JP2010029003A - Power quality evaluation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To presume a failure in a load facility which deteriorates power quality and abnormality indicating its symptom, at an early stage. <P>SOLUTION: A power quality evaluation system includes: a harmonic component calculation means 11 that analyzes waveform of the electric amount 5, such as, a voltage or a current supplied to the load facility 3 from a high-order power system, and calculates the harmonic components: a harmonic abnormal database 17, which stores the failure in the load facility 3 and a plurality of abnormal harmonic components 16, inferred as harmonic abnormality indicating the symptom of the failure; a harmonic component agreement calculation means 13, that calculates the harmonic component agreement level between an actual measurement harmonic component calculation result 15 obtained by the harmonic component calculation means 11 and the plurality of abnormal harmonic components 16 stored in the harmonic abnormal database 17; and harmonic abnormality output means 14, 31 by which the failure in the load facility 3 and the harmonic abnormal patterns indicating the symptom of the failure are specified from each calculated harmonic component agreement level to output or display a specified signal. <P>COPYRIGHT: (C)2010,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, several techniques have been proposed as a method for managing the power state by analyzing harmonics of electric equipment generated in the power system.

  One technique is to collect a sample of waveforms for each failure factor 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 a fluctuation active part and a fluctuation reactive part before and after the transient state of the fundamental wave active power and fundamental wave reactive power in the consumer, and loads the consumer based on the magnitude of the fluctuation, Specify the operating conditions such as turning on / off power factor correction capacitors and transformers.

In this technology, the current at the time of customer equipment input is frequency-analyzed, the change pattern of the harmonic component that varies with the equipment, which is the waveform pattern of the harmonic component, and the harmonic component ratio changes with time is extracted. It specifies the operating state of the house facilities and the facility where the failure occurs (Patent Document 2).
Japanese Patent Laid-Open No. 06-217451 Japanese Patent No. 3952355

  However, the former technique only identifies the cause of the ground fault of the high-voltage distribution line, and the latter technique mainly identifies the operation state of the customer equipment on / off, and the abnormal state of the harmonics. Therefore, it is not a power quality evaluation system that estimates failure of load facilities and abnormalities that are precursors.

  The present invention has been made in view of the above circumstances. The measured harmonic component is calculated from the amount of electricity such as voltage and current supplied from the upper power system to the load facility, and the measured harmonic component calculation result is stored in advance. It is an object of the present invention to provide an electric power quality evaluation system that estimates at an early stage a failure of a load facility that deteriorates electric power quality based on the harmonic abnormal harmonic component and an abnormality that is a precursor thereof.

  In order to solve the above-described problems, the power quality evaluation system according to the present invention performs waveform analysis on the amount of electricity such as voltage and current supplied from a power system to a load facility composed of various devices and equipment, and performs harmonic analysis. Harmonic component calculation means for calculating components, and harmonics that store a plurality of harmonic abnormal harmonic components that are estimated to be a failure of a device or device constituting the load facility or a harmonic abnormality that is a precursor of the failure Harmonic component for calculating a harmonic component coincidence between an abnormal database, a measured harmonic component calculation result obtained by the harmonic component calculating means, and a plurality of harmonic abnormal harmonic components stored in the harmonic abnormal database The degree of coincidence calculation means, and the harmonic component pattern that is a precursor to the failure or failure of the equipment, equipment, etc. included in the load facility, from the degree of coincidence of the harmonic components calculated by the harmonic component coincidence degree calculation means Identify a structure in which a harmonic error output means for outputting or displaying.

  According to the present invention, the actual harmonic component is calculated from the amount of electricity such as voltage and current supplied to the load equipment from the upper power system, and the actual harmonic component calculation result and the harmonic abnormal harmonic component stored in advance are calculated. Based on the above, it is possible to provide a power quality evaluation system that can quickly estimate a failure of a load facility that deteriorates power quality and an abnormality that is a precursor thereof.

(First embodiment)
FIG. 1 is a system diagram showing an example in which a power quality evaluation system 1 according to the present invention is applied to a power system.
In the power quality evaluation system 1, for example, a measuring device 4 is installed between a bus 2 that receives power from a higher power system and a load facility (including various devices, equipment, etc.) 3. The harmonic component superimposed on the voltage and current is calculated from the quantity of electricity 5 including the voltage and current supplied to the load equipment 3 to be operated, and the actual harmonic component calculation result and the harmonic abnormal harmonics stored in advance are calculated. Based on the components, the failure of the load facility and the anomaly that is a precursor thereof are estimated.

FIG. 2 is a schematic configuration diagram showing the first embodiment of the power quality evaluation system 1 according to the present invention.
The power quality evaluation system 1 uses a computer to perform software processing according to a certain processing procedure. Functionally, the power quality evaluation system 1 includes harmonic component calculation means 11, data storage means 12, harmonic components. The degree of coincidence calculation means 13 and harmonic abnormality estimation means (corresponding to harmonic abnormality output means in a broad sense) 14 are configured.

  The harmonic component calculation means 11 calculates the harmonic component by analyzing the waveform of the electric quantity 5 such as voltage and current supplied from the higher power system measured by the measuring device 4, and obtains the measured harmonic component calculation result 15. Acquired and sent to the harmonic component coincidence calculation means 13.

