KR20220036608A - System and Method for predicting functional stop of power facility based on earthquake early warning - Google Patents

Abstract

Disclosed is a power facility function stop prediction system that predicts impact on power facility in advance using the magnitude of seismic waves measured in the vicinity based on early earthquake information. The power facility function stop prediction system comprises: a multiple seismic observation device that observes surface of the earth and respectively generates a plurality of seismic observation information; and a terminal which calculates the shortest distance between an installation point of a structure in which the power facility is located and an earthquake fault line based on a plurality of the seismic observation information, and predicts the impact on the power facility in advance using physical response information calculated according to a physical characteristic of the structure.

Description

System and Method for predicting functional stop of power facility based on earthquake early warning

The present invention relates to a technology for predicting power facility stoppage, and more particularly, a system and method for predicting a power facility stoppage in advance using the magnitude of a seismic wave measured nearby based on earthquake early information. it is about

One of the major damages related to power facilities during an earthquake is a blackout. If the main facilities (turbine trip, etc.) of large-scale power plants such as nuclear power plants and thermal power plants near the earthquake site stop functioning at the same time, the power supply source (generator) is separated from the system and the frequency of the power system is rapidly lowered. Even if various circuit breakers and protective relays in the power system operate, frequency recovery becomes difficult and a major blackout occurs.

In the case of a major power outage in the power system in 2018, when the Fukaido earthquake (magnitude 6.6) occurred, the system collapsed due to a turbine stop at a nearby thermal power plant, and a major power outage occurred throughout Fukaido. There are cases where it was stopped and resulted in huge economic damage.

Meanwhile, it is necessary to take precautionary measures as soon as possible to prevent a major blackout, which is the worst situation in power system operation. Therefore, in order to accurately determine whether seismic waves are damaged before they reach power facilities, and to take precautionary measures to prevent the collapse of the power system, it is necessary to accurately predict the failure of power facilities by using an earthquake early warning and to Therefore, it is necessary to accurately predict the situation of the power system in real time.

In addition, if power facility failures are not accurately estimated, local forced blackouts may occur in the process of taking unnecessary and excessive measures to prevent major blackouts. Or, conversely, if insufficient measures are taken, the system may become unstable and a major blackout may be induced. The most important information to predict power facility failure using earthquake early warning is the shortest distance to an earthquake fault caused by an earthquake.

However, the earthquake early warning service currently provided by the Korea Meteorological Administration provides information on the magnitude and location of an earthquake, but does not provide information on the length and direction of the earthquake fault. Earthquake Early Warning is a service that notifies the arrival of seismic waves several to tens of seconds before they reach a specific site by using P waves that are 1.73 times faster than S waves that cause damage to structures.

In general, when a large-scale earthquake occurs, an underground seismic fault plane with an area of several tens of km ² is accompanied by a surface seismic fault rupture of several tens of km. In general, such seismic fault plane information is analyzed using long-distance low-frequency measurement signals (150 km or more) rather than using short-distance (within 50 km) observation data located near the earthquake site. It is difficult to promptly notify the results of fault characteristics (length, direction).

In addition, the reason why the length and direction of an earthquake fault is important is that the shortest distance between the earthquake fault plane and the site of interest is important for the magnitude of the seismic wave, which has a great impact on engineering, not the first point where the earthquake occurred. Therefore, if the direction of the earthquake fault is not known, there is a problem in that the earthquake damage may be underestimated or overestimated because the distance error may reach several tens of km when evaluating the nearby earthquake damage.

1. Korean Patent No. 10-1930174 (Registration Date: December 11, 2018)

The present invention has been proposed to solve the problems according to the above background technology, and a system and method for predicting power facility function stoppage by using the magnitude of a seismic wave measured nearby based on early earthquake information Its purpose is to provide

In addition, according to the present invention, the length/direction of an earthquake fault is calculated using the values spatially interpolated to grid points by taking the magnitude of the measured seismic wave as an input, and the shortest distance to the power facility is calculated based on this, and then the power facility Another object of the present invention is to provide a system and method for predicting power facility outages in advance.

The present invention provides a power facility stop prediction system for predicting the impact of power facilities in advance using the magnitude of seismic waves measured in the vicinity based on earthquake early information in order to achieve the task presented above.

The power facility function stop prediction system,

a plurality of seismic observation apparatuses for observing the earth's surface and generating a plurality of seismic observation information, respectively; and

The shortest distance between the installation point of the structure in which the power facility is located and the earthquake fault line is calculated based on a plurality of the earthquake observation information, and the influence of the power facility is calculated using the physical response information calculated according to the physical characteristics of the structure. It is characterized in that it includes; a terminal that predicts in advance.

In this case, the plurality of seismic observation information is characterized in that it includes an initial location of an earthquake wave, an earthquake magnitude, and an earthquake occurrence time.

In addition, the terminal, a collection unit for collecting a plurality of the earthquake observation information; a calculation unit for generating a corrected seismic wave by correcting a real-time ground amplification factor for a seismic wave among a plurality of the seismic observation information, and calculating the shortest distance using the corrected seismic wave; and a determination unit that calculates whether damage has occurred by power facility using the shortest distance and the physical response information, determines whether the power system is out of power according to the damage by power facility, and generates notification information; characterized in that it comprises a do.

