Electrode current sharing system and electrode current sharing method for coast grounding electrode

Abstract

The invention discloses an electrode current sharing system and an electrode current sharing method for a coast grounding electrode. The electrode current sharing system comprises a plurality of electrode wells, a plurality of adjustable resistors, a current monitoring subsystem, a remote control subsystem and a current sharing adjusting subsystem. Each electrode well is connected in series with one adjustable resistor; the current monitoring subsystem is used for monitoring the current of a plurality of electrode wells, outputting monitoring data and sending out an alarm signal when the current of the electrode wells exceeds a preset threshold value; the remote control subsystem is used for receiving the monitoring data and the alarm signal, and outputting an adjustment control signal when determining that the distribution of more than M electrode wells is not uniform based on the monitoring data and the alarm signal; and the current sharing adjusting subsystem responds to the adjusting control signal and adjusts the plurality of adjustable resistors until each electrode well distributes current uniformly. According to the invention, the electrode well with abnormal discharge can be monitored, and the current sharing effect of the electrode well of the coast grounding electrode can be realized by adjusting the adjustable resistor.

Description

Technical Field

[0001] The present invention relates to the technical field of grounding electrode current balancing, and in particular to an electrode current balancing system and an electrode current balancing method for a coast grounding electrode. Background Art

[0002] DC transmission technology is the main technical means to solve the problem of power production bases being far away from major power consumption areas, and DC grounding electrodes are an important part of DC transmission. In coastal long-distance DC transmission projects or cross-sea DC transmission projects, the use of coastal grounding electrodes is the best choice, which can take advantage of the low resistivity characteristics of water-containing sand, thereby obtaining relatively low grounding resistance with a smaller grounding electrode project scale.

[0003] Coastal grounding electrodes are generally designed to be arranged in a line along the coastline because the electrodes need to be buried below the sea level. Taking vertical electrodes as an example, 2 to 3 rows of vertical electrode wells are usually arranged along the beach. Dozens of such electrodes are arranged linearly. If the traditional diversion method is used to connect all electrodes in parallel through cables, serious end effects will occur. The current allocated to the electrode wells at the end position will be much larger than that of the electrode wells in the middle position. The end electrodes will produce strong electrochemical reactions due to the excessive overflow density. In addition to seriously consuming the life of the end electrodes, the gases released by the electrochemical reactions will produce a "gas resistance" effect, causing the electrodes to be unable to discharge normally. The "gas resistance" effect will gradually transfer to the middle position until the entire grounding resistance value is greatly increased. In addition, the distances between the electrode wells and the diversion center are different, so the resistance of the diversion cable of each electrode well is different, which will also lead to uneven diversion. The closer the electrode is to the conduction center, the greater the current allocated to it, and the farther the electrode is from the conduction center, the smaller the current allocated to it. This uneven current distribution will also lead to the spread of the "air resistance" effect, which will eventually increase the overall resistance of the grounding electrode and affect the normal operation of DC power transmission.

[0004] At present, there is no successful coastal DC grounding electrode in China. The "Nanqiao" grounding electrode in Shanghai in the 1980s was a coastal linear horizontal grounding electrode, which was eventually scrapped due to the end effect problem. How to evenly distribute the current to various parts of the electrode is the prerequisite for the good operation of the coastal grounding electrode. The existing ordinary land vertical DC grounding electrodes, such as Figure 1 As shown in the figure, a circular or elliptical arrangement is adopted, and each electrode well is connected to the busbar located at the center of the flow diversion in the circular ring through an independent guide cable, and no current equalization measures are taken. Although the circular or elliptical vertical electrode well can avoid the end effect problem, the current diversion of the electrode well is completely determined by the grounding resistance value of each electrode well and the resistance value of the cable connecting the electrode well. When the electrode wells are arranged in a straight line in the coastal grounding electrode, the end effect cannot be avoided. Summary of the invention

[0005] The present invention provides an electrode current equalizing system and an electrode current equalizing method for a coastal grounding electrode to solve the above-mentioned technical problems and achieve an electrode well current equalizing effect for a coastal grounding electrode.

[0006] In order to solve the above technical problems, the present invention provides an electrode current sharing system for a coastal grounding electrode, comprising: a plurality of electrode wells, a plurality of adjustable resistors, a current monitoring subsystem, a remote control subsystem and a current sharing regulating subsystem;

[0007] In a plurality of electrode wells, each electrode well is connected in series with an adjustable resistor;

[0008] The current monitoring subsystem is used to monitor the current of several electrode wells and output monitoring data; when the current of an electrode well exceeds a preset threshold, an alarm signal is issued;

[0009] The remote control subsystem is used to receive monitoring data and alarm signals, and output a regulation control signal when it is determined based on the monitoring data and the alarm signals that more than M electrode wells have uneven flow distribution, where M is a preset positive integer;

[0010] The current equalization regulating subsystem adjusts a plurality of adjustable resistors in response to the regulating control signal until the current distribution in each electrode well is uniform.

