since there is a difference of 50 Hz / 60 Hz in the power supply, it is necessary to normalize the horizontal axis in order to evaluate various data in a unified manner. Therefore, the phase axis normalization unit 114 sets the horizontal axis in the current waveform diagram as the phase of 0 to 360 degrees from the time, and interpolates the data so that the number of samples is fixed. As the interpolation method, the same method as that of the data interpolation unit 112 can be used.

Next, the current amplitude normalization unit 115 normalizes the three-phase current data so that the current amplitude becomes a predetermined value. Since the current amplitude normalizing unit 115 differs in the current amplitude depending on the data (measurement target), the amplitude is normalized so that each process described later can be standardized. For example, the current amplitude normalizing unit 115 normalizes the current amplitude so that the average amplitude of the three-phase current for the measurement target time (60 cycles for 1 second) becomes 1. If normalization is performed for each phase, it becomes impossible to capture an abnormal event in which the amplitude changes for only one phase, so all three phases are normalized with the same value.

FIG. 8 shows an example of current Iu (an example of overwriting for 60 cycles) after normalizing the vertical axis and the horizontal axis with the horizontal axis as the phase and the vertical axis as the current value. The unit "deg.pu" on the horizontal axis represents the normalized phase (degrees), and the unit "A.pu" on the vertical axis represents the normalized current value (ampere).

Next, the three-phase two-phase conversion unit 116 converts the sampling values Iu, Iv, and Iw of the three-phase current data into the two-phase current data Id and Iq by the following equation (1) called Park conversion or dq conversion. ..

Further, the three-phase two-phase conversion unit 116 obtains the Park's Vector Ip by the following equation (2). This Ip means the radius of the circle of the phase plane consisting of Id and Iq. Further, Ip (hereinafter, referred to as a phase plane radius Ip) represents the magnitude of a vector having a horizontal component and a vertical component as Id and Iq.

From the above, when the three-phase current is an ideal sine wave with an amplitude Im and the phase is shifted by 120 degrees, the ideal dq-axis current is expressed by the following equation.

The phase plane is a graph (figure) in which a plurality of types of data are divided into two combinations and the data at the same time are plotted on the vertical axis and the horizontal axis (Japanese Patent Laid-Open No. 2017-21182). In the present embodiment, the phase plane is a graph in which the two-phase current data Id and Iq are plotted on the horizontal axis and the vertical axis, and the coordinates determined by Id and Iq at the same time are plotted. When a slight change occurs in the data, the change in the time response results in a similar response waveform, which is often difficult to distinguish, but on the phase plane, even a slight change has the effect of being able to expand graphically. Changes in characteristics can be captured from the difference in shape.

FIG. 9 shows an example of two-phase current data Id and Iq and a phase plane radius Ip with the horizontal axis as the phase and the vertical axis as the current value.

Next, the phase plane error radius calculation unit 117 (error calculation unit) calculates the error from the reference data of the vector having each phase Id and Iq of the two-phase current data as the horizontal component and the vertical component, and uses it as error data. It is output to the phase plane error radius expansion unit 1181 and the like. Here, the reference data is data as a comparison reference with respect to a vector having each phase Id and Iq of the two-phase current data as a horizontal component and a vertical component, and is data at the normal time. The reference data shall correspond to, for example, the ideal value (calculated value) of the magnitude of the vector (phase plane radius Ip), or the two-phase current data based on the three-phase current data sampled at the normal time. Can be done. Further, the phase plane error radius expansion unit 1181 included in the processing output unit 118 expands the error calculated by the phase plane error radius calculation unit 117.

For example, the phase plane error radius calculation unit 117 calculates the error by subtracting the Ip ideal value (reference data of a constant value) from the phase plane radius Ip calculated by the three-phase two-phase conversion unit 116 from the equation (2). can do. That is, the phase plane error radius calculation unit 117 subtracts the amplitude Im × √6 / 2 shown in the equation (3.3) from the calculated phase plane radius Ip to obtain the phase plane radius Ip and the reference data (Ip ideal). The error with the value) (the error in this case is called the phase plane error radius δIp) can be calculated. Since the phase plane radius Ip corresponds to the radius of the circle of the phase plane consisting of Id and Iq, the error from the ideal value of Ip corresponds to the radius error in the phase plane.

