JP2010273481A - Power quality evaluation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To estimate a device failure that degrades power quality and an abnormal state as a sign thereof, from a failure probability of each component constituting the device. <P>SOLUTION: The power quality evaluation system includes: failure estimation devices 8a-8d which calculate a matching degree of harmonic component between an actually measured harmonic component calculation result obtained by waveform analysis of the electrical quantity acquired from each component of a device connected to a power grid, and a plurality of harmonic failure harmonic component comprising a harmonic failure pattern which is estimated as a failure of each component stored in advance as well as a harmonic failure representing an abnormal state as a sign thereof, and based on the matching degree of harmonic component, specifies a failure of each component and a harmonic failure pattern which is a sign of the failure and outputs it as a harmonic failure estimation result. The system also includes: a plurality of failure probability conversion process parts 10A which convert the harmonic failure estimation results output from the failure estimation devices to failure probabilities, and an entire failure probability estimation process part for estimating the entire failure estimation result of the device based on the converted failure probability of each component. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power quality evaluation system that evaluates deterioration of power quality due to harmonics, voltage fluctuation, voltage imbalance, instantaneous voltage drop, and the like generated in a power system.

  2. Description of the Related Art Conventionally, a power quality measuring device and a power quality analyzing device that measure or analyze the degree of power quality such as harmonics, voltage fluctuation, voltage imbalance, and instantaneous voltage drop generated in a power system have been put into practical use.

  One technique is to collect samples of failure factor-specific waveforms in advance using a simulated high-voltage distribution line, and analyze harmonic components up to a predetermined order of each sample waveform. And after calculating | requiring the sum total of the average value for every order of a harmonic content rate according to a failure factor, the maximum value and minimum value of the sum total data according to a failure factor are calculated and memorize | stored. Estimate the cause of the ground fault of the high-voltage distribution line based on whether or not the current waveform flowing in the zero phase of the actual high-voltage distribution line is in the range between the maximum and minimum values for each failure factor (Patent Document 1).

  Another technique detects fluctuation active and fluctuation reactive parts before and after the transient state of the fundamental wave active power and fundamental wave reactive power in the consumer's power supply system, and the consumer is based on the magnitude of the fluctuation. Operating conditions such as turning on / off the load, power factor improving capacitor, transformer, etc. This technology also performs frequency analysis of the current when the power supply system is turned on, and the waveform pattern of the harmonic component differs for each device constituting the power supply system, and the change pattern in which the harmonic component ratio changes with time. Assuming that the situation is satisfied, the operating state of the power supply system of the consumer and the failure generating device are specified (Patent Document 2).

Japanese Patent Laid-Open No. 06-287451 Japanese Patent No. 31052355

  However, the former technology only identifies the cause of the ground fault of the high-voltage distribution line, and the latter technology mainly identifies the operating state of the customer's power supply system on / off, It is not a power quality evaluation system that estimates a failure of a device connected to the power system from the abnormal state or an abnormality that is a precursor.

  The present invention has been made in view of the above circumstances, taking in electric quantities such as voltage and current supplied to each component constituting a device connected to the power system, while considering the failure probability of each component. An object of the present invention is to provide a power quality evaluation system for estimating a failure of the apparatus or an abnormality that is a precursor thereof.

  In order to solve the above-mentioned problems, the power quality evaluation system according to the present invention is extracted from various components connected to the power system, for example, main components constituting individual devices such as an uninterruptible power supply, a generator, and load equipment. Harmonic abnormalities that are estimated to be harmonic abnormalities that indicate the failure of each major part that is stored in advance and the abnormalities that are precursors to it, as well as the actual harmonic component calculation results obtained by analyzing waveforms of electrical quantities such as voltage and current. Calculate the harmonic component coincidence with a plurality of harmonic abnormal harmonic components consisting of patterns, and identify the harmonic anomaly pattern that indicates the malfunction and precursor abnormality of each major component from each harmonic component coincidence, A failure estimation device for each major part that is output as a harmonic abnormality estimation result, and a plurality of failure probability conversion processes that convert the harmonic abnormality estimation results output from each failure estimation device into failure probabilities, respectively. Stage and a configuration in which a total failure probability estimation processing unit for estimating the abnormality as a failure or its precursors of the device from the failure probability of each major part obtained by each failure probability conversion processing means.

  In addition, as the failure estimation apparatus for each main part, the amount of electricity such as voltage and current supplied to a plurality of main parts constituting the apparatus connected to the power system is analyzed, and the harmonic component is calculated. Harmonic component calculation means, a harmonic abnormality database that stores a plurality of harmonic abnormal harmonic components that are estimated in advance as a harmonic abnormality indicating a failure of each main part or an abnormality that is a precursor thereof, and the harmonic component Harmonic component coincidence calculation means for calculating the harmonic component coincidence between the actual harmonic component calculation result obtained by the calculation means and a plurality of harmonic abnormal harmonic components stored in the harmonic abnormality database; From the harmonic component coincidence calculated by the wave component coincidence calculation means, a harmonic abnormality pattern indicating a failure of each major component or an abnormality that is a precursor thereof is identified and output as a harmonic abnormality estimation result. A configuration and a harmonic abnormality estimation means.

  Further, the power quality evaluation system according to the present invention has a harmonic component coincidence degree with respect to a harmonic abnormality pattern having a harmonic abnormality harmonic component having a high harmonic component coincidence degree for each of a plurality of main components constituting the device. It is the structure which displays in order of a high harmonic abnormality pattern.

  Furthermore, the power quality evaluation system according to the present invention displays the harmonic component coincidence for each harmonic abnormality pattern from the harmonic component coincidence calculating unit on the display device instead of the harmonic abnormality estimating unit, and In a configuration provided with a result display control means for repeatedly calculating the harmonic component coincidence every predetermined time and displaying a time-series change between the harmonic abnormality pattern and the harmonic component coincidence on the display device. is there.