[0011] The beneficial effects of the present invention are:

[0012] The electrode current equalization system of the coastal grounding electrode proposed in the present invention can monitor the current of several electrode wells through the current monitoring subsystem. When the current of an electrode well exceeds a preset threshold, the current monitoring subsystem sends an alarm signal. When the remote control subsystem determines that more than M electrode wells have uneven current diversion based on the monitoring data and the alarm signal, it outputs an adjustment control signal to adjust several adjustable resistors until the current diversion of each electrode well is uniform. Therefore, the present invention can monitor electrode wells with abnormal leakage, and when more than M electrode wells have uneven current diversion, the current is evenly distributed to each electrode well by adjusting the adjustable resistors connected in series with each electrode well, thereby ensuring that the coastal grounding electrode will not develop into an "air blockage" effect due to excessive overflow density, thereby achieving the electrode well current equalization effect of the coastal grounding electrode.

[0013] As a preferred solution, the adjustable resistor is a stepless adjustable resistor.

[0014] The stepless adjustable resistor can achieve continuous adjustment of the resistance value, rather than being able to adjust to a few fixed resistance points like the traditional resistor. This makes it have the advantage of high adjustment accuracy, and is very useful in situations where the resistance value needs to be accurately controlled, such as the adjustment of precision instruments and equipment. The adjustable resistor in this preferred solution adopts a stepless adjustable resistor, which is convenient for fine-tuning the resistance value during maintenance, ensuring the uniformity of the electrode well shunt throughout the life cycle, and can ensure the accuracy of the adjustment.

[0015] As a preferred solution, the current monitoring subsystem includes: a number of current monitoring devices and a monitoring system cabinet;

[0016] Wherein, each of the current monitoring devices is used to monitor the current of the corresponding electrode well in real time and output monitoring data;

[0017] The monitoring system cabinet is used to collect monitoring data and output the monitoring data to the remote control subsystem; the monitoring system cabinet is also used to send out an alarm signal when it is determined based on the monitoring data that the current in the electrode well exceeds a preset threshold.

[0018] In this preferred solution, a current monitoring subsystem is formed by a plurality of current monitoring devices and a monitoring system cabinet to realize current monitoring of the electrode well. When it is determined that the current in the electrode well exceeds a preset threshold, an alarm signal is issued so that the remote control subsystem outputs an adjustment control signal. The current equalization adjustment subsystem responds to the adjustment control signal to adjust a plurality of adjustable resistors to realize uniform current distribution in each electrode well.

[0019] As a preferred solution, the monitoring system cabinet includes: a comprehensive monitoring host, a switch and an integrated industrial computer;

[0020] Wherein, the comprehensive monitoring host is used to collect monitoring data;

[0021] The switch is used to perform analog-to-digital conversion of monitoring data to update the monitoring data;

[0022] The integrated industrial computer is used to store monitoring data and send the monitoring data to the remote control subsystem.

[0023] This preferred solution forms a monitoring system cabinet through a comprehensive monitoring host, switch and integrated industrial computer, so that the collected monitoring data can be sent to the remote control subsystem in real time remotely, so that the remote control subsystem can monitor the status of each electrode well according to the received monitoring data and perform corresponding operations according to the status of each electrode well to ensure uniform distribution of each electrode well in the coastal grounding electrode.

[0024] As a preferred embodiment, the remote control subsystem is also used to, after adjusting a number of adjustable resistors to make the M electrode wells evenly diverted, determine based on monitoring data and alarm signals that there are still L electrode wells with uneven diversion, then control the L electrode wells to exit operation; L is a positive integer and L is less than M.

[0025] This preferred solution monitors the current and diversion uniformity of each electrode well in the coastal grounding electrode through the current monitoring subsystem. When it is determined that there is uneven diversion in individual electrode wells, these electrode wells are controlled to exit operation through the remote control subsystem, thereby achieving online disconnection of individual electrode wells with abnormal diversion without affecting the normal operation of the entire coastal grounding electrode.

[0026] As a preferred solution, the remote control subsystem includes: a plurality of load switches; the load switches are used to control whether the corresponding electrode well is out of operation.

