Converter valve voltage-sharing electrode failure detection method and device

Abstract

The invention belongs to the technical field of converter valve cooling control, and particularly relates to a converter valve voltage-sharing electrode failure detection method and device. A direct-current voltage excitation source is connected to the metal position where the voltage-sharing electrode equipotential lines at the two ends of the converter valve tower valve module are connected, a first leakage current loop from the voltage-sharing electrode to the deionized water and a second leakage current loop from the metal water pipe to the deionized water are formed, and the current of the first leakage current loop and the current of the second leakage current loop are measured respectively; the failure rate of the voltage-sharing electrode is determined based on the current of the first leakage current loop and the current of the second leakage current loop, whether the voltage-sharing electrode fails or not is determined according to the failure rate of the voltage-sharing electrode, the obtained failure result is more accurate, the voltage-sharing electrode and the electrode equipotential line do not need to be disassembled, the detection efficiency is higher, and the voltage-sharing electrode is not damaged.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cooling control of converter valve, and particularly relates to a converter valve equalizing electrode failure detection method and device. BACKGROUND

[0002] The converter valve is a key equipment of the high-voltage direct current transmission system, and each component will generate a large amount of heat during operation, so that a valve cooling system needs to be used to cool the converter valve. The valve cooling system takes away the heat in the converter valve assembly through circulating cooling water, and exchanges the heat in the aluminum alloy radiator to the environment, so as to make the converter valve work normally. The cooling water generally uses deionized water, and the conductivity of the deionized water is usually 0.1 μS / cm-0.5 μS / cm. Since the cooling water of the valve cooling system flows through metal components (including metal pipelines, radiators and other metal components) of different potentials, the water path between the metal components of different potentials will generate a leakage current in a high-voltage and complex electromagnetic field environment, so that the metal components will be subjected to electrolytic corrosion. Therefore, the existing technology generally arranges an equalizing electrode in the water path of the converter valve cooling system, so that the leakage current is transferred from the metal to the inert equalizing electrode, and the metal components have the same potential through the equipotential line of the equalizing electrode, so as to avoid the corrosion of the metal equipment.

[0003] The equalizing electrode is continuously scaled during work, and the scale layer falling off will cause the electrode failure to cause the corrosion of the metal water pipe, so that the scaling of the equalizing electrode needs to be grasped in time, and the scale needs to be removed in time when scaling occurs, so as to avoid the failure of the equalizing electrode. The existing technology is to periodically check the equalizing electrode, and the checking method is to disassemble the equalizing electrode after draining water, measure the thickness of the equalizing electrode, and judge whether the electrode is failed through the thickness. The process of disassembling the equalizing electrode is relatively cumbersome, and the accuracy of the equalizing electrode failure result detected according to the thickness is low, and repeatedly disassembling the equalizing electrode is easy to make the sealing gasket loose, so that the equalizing electrode failure checking efficiency is low and the equalizing electrode is damaged. SUMMARY

[0004] The purpose of the present application is to provide a converter valve equalizing electrode failure detection method and device, which can solve the problems of low failure detection efficiency, low detection accuracy and easy damage to the equalizing electrode caused by the existing method of periodically disassembling the equalizing electrode and detecting the failure of the equalizing electrode according to the thickness of the equalizing electrode.

[0005] The application provides a method for detecting failure of a voltage-sharing electrode of a converter valve, which comprises the following steps: connecting a DC voltage excitation source to metal at both ends of a voltage-sharing electrode of a valve module of a converter valve tower, forming a first leakage current loop from the voltage-sharing electrode to deionized water and a second leakage current loop from the metal water pipe to the deionized water; measuring the currents of the first leakage current loop and the second leakage current loop respectively; determining a voltage-sharing electrode failure rate based on the currents of the first leakage current loop and the second leakage current loop, and determining whether the voltage-sharing electrode is failed according to the voltage-sharing electrode failure rate.

[0006] Further, the calculation formula of the voltage-sharing electrode failure rate is as follows:

[0007]

[0008] wherein η is the voltage-sharing electrode failure rate, I1 is the current of the first leakage current loop, and I2 is the current of the second leakage current loop.

