KR100594349B1 - System and method for delineation of hvdc (high voltage direct current)cable/cast iron pipeline buried beneath the seafloor by vectoral 3-axis measurement of the magnetic field - Google Patents

Abstract

The present invention relates to a continuous path detection device and a method for direct current transmission line and cast iron pipe embedded in the seabed by three-axis magnetic field measurement, the object of the transmission line embedded in the seabed using a three-axis magnetic field measurement sensor and It provides a device and method for measuring the three components of the magnetic field generated by the surrounding cast iron pipe to protect him, and processing / interpreting the measured data in the host computer to continuously detect the trajectory of the DC transmission line / cast iron pipe running. There is. The configuration of the present invention is a three-axis magnetic field measuring sensor for measuring the three components of the magnetic field generated by the transmission line embedded in the seabed and the surrounding cast iron pipe to protect it in the device for detecting the continuous path of the DC transmission line and cast iron pipe ; 4-channel low noise multiplexer allowing three components to be measured within 1 msec; A high precision digital measurement unit having a sigma delta 25 bit resolution for converting an analog signal into a digital signal; A real-time precision position tracking unit of a DGPS-RTK method for transmitting the coordinates of the point where the three-axis magnetic field measuring sensor measures three components of the magnetic field to a host computer; And a main computer for integrating / controlling / measuring / processing / analyzing the devices to detect a continuous path of a transmission line / optical cable / cast iron pipe.

3-axis magnetic field, subsea, DC power line, cast iron pipe, continuous path detection

Description

System and method for delineation of HVDC (High Voltage Direct Current) cable / cast iron pipeline buried beneath the seafloor by vectoral 3 -axis measurement of the magnetic field}

1A and 1B are side and plan views for explaining the operation of a device for detecting a path of a DC transmission line and a cast iron pipe by three-axis magnetic field measurement,

FIG. 2 illustrates an embodiment of the apparatus illustrated in FIG. 1; FIG.

3 is an exemplary diagram of a DC transmission line arrangement;

4a to 4c are graphs of data measured on a rubber boat on the sea (sideline L300),

5A to 5C are graphs (sideline L400) of data measured on a rubber boat on the sea.

The present invention relates to a continuous path detection device and a method for the direct current transmission line and cast iron pipe embedded in the seabed by three-axis magnetic field measurement, in detail the three-axis magnetic field measurement sensor, the direct current transmission line embedded in the seabed and the protection thereof The present invention relates to a continuous path detection apparatus and method for measuring three components of a magnetic field generated by an enclosed cast iron pipe, and processing / interpreting the measured data in a host computer to track the trajectory of the DC transmission line / cast iron pipe.

In Korea, there are power plants mainly on land, and in consideration of various points, in many cases, electricity generated from land is sent to the island, and if it is very disadvantageous to send electricity from land, it is necessary to install and generate a generator on its own. And supplies to the island. In the case of Jeju Island, land-based electricity is sent through submarine transmission lines. Since communication optical cables are not affected by electric or magnetic fields due to their physical characteristics, they can be sent along the same route along with transmission lines. In this case, a cast iron pipe is used to protect the transmission line and the optical cable from damage caused by work in the sea such as fishing or aquaculture.

The transmission line / optical cable paths of various coastal areas of Korea, which are installed as described above, are realistically incorrectly displayed on the chart data, which is the basis of the navigational DGPS system. For this reason, when fishing or farming, unintentionally, the transmission line / optical cable is damaged, causing enormous damage each year. The root cause of this damage is that, in fact, more than half or no current state diagrams of transmission / optical cables laid or embedded within 2 meters of the seabed are incorrectly displayed.

As of 2005, billions of billions of dollars are invested every year to prevent damage to transmission lines / optical cables. However, the detection method of transmission line / optical cable location depends only on the naked eye detection by divers. Is practically difficult and also unscientific and systematic in the way of detecting transmission line / optical cable location. In order to fundamentally solve these problems, it is urgent to build a digital data bank by introducing modern detection technology.

In addition, as of 2005, when attempting to apply the electromagnetic detection method such as radar used to locate and maintain the transmission line / optical cable on land, the electrical conductivity of seawater is very high as 0.3 Ohm-M. Therefore, since all electromagnetic energy is lost in seawater even before reaching the transmission line / optical cable embedded in the seabed, the detection of the transmission line / optical cable is practically impossible.