  According to the present invention, the failure probability of each component and the failure probability of each component from the harmonic component obtained by waveform analysis by taking in electric quantities such as voltage and current supplied to each component constituting the apparatus connected to the power system. Therefore, it is possible to provide a power quality evaluation system that can estimate a failure of a device and an abnormality that is a precursor thereof.

The system conceptual diagram of the power supply system of the consumer which applied the electric power quality evaluation system which concerns on this invention. The schematic block diagram which shows 1st Embodiment of the electric power quality evaluation system which concerns on this invention. The figure explaining the relationship between each principal component which comprises an apparatus, and the amount of electricity. The block diagram which shows one specific example of the apparatus abnormality estimation apparatus of FIG. Explanatory drawing for demonstrating the effect | action of the apparatus abnormality estimation apparatus shown in FIG. Explanatory drawing for demonstrating the effect | action of the whole failure probability estimation process part shown in FIG. The block diagram which shows one specific example of the failure estimation apparatus shown in FIG. The figure explaining the voltage waveform example for two phases between lines which is an example of the amount of electricity. The block diagram which used the FFT process part which is a specific example of a harmonic component calculation means. The figure which shows an example of the measurement harmonic component result calculated by the harmonic component calculation means. Explanatory drawing which shows the example of the several harmonic abnormality pattern which consists of multiple orders estimated with the harmonic abnormality memorize | stored in a harmonic abnormality database. The figure explaining the functional block and processing content of a harmonic component coincidence calculation means. The figure explaining normalization of the harmonic component by a harmonic component coincidence calculation means. The figure explaining the example in which the normalized measurement harmonic component result and the normalized harmonic generator harmonic component correspond. The figure explaining the example in which the normalized actual harmonic component result and the normalized harmonic generator harmonic component are not in agreement at all. The figure explaining the example in which the normalized actual harmonic component result and the normalized harmonic generator harmonic component partially correspond. The figure showing the relationship between the degree of coincidence of the standardization measurement harmonic component calculation result and the standardization harmonic abnormal harmonic component, and the standardization difference total value. The figure showing the relationship between a harmonic component coincidence degree and the standardization difference total value from another viewpoint. The block diagram which shows a specific example of the harmonic abnormality estimation means shown in FIG. The figure explaining the relationship between a harmonic abnormal harmonic component and a harmonic component coincidence degree. The figure which shows the example of a display of a harmonic component coincidence degree and a harmonic abnormal pattern. The other structural example figure of the failure estimation apparatus explaining 2nd Embodiment of the electric power quality evaluation system which concerns on this invention. The figure which shows the example of a display of the time-sequential change of the harmonic component coincidence for every several harmonic abnormal pattern acquired for every fixed time. The schematic block diagram which shows 3rd Embodiment of the electric power quality evaluation system which concerns on this invention. The figure which shows the example of 1 display of the failure probability of the main components which comprise an apparatus, and the failure probability of an apparatus. The figure which shows the example which displayed the failure probability of the main components which comprise an apparatus, and the failure probability of the said apparatus as a time-sequential change with a predetermined time interval. The figure explaining the example which outputs alarm information, when the failure probability of the main components which comprise an apparatus, and the failure probability of the said apparatus are larger than the predetermined value defined beforehand. The figure explaining the example which forecasts a future failure probability from the failure probability of the main components which comprise an apparatus, and the failure probability of the said apparatus.

  Prior to the description of embodiments of the present invention with reference to the drawings, the background to the realization of the present invention will be described below.

  Various devices (for example, an uninterruptible power supply (UPS), a generator, a load facility, etc.) constituting a power supply system are connected to a power system bus of a consumer connected to a higher-level commercial power system. When evaluating the power quality of such a power supply system, even if one device is normal, if another device has a failure or an anomaly that is a precursor, the power quality deteriorates and is viewed from the power supply system as a whole In the future, there is a possibility of suffering major damage such as operation suspension.

  Furthermore, when a device has a failure or an abnormality that is a precursor thereof, there are many examples in which a major component constituting the device has a failure or a precursor abnormality. For this reason, it is necessary to grasp the possibility of failure or abnormality of the main components constituting the apparatus, and as a result, it is possible to more accurately estimate the failure of the apparatus or the abnormality that is a precursor.

  Therefore, the present inventors realize a system for appropriately evaluating the power quality based on the above situation.

(First embodiment)
FIG. 1 is a system conceptual diagram showing an example in which the power quality evaluation system according to the present invention is applied to a power system.
The bus 1 that receives power supplied from the upper power system includes various devices that vary depending on the customer, for example, an uninterruptible power supply (hereinafter referred to as UPS) 2a, a generator 2b, a load facility 2c, and many others. The device is connected.

  By way of example, UPS 2a is composed of main parts 11a to 11d such as a fan, a capacitor, a D / D converter, a substrate, and a battery, and any one of these main parts 11a to 11d is broken or a precursor. If an abnormality has occurred, it will cause the power quality to deteriorate.

  Therefore, the measuring devices 3a, 3b, 3c, and 3d are connected to the main parts 11a to 11d, respectively, and the electric quantities 4a, 4b, 4c, and 4d including the voltage and current supplied to the main parts 11a to 11d are measured, The data is transmitted to the power quality evaluation system 6 through the transmission systems 5a, 5b, 5c and 5d. The power quality evaluation system 6 calculates the harmonic component superimposed on the voltage and current, and based on the calculated actual harmonic component calculation result and the harmonic abnormal harmonic component stored in advance, the failure of the device 2a And anomalies that are precursors.

  In addition, although measuring device 3a, 3b, 3c, 3d was connected to each main component 11a-11d separately, for example, one measuring device is selectively connected to each main component 11a-11d, and the required electric quantity is obtained. The structure which acquires may be sufficient.

FIG. 2 is a schematic configuration diagram showing the first embodiment of the power quality evaluation system 6 according to the present invention. 2 to 4 correspond to the first aspect.
The power quality evaluation system 6 analyzes the electric quantities 4a, 4b, 4c, 4d sent from the measuring devices 3a, 3b, 3c, 3d through the transmission systems 5a, 5b, 5c, 5d, and the harmonic abnormality estimation result 7a. , 7b, 7c, 7d, and a failure estimation device 8a, 8b, 8c, 8d, and a device abnormality estimation device 10 that outputs a device abnormality estimation value 9 from these harmonic abnormality estimation results 7a, 7b, 7c, 7d. Is done.