[0009] To solve the above technical problems, the application further provides a device for detecting failure of a voltage-sharing electrode of a converter valve, which comprises a DC voltage excitation source, a current measurement module and a failure determination module; the DC voltage excitation source is connected to metal at both ends of a voltage-sharing electrode of a valve module of a converter valve tower, for forming a first leakage current loop from the voltage-sharing electrode to deionized water and a second leakage current loop from the metal water pipe to the deionized water; the current measurement module is used for measuring the currents of the first leakage current loop and the second leakage current loop; and the failure determination module is used for determining a voltage-sharing electrode failure rate based on the currents of the first leakage current loop and the second leakage current loop, and determining whether the voltage-sharing electrode is failed according to the voltage-sharing electrode failure rate.

[0010] Further, the calculation formula of the voltage-sharing electrode failure rate is as follows:

[0011]

[0012] wherein η is the voltage-sharing electrode failure rate, I1 is the current of the first leakage current loop, and I2 is the current of the second leakage current loop.

[0013] The beneficial effects of the above technical solutions are: the present application is an opening-type invention and creation, without changing any connection of the valve module, according to the shunt effect of the equal-potential line of the equalizing electrode on the current flowing through the metal water pipe, a DC voltage excitation source is connected to the metal at the equal-potential line connection of the equalizing electrode at both ends of the converter valve tower valve module to apply a DC voltage excitation, forming a first leakage current loop of the equalizing electrode to the deionized water and a second leakage current loop of the metal water pipe to the deionized water, determining the equalizing electrode failure rate based on the currents of the two loops, directly judging the equalizing electrode failure condition according to the equalizing electrode failure rate, the failure result obtained is more accurate, and without disassembling the equalizing electrode and the equal-potential line, whether the electrode is failed can be judged, the detection efficiency is higher and the equalizing electrode is not damaged, greatly accelerating the failure inspection efficiency of the equalizing electrode by the on-site maintenance personnel, thereby ensuring the safe operation of the converter valve, and having high application value in the fields of electrical tests and converter valve maintenance.

[0014] To solve the above technical problems, the present application further provides a converter valve equalizing electrode failure detection method, comprising: connecting a DC voltage excitation source to the metal at the equal-potential line connection of the equalizing electrode at both ends of the converter valve tower valve module to form a first leakage current loop of the equalizing electrode to the deionized water and a second leakage current loop of the metal water pipe to the deionized water; selecting the equalizing electrode symmetrically arranged in the converter valve tower water pipe, respectively for the scale side and the non-scale side, and calibrating the non-scale side equalizing electrode failure rate based on the current of the first leakage current loop and the current of the second leakage current loop of the non-scale side; measuring the current of the first leakage current loop of the scale side and the current of the first leakage current loop of the non-scale side, and calculating the scale side equalizing electrode failure rate in combination with the calibrated non-scale side equalizing electrode failure rate; or measuring the equal-potential line voltage drop of the scale side equalizing electrode and the equal-potential line voltage drop of the non-scale side equalizing electrode, and calculating the scale side equalizing electrode failure rate in combination with the calibrated non-scale side equalizing electrode failure rate; and determining whether the equalizing electrode is failed according to the equalizing electrode failure rate.

[0015] Further, the scale side equalizing electrode failure rate is calculated according to the following formula:

[0016]

[0017] Or,

[0018] Wherein, η 结垢 is the scale side equalizing electrode failure rate, η 标定 is the non-scale side equalizing electrode failure rate, I 1结垢 is the current of the first leakage current loop of the scale side, I 1非结垢 is the current of the first leakage current loop of the non-scale side; U 1结垢 is the equal-potential line voltage drop of the scale side equalizing electrode, and U 1非结垢 is the equal-potential line voltage drop of the non-scale side equalizing electrode.

[0019] Furthermore, the DC voltage excitation source is a constant voltage source. The rated current of the constant voltage source is determined based on the rated voltage of the constant voltage source and the resistance value of the valve module's voltage equalization circuit. The rated voltage of the constant voltage source is determined based on the maximum resistance value of the water circuit where the voltage equalization electrode is located and the measurement accuracy.

[0020] Furthermore, the rated current of the constant voltage source satisfies the following formula:

[0021]

[0022] Where I3 is the rated current of the constant voltage source, U is the rated voltage of the constant voltage source, and R1 is the resistance of the valve module equalization circuit.