An object of the present invention for solving the above problems is to measure the three components of the magnetic field generated by the transmission line embedded in the seabed and the cast iron pipe enclosed to protect it, using a three-axis magnetic field measurement sensor, The present invention provides a device and method for continuously detecting the trajectory of a DC transmission line / cast iron pipe by processing / interpreting data at a main computer.

When explaining the basic concept of the present invention to achieve the object as described above and to perform the problem for eliminating the conventional defects as follows.

If the current flowing through the transmission line is 60 Hz alternating current and the distance between the (+) and (-) lines is close to zero, the magnetic field generated by the current flowing through the (+) line and the current flowing through the (-) line The direction of the magnetic field produced by them is opposite and equal in magnitude, so they are completely canceled out.

However, when alternating current flows equally and the distance between the two lines is not zero, a synthetic alternating magnetic field is generated that is not completely canceled out. However, measuring the generated AC magnetic field is more difficult than measuring the DC magnetic field.

On the other hand, when the current flowing through the transmission line is direct current and the distance between the (+) and (-) lines is close to zero, the magnetic field generated by the current flowing through the (+) line and the current flowing through the (-) line The direction of the generated magnetic fields is opposite and the same magnitude, so they are completely canceled out.

However, if direct current flows equally and the distance between the two lines is not zero, a synthetic direct magnetic field is produced that is not completely canceled out. In this case, it is easier to measure the generated DC magnetic field than to measure the AC magnetic field.

For example, as of 2005, the transmission of the Jeju road is using DC, which is the last of the four types, and the position of the DC transmission line can be detected by measuring the magnetic field generated by the current flowing in the DC transmission line. .

In addition, in order to protect the transmission line / optical cable, the surrounding cast iron tube generates a strong induction magnetic field in response to the surrounding earth magnetic field. Therefore, a magnetic field of a different nature from the magnetic field generated by the current flowing through the transmission line is also generated. It will exist.

In addition, the earth magnetic field exists in any space without a transmission line / cast iron pipe, and the magnitude and direction of the magnetic field as a vector are not largely changed unless there is a material to generate a strong magnetic field around.

The magnetic field is a vector, and when a magnetic field of any of the above causes exists simultaneously in a space, the magnetic field we measured around the transmission line / optical cable, considering that the magnetic field in that space is the vector sum of those magnetic fields. Can be deduced from the vector sum of the various magnetic fields. Therefore, the remaining magnetic field after subtracting the background earth magnetic field from the measured magnetic field becomes the sum of the magnetic field caused by the current flowing through the transmission line and / or the magnetic field caused by the cast iron pipe.

On the other hand, our goal is to continuously track the location of the transmission line / optical cable to detect its path, so that the remaining magnetic field is either of the above two causes or both. It becomes.

The present invention according to the above concept will be described.

An apparatus for detecting a continuous path of a direct current transmission line and a cast iron pipe, the present invention comprises: a three-axis magnetic field measuring sensor for measuring the three-axis component of the magnetic field generated by the transmission line embedded in the seabed and the surrounding cast iron pipe to protect it; A four-channel low noise multiplexer for transmitting a three-axis component signal measured by a three-axis magnetic field measurement sensor to a high precision digital measurement unit with low noise; An amplifier and a noise removing filter for amplifying the three-axis component signal from the three-axis magnetic field sensor and the four-channel low noise multiplexer and removing noise; An ultra-precision digital measurement unit having a resolution of at least 25 bits of the sigma delta; Real-time precision location tracking unit of DGPS-RTK; And a main computer for integrating / controlling / measuring / processing / analyzing each device to detect a continuous path of a transmission line / optical cable / cast iron pipe.