[0027] This preferred solution controls the corresponding electrode well to exit operation through a load switch. When there are still some electrode wells with uneven current distribution after adjusting a number of adjustable resistors, these electrode wells are controlled to exit operation through a load switch, so as to realize online disconnection of the electrode wells with abnormal current distribution, without affecting the normal operation of the entire coastal grounding electrode.

[0028] As a preferred solution, the remote control subsystem further includes: a photoelectric signal conversion device;

[0029] The remote control subsystem is also used to output an optical fiber control signal when it is determined based on monitoring data and alarm signals that there are still L electrode wells with uneven flow distribution after adjusting a number of adjustable resistors to make the M electrode wells evenly distributed;

[0030] The photoelectric signal conversion device is used to receive the optical fiber control signal and convert the optical fiber control signal into an electrical signal; the electrical signal is used to control the opening and closing of a plurality of load switches.

[0031] When it is determined that there are L electrode wells with uneven current diversion, this preferred solution outputs a fiber optic control signal through the remote control subsystem, and the optoelectronic signal conversion device converts the received fiber optic control signal into an electrical signal, which can enable the load switch to control individual electrode wells to exit operation under the control of the electrical signal, thereby achieving online disconnection of individual electrode wells with abnormal current diversion, thereby ensuring the normal operation of the entire coastal grounding electrode.

[0032] Accordingly, in order to solve the above technical problems, the present invention further provides an electrode current balancing method for a coast grounding electrode, which is applied to an electrode current balancing system for a coast grounding electrode as described in any one of the above, and the electrode current balancing method for the coast grounding electrode comprises:

[0033] During the operation of the coast grounding electrode, the current in each electrode well is monitored to obtain current monitoring data;

[0034] When it is determined based on the current monitoring data that more than M electrode wells have uneven current distribution, a number of adjustable resistors are adjusted until the current distribution of each electrode well is uniform; wherein each electrode well is connected in series with an adjustable resistor, and M is a preset positive integer.

[0035] When uneven current distribution occurs in large-area electrode wells of the coast grounding electrode, the invention adjusts the adjustable resistor connected in series with each electrode well to make the current distribution of each electrode well uniform, thereby ensuring the uniformity of current distribution of the electrode wells during the whole life cycle.

[0036] As a preferred solution, the electrode current equalization method of a coast grounding electrode further includes:

[0037] During the debugging period after the construction of the coast grounding electrode is completed, after the second test current is passed through the coast grounding electrode, the resistance values ​​of several adjustable resistors are adjusted based on the resistance range set until the current is evenly distributed in each electrode well.

[0038] This preferred solution adjusts the resistance values ​​of several adjustable resistors based on the resistance range set during the debugging period after the construction of the coastal grounding electrode is completed, until the current is evenly distributed in each electrode well, which can ensure the actual stable operation of the coastal grounding electrode.

[0039] As a preferred solution, the method for obtaining the resistance range set includes:

[0040] After passing the first test current through the coast grounding electrode, measure the current in each electrode well and the ground potential rise of the coast grounding electrode;

[0041] Based on the current of each electrode well and the ground potential rise of the coast grounding electrode, the equivalent resistance of each electrode well is calculated to obtain the equivalent resistance of each electrode well;

[0042] Determine the maximum single-hole electrode well resistance among the equivalent resistances of each electrode well;

[0043] Based on the maximum single-hole electrode well resistance and the equivalent resistance of each electrode well, the resistance range of each adjustable resistor is determined respectively to obtain a resistance range set.

[0044] Adjusting any adjustable resistor on site will result in changes in the current shunt of each electrode. The preferred solution adjusts the resistance values ​​of several adjustable resistors based on a resistance range set and pre-calculates the resistance range set, which can improve the accuracy and efficiency of adjusting the adjustable resistors and is beneficial to achieving current equalization in the electrode wells of the coastal grounding electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 : A schematic diagram of an existing common vertical DC grounding electrode current conduction method provided by an embodiment of the present invention;

[0046] Figure 2 : A structural schematic diagram of an embodiment of an electrode current sharing system for a coast grounding electrode provided by the present invention;

[0047] Figure 3 : A structural schematic diagram of an embodiment of a current monitoring subsystem provided by the present invention;

[0048] Figure 4 : A structural schematic diagram of another embodiment of an electrode current sharing system for a coast grounding electrode provided by the present invention;