[0023] To address the aforementioned technical problems, this invention also provides a device for detecting the failure of the equalizing electrode in a converter valve, comprising a DC voltage excitation source, a measurement module, and a failure determination module. The DC voltage excitation source is connected to the metal portion where the equipotential lines of the equalizing electrodes at both ends of the converter valve tower module are connected, forming a first leakage current loop from the equalizing electrode to deionized water and a second leakage current loop from the metal water pipe to deionized water. The measurement module measures the current in the first leakage current loop on the scaling side and the current in the first leakage current loop on the non-scaling side, or measures the voltage drop across the equipotential line of the equalizing electrode on the scaling side and the voltage drop across the equipotential line of the equalizing electrode on the non-scaling side. The failure determination module calculates the failure rate of the equalizing electrode on the scaling side by combining the calibrated failure rate of the equalizing electrode on the non-scaling side with the measurement data from the measurement module, and determines whether the equalizing electrode has failed based on the failure rate. The equalizing electrodes on the scaling side and the non-scaling side are symmetrically arranged in the water pipe of the converter valve tower. The calibrated failure rate of the equalizing electrode on the non-scaling side is determined based on the current in the first and second leakage current loops on the non-scaling side.

[0024] Furthermore, the failure rate of the scaling-side equalizing electrode is calculated according to the following formula:

[0025]

[0026] or,

[0027] Where, η 结垢 For the failure rate of the equalizing electrode on the scaling side, η 标定 For the failure rate of the equalizing electrode on the non-scaling side, I 1结垢 I is the current in the first leakage current loop on the scaling side. 1非结垢 U is the current in the first leakage current loop on the non-scaling side; 1结垢 U is the voltage drop across the equipotential line of the equalizing electrode on the scaling side. 1非结垢 The voltage drop of the equipotential line of the equalizing electrode on the non-scaling side.

[0028] The beneficial effects of the above technical solution are as follows: This invention is a pioneering invention that does not change any connection of the valve module. Based on the effect of the equalizing electrode diverting the current flowing through the metal water pipe through the equipotential line, a DC voltage excitation source is connected to the metal connection point of the equalizing electrode at both ends of the converter valve tower valve module to apply DC voltage excitation, forming a first leakage current loop from the equalizing electrode to the deionized water and a second leakage current loop from the metal water pipe to the deionized water. Through years of maintenance statistics, the structural pattern of the equalizing electrode is that "scale will form on the electrode surface where the leakage current flows from the electrode to the deionized water, and vice versa." That is, the equalizing electrodes symmetrically arranged in the water pipe of the converter valve tower satisfy the characteristic of unilateral scaling. Therefore, this invention first pre-calibrates the failure rate of the non-scaling side equalizing electrode based on the current in the two circuits of the non-scaling side equalizing electrode. During testing, it is only necessary to measure the current in the first leakage current circuit on the scaling and non-scaling sides, or measure the voltage drop of the equipotential line of the equalizing electrodes on the scaling and non-scaling sides. The failure rate of the scaling side equalizing electrode can then be calculated based on the calibrated failure rate of the non-scaling side equalizing electrode. The failure status of the equalizing electrode can be directly judged based on the failure rate, resulting in more accurate failure results. Furthermore, it does not require disassembling the equalizing electrode and the electrode equipotential line to determine whether the electrode has failed, resulting in higher detection efficiency and no damage to the equalizing electrode. This greatly accelerates the efficiency of on-site maintenance personnel in checking the failure of the equalizing electrode, thereby ensuring the safe operation of the converter valve. It has high application value in the fields of electrical testing and converter valve maintenance. Attached Figure Description

[0029] Figure 1 This is a flowchart of the failure detection of the equalizing electrode of the converter valve in Embodiment 1 of the present invention;

[0030] Figure 2 This is a schematic diagram of the converter valve equalization electrode failure detection circuit in Embodiment 1 of the present invention.

[0031] Figure 3 This is a schematic diagram of the instrument connection for detecting the failure of the equalizing electrode of the converter valve in Embodiment 1 of the present invention.

[0032] Figure 4 This is a schematic diagram of the instrument connection for detecting the failure of the equalizing electrode of the converter valve in Embodiment 2 of the present invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the present invention clearer, the specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0034] This invention utilizes the effect of the equalizing electrode to shunt the current flowing through the metal water pipe through the equipotential line. A voltage source is applied to the location of the equalizing electrode to form a loop for testing the shunt current of the equalizing electrode and the leakage current at the connection of the metal water pipe. The failure rate of the equalizing electrode is evaluated by testing the current in the two loops.