  Here, when the apparatus 2 (for example, UPS 2a) is composed of, for example, main parts 11a, 11b, 11c, and 11d as shown in FIG. 3, the electricity appearing at the input / output of these main parts 11a, 11b, 11c, and 11d. After the quantities 4a, 4b, 4c, and 4d are captured by the corresponding failure estimation devices 8a, 8b, 8c, and 8d, the electrical quantities 4a, 4b, 4c, and 4d are respectively analyzed from the harmonic components obtained by waveform analysis. The wave abnormality estimation results 7a, 7b, 7c, and 7d are taken out and passed to the apparatus abnormality estimation apparatus 10.

  The apparatus abnormality estimation device 10 converts the harmonic abnormality estimation results 7a, 7b, 7c, and 7d into failure probabilities of the main parts 11a, 11b, 11c, and 11d, and from the failure probabilities of these main parts 11a, 11b, 11c, and 11d. An apparatus abnormality estimated value 9 that is the failure probability of the entire apparatus 2 is output.

  Each failure estimation apparatus 8a, 8b, 8c, 8d is specifically configured as shown in FIG.

  The failure estimation device 8a takes in an electric quantity 4a such as an input voltage, an input current, an output voltage, and an output current of the main component 11a from the measuring device 3a corresponding to the main component 11a constituting the device 2, and the failure of the main component 11a Or an anomaly that is a precursor thereof, and outputs a harmonic anomaly estimation result 7a. Similarly, the failure estimation device 8b takes in an electric quantity 4b such as an input voltage, an input current, an output voltage, and an output current of the main component 11b from the measuring device 3b corresponding to the main component 11b constituting the device 2, and the main component The failure of 11b and the abnormality that is a precursor thereof are estimated, and the harmonic abnormality estimation result 7b is output. Similarly, the failure estimation devices 8c and 8d take in the electric quantities 4c and 4d related to the main parts 11c and 11d, estimate the failure of the main parts 11c and 11d and the abnormality that is a precursor thereof, and the harmonic abnormality estimation results 7c and 7d. Is output.

  On the other hand, the apparatus abnormality estimation apparatus 10 receives the harmonic abnormality estimation results 7a, 7b, 7c, 7d from the respective failure estimation apparatuses 8a, 8b, 8c, 8d as shown in FIG. Failure probability conversion for converting and outputting failure probabilities 12a, 12b, 12c, and 12d from 7b, 7c, and 7d to the main parts 11a, 11b, 11c, and 11d after shipping and the years from shipping to failure A processing unit 10A and a total failure probability estimation processing unit 10B that outputs an apparatus abnormality estimated value 9 that is a total failure probability from each failure probability 12a, 12b, 12c, and 12d are provided.

FIG. 5A is a diagram for explaining the operation of the failure probability conversion processing unit 10 </ b> A of the device abnormality estimation device 10.
In the figure, the horizontal axis represents the future elapsed period (year), and the vertical axis represents the harmonic abnormality estimation result 7 (7a to 7d) and the failure probability 12 (12a to 12d) obtained by the failure probability conversion processing unit 10A. ing. The harmonic abnormality estimation result 7 (7a to 7d) and the failure probability 12 (12a to 12d) can be obtained statistically. Specifically, the failure probability 12a can be obtained from the number of years since the shipment of the main part, for example, 11a, the number of years from shipment to failure, and the number of shipped main parts 11a, and the shipment of the main part 11a. The harmonic abnormality estimation result 7a corresponding to the failure probability can be obtained from the average value of the harmonic abnormality estimation results of years from.

FIG. 5B is a diagram for explaining the operation of the total failure probability estimation processing unit 10B of the apparatus abnormality estimation apparatus 10.
The overall failure probability estimation processing unit 10B can obtain the overall failure probability 12 from the mutual relationship between the failure probabilities 12a, 12b, 12c, and 12d obtained by the failure probability conversion processing unit 10A.

For example, as shown in FIG. 6A, if all failure probabilities 12a, 12b, 12c, and 12d are in an OR relationship, the entire failure probability 12 is obtained from the following equation (1-1).
Total failure probability 12 = 1− (1−failure probability 12a) × (1−failure probability 12b)
X (1-failure probability 12c) x (1-failure probability 12d) (1-1)
As shown in FIG. 6B, if all failure probabilities 12a, 12b, 12c, and 12d are in an AND relationship, the entire failure probability 12 is obtained from the following equation (1-2).
Total failure probability 12 = failure probability 12a × failure probability 12b
X Failure probability 12c x Failure probability 12d (1-2)
Furthermore, as shown in FIG. 6C, if the failure probabilities 12a and 12b are OR, the failure probabilities 12c and 12d are OR, and the OR outputs are ANDed, the overall failure probability 12 is expressed by the following formula ( Obtained from 1-3).
Overall failure probability 12 = {1− (1−failure probability 12a) × (1−failure probability 12b)}
X {1- (1-failure probability 12c) * (1-failure probability 12d)} (1-3)
Further, as shown in FIG. 6D, if the failure probabilities 12a and 12b are AND, the failure probabilities 12c and 12d are AND, and each AND output is OR, the overall failure probability 12 is expressed by the following formula ( Obtained from 1-4).
Total failure probability 12 = 1− (1−failure probability 12a × failure probability 12b)
X (1-failure probability 12c x failure probability 12d) (1-4)
Therefore, the overall failure probability estimation processing unit 10B estimates the overall failure probability 12 as described above, and outputs it as the apparatus abnormality estimated value 9.