Further, the phase plane error radius expansion unit 1181 calculates the expansion error radius δIpmag by expanding the phase plane error radius δIp by a constant multiple Kmag (Kmag is 1 or more) in order to expand the generated phase plane change. do. The expansion error radius δIpmag is calculated as follows.

The error from the reference data of the vector having each phase Id and Iq of the two-phase current data as the horizontal component and the vertical component is not limited to the phase plane error radius δIp, and may be, for example, the circumferential angle error δθ described later. good.

Next, the error expansion phase plane drawing unit 1182 expands the error from the reference data of the vector having each phase Id and Iq of the two-phase current data as the horizontal component and the vertical component, and expands the error from the reference data in a periodic unit on a predetermined unit circle. The process of superimposing is performed for a plurality of cycle units, and as the output of the processing result by the processing output unit 118, the unit circle on which the enlarged error is superimposed is superimposed for a plurality of cycle units and drawn on the predetermined display unit 13. The error expansion phase plane drawing unit 1182 draws the error expansion phase plane by superimposing the expansion error radius δIpmag on the unit circle having the radius 1, for example. Specifically, the points on the dq plane determined by the "Id component" and the "Iq component" obtained by the following equations are drawn by overlapping for a plurality of cycles for each cycle.

An example of drawing an error-enlarged phase plane by the error-enhanced phase plane drawing unit 1182 will be described with reference to FIGS. 10 to 14. FIG. 10 shows an example of normal data used in this drawing example. The horizontal axis is the normalized phase, and the vertical axis is the topological surface error radius δIp for the upper waveform and the circumferential angle error δθ for the lower waveform. The phase plane error radius δIp (δr) is an error from the Ip ideal value (constant value reference data) of the phase plane radius Ip, and the circumferential angle error δθ is the phase value determined from the sampling time (sampling number) (sampling number). It is an error between the reference data) and the phase θ calculated from the equation (5.3). FIG. 11 shows an example of data at the time of abnormality used in this drawing example. Similar to FIG. 10, the horizontal axis is the normalized phase, and the vertical axis is the topological surface error radius δIp for the upper waveform and the circumferential angle error δθ for the lower waveform.

FIG. 12 shows a phase plane in which a three-phase current is directly converted into two phases and taken as it is on two axes without normalization. The solid line is the normal data, and the broken line is the abnormal data. On the current phase plane shown in FIG. 12, the normal data and the abnormal data are almost circular and have no difference.

FIG. 13 shows the error expansion phase plane in the normal state. The currents are overlapped for 60 cycles, but the data for each cycle are almost overlapped. The shape is slightly distorted from the circle (due to the original current quality and equipment configuration).

FIG. 14 shows an error-expanded phase plane at the time of abnormality. There is a variation in the current in 60 cycles. The shape is also distorted compared to normal.

According to this embodiment, it is possible to visualize changes in current that cannot be understood by simply drawing the phase plane as variations on the phase plane and shape distortion.

Next, with reference to FIGS. 15 to 18, an example in which the phase plane error radius calculation unit 117 corresponds to the two-phase current data based on the three-phase current data sampled at the normal time will be described. do. In the above example, when calculating the phase plane error radius δIp, the error from the ideal Ip (fixed value) calculated from the ideal current was calculated, but if the normal data of the target plant can be obtained, the normal data. By storing the average two-phase current data Id and Iq of the above and using the phase plane radius Ip calculated from them for error calculation as reference data, it is possible to visualize the difference from the normal, not the difference from the ideal. Become.

FIG. 15 shows a phase plane (error-enhanced phase plane) in which the error from the phase plane radius Ip obtained from the three-phase current data in the normal state (1) is expanded with the ideal value of the phase plane radius Ip as the reference data.

FIG. 16 shows a phase plane (error expansion phase plane) using the average of the normal time (1) as the reference data with respect to the three-phase current data in the normal time (1). The error-enhanced phase plane of FIG. 16 is slightly distorted into a hexagonal shape, but as expected, this figure is almost circular.

FIG. 17 shows a phase plane (error expansion phase) using the average of the normal time (1) as the reference data with respect to the three-phase current data of the normal time (2), which is the data of the normal time different from the normal time (1). Surface) is shown. It is assumed that it will be circular in almost the same manner as in FIG.