In addition, the ground amplification factor is characterized in that it is corrected using a site characteristic correction filter according to the hardness of the ground of the structure in which the power facility is installed.

In addition, the corrected seismic wave is characterized in that it is interpolated to a preset grid point position.

In addition, the length of the seismic fault for the seismic fault line and the direction of the earthquake fault are estimated by using the magnitude of the seismic wave interpolated to the grid point position.

(여기서, M은 지진규모이고, R은 최단거리이고, R_O는 지각두께(맨틀까지의 깊이)의 2배로 정하는 거리이고, c₁ 내지 c₉는 계수값이다)으로 정의되는 것을 특징으로 한다.In addition, the estimation is

(where M is the earthquake magnitude, R is the shortest distance, R _O is the distance determined by twice the crust thickness (depth to the mantle), and c ₁ to c ₉ are coefficient values) .

(여기서, i는 양의 정수이고, M은 지진 크기이고,

는 계수값이다)으로 정의되는 것을 특징으로 한다.In addition, the shortest distance (R) is the equation

(where i is a positive integer, M is the magnitude of the earthquake,

is a coefficient value).

In addition, the physical property is characterized in that it includes a natural frequency of the structure, a damping ratio, and an amplification factor.

In addition, according to the shortest distance and the physical characteristics, it is characterized in that the magnitude of the seismic wave observed at the site of the structure in which the power facility is located is converted into the magnitude of the input seismic wave at the installation point of the power facility.

In addition, the type of the magnitude of the input seismic wave is the same unit as the vibration limit standard of the power facility, and the unit is a combination of displacement, speed, and acceleration.

In addition, the vibration limit criterion is a criterion for stopping the function of the power facility, and the vibration limit criterion is characterized in that it includes a vibration limit value (PGA _th ) and a vibration limit value duration (D _th ).

(여기서, PGA_th는 진동 제한치이고, PGA는 지진파 크기이고, Dur은 지진파 지속 시간이다)으로 정의되는 것을 특징으로 한다.In addition, the vibration limit value (PGA _th ) and the vibration limit value duration (D _th ) are expressed by the formula

(where PGA _th is the vibration limit value, PGA is the seismic wave magnitude, and Dur is the seismic wave duration).

In addition, the seismic wave size is characterized in that the triangle.

In addition, the prediction is characterized in that it is made by comparing the magnitude of the input seismic wave with a preset seismic wave risk reference value for each power facility to determine whether damage occurs.

In addition, the seismic fault line is characterized in that it represents the length and direction of the earthquake fault.

In addition, the seismic wave is characterized in that the S wave.

On the other hand, in another embodiment of the present invention, (a) a plurality of seismic observation apparatus observing the earth's surface to generate a plurality of seismic observation information, respectively; (b) calculating, by the terminal, the shortest distance between the installation point of the structure in which the power facility is located and the earthquake fault line based on a plurality of the earthquake observation information; and (c) predicting, by the terminal, in advance of the impact of the power facility using the physical response information calculated according to the physical characteristics of the structure; provide a way

According to the present invention, it is possible to prevent a loss of related electricity sales by preventing a major blackout due to an earthquake.

In addition, as another effect of the present invention, it is possible to quantitatively present the annual probability of exceedance for a major blackout accident by probabilistic analysis of a major blackout accident caused by an earthquake, and this is the basic plan for power system operation. It can be said that it can be used for

In addition, as another effect of the present invention, it can be used as basic data to evaluate the effect of power facilities on the active earthquake fault (the Yangsan earthquake fault near Gyeongju and the Ulsan earthquake fault), which has recently emerged nationally, and to reinforce the power system. It can be said that

1 is a block diagram of an earthquake early warning-based power facility function stop prediction system according to an embodiment of the present invention.
2 is a schematic diagram of ground amplification and structure amplification according to an earthquake in a structure in which a power facility is located according to an embodiment of the present invention.
3 is a flowchart illustrating a process of calculating the shortest distance between a power facility point and an interstitial line based on an earthquake early warning according to an embodiment of the present invention.
4 is a flowchart illustrating a process of predicting a functional stop of a power facility using the shortest distance calculated according to FIG. 3 .
5 is a conceptual diagram of an earthquake fault shape (length, direction) and distance of an earthquake at the time of an earthquake early warning according to an embodiment of the present invention.
6 is a diagram illustrating a simplified calculation concept for an excessive duration of a vibration limit for seismic waves according to an embodiment of the present invention.

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and those of ordinary skill in the art to which the present invention pertains. It is provided to fully inform the person of the scope of the invention, and the present invention is only defined by the scope of the claims. Sizes and relative sizes of components indicated in the drawings may be exaggerated for clarity of description.

Like reference numerals refer to like elements throughout, and "and/or" includes each and every combination of one or more of the recited items.

The terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, a referenced element, step, operation and/or element to "comprises" and/or "consisting of" does not exclude the presence or addition of one or more other elements, steps, operations and/or elements. .