  The harmonic wave is a collection of sine waves having a frequency n times (n is an integer of 2 or more) of the fundamental wave superimposed on the fundamental wave. The waveform of a general electric quantity including harmonics is a fundamental wave having a commercial frequency as a fundamental frequency and each sine wave (harmonic component) having a frequency that is n times the fundamental frequency (period is 1 / n). It is expressed as the sum of Hereinafter, a sine wave whose primary component is a primary component, a sine wave whose period is 1/2 of the fundamental wave (frequency is twice), a secondary component, and a sine wave whose period is 1/3 of the fundamental wave (frequency is 3 times) A sine wave whose period is 1 / n (frequency is n times) of the fundamental wave is hereinafter referred to as an n-order component.

  The data storage means 12 stores various data for evaluating power quality, and has a harmonic abnormality pattern 21 (see, for example, FIG. 6) having a plurality of orders presumed to be harmonic abnormalities in advance. A harmonic abnormality database 17 for storing harmonic components (hereinafter referred to as harmonic abnormal harmonic components) 16 is provided, and the actually measured harmonic component calculation result 15 acquired by the harmonic component calculation means 11 is also stored. .

  The harmonic component coincidence calculation means 13 generates harmonics from the measured harmonic component calculation result 15 and the harmonic abnormal harmonic component 16 having the harmonic abnormal pattern 21 having a plurality of orders stored in the harmonic abnormal database 17. It has a function of calculating the component coincidence degree 18.

  The harmonic abnormality estimation means 14 converts the harmonic abnormality pattern 21 having a higher harmonic component coincidence 18 from the harmonic component coincidence 18 calculated by the harmonic component coincidence calculation means 13 to the possibility of harmonic abnormality. Is estimated as a higher harmonic abnormality pattern 21, and the estimated higher harmonic abnormality pattern 21 is output as a higher harmonic abnormality estimation result 20.

  The output format of the harmonic abnormality estimation result 20 is, for example, displayed on a display device, printed out from a printer, stored in the data storage unit 12 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 power quality evaluation system 1 as described above will be described.
FIG. 3 is a diagram illustrating an example of a voltage waveform for two phases between lines, which is an example of the amount of electricity.

  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 11 takes in an electric quantity 5 such as voltage and current supplied to the load facility 3 through the transmission system from the measuring device 4 installed between the bus 2 and the load facility 3, or The quantity of electricity 5 transmitted from the measuring device 4 through the transmission system is received, and a component for each order of harmonics included in the fundamental voltage wave included in the quantity of electricity 5 is calculated. That is, the harmonic component calculation means 11 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) method is known as a method for calculating 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 11a having a high-speed Fourier transform function.

  The reason for this is that when harmonics enter the commercial frequency, the commercial frequency is distorted, and the harmonic component is obtained by Fourier transform, etc., but the observation data (measurement data) is discrete from the operating characteristics of the equipment. There may be a case where the sampling data is correct. 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 11a having a high-speed Fourier transform function is a conversion method devised so as to be able to solve the discrete Fourier transform at high speed, and can cope with either continuous or discrete sampling data. .

  The FFT processing unit 11 a analyzes the waveform of the quantity of electricity 5 and extracts a harmonic component for each order included in the quantity of electricity 5.

  FIG. 5 is a diagram showing an example of the actually measured harmonic component result calculated by the harmonic component calculating means 11 for the voltage waveform for two phases between the lines, using the FFT processing unit 11a, and for each harmonic order. It is the example which calculated the harmonic component. 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 size (1)
On the other hand, as described above, the harmonic abnormality harmonic component 16 is stored in the harmonic abnormality database 17, and the harmonic abnormality harmonic component 16 includes a plurality of order components and their respective orders as shown in FIG. It is represented by a harmonic anomaly pattern 21 made up of component magnitudes (harmonic content), and each has a characteristic feature of a pattern composed of combinations of order components estimated to be harmonic anomalies. Incidentally, FIG. 6 shows three harmonic abnormality patterns 21A, 21B, and 21C as an example.

  By the way, the harmonic abnormality is not only a failure of various devices and devices constituting the load facility, but also often indicates a failure of these devices and devices. Therefore, in the harmonic abnormality database 17, in addition to failure of various devices and equipment constituting the load facility, a harmonic abnormality pattern 21 including a combination of order components and a content ratio of each order component is also stored. Has been.

  Here, the horizontal axis of the harmonic abnormality pattern 21 shown in FIG. 6 is represented by the harmonic order, and the vertical axis is represented by the harmonic content. The harmonic content is calculated for each harmonic order as described above. Calculated in (1).

  FIG. 7 is a diagram for explaining the functional blocks and processing contents of the harmonic component coincidence calculation means 13.

  The harmonic component coincidence calculation means 13 is obtained by the normalization calculation processing unit 13a that executes a process of normalizing so that the total of the actual harmonic component calculation results 15 becomes 1, and the normalization calculation processing unit 13a. Normalization result (standardized value) of the measured harmonic component calculation result 15 and the harmonic abnormality harmonic component 16 stored in the harmonic abnormality database 17 are normalized so that the sum of the harmonic components becomes 1. A coincidence calculation processing unit 13b is provided for calculating the coincidence with the obtained value.

  When the harmonic component coincidence calculation means 13 receives the measured harmonic component calculation result 15, the normalization calculation processing unit 13 a executes the normalization process, and the harmonic components of the respective orders included in the measured harmonic component calculation result 15. Is normalized so that the sum of 1 becomes 1.

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

J-order component after normalization = j-th harmonic component before normalization / total value of harmonic components before normalization
(2)
FIG. 8 is a diagram for explaining normalization of harmonic components.