FIG. 7 is a diagram showing a specific configuration example of each failure estimation device 8 (8a, 8b, 8c, 8d), and corresponds to claim 2.
The failure estimation device 8 (8a, 8b, 8c, 8d) uses a computer to perform software processing according to a certain processing procedure. Functionally, the fault estimation device 8 and data The recording unit 22, the harmonic component coincidence calculation unit 23, and the harmonic abnormality estimation unit 24 are configured.

  The harmonic component calculation means 21 calculates the harmonic component by analyzing the waveform of the electric quantity 4 (4a to 4d) described above, obtains the actually measured harmonic component calculation result 25, and sends the harmonic component coincidence calculation means 23 to the harmonic component coincidence calculation means 23. Send it out.

  Specifically, the data recording unit 22 stores the actual harmonic component calculation result 25 acquired by the harmonic component calculating unit 21 and also stores harmonic abnormality that stores various pattern data for evaluating power quality. A database 26 is provided. The harmonic abnormality database 26 stores harmonic components (hereinafter referred to as harmonic abnormal harmonic components) 27 that are presumed to be harmonic abnormalities that are a precursor of abnormality or failure of the main components 11a, 11b, 11c, and 11d in advance. A pattern (hereinafter referred to as a harmonic abnormality pattern) 28 (see FIG. 11 described later) is stored.

  The harmonic component coincidence calculation means 23 is based on the actually measured harmonic component calculation result 25 and the harmonic abnormal harmonic component 27 having a plurality of harmonic abnormality patterns 28 having a plurality of orders stored in the harmonic abnormality database 26. It has a function to calculate the harmonic component coincidence 29.

  The harmonic abnormality estimation unit 24 converts the harmonic abnormality pattern 28 having a higher harmonic component coincidence 29 from the harmonic component coincidence 29 calculated by the harmonic component coincidence calculation unit 23 to the possibility of harmonic abnormality. Is estimated as a higher harmonic abnormality pattern 28, and the estimated higher harmonic abnormality pattern 28 is output as a higher harmonic abnormality estimation result 7 (7a, 7b, 7c, 7d).

  The output format of the harmonic abnormality estimation result 7 is, for example, displayed on a display device, printed out from a printer, stored in the data recording unit 22 or a separate storage unit, or externally via a dedicated transmission line or the like. There are formats to output to the output device.

Next, the operation of the failure estimation apparatus 8 (8a, 8b, 8c, 8d) as described above will be described.
FIG. 8 is a diagram for explaining an example of a voltage waveform for two phases between lines, which is an example of the electric quantity 4.

  In the figure, the horizontal axis represents time, and the vertical axis represents voltage. Now, assuming that the voltages for the three phases are Va, Vb, and Vc, the line voltages for the three phases are Vab, Vbc, and Vca. In the example for two phases, the line voltages are Vab and Vbc.

  First, the harmonic component calculation means 21 takes in an electric quantity 4a such as a voltage and a current input / output to / from a main component constituting the apparatus 2, or an electric quantity transmitted from the measuring apparatus 3a through the transmission system 5a. 4a is received and the component for every order of the harmonic contained in the fundamental voltage wave contained in the said electric quantity 4a is calculated. That is, the harmonic component calculation means 21 regards the harmonic component as the sum of each order component, and calculates the harmonic component for each order.

  The most commonly used fast Fourier transformation (FFT) is known as a method for calculating the components for each harmonic order. In the present embodiment, an example is shown in FIG. Harmonic component calculation processing is executed using an FFT processing unit 21a having a high-speed Fourier transform function.

The reason for using the FFT processing unit 21a having a high-speed Fourier transform function is as follows.
The harmonics are represented as a collection of sine waves having a constant period and different periods. Assuming that the fundamental wave is primary, the period is 1/2 of the fundamental wave (frequency is twice), the period is 1/3 of the fundamental wave (frequency is 3 times), the third is fundamental, and the fundamental wave is 1 / n ( The frequency is n times) is called the nth order.

  When harmonics enter the commercial frequency, it is said that the commercial frequency is distorted, and the harmonic component is obtained by Fourier transform or the like, but the observation data (measurement data) is discrete from the operating characteristics of the device 2 and parts. There may be sampling data. When obtaining harmonic components from such sampling data, it is necessary to use a technique called discrete Fourier transform. In this respect, the FFT processing unit 21a having a high-speed Fourier transform function is a conversion method devised so as to solve the discrete Fourier transform at high speed, and can deal with either continuous or discrete sampling data. It can be said that it is the most versatile one for analysis.

  Therefore, the FFT processing unit 21a analyzes the waveform of the electric quantity 4a and extracts a harmonic component for each order included in the electric quantity 4a. Waveform analysis is similarly performed for the electric quantities 4b, 4c, and 4d, and harmonic components for each order included in the electric quantities 4b, 4c, and 4d are extracted.

  FIG. 10 is a diagram showing an example of the actually measured harmonic component result calculated by the harmonic component calculating means 21 for the voltage waveform for two phases between lines. Specifically, it is an example in which the harmonic component for each order of the harmonic is calculated for the quantity of electricity 4 shown in FIG. 8 using the FFT processing unit 21a. In this example, the harmonic content of Vab and Vbc is shown. In the figure, the horizontal axis represents the harmonic order, and the vertical axis represents the harmonic content.

Here, the harmonic content is calculated for each order of harmonics and is expressed by the following equation.
Harmonic content (order) = Harmonic magnitude (order) ÷ Fundamental wave magnitude (2)
On the other hand, as described above, the harmonic abnormal harmonic component 27 is stored in the harmonic abnormal database 26. As shown in FIG. 11, the harmonic abnormal harmonic component 27 includes a plurality of order components and their respective orders. It is represented by a harmonic anomaly pattern 28 made up of component magnitudes (harmonic content), each having a characteristic pattern composed of combinations of order components estimated to be harmonic anomalies.

  By the way, the harmonic abnormality is not only an abnormality of the main parts 11a, 11b, 11c, and 11d constituting the apparatus 2, but is often a precursor of a failure of the main parts 11a, 11b, 11c, and 11d. Therefore, in the harmonic abnormality database 26, as shown in FIG. 11, in addition to the abnormality of the main parts 11a, 11b, 11c, and 11d constituting the apparatus 2, the combination of the order components and the order components that are precursors to the failure are stored. A plurality of harmonic abnormality patterns 28A, 28B, and 28C having a content rate are stored.