Although it is used to describe various elements such as first and second, these elements are not limited to these terms, of course. These terms are only used to distinguish one component. Accordingly, it goes without saying that the first component mentioned below may be the second component within the spirit of the present invention.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly defined in particular.

Hereinafter, an earthquake early warning-based power facility function stop prediction system and method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of an earthquake early warning-based power facility function stop prediction system 100 according to an embodiment of the present invention. Referring to FIG. 1 , the power facility function stop prediction system 100 is a seismic observation device 110 that generates seismic observation information by observing the ground surface, and receives seismic observation information from the seismic observation device 110 to observe the earthquake. It may be configured to include a terminal 120 that predicts the influence of the power facility in advance by calculating the shortest distance to the power facility based on the information.

The seismic observation apparatus 110 performs a function of generating seismic observation information by observing the earth's surface. The seismic observation information may include an initial location of an earthquake wave, an earthquake magnitude, an earthquake occurrence time, and the like. In FIG. 1 , one seismic observation device 110 is illustrated for convenience of understanding, but multiple seismic observation devices may be configured. In other words, a plurality of seismic observatories may be installed at a predetermined distance, and seismic observation devices are installed at the seismic observatories. The seismic observation device 110 is a seismic sensor (not shown), a seismograph (not shown) that is connected to the earthquake sensor (not shown) to record seismic observation information, and a communication circuit (not shown) for transmitting the seismic observation information to the outside. and so on.

In general, the earthquake sensor uses an electromagnetic method in which a current is generated when the magnet vibrates by suspending a magnet at the end of a spring and winding a coil around the magnet, but is not limited thereto, and an analog earthquake sensor is also possible. Of course, a speed sensor, an acceleration sensor, etc. may be included for the magnitude of the earthquake, the location of the occurrence, the depth of occurrence, the time of occurrence, the intensity, and the like.

Also, the seismic observation apparatus 110 may be connected to a management server that receives seismic observation information from the seismic observation apparatus 110 and converts the seismic observation information into a database.

The terminal 120 may include a collection unit 121 , a calculation unit 122 , a determination unit 123 , an output unit 124 , a storage unit 126 , and the like. The collection unit 121 is connected to the seismic observation device 110 through wired/wireless communication with the network 10 and performs a function of obtaining seismic observation information. To this end, a microprocessor, a modem, a LAN card, a circuit, and the like are configured. The terminal may be a computer, a server, a notebook computer, a smart pad, or the like.

The calculator 122 collects seismic observation information and the like acquired through the collection unit 121 and stores it in the storage unit 126 . In addition, the shortest distance between the power facility point and the earthquake fault line is calculated, and the response of the power facility according to the structure natural frequency and damping ratio of the power facility is calculated.

The determination unit 123 uses the shortest distance calculated by the calculation unit 122 and the response information to calculate whether or not a plurality of power facilities have been damaged, and calculates the effect of the power system according to whether each power facility is damaged in real time by calculating the power system. It performs a function of generating notification information that informs whether there is a major power outage.

The output unit 124 performs a function of displaying information processed by the calculation unit 122 , the determination unit 123 , and the like. Accordingly, the output unit 124 may generate notification information using a combination of text, voice, and graphics. To this end, the output unit 124 may include a display, a sound system, and the like.

The display may be a liquid crystal display (LCD), a light emitting diode (LED) display, a plasma display panel (PDP), an organic LED (OLED) display, a touch screen, a cathode ray tube (CRT), a flexible display, or the like. In the case of a touch screen, it may function as an input means.

The calculation unit 122 and the determination unit 123 illustrated in FIG. 1 mean a unit for processing at least one function or operation, which may be implemented as software and/or hardware. In hardware implementation, application specific integrated circuit (ASIC), digital signal processing (DSP), programmable logic device (PLD), field programmable gate array (FPGA), processor, microprocessor, other It may be implemented as an electronic unit or a combination thereof.

In software implementation, software composition component (element), object-oriented software composition component, class composition component and task composition component, process, function, attribute, procedure, subroutine, segment of program code, driver, firmware, microcode, data , databases, data structures, tables, arrays, and variables. Software, data, etc. may be stored in a memory and executed by a processor. The memory or processor may employ various means well known to those skilled in the art.

The storage unit 126 performs a function of storing seismic observation information, data generated by the calculation unit 122 and/or the determination unit 123 , information related to power facilities, programs, software, and the like. The storage unit 126 may be configured in the terminal 120 or may be configured in a separate server. Accordingly, the storage unit 126 may include a flash memory type, a hard disk type, a multimedia card micro type, and a card type memory (eg, Secure Digital (SD)). or XD (eXtreme Digital) memory, etc.), RAM (Random Access Memory, RAM), SRAM (Static Random Access Memory), ROM (Read Only Memory, ROM), EEPROM (Electrically Erasable Programmable Read Only Memory), PROM (Programmable Read) Only memory), a magnetic memory, a magnetic disk, and an optical disk may include at least one type of storage medium. In addition, it may operate in relation to a web storage that performs a storage function on the Internet and a cloud server.