  As the harmonic component, the maximum order of the harmonic abnormal harmonic component 16 of the harmonic abnormal database 17 may not match the maximum order of the harmonic component of the actually measured harmonic component calculation result 15. For example, although the maximum order of the harmonic component of the actually measured harmonic component calculation result 15 is up to 25th order, the maximum order of the harmonic abnormal harmonic component 16 may be up to 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 17 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 formula (2) is the total value up to the 20th order of the harmonic components before normalization.

  The degree-of-match calculation processing unit 13b stores the value after the standardization of the actual harmonic component calculation result 15 (hereinafter referred to as the standardized actual harmonic component calculation result 22; see FIG. 9A) 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 16 (hereinafter referred to as the normalized harmonic abnormal harmonic component 23; see FIG. 9B) is taken for each order, and the equation The total value (hereinafter referred to as the normalized difference total value 24) is calculated as in (3).

Normalized difference total value 24 = | Second-order component after normalization (measured harmonic component calculation result 15) -Second-order component after normalization (harmonic abnormal harmonic component 16) | + | Third-order component (measured harmonic component calculation result 15) -normalized third-order component (harmonic abnormal harmonic component 16) | + …… + | n-th component after normalization (measured harmonic component) Calculation result 15) -n-order component after normalization (harmonic abnormal harmonic component 16) |
= | Second order component (standardized actual harmonic component calculation result 22) -second order component (normalized harmonic abnormal harmonic component 23) | + | third order component (standardized actual harmonic component calculation result 22) ) -3rd order component (standardized harmonic abnormal harmonic component 23) | +... + | Nth order component (standardized actual harmonic component calculation result 22) -nth order component (standardized harmonic abnormal harmonic component) Wave component 23) |
...... (3)
From this equation (3), when the normalized measured harmonic component calculation result 22 and the normalized harmonic abnormal harmonic component 23 completely coincide, the normalized difference total value 24 becomes zero.

  FIG. 9 is a diagram illustrating an example in which the normalized actual harmonic component calculation result 22 and the normalized harmonic abnormal harmonic component 23 completely match. That is, the coincidence calculation processing unit 13b, based on the formula (3), if the standardized actual harmonic component calculation result 22 and the standardized harmonic abnormal harmonic component 23 completely match, the standardized difference total The value 24 becomes zero.

  On the other hand, if the normalized measured harmonic component calculation result 22 and the normalized harmonic abnormal harmonic component 23 do not completely match based on the equation (3), the total value of the normalized measured harmonic component calculated result 22 Since the total value of the normalized harmonic abnormal harmonic component 23 is 1 respectively, the normalized difference total value 24 is 2. For example, as shown in FIG. 10, normalized measured harmonic component calculation result 22 including third and fifth harmonic components and normalized harmonic abnormal harmonic component including seventh and ninth harmonic components. In the case of 23, 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 24 of the normalized difference absolute value is 2.

  FIG. 11 is a diagram illustrating an example in which the normalized actual harmonic component calculation result 22 and the normalized harmonic abnormal harmonic component 23 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 result 22, the normalized measured harmonic component calculation result 22 having a third harmonic component that does not match is 0.6. Of the total value 1 of the normalized harmonic abnormal harmonic component 23, the normalized harmonic abnormal harmonic component 22 having the seventh harmonic component that does not match is 0.6. As a result, the total value 24 of the normalized difference absolute value is 0.6 + 0.6 = 1.2.

  Therefore, the normalized difference total value 24 is an intermediate value from the value 0 (zero) when the two completely match to the value 2 when the two completely match.

  FIG. 12 is a diagram illustrating the relationship between the degree of coincidence between the normalized actual measurement harmonic component calculation result 22 and the normalized harmonic abnormal harmonic component 23 and the normalized difference total value 24. As can be seen from this figure, the normalized difference total value 24 of perfect match is 0, and the normalized difference total value 24 of completely mismatch is 2, and when it partially matches, it becomes an intermediate value. It represents.

Here, the definition of the harmonic component matching degree 18 is considered.
Now, when the normalized measured harmonic component calculation result 22 and the normalized harmonic anomalous harmonic component 23 are completely coincident, 100%, when they are not coincident at all, −100%, and the middle is 0%. Then, it can be expressed as shown in FIG.

Therefore, the conversion equation between the harmonic component matching degree 18 and the normalized difference total value 24 shown in FIG. 13 can be expressed by equation (4). As a result, the result calculated by Expression (4) can be defined as the harmonic component coincidence degree 18.
Harmonic component coincidence 18 = (1−standardized difference total value 24) × 100 (%) (4)
That is, the coincidence degree calculation processing unit 13b calculates the harmonic component coincidence degree 18 with the actually measured harmonic component calculation result 15 for each harmonic abnormal harmonic component 16 by the equation (4), and the harmonic abnormality estimating means 14 To pass.

  Based on the harmonic component coincidence 18 for each harmonic abnormal harmonic component 16 received from the harmonic component coincidence calculating unit 13, the harmonic abnormality estimating unit 14 generates a harmonic abnormality pattern 21 that becomes a harmonic abnormality. presume.

  FIG. 14 is a diagram for explaining the functional blocks and processing contents of the harmonic abnormality estimation means 14.

  The harmonic abnormality estimation means 14 includes a matching degree rearrangement processing unit 14a and a harmonic abnormality extraction unit 14b.

  The coincidence rearrangement processing unit 14a performs a process of rearranging the harmonic abnormal harmonic component 16 based on the harmonic component coincidence degree 18 of the harmonic abnormal harmonic component 16, and includes, for example, a harmonic component. A process of rearranging in descending order of the degree of coincidence 18 is executed.