[0035] Method Implementation Method 1

[0036] The present invention provides a method for detecting the failure of the equalizing electrode of a converter valve, such as... Figure 1 As shown, it includes the following steps:

[0037] 1. Establish failure criteria for equalizing electrodes.

[0038] A DC voltage excitation source is connected to the metal joint where the equipotential lines of the equalizing electrodes at both ends of the converter valve tower valve module are connected, forming a first leakage current loop from the equalizing electrode to deionized water, a second leakage current loop from the metal water pipe to deionized water, and a shunt loop through the equalizing resistor. A DC voltage excitation is applied to the steel beam where the equipotential lines at both ends of the valve module are connected, and the currents I1 in the first leakage current loop and I2 in the second leakage current loop are measured using a current transformer. The failure rate η of the equalizing electrode is defined based on the currents in the first and second leakage current loops.

[0039] The formula for calculating the failure rate of the equalizing electrode is:

[0040]

[0041] The failure rate of the equalizing electrode is between 0 and 1. η = 0 means that the equalizing electrode is most effective, and it essentially diverts the current at the metal pipe connection point, resulting in virtually no leakage current. η = 1 means that the electrode is completely ineffective, and it has no effect on diverting the current in the metal pipe. In this case, there is a large leakage current at the metal pipe connection point, which easily corrodes the connection.

[0042] 2. Select a suitable voltage excitation source.

[0043] The DC voltage excitation source can be a constant voltage source, and the test circuit connected to the constant voltage source is as follows: Figure 2 As shown in Table 1, the rated voltage of the constant voltage source is determined based on the maximum resistance R0 of the water circuit where the equalizing electrode is located and the measurement accuracy. Currently, high-precision microvoltmeters can achieve a measurement accuracy of 0.1 μV. To achieve accurate current measurement, the voltage drop across the equipotential line must be in the μV range when η = 0, and I1 + I2 should be greater than 20 μA. The water circuit structure varies, and the resistance of different water circuit structures is generally between 30 MΩ and 200 MΩ. Therefore, the rated voltage of the constant voltage source required for different water circuit structures can be calculated using Ohm's law, as shown in Table 1.

[0044] Table 1

[0045]

[0046]

[0047] The rated current of the constant voltage source is determined based on the rated voltage of the constant voltage source and the resistance value of the valve module's voltage equalization circuit. Therefore, the resistance value R1 of the valve module's voltage equalization circuit satisfies the following formula:

[0048] R1 = n × R2

[0049] Where n is the number of series equalizing resistors in the valve module, and R2 is the resistance value of a single equalizing resistor.

[0050] Since the current flowing through the valve module's equalization circuit is much greater than the water leakage current, the rated current of the constant voltage source satisfies the following formula:

[0051]

[0052] Where I3 is the rated current of the constant voltage source.

[0053] 3. Connect a DC voltage excitation source to the metal connection point where the equalizing electrodes at both ends of the converter valve tower valve module are connected, and calculate the failure rate of the equalizing electrodes.

[0054] like Figure 3 As shown, without removing any leads, the DC voltage excitation source determined in step 2 is connected to the metal connection point where the equipotential lines of the equalizing electrodes at both ends of the converter valve tower module are connected, forming a first leakage current loop from the equalizing electrode to the deionized water, and a second leakage current loop from the metal water pipe to the deionized water. A voltage is applied to the converter valve module, and then the test method in step 1 is used to detect the failure of the equalizing electrode. The failure rate of the equalizing electrode determines whether it has failed.

[0055] Method Implementation Method Two

[0056] Based on years of maintenance statistics, the structural pattern of the equalizing electrodes is that "scale will form on the electrode surface where leakage current flows towards the deionized water, and vice versa." In other words, the equalizing electrodes symmetrically arranged in the water pipes of the converter valve tower exhibit unilateral scaling characteristics. Figure 2 If the left electrode scales, the right electrode will not scale, and vice versa. Therefore, the failure rate of the equalizing electrode includes the failure rate of the equalizing electrode on the scaling side and the failure rate of the equalizing electrode on the non-scaling side. The equalizing electrodes on the scaling side and the non-scaling side are symmetrically arranged in the water pipes of the converter valve tower.