FIG. 18 shows a phase plane (error-enlarged phase plane) using the average of normal time (1) as reference data for abnormal data.

Next, the shape strain evaluation value calculation unit 1183 (strain evaluation value calculation unit) within the period unit of the error from the reference data of the vector having each phase Id and Iq of the two-phase current data as the horizontal component and the vertical component. The value corresponding to the variation is calculated as a shape strain evaluation value (strain evaluation value). The shape strain evaluation value calculation unit 1183 obtains, for example, the average value of each error of a plurality of cycle units at a plurality of points in the cycle unit, and calculates the value corresponding to the standard deviation of each average value as the shape strain evaluation value. ..

Next, the radius variation evaluation value calculation unit 1184 (variation evaluation value calculation unit) is a plurality of periodic units of errors from the reference data of the vector having each phase Id and Iq of the two-phase current data as the horizontal component and the vertical component. The value corresponding to the variation between the two is calculated as the radius variation evaluation value (variation evaluation value). The radius variation evaluation value calculation unit 1184 obtains, for example, the standard deviation of each error of a plurality of periodic units at a plurality of points in the periodic unit, and calculates the value corresponding to the average value of each standard deviation as the radius variation evaluation value. ..

Next, the phase plane abnormality calculation unit 1185 (abnormality calculation unit) calculates the phase plane abnormality (abnormality) indicating the degree of abnormality based on the shape strain evaluation value and the radius variation evaluation value, and processes the output unit. As the processing result of 118, at least one of the phase surface abnormality degree or the determination result comparing the phase surface abnormality degree and the predetermined threshold value is output. The phase plane abnormality calculation unit 1185 calculates, for example, a value obtained by adding a value obtained by multiplying the shape strain evaluation value by the first weighting coefficient and a value obtained by multiplying the radius variation evaluation value by the second weighting coefficient as the phase plane abnormality degree. do.

In the present embodiment, the changes in the error expansion phase plane that occur at the time of abnormality are roughly divided into (1) a pattern in which the distortion of the shape becomes large (FIG. 19) and (2) a pattern in which the variation in radius becomes large (FIG. 21). ) And the merged pattern (strain angle deviation) of (3), (1) and (2) (FIG. 23).

FIG. 19 shows a phase plane (error expansion phase plane) using the average of the normal time (1) as the reference data with respect to the three-phase current data in the abnormal time (1). Further, FIG. 20 has a normalized phase on the horizontal axis and a phase plane error radius δIp on the vertical axis, and shows the data at the time of abnormality (1) shown in FIG.

FIG. 21 shows a phase plane (error expansion phase plane) using the average of the normal time (1) as the reference data with respect to the three-phase current data in the abnormal time (2). Further, FIG. 22 shows the data at the time of abnormality (2) shown in FIG. 21 with the normalized phase on the horizontal axis and the phase plane error radius δIp on the vertical axis.

FIG. 23 shows a phase plane (error expansion phase plane) using the average of the normal time (1) as the reference data with respect to the three-phase current data in the abnormal time (3). Further, FIG. 24 shows the data at the time of abnormality (3) shown in FIG. 23, with the horizontal axis representing the normalized phase and the vertical axis representing the phase plane error radius δIp.

Focusing on the phase plane error radius δIp, if there is no change due to the “1” period but there is a fluctuation in the phase plane error radius δIp, or if the offset of the “2” phase plane error radius δIp changes, then “3” “ There is a pattern of merging "1" and "2".

"1" has a variation between 360 degrees when the average value is calculated for each phase on the horizontal axis. "2" is large on average when the standard deviation is calculated for each phase on the horizontal axis.

Therefore, in the present embodiment, for the evaluation of the shape strain, the one-period standard deviation of the average value in each phase of the phase plane error radius δIp is evaluated as the shape strain evaluation value. Further, regarding the evaluation of the radius variation, the one-period average of the standard deviation in each phase of the phase plane error radius δIp is evaluated as the radius variation evaluation value. Further, these are combined to form weight coefficients K1 and K2 (first weight coefficient, second weight coefficient), and the degree of abnormality is defined by the following equation.