[0049] Figure 5 : A flow chart of an embodiment of a method for equalizing current of an electrode of a coast grounding electrode provided by the present invention. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] At present, there is no successful coastal DC grounding electrode in China. The "Nanqiao" grounding electrode in Shanghai in the 1980s was a coastal linear horizontal grounding electrode, which was eventually scrapped due to the end effect problem. How to evenly distribute the current to various parts of the electrode is the prerequisite for the good operation of the coastal grounding electrode. The existing ordinary land vertical DC grounding electrodes, such as Figure 1 As shown in the figure, a circular or elliptical arrangement is adopted, and each electrode well is connected to the busbar located at the center of the guide in the ring through an independent guide cable. The busbar of the coastal grounding electrode is connected to the converter station through the DC grounding electrode line, and no current equalization measures are taken. Although the circular or elliptical vertical electrode wells can avoid the end effect problem, the current diversion of the electrode wells is completely determined by the grounding resistance value of each electrode well and the resistance value of the cable connecting the electrode wells. When the coastal grounding electrode adopts a straight-line arrangement of the electrode wells, the end effect cannot be avoided.

[0052] Embodiment 1

[0053] In order to solve the above technical problems, the present invention provides an electrode current equalization system for a coastal grounding electrode, which can achieve a current equalization effect in an electrode well of a coastal grounding electrode.

[0054] Please refer to Figure 2 , Figure 2 A schematic structural diagram of an embodiment of an electrode current equalizing system for a coast grounding electrode provided by the present invention.

[0055] like Figure 2 As shown, the electrode current sharing system of the coast grounding electrode includes: a plurality of electrode wells, a plurality of adjustable resistors, a current monitoring subsystem, a remote control subsystem and a current sharing regulating subsystem;

[0056] In a plurality of electrode wells, each electrode well is connected in series with an adjustable resistor;

[0057] The current monitoring subsystem is used to monitor the current of several electrode wells and output monitoring data; when the current of an electrode well exceeds a preset threshold, an alarm signal is issued;

[0058] The remote control subsystem is used to receive monitoring data and alarm signals, and output a regulation control signal when it is determined based on the monitoring data and the alarm signals that more than M electrode wells have uneven flow distribution, where M is a preset positive integer;

[0059] The current equalization regulating subsystem adjusts a plurality of adjustable resistors in response to the regulating control signal until the current distribution in each electrode well is uniform.

[0060] The electrode current equalization system of the coastal grounding electrode proposed in the present invention can monitor the current of several electrode wells through the current monitoring subsystem. When the current of an electrode well exceeds a preset threshold, the current monitoring subsystem sends an alarm signal. When the remote control subsystem determines that more than M electrode wells have uneven current diversion based on the monitoring data and the alarm signal, it outputs an adjustment control signal to adjust several adjustable resistors until the current diversion of each electrode well is uniform. Therefore, the present invention can monitor electrode wells with abnormal leakage, and when more than M electrode wells have uneven current diversion, the current is evenly distributed to each electrode well by adjusting the adjustable resistors connected in series with each electrode well, thereby ensuring that the coastal grounding electrode will not develop into an "air blockage" effect due to excessive overflow density, thereby achieving the electrode well current equalization effect of the coastal I-shaped grounding electrode.

[0061] Furthermore, the adjustable resistor is a stepless adjustable resistor.

[0062] In this embodiment, the adjustable resistor needs to have a sufficient resistance adjustment range, and the adjustable range can be set from 0Ω to 2 to 3 times the calculated maximum single-hole electrode well resistance.

[0063] The stepless adjustable resistor can realize continuous adjustment of the resistance value, instead of being able to adjust to a few fixed resistance points like the traditional resistor. This makes it have the advantage of high adjustment accuracy, which is very useful in occasions where the resistance value needs to be accurately controlled, such as the adjustment of precision instruments and equipment. The adjustable resistor in this embodiment adopts a stepless adjustable resistor, which is convenient for fine-tuning the resistance value during maintenance, ensuring the uniformity of the electrode well shunt during the entire life cycle, and can ensure the accuracy of adjustment.

[0064] Please refer to Figure 3 , Figure 3 A schematic structural diagram of an embodiment of a current monitoring subsystem provided by the present invention.

[0065] Further, the current monitoring subsystem includes: a number of current monitoring devices and a monitoring system cabinet;

[0066] Wherein, each of the current monitoring devices is used to monitor the current of the corresponding electrode well in real time and output monitoring data;

[0067] The monitoring system cabinet is used to collect monitoring data and output the monitoring data to the remote control subsystem; the monitoring system cabinet is also used to send out an alarm signal when it is determined based on the monitoring data that the current in the electrode well exceeds a preset threshold.