  Here, in FIG. 11, the horizontal axis represents the harmonic order, and the vertical axis represents the harmonic content, and this harmonic content is calculated by Equation (2) for each harmonic order as described above. The

  FIG. 12 is a diagram for explaining the functional blocks and processing contents of the harmonic component coincidence calculation means 23.

  The harmonic component coincidence calculation means 23 is obtained by the normalization calculation processing unit 23a that executes a process of normalizing so that the total of the actual harmonic component calculation results 25 becomes 1, and the normalization calculation processing unit 23a. Normalization result (normalized value) of the measured harmonic component calculation result 25 and the harmonic abnormality harmonic component 27 stored in the harmonic abnormality database 26 are normalized so that the sum of the harmonic components becomes 1. A coincidence calculation processing unit 23b is provided for calculating the coincidence with the obtained value.

  When the harmonic component coincidence calculation means 23 receives the measured harmonic component calculation result 25, the normalization calculation processing unit 23 a executes the normalization process, and the harmonic components of the respective orders included in the measured harmonic component calculation result 25. Is normalized so that the sum of 1 becomes 1.

  In normalization, a j-th order component (j is a natural number of 2 or more) after normalization is calculated using the following equation (3).

J-order component after normalization = j-th harmonic component before normalization / total value of harmonic components before normalization
...... (3)
FIG. 13 is a diagram illustrating normalization of harmonic components.

  As the harmonic component, the maximum order of the harmonic abnormal harmonic component 27 in the harmonic abnormal database 26 may not match the maximum order of the harmonic component of the actually measured harmonic component calculation result 25. For example, although the maximum order of the harmonic component of the actually measured harmonic component calculation result 25 is up to the 25th order, the maximum order of the harmonic abnormal harmonic component 27 may be only up to the 20th order, for example. In such a case, the lower order of both orders, that is, the maximum order 20 of the harmonic anomalous harmonic component 27 having the lowest maximum order is matched, and both harmonic components up to the 20th order are extracted and normalized. . As a result, the denominator of the equation (3) is the total value up to the 20th order of the harmonic components before normalization.

  The degree-of-match calculation processing unit 23b stores the value after the standardization of the actual harmonic component calculation result 25 (hereinafter referred to as a standardized actual harmonic component calculation result 32; see FIG. 14A) and the harmonic abnormality database 17. The absolute value of the difference from the value after the standardization of the stored harmonic abnormal harmonic component 27 (hereinafter referred to as the normalized harmonic abnormal harmonic component 33; see FIG. 14B) is taken for each order, and the equation The total value (hereinafter referred to as the normalized difference total value 34) is calculated as in (4).

Total normalized difference 34 = | Second-order component after normalization (actually measured harmonic component calculation result 25) -Second-order component after normalization (harmonic abnormal harmonic component 27) | + | Third-order component (measured harmonic component calculation result 25) -normalized third-order component (harmonic abnormal harmonic component 27) | + …… + | n-th normalized component (measured harmonic component) Calculation result 25) -n-order component after normalization (harmonic abnormal harmonic component 27) |
= | Second order component (standardized measured harmonic component calculation result 32) -second order component (standardized harmonic abnormal harmonic component 33) | + | third order component (standardized measured harmonic component calculated result 32) ) -3rd order component (standardized harmonic abnormal harmonic component 33) | +... + | Nth order component (standardized measured harmonic component calculation result 32) -nth order component (standardized harmonic abnormal harmonic component) Wave component 33) |
... (4)
From this equation (4), when the normalized measured harmonic component calculation result 32 and the normalized harmonic abnormal harmonic component 33 completely coincide, the normalized difference total value 34 becomes zero.

  FIG. 14 is a diagram illustrating an example in which the standardized actual harmonic component calculation result 32 and the standardized harmonic abnormal harmonic component 33 completely match. That is, the coincidence calculation processing unit 23b, based on the formula (4), calculates the normalized difference sum when the normalized measured harmonic component calculation result 32 and the normalized harmonic abnormal harmonic component 33 completely match. The value 34 is zero.

  On the other hand, if the normalized measured harmonic component calculation result 32 and the normalized harmonic abnormal harmonic component 33 do not completely match based on the equation (4), the total value of the normalized measured harmonic component calculated result 32 Since the total value of the normalized harmonic abnormal harmonic components 33 is 1, the normalized difference total value 34 is 2. For example, as shown in FIG. 15, a normalized measured harmonic component calculation result 32 including third and fifth harmonic components, and a normalized harmonic abnormal harmonic component including seventh and tenth harmonic components. In the case of 33, the orders are completely inconsistent. However, since both are standardized, the total value of the multiple orders is 1, respectively. As a result, the total value 34 of the normalized difference absolute value is 2.

  FIG. 16 is a diagram illustrating an example in which the normalized actual harmonic component calculation result 32 and the normalized harmonic abnormal harmonic component 33 partially match. In this example, the fifth-order harmonic components match, but the other-order harmonic components do not match. In such a case, out of the total value 1 of the normalized measured harmonic component calculation results 32, the normalized measured harmonic component calculation result 32 having a third harmonic component that does not match is 0.6. Of the total value 1 of the normalized harmonic abnormal harmonic component 33, the normalized harmonic abnormal harmonic component 32 having a seventh harmonic component that does not match is 0.6. As a result, the total value 34 of the normalized difference absolute values is 0.6 + 0.6 = 1.2.

  Therefore, as described above, the degree of coincidence between the standardized actual harmonic component calculation result 32 and the standardized harmonic abnormal harmonic component 33 does not match at all, or does not match at all. It can be seen that the normalized difference total value 34 is represented by a value from 2 (when not matching at all) to 0 (when matching at all).