The network 10 performs a function of communicatively connecting the earthquake observation device 110 and the terminal 120 . Communication connection can be RS232, RS485, Modbus, CC-Link communication, Ethernet communication, etc. Of course, the network 10 means a connection structure capable of exchanging information between each node, such as a plurality of terminals and servers, and includes a public switched telephone network (PSTN), a public switched data network (PSDN), a comprehensive information network ( Integrated Services Digital Networks (ISDN), Broadband ISDN (BISDN), Local Area Network (LAN), Metropolitan Area Network (MAN), Wide LAN (WLAN), etc. can be,

However, the present invention is not limited thereto, and wireless communication networks such as CDMA (Code Division Multiple Access), WCDMA (Wideband Code Division Multiple Access), Wibro (Wireless Broadband), WiFi (Wireless Fidelity), and HSDPA (High Speed Downlink Packet Access) ) network, Bluetooth, Near Field Communication (NFC) network, satellite broadcasting network, analog broadcasting network, DMB (Digital Multimedia Broadcasting) network, and the like. Alternatively, it may be a combination of these wired communication networks and wireless communication networks.

2 is a schematic diagram of ground amplification and structure amplification according to the occurrence of an earthquake in the structure 230 in which the power facility is located according to an embodiment of the present invention. Referring to FIG. 2 , the structure 230 in which the power equipment is located is disposed on the ground surface 220 . Of course, in general, there is a bedrock 210 under the ground surface 220 for stable fixing of the structure 230 . The bedrock 210 may be naturally generated or may have an artificial concrete structure. Of course, the structure 230 may be installed even in a site without such bedrock.

Accordingly, seismic waves 201 and 202 are transmitted to the structure 230 from the seismic source 200 along the seismic wave path. The seismic waves 201 and 202 become S waves. For the size of the S wave observed at the point, the input size at the installation point of the power facility is estimated by considering the dynamic characteristic factors (natural frequency (fn), damping ratio (ξ), amplification factor, etc.) of the structure where the main power facility is located. can be

The type of input size of the power facility installation point should be the same unit as the vibration limit standard 231 of the power facility, and may be displacement, speed, or acceleration, or a combination of these units. In addition, the vibration limit criterion for stopping the function of main equipment is not only the magnitude of the vibration value but also the duration of consideration. In other words, the function stops only if the vibration limit is continuously exceeded for a certain duration (eg 3 seconds).

3 is a flowchart illustrating a process of calculating the shortest distance between a power facility point and an earthquake fault line based on an earthquake early warning according to an embodiment of the present invention. Referring to FIG. 3 , the terminal 120 receives an earthquake early warning according to earthquake observation information from the observation device 110 (step S310 ). The information included in such an earthquake early warning is the magnitude of the earthquake (generally earthquake magnitude 5.0 or higher), the location of the seismic wave (in units of latitude and longitude 1/100°), and the time of occurrence (in units of sec).

In Korea, after the Gyeongju earthquake (September 12, 2016), the largest earthquake since earthquake observations in the 1970s, the Korea Meteorological Administration has been providing services to the public. The general service is provided within 10 to 20 seconds after the earthquake. The earthquake early service generates information related to the earthquake early warning using the P wave (6.3 km per second) of an earthquake that is relatively weak in size and has a fast propagation speed. do. As described above, there is no distance information according to the length/direction of an earthquake fault, which is essential for determining whether power facilities are damaged in an earthquake early warning. Accordingly, an embodiment of the present invention proposes a procedure for calculating such distance-related information.

Thereafter, the terminal 120 directly induces earthquake damage based on the location information at the time of occurrence of the earthquake obtained from the earthquake early warning, but an S wave having a rather low propagation speed (3.5 km/sec) can be measured. Data from nearby seismic observatories are collected in real time (step S320).

When about 10 seconds have elapsed after the earthquake, which is the time when the earthquake early warning is issued, the S-wave would have reached within a radius of about 30 km (=3.5 km/sec×10 sec) near the earthquake, and in this case, the installed density of the seismic observatory (approx. 30km interval), it is expected that S-waves will be observed at less than 10 observatories. In general, seismic observatories in about 56 substations and 155 national seismic observatories are observed in real time in connection with a server (which may be a server connected to an observation device).

Thereafter, the calculator 122 of the terminal 120 corrects the ground amplification factor for the collected seismic waves in real time. While general earthquake early warning uses the arrival time of the P-wave of the seismic wave, in an embodiment of the present invention, information on the seismic fault is estimated using the size of the S-wave of the seismic wave.

In this case, it is necessary to correct the ground amplification factor, which greatly affects the S wave size. In general, if the condition of the site where the observation device 110 is installed is hard ground, the amplification rate is hardly (about 1.0 times), but when the ground is soft, it may have an amplification characteristic of about 2 to 10 times.

There are various methods for correcting the ground amplification factor, but it can be corrected by processing the filtering signal in real time using a site characteristic correction filter according to the hardness of the ground of the structure where the power facility is installed. For this, Korean Patent No. 10-1086448 (Method for estimating seismic motion intensity of adjacent sites through time domain site response characteristic conversion of seismic waveform', Applicant: Korea Electric Power Corporation) (Registration date: November 17, 2011) has been disclosed.