  The harmonic abnormality extraction unit 14b selects a pattern 21 that is estimated to be a harmonic abnormality from the harmonic abnormality patterns 21 having the harmonic abnormality harmonic components 16 that are rearranged in order from the highest harmonic component matching degree 18. Extracted and output as harmonic abnormality estimation result 20.

  FIG. 15 is a diagram for explaining the relationship between the harmonic abnormal harmonic component 16 and the harmonic component coincidence degree 18.

  The harmonic abnormality estimation unit 14 arranges the harmonic abnormality patterns 21 corresponding to the harmonic abnormal harmonic components 16 in order from the left in the descending order of the harmonic component coincidence 18 when the matching degree rearrangement processing unit 14a arranges the harmonic abnormal patterns 21 from the left. As shown in FIG. 15, it can be considered that the harmonic component coincidence 18 falls between 100% and −100%, the higher the harmonic abnormality is as it is on the left side, and the lower the harmonic abnormality is as it is on the right side.

  Therefore, the harmonic abnormality extraction unit 14b of the harmonic abnormality estimation means 14 sets the harmonic abnormality extraction threshold 25 while considering the possibility of affecting the power quality through the accumulation of experiments and experience. It is possible to extract a harmonic abnormality pattern 21 having a harmonic abnormality harmonic component 16 having a wave component matching degree 18 higher than the harmonic abnormality extraction threshold 25 as a harmonic abnormality. That is, the harmonic abnormality extraction unit 14b outputs the harmonic abnormality harmonic component 16 existing above the harmonic abnormality extraction threshold 25 as a harmonic abnormality estimation result 20 as shown in FIG.

  Note that the harmonic abnormality estimation means 14 may be arranged in the descending order of the harmonic component matching degree 18 and output as the harmonic abnormality estimation result 20 without providing the harmonic factor extraction threshold 25.

  FIG. 16 is a diagram illustrating an example in which the harmonic abnormality estimation result 20 is displayed on the display device without providing the harmonic abnormality extraction threshold value 25.

  In the figure, the vertical axis represents the harmonic component coincidence 18 and the horizontal axis represents the harmonic abnormality pattern 21, which are displayed from the left to the right in the descending order of the harmonic component coincidence 18.

  Therefore, according to the embodiment as described above, the amount of electricity such as the voltage and current of the consumer who receives power supply from the power system through the transmission system is collected, and the harmonic component which is one of the power quality , And the degree of coincidence between the measured harmonic component and the previously stored harmonic abnormal harmonic component 16 is calculated, and the harmonic abnormal pattern 21 having a high degree of coincidence of the harmonic abnormal harmonic component 16 is extracted. The harmonic abnormality pattern 21 that deteriorates the evaluation of the power quality can be estimated reliably and accurately.

  The harmonic component coincidence calculation unit 13 includes a normalization calculation processing unit 13 a that normalizes the total of the actual harmonic components 15 obtained by the harmonic component calculation unit 11 to be 1, and a coincidence calculation processing unit. 13b, and the coincidence calculation processing unit 13b normalizes the actually measured harmonic component calculation result 22 normalized by the normalization calculation processing unit 13a and the harmonic abnormal harmonic component 23 stored in the harmonic abnormality database 17. Since the degree of coincidence is calculated from the difference from each normalized harmonic abnormal harmonic component 23 that has been standardized so that the sum of the harmonic components for each unit is 1, it can be displayed in order of the degree of coincidence. The harmonic abnormality patterns 21 can be displayed side by side in an easy-to-see manner, and it is easy to grasp which harmonic abnormality pattern 21 has the most influence on the power quality.

(Second Embodiment)
FIG. 17 is a configuration diagram in which a result display control unit 31 is provided instead of the harmonic abnormality estimation unit 14 which is one component of the power quality evaluation system 1. These harmonic abnormality estimation means 14 and result display control means 31 correspond to harmonic abnormality output means in a broad sense.

  That is, the power quality evaluation system 1 is newly added to the output side of the harmonic component coincidence calculation unit 13 in addition to the harmonic component calculation unit 11, the data storage unit 12, and the harmonic component coincidence calculation unit 13 shown in FIG. The result display control means 31 is provided.

  The harmonic component coincidence calculation means 13 calculates the harmonic component coincidence 18 for each harmonic abnormality pattern 21 and stores and outputs it in a predetermined storage area of the data storage means 12, for example.

  The result display control means 31 displays the harmonic component coincidence degree 18 for each harmonic abnormality pattern 21 output from the harmonic component coincidence degree calculating means 13 on the display device 32 and calculates the harmonic component at regular intervals. Returning to the means 11, the processing by the constituent means 11, 13, and 31 is repeatedly executed. As a result, the harmonic component coincidence degree 18 for each harmonic abnormality pattern 21 for each time is stored in a time series in a predetermined storage area of the data storage means 12 over a required period (for example, 24 hours). The

  FIG. 18 is a diagram illustrating a display example of the harmonic component coincidence degree 18 for each of the harmonic abnormality patterns 21A, 21B, 21C, and 21D by the result display control unit 31. The vertical axis represents the harmonic component coincidence degree 18, and the horizontal axis represents time.