In another aspect, the present invention provides a method for detecting a continuous path of the DC transmission line and cast iron pipe, comprising the steps of: interfacing the devices with each other; Loading and operating the entire system interfaced with each other by acquiring the 3-axis magnetic field value and the coordinates of the measuring points and recording them on the host computer; And extracting a continuous path of a transmission line / optical cable / cast iron pipe by integrating and interpreting the data recorded by the above operation.
More specifically, a method of detecting a continuous path of a DC transmission line and a cast iron pipe includes a three-axis magnetic field measuring sensor that measures a three-axis component magnetic field generated by a cast iron pipe enclosed to protect the transmission line and the transmission line embedded in the seabed. Measuring a magnetic field using a high-precision digital signal through a four-channel low noise multiplexer, an amplifier and a noise canceling filter connected to the three-axis magnetic field sensor and the signal of the three-axis component of the magnetic field measured by the three-axis magnetic field measurement sensor Transmitting a three-axis analog signal from the 4-channel low noise multiplexer, an amplifier, and a noise canceling filter to a measurement unit, and converting a high precision digital measurement unit having an A / D converter into a digital signal and transmitting the result to a main computer. And the three-axis magnetic field measuring sensor measures the three-axis component signal of the magnetic field. Transmitting the position coordinates of the point to the main computer through the real-time location tracking unit of the DGPS-RTK method; analyzing and processing data transmitted through the digital measurement unit and the location tracking unit at the main computer; and the three-axis magnetic field sensor 3-axis magnetic field consisting of the operation of processing the signal of the 3-axis component measured by the coordinates and the coordinates of the measurement position in the main computer to record and store the transmission line and cast iron pipe path in the memory of the main computer and to display it on the monitor of the computer The measurement results in continuous path detection of the DC transmission line and the cast iron pipe embedded in the seabed.

Hereinafter, the configuration and the operation of the embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1a, b is a conceptual diagram illustrating the operation of the device for detecting the path of the DC transmission line and cast iron pipe by the three-axis magnetic field measurement, Figure 1a is a side view, Figure 1b is a plan view, the three-axis magnetic field measurement sensor A ship with a main computer connected to it and connected with a communication cable travels along a certain path and detects whether there is a transmission line or a cast iron pipe. The cross-sectional configuration of the transmission line / cast iron pipe is configured such that the transmission line (+) and the transmission line (-) are positioned below and the optical cable is positioned above the cast iron pipe that protects the outside as described above.

FIG. 2 illustrates an exemplary embodiment of the apparatus illustrated in FIGS. 1A and 1B. The apparatus for detecting a continuous path of a DC transmission line and a cast iron pipe according to the present invention is described in detail by sensing a magnetic field while moving a seabed. A three-axis magnetic field measurement sensor, a four-channel low noise multiplexer connected to this three-axis magnetic field measurement sensor to measure three components within 1 msec, and a sigma connected to the four-channel low noise multiplexer to convert an analog signal into a digital signal Ultra-precision digital measuring unit that has delta 25 bit resolution and calculates the direction of transmission line and cast iron pipe embedded in the sea floor with three-axis digital signal, and is connected to this ultra-precision digital measuring unit to receive signals in real time And a main computer for integrating / controlling / measuring / processing / analyzing the above devices. An amplifier and a noise removing filter for amplifying a weak three-axis component signal from the three-axis magnetic field measuring sensor and a four-channel low noise multiplexer and removing noise are provided.

The three-axis magnetic field measurement sensor and the multiplex are connected by a Kevlar cable having a function of shielding electromagnetic noise from the outside, and can be extended to 150 m.

The multiplexer and the digital measurement unit are connected by using a serial communication method through which control / communication is performed.

The digital measurement unit and the main computer are connected by using an I2C communication method, and eventually the magnetic field values measured by the magnetic field measuring sensor are transmitted to the main computer.

The real-time precision location tracking unit and the main computer are connected in a serial communication manner, whereby the location tracking unit is configured to transmit the location coordinates calculated by DGPS-RTK (real-time mobile survey using differential GPS) to the main computer.

When the background magnetic field vector in the south of Korea is m _amb , it is expressed by decomposing it into three components in the coordinate system where the geographical north is the x axis, the geographical east is the y axis, and the vertical down is the z axis. (mx _amb , my _amb , mz _amb ), and the size | m _amb | is slightly smaller than 50000 nT, for example, a change in the range of 10 km x 10 km rarely exceeds several hundred nT. On the other hand, the size in the central part of Korea is about 50000 nT, slightly larger than 50000 nT in the north.

And when the magnetic field (current) vector generated by the direct current flowing through the transmission line is m _cur , it is expressed as three components in the same coordinate system (mx _cur , my _cur , mz _cur ). The size | m _cur | varies greatly from 0 to tens of thousands of nT depending on the amount of current flowing and the relative positional relationship between the measuring sensor and the transmission line.