In the example shown in FIG. 25, the shape strain evaluation values are the average of each point d11 and d21, the average of each point d12 and d22, and the average of each point d13 and d23 at each phase P1, P2, P3 and P4. And the average of each point d14 and d24 is calculated, and the standard deviation of the average value obtained in one cycle (0 to 360 degrees) can be used as the shape strain evaluation value. In FIG. 25, the horizontal axis is the normalized phase, the vertical axis is the phase plane error radius δIp, and the phase plane error radius δIp for two cycles is shown as data Ip1 and data Ip2.

Further, in the example shown in FIG. 25, the radius variation evaluation values are the standard deviations of the points d11 and d21, the standard deviations of the points d12 and d22, and the points d13 and d23 at each phase P1, P2, P3 and P4. The standard deviation and the standard deviation of each point d14 and d24 can be calculated, and the average value obtained in one cycle (0 to 360 degrees) can be used as the radius variation evaluation value.

Further, the values of the weighting coefficients K1 and K2 can be determined, for example, as follows. That is, for example, abnormal data may be accumulated and manually determined from the data. Since the strain and variation are separated, K1 can be kept small if the power supply quality is known to be poor and the shape is known to be distorted (and vice versa). Further, in the case of the ideal current reference, it is possible to reduce K1 without evaluating the strain and increase K1 to start the evaluation of strain when normal data is accumulated. As a result, it is possible to avoid issuing an abnormality warning due to the occurrence of shape distortion due to power supply quality or the like at the first measurement. Further, the optimum solution of K1 and K2 may be searched by reinforcement learning using the abnormal data as the test data. For example, when there are 10 pieces of data known to be normal and 30 pieces of data known to be abnormal, the shape strain evaluation value and the radius variation evaluation value are calculated, respectively. Therefore, the weights of K1 and K2 are automatically searched so that the abnormal data is determined to be abnormal and the normal data is determined to be normal.

As other anomalies, not only the variation in the phase plane error radius δIp but also the circumferential angle error δθ described with reference to FIG. 10 and the like may be included. It may also be calculated based on the area of the circle.

(Operation example of analyzer)
Next, an operation example of the analyzer 1 shown in FIG. 1 will be described with reference to FIG. The process shown in FIG. 2 is started, for example, in response to a predetermined instruction operation by the operator. In the process shown in FIG. 2, first, the current data reading unit 111 reads the three-phase current data (step S11). Next, the data interpolation unit 112 and the period unit division unit 113 interpolate the three-phase current data and perform division for each period (step S12). Next, the phase axis normalization unit 114 normalizes the three-phase current data with the horizontal axis as the phase (step S13). Next, the current amplitude normalization unit 115 normalizes the current amplitude of the three-phase current data (step S14). Next, the three-phase two-phase conversion unit 116 converts the three-phase current data into the two-phase current data (step S15). Next, the phase plane error radius calculation unit 117 calculates the phase plane error radius, and the phase plane error radius expansion unit 1181 expands the error radius (step S16). Next, the error-enhanced phase plane drawing unit 1182 draws the error-enhanced phase plane (step S17). Next, the shape strain evaluation value calculation unit 1183 calculates the shape strain evaluation value (step S18). Next, the radius variation evaluation value calculation unit 1184 calculates the radius variation evaluation value (step S19). Next, the phase plane abnormality calculation unit 1185 calculates the phase plane abnormality (step S20), and evaluates the phase plane abnormality by, for example, comparing the calculated phase plane abnormality with a predetermined threshold value (step). S21), the comparison result with the threshold value and the degree of phase plane abnormality are displayed as evaluation results on, for example, the display unit 13 (step S22).

(Action / effect)
As described above, according to the present embodiment, the phase plane can be drawn by using the three-phase current of the electric motor 3, and the abnormality diagnosis can be performed from the phase plane. Since the three-phase current is out of phase by 120 degrees, if the phase plane is simply drawn with two of them, it becomes an oblique ellipse. Therefore, in the present embodiment, a process of converting a three-phase current into a two-phase current is performed. In addition, by calculating and expanding the error from the ideal current, the change in the phase plane due to the abnormality is expanded. In addition, from the characteristics of the phase plane, the shape strain and radius variation of the phase plane are quantified as feature quantities, and the degree of abnormality is defined as the linear sum thereof, which can be applied to abnormality diagnosis.