  The example of FIG. 18 is a display example for 24 hours a day. That is, the harmonic component coincidence calculation means 13 accumulates the harmonic component coincidence 18 of the harmonic abnormality patterns 21A, 21B, 21C, and 21D in a time series for 24 hours a day, and the result display control means 31 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 the change in the harmonic component matching degree 18 for each harmonic abnormality pattern 21 for each time over a required period. Therefore, the transition of the temporal change of each harmonic abnormality pattern 21 can be grasped, and it can be determined that the specific harmonic abnormality pattern 21 becomes significantly abnormal in any time zone.

(Third embodiment)
FIG. 19 is a schematic configuration diagram showing a third embodiment of the power quality evaluation system 1 according to the present invention.
In this embodiment, instead of the harmonic component calculation means 11 which is one component of the power quality evaluation system 1 shown in FIG. This is a configuration provided with a harmonic component calculation means 11A to which a function (see FIG. 20) is added. Therefore, since the other structure is the same as that of FIG.

  That is, the harmonic component calculation unit 11A includes an FFT processing unit 11a and a current direction calculation processing unit 11b as shown in FIG. The current direction calculation processing unit 11b determines whether the direction of the harmonic voltage of the kth order (k is a natural number satisfying 2 or more and n or less) which is a harmonic of a certain order and the direction of the harmonic current are the same direction or the reverse direction. Judgment is made from the phase difference between the vector and the current vector, and the measured harmonic component calculation result 15 including the current direction is stored in, for example, the data storage means 12. Accordingly, the harmonic abnormality estimation means 14 shown in FIG. 19 can output, for example, the harmonic abnormality estimation result 20 up to the direction of the current from the apparatus or device that becomes the harmonic abnormality generation source, and displays it on the display device 32. It becomes possible.

FIG. 21 is a diagram for explaining an example of the calculation of the direction (current vector) of the harmonic current performed by the current direction calculation processing unit 11b.
Assuming that a voltage vector 33 of a harmonic voltage of a certain order n and a current vector 34 of a harmonic current of a certain order n, if the delay and advance of the current vector 34 viewed from the voltage vector 33 are within 90 degrees, the current vector 34 is The direction is the same as the voltage vector 33. Conversely, if the delay or advance of the current vector 34 exceeds 90 degrees, the direction of the current vector 34 is opposite to that of the voltage vector 33.

  In the example of FIG. 21, with respect to the voltage vector 33, the current vector 34A and the current vector 34B are in the same direction, and the current vector 34C and the current vector 34D are in the opposite direction.

  Therefore, by adding the current direction calculation processing unit 11b as described above and determining the direction of the harmonic current for each harmonic order, in addition to the effects of the above-described embodiment, the apparatus can be used from the direction of the harmonic current. It is possible to find and display the direction of a device (a harmonic abnormality generating source) that generates a malfunction such as a malfunction or a harmonic abnormality that is a precursor thereof. That is, it can be determined in which direction the abnormality of the harmonic is.

  Therefore, according to this embodiment, the accuracy of the harmonic abnormality estimation result can be further improved as compared with the power quality evaluation system 1 of the first and second embodiments.

(Fourth embodiment)
FIG. 22 is a schematic configuration diagram showing a fourth embodiment of the power quality evaluation system 1 according to the present invention.

  In this embodiment, the power transmission line 6A from the upper power system to the bus 2 and the power transmission line 6B as a lower power system connected from the bus 2 to the load facility 3B and the lower power line connected from the bus 2 to the load facility 3C. The measuring devices 4A, 4B, and 4C are individually installed on the power transmission line 6C that is the power system, and the electric quantity (voltage, current) 5A from the measuring devices 4A, 4B, and 4C through the transmission systems 7A, 7B, and 7C, respectively. 5B and 5C are incorporated into the power quality evaluation system 1 to evaluate the power quality.

  The power quality evaluation system 1 uses the harmonic component calculation means 11 and 11A shown in FIGS. 2, 17 and 19 to sequentially transmit each of the transmissions based on the electric quantities 5A, 5B and 5C measured by the measuring devices 4A, 4B and 4C. For example, the harmonic component of the current flowing through the electric wires 6A, 6B, and 6C is calculated, and the actually measured harmonic component calculation result 15 is acquired and stored in the data storage unit 12. Further, the harmonic component coincidence calculation means 13 calculates the harmonic component coincidence 18 between each actually measured harmonic component calculation result 15 and the harmonic abnormal harmonic component 16. Then, the harmonic abnormality estimation means 14 calculates the harmonic abnormality estimation results 20A, 20B, and 20C of the currents flowing through the transmission lines 6A, 6B, and 6C based on the harmonic component coincidence 18 of the respective measured harmonic component calculation results 1. Output.

  As a result, the harmonic abnormality estimation means 14 causes the harmonic abnormality estimation result 20A having the direction and the harmonic abnormality pattern 21 that causes the harmonic abnormality flowing in the transmission line 6A, and the harmonic abnormality flowing in the transmission line 6B. A harmonic abnormality estimation result 20B having a direction with the harmonic abnormality pattern 21 that becomes a factor, and a harmonic abnormality estimation result 20C having a direction with the harmonic abnormality pattern 21 that causes a harmonic abnormality flowing in the transmission line 6C are output. it can.

  FIG. 23 shows a harmonic generation source and a harmonic current for explaining a method of identifying a harmonic abnormality generation source from the electric quantities 5A, 5B, and 5C acquired from the measurement devices 4A, 4B, and 4C shown in FIG. It is a figure which shows the relationship.

  For example, assuming that a harmonic abnormality generating source exists in the load facility 3B, for example, the harmonic current 36B passes through the transmission line 6B, the bus 2, and the transmission line 6A under the influence of the harmonic abnormality generation source. Then, it flows into the upper power system, or flows into the load facility 3C through the transmission line 6C.