  FIG. 17 is a diagram showing the relationship between the degree of coincidence between the normalized actual harmonic component calculation result 32 and the normalized harmonic abnormal harmonic component 33 and the normalized difference total value 34. As is clear from this figure, the standardized difference total value 34 when there is no coincidence is 2, and the standardization difference total value 34 when there is a complete coincidence is 0, which is a partial match. Represents an intermediate value.

Here, the definition of the harmonic component coincidence 29 is considered.
Now, when the normalized measured harmonic component calculation result 32 and the normalized harmonic anomalous harmonic component 33 are completely matched, it is 100%, when they are not matched at all, it is -100%, and the middle is 0%. In this way, it can be expressed as shown in FIG.

Therefore, a conversion equation between the harmonic component coincidence 29 and the normalized difference total value 34 shown in FIG. 18 can be expressed by equation (5). As a result, the result calculated by Equation (5) can be defined as the harmonic component coincidence 29.
Harmonic component coincidence 29 = (1−standardized difference total value 34) × 100 (%) (5)
That is, the coincidence calculation processing unit 23b calculates the harmonic component coincidence 29 with the actually measured harmonic component calculation result 25 for each harmonic abnormal harmonic component 27 according to the equation (5). To pass.

  Based on the harmonic component coincidence 29 for each harmonic abnormal harmonic component 27 received from the harmonic component coincidence calculating unit 23, the harmonic abnormality estimating unit 24 generates a harmonic abnormality pattern, for example, 28A. , 28B, 28C are estimated.

  FIG. 19 is a diagram for explaining functional blocks and processing contents of the harmonic abnormality estimation means 24.

  The harmonic abnormality estimation means 24 includes a matching degree rearrangement processing unit 24a and a harmonic abnormality extraction unit 24b.

  The matching degree rearrangement processing unit 24a performs processing for rearranging the harmonic abnormal harmonic component 27 based on the harmonic component matching degree 29 of the harmonic abnormal harmonic component 27, for example, a harmonic component. A process of rearranging in descending order of the degree of coincidence 29 is executed.

  The harmonic abnormality extraction unit 24b selects a pattern 28 that is estimated to be a harmonic abnormality from the harmonic abnormality patterns 28 having the harmonic abnormality harmonic components 27 that are rearranged in order from the highest harmonic component matching degree 29. Extracted and output as harmonic abnormality estimation result 7.

  FIG. 20 is a diagram for explaining the relationship between the harmonic abnormal harmonic component 27 and the harmonic component coincidence 29.

  The harmonic abnormality estimation means 24 arranges the harmonic abnormality patterns 28 corresponding to the harmonic abnormal harmonic components 27 in order from the left in order from the highest harmonic component coincidence 29 when the matching degree rearrangement processing unit 24a arranges the harmonic abnormality patterns 28 from the left side. As shown in FIG. 20, it can be considered that the harmonic component coincidence 29 falls within the range of 100% to −100%, the higher the harmonic anomaly is, the lower the harmonic anomaly is.

  Accordingly, the harmonic abnormality extraction unit 24b of the harmonic abnormality estimation means 24 sets the harmonic abnormality extraction threshold 35 in consideration of the possibility of affecting the power quality through the accumulation of experiments and experience. It is possible to extract a harmonic abnormality pattern 28 having a harmonic abnormality harmonic component 27 having a wave component matching degree 29 higher than the harmonic abnormality extraction threshold 35 as a harmonic abnormality. That is, the harmonic abnormality extraction unit 24b outputs the harmonic abnormality harmonic component 27 existing above the harmonic abnormality extraction threshold 35 as the harmonic abnormality estimation result 7 as shown in FIG.

  Note that the harmonic abnormality estimation means 24 may output the harmonic abnormality estimation result 7 by rearranging the harmonic component coincidence 29 in descending order without providing the harmonic abnormality extraction threshold 35.

  FIG. 21 is a diagram illustrating an example in which the harmonic abnormality estimation result 7 is displayed on the display device without providing the harmonic abnormality extraction threshold 35. In the figure, the vertical axis represents the harmonic component coincidence 29 and the horizontal axis represents the harmonic abnormality pattern 28, which is a display example arranged from left to right in the descending order of the harmonic component coincidence 29. This corresponds to claim 3.

  Therefore, according to the above embodiment, it is one of the power quality from the electric quantities 4a to 4d such as voltage and current acquired from the main components 11a to 11d of the device 2 connected to the power system. Harmonic components are extracted, and the degree of coincidence between these actually measured harmonic components and the harmonic abnormal harmonic component 27 having the harmonic abnormal pattern 28 that is a precursor of abnormality or failure that is stored in advance is calculated. After the harmonic components of the wave abnormality pattern 28 are used as the harmonic abnormality estimation results of the main components 11a to 11d, the failure probabilities of the main components 11a to 11d are extracted from the harmonic abnormality estimation results 7a to 7d. Since the abnormal estimated value (failure probability) 12 of the entire apparatus 2 is taken out, which of the main components 11a to 11d has a high failure probability, and thus which of the main components 11a to 11d is not abnormal. It can be estimated whether the aura to be a failure has occurred.

  As a result, it is possible to accurately estimate which of the main parts 11a to 11d the abnormality of the device 2 itself or a sign of failure is based on.

(Second embodiment: corresponding to claim 4)
FIG. 22 is a diagram illustrating a functional configuration of the failure estimation device 8 (8a to 8d) in the power quality evaluation system 6, and particularly a diagram in which a result display control unit 41 is provided in place of the harmonic abnormality estimation unit 24 described above. It is.

  That is, the power quality evaluation system 6 calculates the actual harmonic component calculation result 25 by the harmonic component calculation means 21 and passes it to the harmonic component coincidence calculation means 23. The harmonic component coincidence calculation means 23 calculates the harmonic component coincidence 29 for each harmonic abnormality pattern 28, and stores and outputs it in a predetermined area of the data recording means 22, for example.