In brief, since the ground amplification rate correction step does not require earthquake characteristic information (scale, location), it can also be selectively performed on the collected S-wave time period measurement data. On the other hand, if seismic observation data is received in real time from the server regardless of this, ground amplification correction filtering is performed on all station data in advance, stored in the server's memory buffer, and then the corrected data is simply extracted when an earthquake occurs. So you can use it faster.

The coefficient of the ground amplification correction filter is expressed as a finite number of coefficients (eg, 40) having the same time interval as the sampling per second of the measurement data, and the frequency-specific ground amplification function for the nearby bedrock is calculated as the Fourier spectrum. It is derived with a time domain filter having a linear phase with amplitude magnitude. In this case, filtering is performed through convolution of measurement data and filter coefficients.

On the other hand, the S-wave observation data in the short-range area used in step S320 can also be used for other types of data other than the seismic measurement data of the seismic observatory connected to the server. For example, it may be an IoT (Internet of Things) vibration sensor installed in a power facility or an IoT vibration sensor measurement data installed in other facilities, and the value of a vibration sensor built in a portable phone can be received and utilized in real time.

Thereafter, the corrected S-wave is interpolated to a more dense (approximately 2 km) uniform grid point position (step S340). Various methods can be used for such spatial interpolation, and it is performed to generate data for a larger number of virtual observation points in order to reliably estimate the length and direction of an earthquake fault.

As mentioned above, there are approximately 10 or fewer seismic waves collected in the vicinity of 30 km. However, when interpolation is performed, S-wave size information at approximately 200 to 300 grid points can be estimated. Also, in general, interpolation of grid points is performed over a wider range including the seismic observation area, and the spatial range of grid points used after interpolation can be limited to an area that is greater than or equal to the minimum value of the observed values.

Thereafter, the length/direction of the seismic fault is estimated from the interpolated S-wave magnitude at the grid point position (step S350). The principle of estimation is that as the shortest distance (R) from the seismic fault increases, a specific function (the magnitude-distance reduction function of seismic waves, PGA=f(M,R)) reflecting the characteristic that the magnitude of the S wave decreases as the predicted value This is a method to search the length/direction of seismic faults in which the sum of errors with N observations (PGA') is minimized.

The equation for PGA is generally expressed as a function, where M is the earthquake magnitude, R is the shortest distance, and R _O is the distance determined by twice the crust thickness (depth to the mantle), and the Korean Peninsula is about 50 -60 km. In other words, theoretically, it is the distance at which seismic waves transition from a three-wave source spherical geometric damping to a two-dimensional cylindrical geometric damping. The crust is hard and the mantle under the crust is soft, so it can be said that waves are trapping in the crust beyond the transition distance.

In addition, c ₁ ~ c ₉ are coefficient values empirically derived using PGA observed or theoretically derived in the relevant area with the ranges of M and R that are important for engineering.

In this case, various optimization algorithms and error units can be used. In particular, the length of an earthquake fault can be fixed using an empirically presented equation for earthquake magnitude, or it can be changed to a distribution with an appropriate standard deviation. For this equation, see "Wells, DL and Coppersmith KJ, New empirical relationships among magnitude, rupture length, rupture width, rupture area, and surface displacement, Bulletin of the Seismological Society of America (1994) 84 (4): 974-1002" is disclosed in

In addition, the change in the length/direction of the earthquake fault may be used by constraining the location of the earthquake provided as an early earthquake warning to be located on the earthquake fault line, or the location of the earthquake estimated by a separately estimated method may be used. . This is disclosed in Registered Patent No. 10-1386255 (title of invention: 'seismic measuring device and earthquake measuring method', applicant: Korea Electric Power Corporation) (registration date: April 10, 2014).

In general, in the case of an earthquake occurring in the sea, it is desirable to impose a constraint on the location of the earthquake occurrence provided as an early earthquake warning on the earthquake fault line. On the other hand, when the magnitude-distance function of seismic waves is uniformly used, the predicted magnitude of the seismic wave is consistently smaller or larger than the actual observed value depending on the distance depending on the seismic wave attenuation characteristics according to the distance to the area where the earthquake occurred. can indicate

Therefore, as an appropriate error unit, it is preferable to use the standard deviation magnitude (STD) of the log function error, which can consider the spatial error pattern rather than the absolute error magnitude. This can be expressed as a mathematical formula as follows.

Here, ERR is an error value, lnERR _i = ln(PGA' _i )-ln(PGA _i ), bias(lnERR _i ) = lnERR _i / N (average of errors). Also, N > i, and N,i is a positive integer.

A more preferable method is to correct or newly derive the f(M, R) function in quasi-real time in consideration of seismic wave attenuation by region according to the location of the earthquake, and then use the theoretically most suitable function. This is disclosed in "Yeon Kwan-hee, Inverse Calculation of Two-Dimensional Q Tomography for the Southern Region of the Korean Peninsula (Dissertation), 2007".