  At this time, the power quality evaluation system 1 acquires the direction of the harmonic current flowing through each of the transmission lines 6A, 6B, and 6C through the measuring devices 4A, 4B, and 4C as described above. 18, it can be estimated that the harmonic abnormality generating source is the load facility 3 </ b> B based on the direction of the harmonic currents of the transmission line 6 </ b> A, the transmission line 6 </ b> B, and the transmission line 6 </ b> C.

  That is, the harmonic component calculation means 11A of the power quality evaluation system 1 calculates the harmonic component by the FFT processing unit 11a, while the current direction calculation processing unit 11b includes the direction of the harmonic current 36 flowing from the harmonic abnormality generating source. The measured harmonic component calculation result 15 is taken out.

  The harmonic component coincidence calculation means 13 calculates the coincidence between the measured harmonic component calculation result 15 including the direction of the harmonic current 36 and the harmonic abnormal harmonic component 16 including the direction of the harmonic current 36, and then the harmonic. It passes to the wave abnormality estimation means 14. As a result, the harmonic abnormality estimation means 14 can identify the harmonic pattern 21 that causes the harmonic abnormality with a high degree of coincidence, and therefore identifies the harmonic abnormality generation source having the harmonic pattern 21 that causes the harmonic abnormality. can do.

  For example, when the harmonic pattern 21 that causes the harmonic abnormality of the harmonic current 36B is a failure of the motor with the inverter, the harmonic abnormality generated from the motor with the inverter causes the power transmission line 6B, the bus 2, and the power transmission line 6A. It can be seen that it flows into the upper power system through, and flows into the load facility 3C through the transmission line 6C.

  Therefore, according to the above embodiment, it becomes a factor of a harmonic abnormality from the direction of each harmonic current 36A, 36B, 36C included in the quantity of electricity measured by a plurality of measuring devices 4A, 4B, 4C. A harmonic abnormality generation source having the harmonic abnormality pattern 21 can be easily identified.

(Fifth embodiment)
FIG. 24 is a schematic configuration diagram showing a fifth embodiment of the power quality evaluation system 1 according to the present invention.

  This power quality evaluation system 1 is based on the premise that measuring devices 4A to 4C are installed on a plurality of transmission lines 6A to 6C, respectively, as shown in FIG. 22 and FIG. As shown in FIG. 25, a harmonic abnormality generation source is specified in accordance with logical condition determination.

  That is, the power quality evaluation system 1 includes harmonic component calculation means 11 and 11A, harmonic component coincidence calculation means 13 and harmonic abnormality estimation means 14A, and each of the measurement devices 4A, 4B, and 4C receives an electric quantity 5A and 5B. 5C, the harmonic abnormality estimation source 14A identifies the harmonic abnormality generation source having the harmonic abnormality pattern 21 that is the harmonic abnormality estimation result 20 or the harmonic abnormality pattern 21, and the harmonic abnormality generation source estimation result 37. Output as.

  FIG. 25 is a diagram for explaining the harmonic abnormality generation source determination (specification) logic 38 by the harmonic abnormality estimation means 14A.

  The harmonic abnormality generation source determination logic 38 includes a harmonic abnormality generation source determination logic 38A when there is one harmonic abnormality generation source and a harmonic abnormality generation source determination when there are a plurality of harmonic abnormality generation sources. It is divided into logic 38B, and a determination is made based on the determination logics 38A and 38B, and a harmonic abnormality generation source is specified.

  For example, the harmonic abnormality generation source determination logic 38A includes a determination logic that the harmonic abnormality generation source is on the higher power system side, a determination logic that the harmonic abnormality generation source is the load facility 3B, and a harmonic abnormality occurrence. It is divided into determination logic that the source is the load facility 3C, and the conditions are defined respectively.

(Sixth embodiment)
FIG. 26 is a schematic configuration diagram showing a sixth embodiment of the power quality evaluation system 1 according to the present invention.

  The power quality evaluation system 1 according to this embodiment includes a new alarm generation in addition to the harmonic component calculation means 11 and 11A, the data storage means 12, the harmonic component coincidence calculation means 13 and the harmonic abnormality estimation means 14 and 14A. In this configuration, means 40 is provided.

  The alarm generation means 40 has a harmonic abnormality generation source identified by the harmonic abnormality estimation means 14 and 14A. Among them, the generation degree of harmonics is high, or the so-called generation cause having a high harmonic component coincidence 18 is obtained. An alarm 42 indicating that the specified harmonic abnormality source is in a harmonic abnormal state or a specific high frequency is applied to the central monitoring control center 41 that centrally manages the load equipment 3 having the harmonic abnormality generation source and the power energy system. An alarm 42 indicating the abnormal pattern 21 is sent out.

  FIG. 27 is a view for explaining an alarm transmission system of the alarm 42 by the alarm generating means 40. In FIG.

  The power quality evaluation system 1 connects the alarm transmission systems 43B and 43C for transmitting the alarm 42 between the load facilities 3B and 3C, and similarly connects the alarm transmission system 43D to the central monitoring and control center 41. Connecting. When the alarm generation means 40 is specified as a harmonic abnormality generation source by the harmonic abnormality estimation means 14 and 14A and the degree of the harmonic is large or the harmonic component matching degree 18 is high, the alarm transmission system 43 is set. The alarm 42 indicating that the harmonic is abnormal or the alarm 42 indicating that the specific high frequency abnormality pattern 21 is notified to the harmonic abnormality generating source that is the cause of the generation of harmonics.