That is, according to the present embodiment, it is possible to visualize a slight change in the current due to an abnormality in the motor 3 and the auxiliary equipment 4. In other words, according to the present embodiment, it is possible to appropriately analyze the influence of abnormalities on the electric motor and auxiliary machinery on the current. In addition, by visualization, not only the abnormality but also the normal condition of the normal state can be visualized (the original power supply quality is not a clean sine wave, etc.). In addition, it can be used for abnormality diagnosis by quantifying the distortion of the shape and the variation of the radius, which are the changes in the phase plane, and defining it as the degree of abnormality. That is, it is possible to quantitatively grasp the variation within the AC cycle and the variation between a plurality of AC cycles.

(Other embodiments)
Although the embodiment of the present disclosure has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes design changes and the like within a range not deviating from the gist of the present disclosure. ..

<Computer configuration>
FIG. 26 is a schematic block diagram showing the configuration of a computer according to at least one embodiment.
The computer 90 includes a processor 91, a main memory 92, a storage 93, and an interface 94.
The diagnostic device 1 described above is mounted on the computer 90. The operation of each of the above-mentioned processing units is stored in the storage 93 in the form of a program. The processor 91 reads a program from the storage 93, expands it into the main memory 92, and executes the above processing according to the program. Further, the processor 91 secures a storage area corresponding to each of the above-mentioned storage units in the main memory 92 according to the program.

The program may be for realizing a part of the functions exerted by the computer 90. For example, the program may exert its function in combination with another program already stored in the storage or in combination with another program mounted on another device. In another embodiment, the computer may include a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to or instead of the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, some or all of the functions realized by the processor may be realized by the integrated circuit.

Examples of the storage 93 include HDD (Hard Disk Drive), SSD (Solid State Drive), magnetic disk, optical magnetic disk, CD-ROM (Compact Disc Read Only Memory), DVD-ROM (Digital Versatile Disc Read Only Memory). , Semiconductor memory and the like. The storage 93 may be an internal medium directly connected to the bus of the computer 90, or an external medium connected to the computer 90 via the interface 94 or a communication line. When this program is distributed to the computer 90 by a communication line, the distributed computer 90 may expand the program to the main memory 92 and execute the above process. In at least one embodiment, the storage 93 is a non-temporary tangible storage medium. The

<Additional Notes>
The analyzer 1 described in the above embodiment is grasped as follows, for example.

(1) The analyzer 1 according to the first aspect has a current data reading unit 111 that reads three-phase current data, which is data obtained by sampling three-phase current supplied to the electric motor 3, and a three-phase current data. The periodic unit dividing unit 113 that divides the three-phase current data into two-phase current data, the three-phase two-phase conversion unit 116 that converts the three-phase current data into two-phase current data, and each phase of the two-phase current data as a horizontal component and a vertical component. An error calculation unit (phase surface error radius calculation unit 117) that calculates an error (phase surface error radius δIp, circumferential angle error δθ) from the reference data of the vector to be output and outputs the error data, and the error data is described above. It is provided with a processing output unit 118 that processes the periodic units and outputs the processing results. According to this aspect and the following aspects, it is possible to appropriately analyze the influence of the abnormality of the motor and accessories on the current.

(2) The analysis device 1 according to the second aspect is the analysis device 1 of (1), and the processing output unit 118 expands the error and superimposes the error on a predetermined unit circle in the cycle unit. The processing is performed for a plurality of the periodic units, and as an output of the processing result, the unit circle on which the enlarged error is superimposed is superimposed for the plurality of the periodic units and drawn on a predetermined display unit 13. According to this configuration, it is possible to visualize a slight change in current due to an abnormality in the motor or auxiliary equipment.