[0068] In this embodiment, a current monitoring subsystem is formed by a plurality of current monitoring devices and a monitoring system cabinet to realize current monitoring of the electrode well, and the monitoring data is remotely output to the remote control subsystem in real time. When it is determined that the current in the electrode well exceeds a preset threshold, an alarm signal is issued so that the remote control subsystem outputs an adjustment control signal. The current equalization adjustment subsystem responds to the adjustment control signal to adjust a plurality of adjustable resistors to realize uniform current distribution in each electrode well.

[0069] In this embodiment, the current measuring device is a small-range, high-precision device.

[0070] On the one hand, the current is small during debugging or maintenance, and the measurement accuracy needs to be ensured; on the other hand, the coast grounding electrode rarely reaches the rated current. According to the operating characteristics of the DC project, it is only a few times a year with a total of several hours. Most of the time, the ground current passing through the coast grounding electrode is less than 10A. Therefore, a small-range, high-precision current measuring device is needed to monitor the status of the electrode well.

[0071] Furthermore, if Figure 3 As shown, the monitoring system cabinet includes: a comprehensive monitoring host, a switch and an integrated industrial computer;

[0072] Wherein, the comprehensive monitoring host is used to collect monitoring data;

[0073] The switch is used to perform analog-to-digital conversion of monitoring data to update the monitoring data;

[0074] The integrated industrial computer is used to store monitoring data and send the monitoring data to the remote control subsystem.

[0075] The present invention forms a monitoring system cabinet through a comprehensive monitoring host, a switch and an integrated industrial computer, so as to realize real-time remote transmission of the collected monitoring data to the remote control subsystem, so that the remote control subsystem can monitor the status of each electrode well according to the received monitoring data and perform corresponding operations according to the status of each electrode well, thereby ensuring uniform flow distribution among the electrode wells in the coastal grounding electrode.

[0076] The present invention performs analog-to-digital conversion on monitoring data through a switch, and can perform analog-to-digital conversion on measured analog signals to obtain digital signals, thereby making it convenient for a computer to read the monitoring data.

[0077] In this embodiment, the monitoring system cabinet also includes a dedicated power supply.

[0078] In this embodiment, wireless communication or optical fiber communication can be used to achieve communication between the monitoring system cabinet and the remote control subsystem.

[0079] Furthermore, the remote control subsystem is also used to, after adjusting a number of adjustable resistors to make the M electrode wells evenly diverted, determine based on monitoring data and alarm signals that there are still L electrode wells with uneven diversion, and then control the L electrode wells to exit operation; L is a positive integer and L is less than M.

[0080] The present invention realizes the monitoring of the current and shunt uniformity of each electrode well in the coastal grounding electrode through the current monitoring subsystem. When it is determined that there is uneven shunt in individual electrode wells, these electrode wells are controlled to exit operation through the remote control subsystem, so that the individual electrode wells with abnormal shunt are disconnected online without affecting the normal operation of the entire coastal grounding electrode.

[0081] Furthermore, the remote control subsystem includes: a plurality of load switches; the load switches are used to control whether the corresponding electrode wells are out of operation.

[0082] The present invention controls the corresponding electrode well to exit operation through a load switch. After adjusting a number of adjustable resistors, if there are still some electrode wells with uneven current diversion, these electrode wells are controlled to exit operation through the load switch, so as to realize online disconnection of the electrode wells with abnormal current diversion, without affecting the normal operation of the entire coastal grounding electrode.

[0083] Furthermore, the remote control subsystem further includes: a photoelectric signal conversion device;

[0084] The remote control subsystem is also used to output an optical fiber control signal when it is determined based on monitoring data and alarm signals that there are still L electrode wells with uneven flow distribution after adjusting a number of adjustable resistors to make the M electrode wells evenly distributed;

[0085] The photoelectric signal conversion device is used to receive the optical fiber control signal and convert the optical fiber control signal into an electrical signal; the electrical signal is used to control the opening and closing of a plurality of load switches.

[0086] When the present invention determines that there are L electrode wells with uneven current diversion, the remote control subsystem outputs an optical fiber control signal, and the photoelectric signal conversion device converts the received optical fiber control signal into an electrical signal, which can enable the load switch to control individual electrode wells to exit operation under the control of the electrical signal, thereby achieving online disconnection of individual electrode wells with abnormal current diversion, thereby ensuring the normal operation of the entire coastal grounding electrode.

[0087] In this embodiment, both the current monitoring subsystem and the remote control subsystem require an external 220 / 380V power supply to provide them with power.