Thereafter, the process of calculating the shortest distance from the estimated length/direction of the earthquake fault to several power facility points located nearby is performed (step S360). At this time, the target site for the electric power facility to be estimated is located outside of 30 km and is located at a distance that the S wave has not yet reached. If the distance from the seismic fault line to the power facility point is calculated, the S-wave size at the point is estimated using the related function based on this information.

If this is expressed in the form of one of various equations, it is shown in Equation 3.

Here, i is a positive integer.

의 계수를 추정해 낼 수 있다. In Equation 1, when M and PGA are known, R of the right-hand side can be calculated. In this case, an explicit function cannot be derived for R. Therefore, after calculating various M, PGA, and R numerical data using Equation 1 above, approximating them in the form of Equation 3 based on these data and fitting

It is possible to estimate the coefficient of

On the other hand, at the location where the P wave, which is faster than the S wave, arrives, the magnitude of the S wave can be estimated by using the magnitude correlation between the P wave and the S wave.

For example, according to a related study (Cen Zhao and John X. Zhao, 2018) that is empirically derived using seismic wave data collected from the Japanese seismic observation network, a specific magnitude (about 6.0 ) and distance (80 km) or less, it has a constant multiple value (about 3.5 times), but above this, it is known to show a tendency to increase linearly with scale or distance (up to 5 times).

For this, see the paper "Cen Zhao and John X. Zhao, 2019, S- and P-Wave Spectral Ratios for On-Site Earthquake Early Warning in Japan, Bulletin of the Seismological Society of America, Vol. 109, No. 1. pp. 395-412".

Targets for power facilities include 154kV substations and large-scale power plants that can have a significant impact on the power system.

The reason for correcting the bias(lnERR _i ) as in the above equation is to correct the limitations of the theoretical functional expression through actual observation data. For physical reasons, in general, when deriving the f(M,R) function formula, the stress drop, which is a seismic characteristic parameter closely related to the magnitude of a seismic wave, is fixed to a specific constant (e.g., 180 bars). The amount of stress drop (eg 100 bars) may be different. Therefore, this difference can be corrected through bias(lnERR _i ).

Thereafter, with respect to the size of the S wave observed at the point, the input seismic wave at the installation point of the power facility takes into account the physical characteristics of the structure in which the main power facility is located (eg, natural frequency, damping ratio, amplification factor, etc. as dynamic characteristics). A step of estimating the size proceeds (step S370).

This process is necessary to convert the magnitude of the S-wave observed at the site of the structure where the power facility is located to the magnitude of the input seismic wave at the installation point of the power facility. At this time, the type of input size of the power facility installation point must be the same unit as the vibration limit standard of the power facility, and may be displacement, speed, or acceleration, or a combination of these units. In addition, the vibration limit criterion for stopping the function of main equipment is not only the magnitude of the vibration value but also the duration of consideration.

In other words, the function stops only if the vibration limit is continuously exceeded for a certain duration (eg 3 seconds). Meanwhile, since the duration of an earthquake wave is also a function of the magnitude and distance (f(M, R)) of the earthquake, similar to the magnitude of the seismic wave, the functional form of the above equation can be applied to the duration.

The simplest method that can be estimated by integrating steps S360 and S370 is to pre-estimate the scale-distance function (scale-distance damping function for the seismic wave size for each natural frequency of the structure) for the vibration response of the natural frequency of the structure. Then, using this function, the magnitude and duration of the input seismic wave to the power facility can be directly calculated.

At this time, the seismic wave magnitude for each natural frequency of the structure is not PGA, which is the maximum value of ground vibration at the base of the structure, but the maximum vibration acceleration value of a single degree of freedom structure with a single natural frequency and damping ratio. SA stands for Spectral Acceleration.

The functional form can be expressed in the same way as the relational expression of PGA for earthquake magnitude-distance. In general, SA decreases in size as the damping ratio increases, and SA for the natural frequency of a specific structure increases as the earthquake scale increases, similar to PGA, and decreases in size with distance. However, the degree of decrease with distance has a different characteristic from that of PGA.

4 is a flowchart illustrating a process of predicting a functional stop of a power facility using the shortest distance calculated according to FIG. 3 . Referring to FIG. 4 , after step S370 , a procedure for determining whether damage is caused by comparing the magnitude of the input seismic wave converted to the power facility installation point with a preset seismic wave risk standard value for each power facility is performed (steps S410 to S430 ). For example, if the input seismic wave magnitude is 3 and the seismic wave risk threshold for each power facility is 4, it is judged that there will be no damage.

In general, seismic design is applied to major power facilities to minimize damage to structures, but vibration-sensitive devices (generator turbine, transformer mechanical protection relay, electronic circuit breaker of switchboard, etc.) function automatically according to related control signals. is tripped. Therefore, the power supply may be cut off in conjunction with this.

The trip vibration reference associated with power plant turbines is as sensitive as approximately 0.2 to 0.3 mm. Accordingly, when damage to a plurality of power facilities is predicted, the effect of the corresponding power system is estimated in real time in step S420.