(3) The analysis device 1 according to the third aspect is the analysis device 1 of (1) or (2), and the processing output unit 118 is a strain evaluation value calculation unit (shape strain evaluation value calculation unit 1183). It has a variation evaluation value calculation unit (radiation variation evaluation value calculation unit 1184) and an abnormality degree calculation unit (phase plane abnormality degree calculation unit 1185), and the strain evaluation value calculation unit is the periodic unit of the error. The value corresponding to the variation in the above is calculated as a strain evaluation value (shape strain evaluation value), and the variation evaluation value calculation unit sets a value corresponding to the variation between a plurality of the periodic units of the error as a variation evaluation value. It is calculated as (radial variation evaluation value), and the abnormality degree calculation unit calculates an abnormality degree (phase plane abnormality degree) indicating the degree of abnormality based on the strain evaluation value and the variation evaluation value, and as the processing result. The degree of abnormality or at least one of the determination results comparing the degree of abnormality with a predetermined threshold is output. According to this configuration, the shape strain and radius variation, which are changes in the phase plane, can be quantified, defined as the degree of abnormality, and used for abnormality diagnosis.

(4) The analyzer 1 according to the fourth aspect is the analyzer 1 of (1) to (3), and the reference data corresponds to an ideal value of the magnitude of the vector, and the error calculation unit. Calculates the difference between the magnitude of the vector and the reference data as the error.

(5) The analyzer 1 according to the fifth aspect is the analyzer 1 of (1) to (3), and the reference data is the two-phase current based on the three-phase current data sampled at the normal time. Corresponding to the data, the error calculation unit calculates the error by comparing the vector and the reference data in the periodic unit.

(6) The analyzer 1 according to the sixth aspect is the analyzer 1 of (1) to (5), further including a data interpolation unit 112 that interpolates the three-phase current data to increase the number of samples. The periodic unit dividing unit 113 divides the three-phase current data interpolated by the data interpolating unit 112 in the periodic unit of the three-phase AC.

(7) The analyzer 1 according to the seventh aspect is the analyzer 1 of (1) to (6), and the three-phase current data is normalized so that the number of samples for one cycle becomes a constant value. The phase axis normalization unit 114 is further provided, and the three-phase two-phase conversion unit 116 converts the three-phase current data normalized by the phase axis normalization unit 114 into the two-phase current data.

(8) The analyzer 1 according to the eighth aspect is the analyzer 1 of (1) to (7), and the current amplitude normalization normalizes the three-phase current data so that the current amplitude becomes a predetermined value. The three-phase two-phase conversion unit 116 further includes a conversion unit 115, and the three-phase two-phase conversion unit 116 converts the three-phase current data normalized by the current amplitude normalization unit 115 into the two-phase current data.

(9) The analysis device 1 according to the ninth aspect is the analysis device 1 of (3), and the strain evaluation value calculation unit has a plurality of points in the cycle unit and each error of the plurality of cycle units. The average value of the above is obtained, the value corresponding to the standard deviation of each of the average values is calculated as the strain evaluation value, and the variation evaluation value calculation unit performs each of the plurality of each of the plurality of cycle units at a plurality of points in the cycle unit. The standard deviation of the error is obtained, the value corresponding to the average value of each standard deviation is calculated as the variation evaluation value, and the abnormality degree calculation unit multiplies the strain evaluation value by the first weighting coefficient. The value obtained by adding the value obtained by multiplying the variation evaluation value by the second weighting coefficient is calculated as the degree of abnormality.

According to the above-mentioned analyzer, analysis method and program, it is possible to appropriately analyze the influence of an abnormality of an electric motor (motor) or auxiliary equipment on an electric current.

1 Analytical device 3 Electric motor 4 Auxiliary machine 11 Processing unit 12 Storage unit 13 Display unit 111 Current data reading unit 112 Data interpolation unit 113 Periodic unit segmentation unit 114 Phase axis normalization unit 115 Current amplitude normalization unit 116 Three-phase two-phase conversion unit 117 Phase plane error radius calculation unit 118 Processing output unit 1181 Phase plane error radius expansion unit 1182 Error expansion Phase plane drawing unit 1183 Shape strain evaluation value calculation unit 1184 Radiation variation evaluation value calculation unit 1185 Phase plane abnormality degree calculation unit

Claims (11)