Also, when m _pip is a magnetic field by cast iron pipe vector generated by the cast iron pipe, it is expressed as (mx _pip , my _pip , mz _pip ) by decomposing it into three components in the same coordinate system. The size | m _pip | also varies greatly from 0 to tens of thousands of nT, depending on the thickness, diameter, and mass ratio of the flowing cast iron pipe and the relative positional relationship between the measuring sensor and the cast iron pipe.

Therefore, when the vector sum of the magnetic fields due to the above three causes is m _tot , it is expressed as (mx _tot , my _tot , mz _tot ) by dividing it into three components in the same coordinate system as above. _tot | is mostly around 50000 nT and can vary from zero to over 100,000 nT, depending on the situation. The size in the middle is around 50000 nT and slightly larger than 50000 nT in the north.

The above-described vector combination m _tot of the magnetic field is decomposed into three components (mx _tot , my _tot , mz _tot ) as the x component, the y component, and the z component of FIG. 2.

The measured magnetic field signal is sequentially recorded in the host computer through an intermediate process such as amplification and filtering while going through a multiplexer and a digital measuring unit.

In the real-time precision position tracking unit of FIG. 2, the coordinates of the GPS antenna are measured by the DGPS-RTK method separately from the magnetic field measurement, and this value is transmitted to the host computer for recording.

Therefore, in the host computer, the magnetic field value and the coordinate value are synthesized and displayed on the screen, and from this data, the coordinates of the point where the magnetic field measuring sensor passes directly above the transmission line / optical cable / cast iron pipe can be extracted. In the pre-selected area, the operation is continued in the form of 'ㄹ' while displaying all the coordinates of the points passing directly above the transmission line / optical cable / cast iron pipe, and connecting them results in the trajectory of the transmission line / cast iron pipe running continuously.

3 is a conceptual diagram of a place where the device designed / configured / manufactured as described above is applied to an actual situation, and is somewhere in the South Sea of Korea. This is a place where you know that there are transmission lines / optical cables / cast-iron pipes, and two wires (pipes 1 and 2, usually two half of the total current through the two transmission lines) are expected to pass. When two were not available for faults, two sides across the total current were sent through one live transmission line (L300 and L400) to measure the magnetic field values above those two lines. In this area, two transmission lines / optical cables / cast iron pipes run almost side by side several hundred meters from northwest to southeast. A sideline that runs from southwest to northeast.

이고, 도 4b는 이러한 자기장의 벡터적 합 m_tot의 수직 아래쪽 성분 mz_tot의 크기 즉, |mz_tot|이며, 도 4a는 자기장의 벡터적 합 m_tot의 크기 즉, |m _tot|이다. 도 5의 세 그림들도 같은 성질을 가지고 있다.As Fig. 4a to 4c and Figures 5a to Figure 5c show the magnetic field values measured above two survey lines L300 and L400 in FIG. 3, respectively, Figure 4c is a vector ever sum Horizontal of m _tot of the magnetic field (H: Horizontal) 2 The vector sum of the components, that is, the size of the vector (mx _tot + my _sum ), | mh _tot | =

4b is the magnitude of the vertical bottom component mz _tot of the vector sum m _tot of this magnetic field, ie | mz _tot |, and FIG. 4a is the magnitude of the vector sum m _tot of the magnetic field, i. m _tot | The three figures of FIG. 5 also have the same properties.

=

인데, 일반적으로 |mz_tot|가 |mh_tot|보다 크므로, |m_tot|의 변화양상은 |mh_tot|의 변화양상보다는 |mz_tot|의 변화양상에 더 가깝게 된다. 위 두 측점은 각각 도 3의 관로 1 및 관로 2를 차례로 지나가는 지점이 된다. 4A to 4C show very distinct anomalies near station 616 and near station 1517, both of which have extreme values (maximum or local values) in the value of FIG. 4c | mh _tot |, and FIG. 4b | mz _tot | The value of is consistent with the inflection point corresponding to two or more intermediate values whose change patterns are opposite to each other. On the other hand, Fig. 4a | m _tot | is a value of | mh _tot | and | a vector arrangements of size | | mz _tot m _tot | =

=

In general, since | mz _tot | is larger than | mh _tot |, the change pattern of | m _tot | is closer to that of | mz _tot | than that of | mh _tot |. The above two points are points passing through pipeline 1 and pipeline 2 in FIG. 3, respectively.