The power system is a single network in which power plants, substations, and transmission and distribution networks are organically linked, and when power demand and supply are balanced, it operates stably at a single frequency (60Hz). However, if a large-scale power supply is stopped due to a sudden disturbance (generally greater than the total power supply reserve ratio), the frequency may drop sharply, causing a major blackout.

Estimation of the real-time power system impact is based on the numerically assumed magnitude and location of the earthquake in advance, and the simulated power system damage scenario DB (Database) is trained using AI (artificial intelligence), etc. It is possible to judge the damage to the power system in real time.

The damage to the power system can be defined in various forms, and for each form, the relational expressions learned in advance by AI for the earthquake occurrence scenario are calculated in advance. Alternatively, damage may be calculated in connection with a real-time power system simulator or the like.

Finally, the process of performing a manual or automatic pre-measurement in preparation for the predicted risk of the power system proceeds (step S440). In other words, the terminal 120 may transmit the damage prediction as notification information to the operator's communication device, or may directly provide the notification information to the manager operation screen. The notification information may be a combination of voice, graphic, and text.

This process also pre-estimates the optimal countermeasure measures through a wide range of earthquake damage scenarios in advance. Preliminary measures may include separation of wide area networks or emergency input of spare power sources.

On the other hand, steps S360 to S440 are steps for predicting the functional stop of electric power facilities when an earthquake occurs. However, this method can be substituted as a method of estimating the related ripple damage.

In addition, in steps S360 to S440, a function stop prediction equation for a specific major facility to be integrated can be derived as a function expression of the shortest distance (R) to an earthquake fault, and the related equation and early warning are linked to provide information about specific facilities in case of an earthquake. It is possible to develop a device that can take precautionary measures, etc.

5 is a conceptual diagram of an earthquake fault shape (length, direction) and distance of an earthquake at the time of an earthquake early warning according to an embodiment of the present invention. Referring to FIG. 5 , in general, when a large-scale earthquake occurs, an underground seismic fault plane with an area of several tens of km ² is accompanied, and a surface earthquake fault rupture of several tens of km is accompanied. In general, such seismic fault plane information is analyzed using long-distance low-frequency measurement signals (150 km or more) rather than using short-distance (within 50 km) observation data located near the earthquake site. It is difficult to promptly notify the results of fault characteristics (length, direction).

The reason why the length (several tens of km) of the earthquake fault 550 and the fault direction (θ) are important is that the magnitude of the seismic wave, which has a large impact on engineering, is determined by the distance (R _EEW ) from the seismic source 501, the first point where the earthquake occurred. This is because the shortest distance (R _true ) from the face of the seismic fault 550 to the site of interest (ie, the location of the power facility) 521 is important. It may be divided into a near area 510 in which the arrival point of the S wave from the true source 501 is drawn as a circle and a far area 520 in which the arrival point of the P wave is drawn as a circle from the true source 501 .

Therefore, if the direction of the earthquake fault is not known, the distance error can reach several tens of km when evaluating nearby earthquake damage, so that the earthquake damage can be underestimated or overestimated. As shown in FIG. 5 , the long distance (R _EEW ) is a distance calculated based on the epicenter provided as an early earthquake warning, but in order to predict the magnitude of the earthquake at the site, the length/direction of the earthquake fault 550 is considered. Then, the shortest distance (R _true ) to the site 521 is estimated. Here, depending on the length/direction of the earthquake fault and the location of the site, the distance difference (=|R _EEW -R _true |) can represent an error of several tens of kilometers.

In one embodiment of the present invention, the direction of the linear earthquake fault is estimated using only the magnitude of seismic waves observed in the vicinity using the national earthquake early warning, and the distance from the linear earthquake fault to the site is estimated, and then the power We propose a method for accurately assessing the impact of equipment.

6 is a diagram illustrating a simplified calculation concept for an excessive duration of a vibration limit for seismic waves according to an embodiment of the present invention. Referring to FIG. 6 , when calculating the excessive duration for the vibration limit value of the power facility installed in the structure 230 in steps S370 of FIG. 3 to S410 of FIG. 4 , the seismic wave must be derived by actually performing a simulation. case it takes a lot of time.

As a solution to this, as shown in FIG. 6 , after assuming a seismic wave as a specific function (that is, a triangle), the seismic wave magnitude (PGA=f(M,R)) and duration that can be determined as a function of the magnitude and distance of the earthquake Using the time (Dur=f(M,R)), you can use a method of simply calculating the overduration time of the vibration limit value.

The vibration limit value (PGA _th ) and the vibration limit value duration (D _th ) are defined as follows.

where PGA _th is the vibration limit, PGA is the seismic wave magnitude, and Dur is the seismic wave duration. In Equation 4 above, it was derived using the proportional expression between the lengths of the three sides of a triangle based on the principle of similarity between a large triangle with the same upper vertex and Dur as the base and a small triangle with Dth as the base inside the large triangle.

In addition, the steps of the method or algorithm described in relation to the embodiments disclosed herein are implemented in the form of program instructions that can be executed through various computer means such as a microprocessor, a processor, a CPU (Central Processing Unit), etc. It can be recorded on any available medium. The computer-readable medium may include program (instructions) codes, data files, data structures, etc. alone or in combination.