In addition, the total distortion rate by Formula (5) is often used for the degree of harmonics.
Total distortion factor = RMS value only for harmonics ÷ RMS value (5)
For example, when the harmonic abnormality generation means is identified by the harmonic abnormality estimation means 14, 14A as the load equipment 3B, the alarm generation means 40 sends the load equipment 3B to the load equipment 3B via the alarm transmission system 43B. Is notified of an alarm 42 indicating that the state is a harmonic abnormal state or an alarm 42 indicating that the specific high frequency abnormality pattern 21 is present.

  Further, the alarm generation means 40 notifies the central monitoring control center 41 via the alarm transmission system 43D that the load equipment 3B is in an abnormal state of harmonics or an alarm 42 that the specific high frequency abnormality pattern 21 is present. To be notified.

  When the alarm generating means 40 generates the alarm 42, the alarm 42 may be generated under the conditions shown in FIG. For example, the harmonic warning level threshold value 44 and a certain time (alarm generation time limit value) 45 are set in advance, and the total distortion obtained by the equation (5) exceeds the harmonic warning level threshold value 44, and When the AND condition when a certain time (alarm generation time limit value) 45 has passed is satisfied, an alarm 42 indicating that the load equipment 3B is in a harmonic abnormal state is generated.

  Alternatively, the total distortion rate exceeds the harmonic warning level threshold value 44 and a certain time (alarm generation time limit value) 45 elapses. Further, as shown in FIG. When the AND condition when the extraction threshold value 25 is exceeded is satisfied, the alarm 42 that the load equipment 3B is in the harmonic abnormal state or the alarm 42 that has the harmonic abnormal pattern 21 having a high harmonic component matching degree 18 Is generated.

Next, another example of the alarm generation system will be described with reference to FIGS. 29 and 30. FIG.
FIG. 29 is a schematic configuration diagram of the power quality evaluation system 1 in which a control command generation means 46 is newly provided in the configuration shown in FIG.

  This power quality evaluation system 1 includes an alarm generation means 40 and a control command generation means 46 on the output side of the harmonic abnormality estimation means 14 and 14A, and the alarm generation means 40 generates an alarm 42 in the manner described above.

  On the other hand, when it is determined that a certain load facility 3 is a harmonic abnormality generation source, the control command generation means 46 sends a control command 47 such as a stop to the load facility 3.

  FIG. 30 is a diagram for explaining a transmission system of the control command 47 by the control command generating means 46.

  In this example, control command transmission systems 48B and 48C are newly connected between the power quality evaluation system 1 and the load facilities 3B and 3C. For example, the harmonic abnormality generation source is generated by the harmonic abnormality estimation means 14 and 14A. When the load facility 3B is identified, the alarm generation means 40 sends an alarm 42 or a high frequency abnormality pattern 21 indicating that the load facility 3B is in a harmonic abnormal state to the load facility 3B via the alarm transmission system 43B. Alarm 42 is generated.

  On the other hand, the control command generation means 46, for example, when the load abnormality 3B is specified as the harmonic abnormality generation source by the harmonic abnormality estimation means 14, 14A, and the degree of the harmonic is large or the harmonic component matching degree 18 is high. The load facility 3 is prevented from becoming abnormal by sending a control command 47 relating to load reduction including stop to the specified load facility 3 via the control command transmission system 48B.

  Further, the alarm generating means 40 indicates that the load equipment 3B is in a harmonic abnormal state and has sent a control command such as a stop to the load equipment 3B to the central monitoring control center 41 via the alarm transmission system 43D. An alarm 42 is generated.

  As a condition for generating the control command 47, a harmonic danger level threshold value 50 and a fixed time (control command generation time limit value) 51 are newly set as shown in FIG. When the total distortion exceeds the harmonic warning level threshold value 44, or the AND condition that the harmonic component coincidence 18 exceeds the harmonic abnormality extraction threshold value 25 as shown in FIG. When, for example, an alarm 42 is generated in the load equipment 3B in a harmonic abnormal state, the total distortion rate exceeds and exceeds the harmonic danger level threshold value 50 indicating the danger level of harmonics. When the time has passed a certain time (control command generation time limit value) 51, a control command 47 for stopping the operation or reducing the operation output is sent to the load equipment 3B that is in a harmonic abnormal state, for example.

  Therefore, according to the embodiment as described above, the amount of electricity is obtained from a plurality of locations in the lower power system from the upper power system to the customer, and the generation factor and location of the harmonic abnormality that is one of the power quality And an alarm that the harmonic abnormality is at a warning level is generated, so that the on-site monitoring staff can grasp that the power quality is deteriorating and can take necessary measures.

  In addition, the amount of electricity is obtained from multiple locations in the lower power system from the upper power system to the customer, and the cause and location of the harmonic abnormality, which is one of the power quality, is estimated. In such a state, since a control command for suppressing the harmonic abnormality is sent to the source of the harmonic abnormality, a disaster due to the harmonic abnormality can be avoided in advance.

  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.