  The result display control means 41 displays the harmonic component coincidence 29 for each harmonic abnormality pattern 28 output from the harmonic component coincidence calculating means 23 on the display device 42 and calculates the harmonic component at regular intervals. Returning to the means 21, the processes by the constituent means 21, 23, 41 are repeatedly executed. As a result, in the predetermined recording area of the data recording means 22, the harmonic component matching degree 29 for each harmonic abnormality pattern 28 for each time is stored in a time series over a required period (for example, 24 hours). The

  FIG. 23 is a diagram showing a display example of the harmonic component coincidence 29 for each of the harmonic abnormality patterns 28A, 28B, 28C, 28D by the result display control means 41. The vertical axis represents harmonic component coincidence 29, and the horizontal axis represents time.

  The example of FIG. 23 is a display example for 24 hours a day. That is, the harmonic component coincidence calculation means 23 accumulates the harmonic component coincidence 29 of the harmonic abnormality patterns 28A, 28B, 28C, and 28D in a time series for 24 hours a day, and the result display control means 41 It is an example displayed.

  According to this embodiment, in addition to the same effects as those of the first embodiment, it is possible to display a change in the harmonic component coincidence 29 for each harmonic abnormality pattern 28 for each predetermined time over a required period. Therefore, the transition of the temporal change of each harmonic abnormality pattern 28 can be grasped, and it can be determined in which time zone the specific harmonic abnormality pattern 28 becomes significantly abnormal.

(Third embodiment)
FIG. 24 is a schematic configuration diagram showing a third embodiment of the power quality evaluation system 6 according to the present invention, and corresponds to claim 5.

  In this embodiment, a data collection processing unit 43 and a display control unit 44 are provided on the output side of the failure probability conversion processing unit 10A and the total failure probability estimation processing unit 10B shown in FIG. Or failure probability 12a, 12b, 12c, 12d of each main part 11a, 11b, 11c, 11d and failure probability 12 of the apparatus 2 are collected every time or every predetermined month and stored in time series in the data recording means 22 or appropriate storage means. To remember. The display control unit 44 reads out the failure probabilities 12a, 12b, 12c, 12d of the main components 11a, 11b, 11c, 11d and the failure probability 12 of the device 2 from the data recording means 22, and displays the display device according to a predetermined display form. 42 is displayed.

  FIG. 25 is a diagram showing one predetermined display form. That is, the data collection processing unit 43 collects the failure probabilities 12a, 12b, 12c, 12d of the main components 11a, 11b, 11c, 11d and the failure probability 12 of the apparatus 2 at predetermined time intervals, And is sent to the display control unit 44. Here, as shown in FIG. 25, the display control unit 44 displays the part name according to the connection of the main parts 11a, 11b, 11c, and 11d constituting the device 2 in advance, and displays the failure probability in the vicinity of the part name. An area is formed, and the failure probabilities 12a, 12b, 12c, 12d of the main components 11a, 11b, 11c, 11d and the entire apparatus failure probability 12 of the apparatus 2 sent from the data collection processing unit 43 are sequentially displayed in the corresponding display area. This is an example of displaying on the display device 42 by writing.

  According to this configuration, the failure probabilities 12a, 12b, 12c, 12d of the main parts 11a, 11b, 11c, 11d are associated with the main parts 11a, 11b, 11c, 11d and the apparatus 2 at predetermined times. Since the overall device failure probability 12 of the device 2 is displayed, the current status of the main components 11a, 11b, 11c and 11d constituting the device 2 and the device 2 can be accurately grasped.

  FIGS. 26A and 26B are diagrams for explaining other predetermined display modes, and correspond to claim 6.

  In a predetermined area of the data recording means 22, the failure probabilities 12a, 12b of the main components 11a, 11b, 11c, 11d are provided every predetermined time, for example, for 24 hours or every month for a predetermined year (for example, 10 years). , 12c, 12d and the data on the overall device failure probability 12 of the device 2 are accumulated in time series, the display control unit 44 indicates that the horizontal axis is time (for example, 24 days a day) as shown in FIG. Time), the vertical axis is the failure probability, and data relating to the failure probability 12a, 12b, 12c, 12d of the main parts 11a, 11b, 11c, 11d and the overall failure probability 12 of the device 2 is read from the data recording means 22 and displayed. In this example, a line graph is displayed at 42.

  In FIG. 26B, the horizontal axis is the year (for example, 10 years), the vertical axis is the failure probability, and the main components 11a, 11b, 10 years from the data recording means 22 as in FIG. In this example, data relating to the failure probabilities 12a, 12b, 12c, 12d of 11c and 11d and the overall failure probability 12 of the device 2 are read and displayed on the display device 42 as a line graph.

  Further, FIGS. 27A and 27B are views for explaining different display modes by the display control unit 44, and correspond to claim 7. FIG.

  That is, the display control unit 44 displays the failure probability of the main parts 7a, 7b,... And the failure probability of the apparatus 2 as shown in FIG. 26, but sets the alarm specified value 45 in advance and sets the main parts 7a, 7b,. This is an example of outputting alarm information for calling attention when the failure probabilities 12a, 12b, 12c, 12d of... And the failure probability 12 of the device 2 become larger than the alarm specified value 45.

  Further, FIG. 28 shows a display example for predicting and forecasting the future failure probability of the main components 11a to 11d constituting the device 2 and the future failure probability recorded in the data recording means 22 or the like. It is. This corresponds to claim 8.

  If the failure probabilities of the main components 11a to 11d are recorded in advance in the data recording means 22 for each predetermined period obtained by the apparatus abnormality estimation apparatus 10 shown in FIG. 4, they are recorded using the least square method. From the past failure probabilities, the coefficients a and b in the following formula (6-1), the coefficients a and b and c in the following formula (6-2), or the coefficient a in the following formula (6-3) are obtained and the formula ( A future failure probability can be obtained by substituting a future year into (6-1) or (6-2).