[0088] Please refer to the following Figure 4 , Figure 4 A schematic structural diagram of another embodiment of an electrode current equalizing system for a coast grounding electrode provided by the present invention.

[0089] like Figure 4 As shown, the same current balancing system is arranged on the diversion branch of each electrode well, and the current balancing system includes a stepless adjustable resistor, a current monitoring subsystem and a remote control subsystem.

[0090] The current monitoring subsystem includes several current monitoring devices, a monitoring system cabinet, power supplies and signal lines. Each current monitoring device is arranged on each electrode well diversion branch and is used for real-time monitoring of the diversion cable current and then detecting the corresponding electrode well. The power supply and signal lines are used to provide electrical energy for the current measuring device and to transmit the measured electrical signal back to the monitoring system cabinet.

[0091] In this embodiment, the current measuring device is a small-range, high-precision device. On the one hand, the current is small during debugging or maintenance, and the accuracy of the measurement needs to be guaranteed; on the other hand, the coast grounding electrode rarely reaches the rated current. According to the operation characteristics of the DC project, it only reaches the rated current several times a year. Most of the time, the ground current through the coast grounding electrode is less than 10A, so a small-range, high-precision current measuring device is needed to monitor the electrode well status.

[0092] In this embodiment, the remote control subsystem includes: an operation monitoring center, a load switch, a photoelectric signal conversion device, a power supply and a control line. When the operation monitoring center determines that the load switch of a certain electrode well branch needs to be opened or closed, the operation monitoring center sends an optical fiber control signal to the photoelectric signal conversion device located in the grounding electrode diversion center, which is converted into an electrical signal and then opens the load switch of the corresponding electrode well branch through the control line.

[0093] In this embodiment, during the later period of power outage and maintenance, the resistance can be adjusted regularly. By regularly adjusting the steplessly adjustable resistance, the uniformity of the current diversion in the electrode well can be ensured throughout the life cycle.

[0094] In this embodiment, when the current of an individual electrode well increases abnormally to exceed the diversion ratio allowed by the design, the current monitoring subsystem sends an alarm signal to the operation monitoring center. After the operation monitoring center determines that the fault is due to uneven diversion of individual electrode wells, the individual faulty electrode wells are shut down through remote control in the system operating load switch, which does not affect the overall operation of the coastal grounding electrode; if the operation monitoring center determines that it is due to uneven diversion of large-area electrode wells, the operation monitoring center can limit the size and time of the ground current, arrange maintenance as soon as possible, and readjust the resistance value of the stepless adjustable resistor.

[0095] Because the coast grounding electrode is a device that passively receives current, it is the operation monitoring center that decides how much current to give to the coast grounding electrode. When the coast grounding electrode has uneven current diversion in the electrode well, the operation monitoring center limits the size and time of the current entering the ground by selecting control measurements. For most of the year, the converter station is bipolar balanced, that is, the positive and negative currents are roughly the same, so the current passing through the grounding electrode is very small (about 10A). If the grounding electrode has uneven current diversion, it can operate normally. At this time, the control strategy of the operation monitoring center only needs to limit the current and time under the possible unipolar operation mode. For example, the original strategy allows the unipolar rated current to run for 2 hours, then after monitoring the uneven current of the grounding electrode, it is changed to allow the unipolar rated current to run for 1 hour. These policy changes need to be confirmed and completed by the operation monitoring center.

[0096] Correspondingly, in order to solve the above technical problems, the present invention also provides an electrode current equalization method for a coast grounding electrode, which is applied to an electrode current equalization system for a coast grounding electrode as described in any one of the above.

[0097] Please refer to Figure 5 , Figure 5 A schematic flow chart of an embodiment of a method for equalizing current of an electrode of a coast grounding electrode provided in an embodiment of the present invention.

[0098] like Figure 5 As shown, the electrode current equalization method of the coast grounding electrode includes steps 101 to 102, specifically:

[0099] Step 101: During the operation of the coastal grounding electrode, the current of each electrode well is monitored to obtain current monitoring data;

[0100] Step 102: When it is determined based on the current monitoring data that more than M electrode wells have uneven current distribution, a number of adjustable resistors are adjusted until the current distribution in each electrode well is uniform; wherein each electrode well is connected in series with one adjustable resistor, and M is a preset positive integer.

[0101] When uneven current distribution occurs in large-area electrode wells of the coast grounding electrode, the invention adjusts the adjustable resistor connected in series with each electrode well to make the current distribution of each electrode well uniform, thereby ensuring the uniformity of current distribution of the electrode wells during the whole life cycle.