The program (instructions) code recorded on the medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs, DVDs, Blu-rays, and the like, and ROM, RAM ( A semiconductor memory device specially configured to store and execute program (instruction) code such as RAM), flash memory, and the like may be included.

Here, examples of the program (instruction) code include not only machine language codes such as those generated by a compiler but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

10: Network
100: power facility stop prediction system
110: observation device
120: terminal
121: collection unit
122: calculator
123: judgment unit
124: output unit
126: storage
200: Jinwon
210: bedrock
220: surface
230: structure

Claims (18)

a plurality of seismic observation devices 110 for generating a plurality of seismic observation information by observing the earth's surface; and
The shortest distance between the installation point of the structure 230 where the power facility is located and the earthquake fault line is calculated based on a plurality of the earthquake observation information, and the physical response information calculated according to the physical characteristics of the structure 230 is used. a terminal 120 for predicting the influence of the power equipment in advance;
Earthquake early warning-based power facility function stop prediction system comprising a.
The method of claim 1,
A plurality of the earthquake observation information, an earthquake early warning-based power facility function stop prediction system, characterized in that it comprises an initial location of the seismic wave, an earthquake magnitude, and an earthquake occurrence time.
3. The method of claim 2,
The terminal 120,
a collection unit 121 for collecting a plurality of the earthquake observation information;
a calculation unit 122 for generating a corrected seismic wave by correcting a real-time ground amplification factor for a seismic wave among the plurality of seismic observation information, and calculating the shortest distance using the corrected seismic wave; and
A determination unit 123 that calculates whether damage by power facility is damaged by using the shortest distance and the physical response information, determines whether the power system is out of power according to the damage by power facility, and generates notification information; Earthquake early warning-based power facility function shutdown prediction system.
4. The method of claim 3,
The ground amplification rate is an earthquake early warning-based power facility function stop prediction system, characterized in that it is corrected using a site characteristic correction filter according to the hardness of the ground of the structure 230 in which the power facility is installed.
4. The method of claim 3,
The earthquake early warning-based power facility function stop prediction system, characterized in that the corrected seismic wave is interpolated to a preset grid point position.
6. The method of claim 5,
An earthquake early warning-based power facility function stop prediction system, characterized in that the length of the earthquake fault line and the direction of the earthquake fault line for the earthquake fault line are estimated using the magnitude of the seismic wave interpolated to the grid point position.
7. The method of claim 6,
The estimation is

(where M is the earthquake magnitude, R is the shortest distance, R _O is the distance determined by twice the crust thickness (depth to the mantle), and c ₁ to c ₉ are coefficient values) Earthquake early warning-based power facility shutdown prediction system.
8. The method of claim 7,
The shortest distance (R) is the equation

(where i is a positive integer, M is the magnitude of the earthquake,

is a coefficient value), characterized in that the earthquake early warning-based power facility function stop prediction system.
9. The method of claim 8,
The physical properties are earthquake early warning-based power facility function stop prediction system, characterized in that it includes the natural frequency, damping ratio, and amplification factor of the structure.
10. The method of claim 9,
Earthquake early warning-based power, characterized in that the magnitude of the seismic wave observed at the site of the structure 230 where the power facility is located is converted into the magnitude of the seismic wave input at the installation point of the power facility according to the shortest distance and the physical characteristics Equipment outage prediction system.
11. The method of claim 10,
The type of the input seismic wave magnitude is the same unit as the vibration limit standard of the power facility, and the unit is a combination of displacement, speed, and acceleration.
12. The method of claim 11,
The vibration limit criterion is a criterion for stopping the function of the power equipment, and the vibration limit criterion is a vibration limit value (PGA _th ) and a vibration limit value duration (D _th ) Earthquake early warning-based power equipment function, characterized in that it includes Stop Prediction System.
13. The method of claim 12,
The vibration limit value (PGA _th ) and the vibration limit value duration (D _th ) are expressed by the equation

(where PGA _th is the vibration limit value, PGA is the seismic wave magnitude, Dur is the seismic wave duration)
14. The method of claim 13,
The earthquake wave size is an earthquake early warning-based power facility stop prediction system, characterized in that the triangle.
12. The method of claim 11,
The prediction is made by comparing the magnitude of the input seismic wave with a preset seismic wave risk reference value for each power facility and determining whether damage is caused.
The method of claim 1,
The earthquake fault line is an earthquake early warning-based power facility function stop prediction system, characterized in that it indicates the length and direction of the earthquake fault.
3. The method of claim 2,
The seismic wave is an S wave, an earthquake early warning-based power facility function stop prediction system.
(a) generating, by a plurality of seismic observation devices 110, a plurality of seismic observation information by observing the ground;
(b) calculating, by the terminal 120, the shortest distance between the installation point of the structure 230 in which the power facility is located and the earthquake fault line based on a plurality of the earthquake observation information; and
(c) predicting, by the terminal 120, in advance of the effect of the power facility using the physical response information calculated according to the physical characteristics of the structure 230;
Earthquake early warning-based power facility function stop prediction method comprising a.

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