On the other hand, in Figures 5a to 5c, there are very distinct abnormalities near the station 609 and near the station 1925, these two points have an extreme value in the value of Figure 5c | mh _tot | as in the case of Figures 4a to 4c, The value of FIG. 5b | mz _tot | coincides with the inflection point, and the change pattern of the value of FIG. 5a | m _tot | is close to the change pattern of | mz _tot |. The above two points are points passing through pipeline 2 and pipeline 1 in FIG. 3, respectively. By setting a lot of side lines as above, the magnetic field is measured, and as the result of the analysis above, the intersections with the pipelines are extracted, and when the intersections are connected, the connecting lines become the continuous paths of the pipelines.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

Using the apparatus and method of the present invention as described above, in the area where the transmission line / optical cable / cast iron pipe is expected to pass, the value measured by lowering the 3-axis magnetic field measurement sensor closer to the seabed and the coordinate value measured by the DGPS-RTK method By integrating and processing with each other, it is possible to detect a continuous path of transmission line / optical cable / cast iron pipe.

On the other hand, since the coordinate values are automatically obtained by the DGPS-RTK system, there is an advantage that the ship does not need to measure while accurately following a preset sideline.

In addition, since the transmission line / optical cable / cast-iron pipe can detect the route actually buried as above, it can be used in the industrial field as a useful invention with the advantage that it can supervise whether the buried is according to the original design drawing. This is a highly expected invention.

Claims (6)

In the continuous path detection device of the transmission line and cast iron pipe embedded in the seabed, A three-axis magnetic field measuring sensor for measuring three components of a magnetic field generated by a cast iron pipe enclosed to protect the transmission line and the transmission line embedded in the seabed; A kevlar cable for transmitting the signal measured by the three-axis magnetic field measuring sensor to shield the electromagnetic noise from the outside in a linear multiplex; A four-channel low noise multiplexer coupled to the three-axis magnetic field sensor and the kevlar cable to transmit a three-axis component of the magnetic field measured by the three-axis magnetic field measurement sensor to a high precision digital measurement unit; An ultra-precision digital measuring unit for amplifying a signal transmitted through the four-channel low noise multiplexer and converting the noise-free analog signal into a digital signal with an A / D converter having high resolution and converting the converted digital signal into a digital signal of three-axis components; A real-time position tracking unit of a DGPS-RTK method in which the three-axis magnetic field sensor transmits coordinates of a point at which the three-axis component signal of the magnetic field is measured to a host computer; The ultra-precision digital measuring unit calculates and processes a three-axis component signal converted into a digital signal as a vector value, and interlocks the processed value with the position information acquired from the position tracking unit, and the information on the embedding path of the transmission line and the cast iron pipe embedded in the seabed. Continuous path detection device of DC transmission line and cast iron pipe embedded in the sea floor by 3-axis magnetic field measurement composed of main computer which records and records the data on the monitor. delete delete delete delete In the continuous path detection method of transmission lines and cast iron pipes embedded in the seabed, Measuring a magnetic field using a three-axis magnetic field measuring sensor measuring a three-axis component magnetic field generated by a transmission line embedded in a seabed and a cast iron pipe enclosed to protect the transmission line; Transmitting a signal of a three-axis component of the magnetic field measured by the three-axis magnetic field measurement sensor to a high precision digital measurement unit through a four-channel low noise multiplexer, an amplifier, and a noise canceling filter connected to the three-axis magnetic field measurement sensor; Converting a three-axis component analog signal from the four-channel low noise multiplexer, an amplifier, and a noise canceling filter into a digital signal by converting a high precision digital measurement unit with an A / D converter into a digital signal; Transmitting, by the 3-axis magnetic field sensor, the position coordinates of the point where the 3-axis component signal of the magnetic field is measured to the host computer through a real-time position tracking unit of the DGPS-RTK method; Analyzing the data transmitted through the digital measuring unit and the position tracking unit in a host computer; The digital signal of the 3-axis component measured by the 3-axis magnetic field measuring sensor is calculated and processed by the host computer as a vector value, and the buried path of the transmission line and the cast iron pipe is interlocked with the processed value and the position information measured by the position tracking unit. Continuous path detection method of DC transmission line and cast iron pipe embedded in the sea floor by 3-axis magnetic field measurement, which is recorded and stored in the memory of the main computer and displayed on the monitor of the computer.

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