[0102] Furthermore, the electrode current equalization method of a coast grounding electrode further includes:

[0103] During the debugging period after the construction of the coast grounding electrode is completed, after the second test current is passed through the coast grounding electrode, the resistance values ​​of several adjustable resistors are adjusted based on the resistance range set until the current is evenly distributed in each electrode well.

[0104] Furthermore, the method for obtaining the resistance range set includes:

[0105] After passing the first test current through the coast grounding electrode, measure the current in each electrode well and the ground potential rise of the coast grounding electrode;

[0106] Based on the current of each electrode well and the ground potential rise of the coast grounding electrode, the equivalent resistance of each electrode well is calculated to obtain the equivalent resistance of each electrode well;

[0107] Determine the maximum single-hole electrode well resistance among the equivalent resistances of each electrode well;

[0108] Based on the maximum single-hole electrode well resistance and the equivalent resistance of each electrode well, the resistance range of each adjustable resistor is determined respectively to obtain a resistance range set.

[0109] During the debugging period after the construction of the coast grounding electrode is completed, the present invention first passes a first test current through the coast grounding electrode to obtain the resistance range of each adjustable resistor and obtain a resistance range set; then, after passing a second test current through the coast grounding electrode, the resistance values ​​of several adjustable resistors are adjusted based on the resistance range set until the current is evenly distributed in each electrode well.

[0110] In this embodiment, the current values ​​of the first test current and the second test current are smaller than the preset current values.

[0111] During the debugging period after the construction of the coast grounding electrode is completed, a relatively small test current is simultaneously passed through all electrode wells of the coast grounding electrode, and the resistance values ​​of several adjustable resistors are adjusted based on a resistance range set until the current is evenly distributed in each electrode well, thereby ensuring the actual stable operation of the coast grounding electrode.

[0112] The present invention adjusts the resistance values ​​of several adjustable resistors based on a resistance range set, and before adjusting the resistance values ​​of the several adjustable resistors, estimates the resistance value to which each resistor needs to be adjusted, so as to pre-calculate the resistance range set, which can improve the accuracy and efficiency of adjusting the adjustable resistors and is beneficial to realizing the electrode well current equalization of the coastal grounding electrode.

[0113] In this embodiment, the adjustable resistor needs to have a sufficient resistance adjustment range, and the resistance adjustment range can be set from 0Ω to 2 to 3 times the calculated maximum single-hole electrode well resistance.

[0114] In this embodiment, one implementation method of the resistance range set is: assuming that the electrode wells are #1, #2, #3, ..., #n, after the first test current is passed, the currents of each electrode well conduction current measured are I1, I2, I3 ..., I n , measure the ground potential rise generated by the entire grounding electrode as U GPR , the equivalent resistance R1, R2, R3, ..., R of each electrode well (including the resistance of the guide cable) can be calculated n For the xth electrode well, the resistance of the series resistor matched with it is the difference between the resistance of the largest single electrode well and the resistance of the xth electrode well, that is, R MAX[1,2,3…n] -R x .

[0115] Adjusting any adjustable resistor on site will cause changes in the current shunt of each electrode. Therefore, before adjustment, it is necessary to estimate the resistance Rx of each electrode well by measuring the current I and the ground potential U. After estimating the resistance value R'x of each adjustable resistor in series, the resistance value Rx of each electrode well plus the value of the adjustable resistor R'x in series are equal.

[0116] Since the surrounding environment may interfere with the measurement and the ground potential U is not easy to measure accurately, theoretically the measurement point needs to be placed at infinity. The present invention determines the resistance range of each adjustable resistor by estimation.

[0117] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0118] The present invention provides an electrode current balancing system and an electrode current balancing method for a coastal grounding electrode, which adopts a stepless adjustable current balancing resistor connected in series with an electrode well, so as to evenly distribute the current on each electrode well; a current measuring device and a load switch are arranged on the diversion branch of each electrode, and the current of each electrode well is monitored online, so as to realize the monitoring of the electrode well with abnormal leakage, the monitoring of the uniformity of the current diversion of each electrode well and the withdrawal of the abnormal electrode well from operation without affecting the normal operation of the entire grounding electrode, and the adjustable resistor can be fine-tuned during maintenance and overhaul to maintain the current density on each electrode within the original design value, so as to ensure the uniformity of the current distribution of the electrode well during the whole life cycle, and realize the current balancing effect of the electrode well of the coastal grounding electrode, so as to ensure that the overflow density is too large and eventually develops into the "air blockage" effect.