The system diagram which shows the example of application to the electric power grid | system of 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 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 from which the normalized actual harmonic component result and the normalized harmonic generator harmonic component are not completely in agreement. 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. Configuration diagram showing a specific example of 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 an example which displayed the harmonic abnormality estimation result on the display apparatus, without providing a harmonic abnormality extraction threshold value. The schematic block diagram which shows 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 block diagram which shows the other example of a harmonic component calculation means. The figure explaining the phase relationship between the voltage vector of the harmonic voltage contained in an electric quantity, and a harmonic current. The schematic block diagram which shows 4th Embodiment of the electric power quality evaluation system which concerns on this invention. The figure explaining the method of specifying a harmonic abnormality generation source from the relationship between a harmonic generation source and a harmonic current. The schematic block diagram which shows 5th Embodiment of the electric power quality evaluation system which concerns on this invention. The figure explaining the harmonic abnormality generation source determination (specification) logic by the harmonic abnormality estimation means shown in FIG. The schematic block diagram which shows 6th Embodiment of the electric power quality evaluation system which concerns on this invention. The figure which shows the alarm transmission system of the alarm which generate | occur | produces from the alarm generation means of FIG. The figure explaining the generating condition of an alarm. The schematic block diagram of the electric power quality evaluation system which provided the control command generation | occurrence | production means newly in the structure shown in FIG. The figure which shows the control command transmission system of the control command which generate | occur | produces from the control command generation means of FIG. The figure explaining the generation conditions of a control command.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electric power quality evaluation system, 3 (3B, 3C) ... Load equipment, 4 (4A, 4B, 4C) ... Measuring apparatus, 5 (5A, 5B, 5C) ... Electric quantity, such as a voltage and an electric current, 6A, 6B, 6C: Transmission line, 7A, 7B, 7C ... Transmission system, 11: Harmonic component calculation means, 11a ... FFT processing section, 11b ... Current direction calculation processing section, 12 ... Data storage means, 13 ... Harmonic component coincidence calculation Means, 13a ... Normalization calculation processing unit, 13b ... Concordance calculation processing unit, 14 ... Harmonic abnormality estimation means, 14a ... Concordance rearrangement processing unit, 14b ... Harmonic abnormality extraction unit, 17 ... Harmonic abnormality database, 31 ... Result display control means, 40 ... Alarm generation means, 41 ... Central monitoring control center, 46 ... Control command generation means.

Claims (8)

Harmonic component calculation means for calculating the harmonic component by analyzing the waveform of the electric quantity such as voltage and current supplied from the power system to the load equipment composed of various devices and equipment,
A harmonic abnormality database that stores a plurality of harmonic abnormal harmonic components that are presumed to be a harmonic abnormality that is a precursor of the failure of the device, equipment, etc. constituting the load facility, and
Harmonic component coincidence calculation means for calculating the harmonic component coincidence between the actually measured harmonic component calculation result obtained by the harmonic component calculating means and a plurality of harmonic abnormal harmonic components stored in the harmonic abnormality database When,
From the harmonic component coincidence calculated by the harmonic component coincidence calculating means, a failure of a device, equipment, etc. included in the load facility or a harmonic anomaly pattern that is a precursor of the failure is identified, output or displayed. A power quality evaluation system comprising a harmonic abnormality output means. In the electric power quality evaluation system according to claim 1,
The harmonic component coincidence calculation means includes a normalization calculation processing means for normalizing so that the total of the measured harmonic components of a plurality of orders obtained by the harmonic component calculation means is 1, and the normalization calculation processing means Harmonic component of each value normalized so that the sum of the measured harmonic components of multiple orders normalized in step 1 and the harmonic abnormal harmonic components of multiple orders stored in the harmonic abnormality database is 1. A power quality evaluation system comprising: a degree of coincidence calculation processing means for calculating a degree of coincidence. In the electric power quality evaluation system according to claim 1 or 2,
The harmonic anomaly output means displays in order from an abnormal harmonic pattern having a harmonic anomalous harmonic component having a high degree of harmonic component coincidence. In the electric power quality evaluation system according to claim 1 or 2,
The harmonic abnormality output means repeatedly executes the harmonic component calculation means and the harmonic component coincidence calculation means for each predetermined time over a required period, whereby the harmonic coincidence degree in each harmonic abnormality pattern is determined. A power quality evaluation system that displays time-series changes. In the electric power quality evaluation system according to claim 1,
The harmonic component calculation means includes means for analyzing a waveform of an electrical quantity such as voltage and current supplied from a power system to a load facility and calculating a harmonic component, and for each order of the harmonic component obtained by the means. Current direction calculation processing means for calculating and storing the direction of the wave current,
A power quality evaluation system characterized in that, from the direction of the harmonic current, it is possible to identify the load equipment that is a harmonic abnormality generation source that generates a malfunction or a harmonic abnormality that is a precursor of the malfunction. In the electric power quality evaluation system according to claim 5,
Measure the amount of electricity such as voltage and current supplied to a plurality of load facilities from a plurality of observation points from the upper power system to the lower power system, and calculate the harmonic current of the plurality of observation points from the measured amount of electricity. A power quality evaluation system characterized by calculating a direction and identifying a position of the specific load facility that is a source of a harmonic abnormality generating a malfunction or a harmonic abnormality that is a precursor of the malfunction. In the electric power quality evaluation system according to claim 6,
The distortion rate for each observation point is calculated, and when the distortion rate exceeds a predetermined harmonic warning level threshold value, alert information is sent to the specific load facility that is the harmonic abnormality generation source. An electric power quality evaluation system comprising an alarm generating means. In the power quality evaluation system according to claim 7,
The distortion rate for each observation point is calculated, and when the distortion rate exceeds a predetermined harmonic danger level threshold value that is larger than the harmonic warning level threshold value, the harmonic abnormality generation source is specified. A power quality evaluation system comprising a control command generating means for sending a control command for shutting down operation or adjusting output to the load equipment.

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