Future failure probability = (a × year + b) × 100 (%) (6-1)
Future failure probability = (a × year ² + b × year + c) × 100 (%) (6-2)
Future failure probability = (1 · exp (−a × year)) × 100 (%) (6-3)
That is, at least the past failure probability of the past failure probability which is the failure estimation result of the device obtained by the failure probability conversion processing unit 10A and the failure failure estimation result of the device obtained by the overall failure probability estimation processing unit 10B. Is assumed as the future failure probability of the device, the arrival of the future failure probability is predicted from the change in the current failure probability of the device, and is displayed on the display device 42 or the like to predict the power quality. Deterioration can be avoided in advance.

  Therefore, according to this configuration, the future failure probability is set from the past failure probability, and an abnormality or a precursor of the failure of the device 2 is accurately predicted from the failure probability of the current device 2 that changes with the passage of time. And can be output as forecast information.

  In addition, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

  For example, in the above-described embodiment, an anomaly or a failure sign of the apparatus 2 is estimated from harmonics superimposed on the electric quantity of electric voltage / current supplied to the main components constituting the apparatus 2. Thus, for example, vibrations, rotation speeds, noises, and the like that characterize the operation of the device 2 and the main components 11a to 11d may be detected and added as auxiliary data when estimating an abnormality or a failure sign of the device 2.

  2 ... load device, 3 (3a, 3b, 3c, 3d) ... measuring device, 4 (4a, 4b, 4c, 4d) ... electric quantity such as voltage and current, 5 (5a, 5b, 5c, 5d) ... transmission System 6 ... Power quality evaluation system 7 (7a, 7b, 7c, 7d) ... Harmonic abnormality estimation result, 8 (8a, 8b, 8c, 8d) ... Failure estimation device, 10 ... Device abnormality estimation device, 10A ... Failure probability conversion processing unit, 10B... Overall failure probability estimation processing unit, 11 (11a, 11b, 11c, 11d)... Main parts, 21... Harmonic component calculation means, 21a. ... harmonic component coincidence calculation means, 23a ... standardization calculation processing section, 23b ... coincidence degree calculation processing section, 24 ... harmonic abnormality estimation means, 24a ... coincidence rearrangement processing section, 24b ... harmonic abnormality extraction section, 25 ... Calculated harmonic component calculation result, 2 ... harmonic abnormality database, 27 ... harmonic abnormality harmonic component, 28 ... harmonic abnormality pattern, 29 ... harmonic component coincidence, 41 ... result display control means, 42 ... display device, 43 ... data collection processing unit, 44 ... Display control unit, 45 ... Alarm specified value.

Claims (8)

Measured harmonic component calculation results obtained by waveform analysis of electrical quantities such as voltages and currents taken out from a plurality of parts constituting a device connected to the power system, and failure of each part stored in advance and its precursor The harmonic component coincidence with a plurality of harmonic abnormality harmonic components composed of the harmonic abnormality pattern that is estimated to be a harmonic abnormality is calculated, and each component failure or its A fault estimation device corresponding to a component that identifies a harmonic abnormality pattern indicating an anomaly that is a precursor and outputs the harmonic abnormality estimation result;
A plurality of failure probability conversion processing means for converting the harmonic abnormality estimation results output from each failure estimation device into failure probabilities,
A power quality evaluation system, comprising: a total failure probability estimation processing means for extracting an abnormal estimated value of the entire apparatus from the failure probability of each part converted by each failure probability conversion processing means. In the electric power quality evaluation system according to claim 1,
The failure estimation device for each major component is a harmonic component calculation means for analyzing the waveform of electric quantities such as voltage and current obtained from a plurality of components constituting the device from the power system, and calculating a harmonic component, Harmonic abnormality database storing a plurality of harmonic abnormal harmonic components estimated as harmonic abnormalities indicating failure of each component or abnormality that is a precursor thereof, and actually measured harmonic components obtained by the harmonic component calculating means The harmonic component coincidence calculating means for calculating the harmonic component coincidence between the calculation result and a plurality of harmonic abnormal harmonic components stored in the harmonic abnormality database, and the harmonic component coincidence calculating means Harmonic abnormality estimation means for identifying a harmonic abnormality pattern indicating a failure of each component or an abnormality that is a precursor thereof from each harmonic component coincidence and outputting the result as a harmonic abnormality estimation result. Power quality assessment system according to claim. In the electric power quality evaluation system according to claim 1 or 2,
About the harmonic abnormal pattern having harmonic abnormal harmonic components of the harmonic component matching degree for each component, the power quality is displayed on the display device in the order of the harmonic abnormal pattern having the higher harmonic component matching degree. Evaluation system. In the electric power quality evaluation system according to claim 2,
Instead of the harmonic abnormality estimation means, the harmonic component coincidence for each harmonic abnormality pattern is displayed on the display device from the harmonic component coincidence calculation means, and the harmonic component coincidence is repeated every predetermined time. And a result display control means for displaying a time-series change between the harmonic abnormality pattern and the harmonic component coincidence on the display device. In the electric power quality evaluation system according to claim 1 or 2,
The power quality, wherein the failure probability of each part obtained by the failure probability conversion processing means and the failure probability which is an abnormality estimation result of the device obtained by the overall failure probability estimation processing means are displayed on the display device, respectively. Evaluation system. In the electric power quality evaluation system according to claim 5,
The failure probability of each part obtained by the failure probability conversion processing means and the failure probability which is the abnormality estimation result of the device obtained by the overall failure probability estimation processing means are displayed in a line graph over a predetermined period. A power quality evaluation system characterized by this. In the electric power quality evaluation system according to claim 5 or 6,
An alarm in which at least the failure probability of the device is determined in advance among the failure probability of each component obtained by the failure probability conversion processing means and the failure probability which is an abnormality estimation result of the device obtained by the overall failure probability estimation processing means An electric power quality evaluation system comprising means for sending alarm information to call attention when a specified value is exceeded. In the electric power quality evaluation system according to claim 5 or 6,
Among the past failure probabilities of each device obtained by the failure probability conversion processing means and the past failure probability which is the abnormality estimation result of the device obtained by the overall failure probability estimation processing means, at least the past of the device A power quality evaluation system comprising a means for predicting and outputting the future failure probability from a change in the current failure probability of the device, with the failure probability as a future failure probability of the device.

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