1. A current data reading unit that reads three-phase current data, which is data obtained by sampling the three-phase current supplied to the motor,
   A periodic unit dividing unit that divides the three-phase current data into three-phase alternating current periodic units,
   A three-phase two-phase converter that converts the three-phase current data into two-phase current data,
   An error calculation unit that calculates an error from the reference data and outputs it as error data for a vector having each phase of the two-phase current data as a horizontal component and a vertical component.
   A processing output unit that processes the error data in the cycle unit and for a plurality of the cycle units and outputs the processing result.
   An analyzer equipped with.
2. The processing output unit expands the error, performs a process of superimposing the error on a predetermined unit circle in the cycle units for a plurality of the cycle units, and superimposes the enlarged error on the output of the processing result. The analyzer according to claim 1, wherein the unit circles are overlapped by a plurality of the periodic units and drawn on a predetermined display unit.
3. The processing output unit has a strain evaluation value calculation unit, a variation evaluation value calculation unit, and an abnormality degree calculation unit.
   The strain evaluation value calculation unit calculates a value corresponding to the variation of the error within the period unit as a strain evaluation value.
   The variation evaluation value calculation unit calculates a value corresponding to the variation between the plurality of cycle units of the error as a variation evaluation value.
   The abnormality degree calculation unit calculates an abnormality degree indicating the degree of abnormality based on the strain evaluation value and the variation evaluation value, and determines that the abnormality degree or the abnormality degree is compared with a predetermined threshold value as the processing result. The analyzer according to claim 1 or 2, which outputs at least one of the results.
4. The reference data corresponds to an ideal value of the magnitude of the vector.
   The analyzer according to any one of claims 1 to 3, wherein the error calculation unit calculates the difference between the magnitude of the vector and the reference data as the error.
5. The reference data corresponds to the two-phase current data based on the three-phase current data sampled at normal times.
   The analyzer according to any one of claims 1 to 3, wherein the error calculation unit calculates the error by comparing the vector and the reference data in the periodic unit.
6. A data interpolation unit that interpolates the three-phase current data to increase the number of samples is further provided.
   The analyzer according to any one of claims 1 to 5, wherein the periodic unit dividing unit divides the three-phase current data interpolated by the data interpolation unit into the periodic units of the three-phase alternating current.
7. Further provided with a phase axis normalization unit that normalizes the three-phase current data so that the number of samples for one cycle becomes a constant value.
   The analyzer according to any one of claims 1 to 6, wherein the three-phase two-phase conversion unit converts the three-phase current data normalized by the phase axis normalization unit into the two-phase current data.
8. Further provided with a current amplitude normalization unit that normalizes the three-phase current data so that the current amplitude becomes a predetermined value.
   The analyzer according to any one of claims 1 to 7, wherein the three-phase two-phase conversion unit converts the three-phase current data normalized by the current amplitude normalization unit into the two-phase current data.
9. The strain evaluation value calculation unit obtains the average value of each of the errors in the plurality of periodic units at a plurality of points in the periodic unit, and calculates the value corresponding to the standard deviation of each average value as the strain evaluation value. death,
   The variation evaluation value calculation unit obtains the standard deviation of each of the errors in the plurality of periodic units at a plurality of points in the periodic unit, and calculates the value corresponding to the average value of the standard deviations as the variation evaluation value. death,
   According to claim 3, the abnormality degree calculation unit calculates the value obtained by adding the value obtained by multiplying the strain evaluation value by the first weighting coefficient and the value obtained by multiplying the variation evaluation value by the second weighting coefficient as the abnormality degree. The analyzer described.
10. The step of reading the three-phase current data, which is the data obtained by sampling the three-phase current supplied to the motor,
    The step of separating the three-phase current data in units of three-phase alternating current cycles,
    The step of converting the three-phase current data into two-phase current data,
    A step of calculating an error from the reference data of a vector having each phase of the two-phase current data as a horizontal component and a vertical component and outputting it as error data.
    A step of processing the error data in the cycle unit and for a plurality of the cycle units and outputting the processing result.
    Analytical methods including.
11. The step of reading the three-phase current data, which is the data obtained by sampling the three-phase current supplied to the motor,
    The step of separating the three-phase current data in units of three-phase alternating current cycles,
    The step of converting the three-phase current data into two-phase current data,
    A step of calculating an error from the reference data of a vector having each phase of the two-phase current data as a horizontal component and a vertical component and outputting it as error data.
    A step of processing the error data in the cycle unit and for a plurality of the cycle units and outputting the processing result.
    A program that causes a computer to run.

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