[0119] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. An electrode current sharing system for a coast grounding electrode, characterized in that: include: Several electrode wells, several adjustable resistors, a current monitoring subsystem, a remote control subsystem and a current equalization regulation subsystem; In a plurality of electrode wells, each electrode well is connected in series with an adjustable resistor; The current monitoring subsystem is used to monitor the current of several electrode wells and output monitoring data; when the current of an electrode well exceeds a preset threshold, an alarm signal is issued; The remote control subsystem is used to receive monitoring data and alarm signals, and output a regulation control signal when it is determined based on the monitoring data and the alarm signals that more than M electrode wells have uneven flow distribution, where M is a preset positive integer; The current equalization regulating subsystem adjusts a plurality of adjustable resistors in response to the regulating control signal until the current distribution in each electrode well is uniform.

2. The electrode current sharing system of a coast grounding electrode according to claim 1, characterized in that: The adjustable resistor is a stepless adjustable resistor.

3. The electrode current sharing system of a coast grounding electrode according to claim 1, characterized in that: The current monitoring subsystem includes: a number of current monitoring devices and a monitoring system cabinet; Wherein, each of the current monitoring devices is used to monitor the current of the corresponding electrode well in real time and output monitoring data; The monitoring system cabinet is used to collect monitoring data and output the monitoring data to the remote control subsystem; the monitoring system cabinet is also used to send out an alarm signal when it is determined based on the monitoring data that the current in the electrode well exceeds a preset threshold.

4. The electrode current sharing system of a coast grounding electrode as claimed in claim 3, characterized in that: The monitoring system cabinet includes: a comprehensive monitoring host, a switch and an integrated industrial computer; Wherein, the comprehensive monitoring host is used to collect monitoring data; The switch is used to perform analog-to-digital conversion of monitoring data to update the monitoring data; The integrated industrial computer is used to store monitoring data and send the monitoring data to the remote control subsystem.

5. The electrode current sharing system of a coast grounding electrode according to claim 1, characterized in that: The remote control subsystem is also used to, after adjusting a number of adjustable resistors to make the M electrode wells evenly diverted, determine based on monitoring data and alarm signals that there are still L electrode wells with uneven diversion, and then control the L electrode wells to exit operation; L is a positive integer and L is less than M.

6. The electrode current sharing system of a coast grounding electrode as claimed in claim 5, characterized in that: The remote control subsystem includes: a plurality of load switches; the load switches are used to control whether the corresponding electrode well is out of operation.

7. The electrode current sharing system of a coast grounding electrode according to claim 6, characterized in that: The remote control subsystem further includes: a photoelectric signal conversion device; The remote control subsystem is also used to output an optical fiber control signal when it is determined based on monitoring data and alarm signals that there are still L electrode wells with uneven flow distribution after adjusting a number of adjustable resistors to make the M electrode wells evenly distributed; The photoelectric signal conversion device is used to receive the optical fiber control signal and convert the optical fiber control signal into an electrical signal; the electrical signal is used to control the opening and closing of a plurality of load switches.

8. A method for equalizing current of electrodes of a coast grounding electrode, characterized in that: An electrode current balancing system for a coast grounding electrode as claimed in any one of claims 1 to 7, wherein the electrode current balancing method for the coast grounding electrode comprises: During the operation of the coast grounding electrode, the current in each electrode well is monitored to obtain current monitoring data; When it is determined based on the current monitoring data that more than M electrode wells have uneven current distribution, a number of adjustable resistors are adjusted until the current distribution of each electrode well is uniform; wherein each electrode well is connected in series with an adjustable resistor, and M is a preset positive integer.

9. The electrode current equalization method of a coast grounding electrode as claimed in claim 8, characterized in that: Also includes: During the debugging period after the construction of the coast grounding electrode is completed, after the second test current is connected to the coast grounding, the resistance values ​​of several adjustable resistors are adjusted based on the resistance range set until the current is evenly distributed in each electrode well.

10. The electrode current equalization method of a coast grounding electrode according to claim 9, characterized in that: The method for obtaining the resistance value range set includes: After passing the first test current through the coast grounding electrode, measure the current in each electrode well and the ground potential rise of the coast grounding electrode; Based on the current of each electrode well and the ground potential rise of the coast grounding electrode, the equivalent resistance of each electrode well is calculated to obtain the equivalent resistance of each electrode well; Determine the maximum single-hole electrode well resistance among the equivalent resistances of each electrode well; Based on the maximum single-hole electrode well resistance and the equivalent resistance of each electrode well, the resistance range of each adjustable resistor is determined respectively to obtain a resistance range set.

Images