[0057] Therefore, a DC voltage excitation source is connected to the metal connection point where the equipotential lines of the equalizing electrodes at both ends of the converter valve tower valve module are connected, forming a first leakage current loop from the equalizing electrodes to the deionized water, and a second leakage current loop from the metal water pipe to the deionized water. Equalizing electrodes symmetrically arranged in the converter valve tower water pipes are selected, representing the scaling side and the non-scaling side, respectively.

[0058] Symmetrically arranged equalizing electrodes satisfy the following formula:

[0059] I 1结垢 +I 2结垢 =I 1非结垢 +I 2非结垢

[0060] The failure rate of the equalizing electrode on the non-scaling side can be pre-calibrated based on the currents in the first and second leakage current loops on the non-scaling side. The currents in the first and second leakage current loops on the non-scaling side can be directly detected using a high-precision electromagnetic current transformer, or detected by connecting an electronic current sensor to the corresponding loop on the non-scaling side.

[0061]

[0062] Therefore, the total current flowing into the PVDF main water pipe can be calculated by measuring the current value of the first leakage current loop on the non-scaling side:

[0063]

[0064] therefore:

[0065]

[0066] Among them, I 1结垢 I is the current in the first leakage current loop on the scaling side. 2结垢 I is the current in the second leakage current loop on the scaling side. 1非结垢 I is the current in the first leakage current loop on the non-scaling side. 2非结垢 η is the current in the second leakage current loop on the non-scaling side. 结垢 For the failure rate of the equalizing electrode on the scaling side, η 标定 The failure rate of the equalizing electrode on the non-scaling side.

[0067] Therefore, in one embodiment, the failure rate of the non-scaling side equalizing electrode can be calibrated in advance. When the maintenance personnel perform failure detection on the equalizing electrode, they measure the current in the first leakage current loop on the scaling side and the current in the first leakage current loop on the non-scaling side, and calculate the failure rate of the scaling side equalizing electrode based on the calibrated failure rate of the non-scaling side equalizing electrode. The failure rate of the equalizing electrode is then used to determine whether the equalizing electrode has failed.

[0068] Due to the two leakage currents I corresponding to the symmetrically arranged equalizing electrodes. 1结垢 and I 1非结垢 Both involve small currents, requiring high measurement accuracy from the electromagnetic current transformer. Therefore, to reduce testing costs, a voltmeter (such as a microvoltmeter) can be used to measure the voltage across the equipotential line of the equalizing electrodes to reflect I. 1结垢 with I 1非结垢 The ratio, due to the resistance R of the equipotential line of the two equalizing electrodes. 线 With a constant Ω (approximately 50 mΩ), the following formula can be further derived:

[0069]

[0070] Among them, U 1结垢 U is the voltage drop across the equipotential line of the equalizing electrode on the scaling side. 1非结垢 The voltage drop of the equipotential line of the equalizing electrode on the non-scaling side.

[0071] Therefore, in another embodiment, the failure rate of the non-fouling side equalizing electrode can be calibrated in advance. For example... Figure 4 As shown, when the maintenance personnel perform failure detection on the equalizing electrode, they can measure the voltage drop of the equipotential line of the equalizing electrode on the scaled side and the voltage drop of the equipotential line of the equalizing electrode on the non-scaled side using a voltmeter. They can then calculate the failure rate of the equalizing electrode on the scaled side by combining the calibrated failure rate of the equalizing electrode on the non-scaled side. Based on the failure rate of the equalizing electrode, they can determine whether the equalizing electrode has failed.

[0072] Device Implementation Method 1

[0073] The present invention provides a failure detection device for the equalizing electrode of a converter valve, comprising a DC voltage excitation source, a current measurement module, and a failure determination module.

[0074] A DC voltage excitation source is connected to the metal part where the equipotential lines of the equalizing electrodes at both ends of the converter valve tower valve module are connected, in order to form the first leakage current loop from the equalizing electrodes to the deionized water, and the second leakage current loop from the metal water pipe to the deionized water.

[0075] The current measurement module is used to measure the current in the first leakage current loop and the second leakage current loop.

[0076] The DC voltage excitation source can be a constant voltage source, and the rated voltage of the constant voltage source is determined based on the maximum resistance R0 of the water circuit where the equalizing electrode is located and the measurement accuracy. The rated current of the constant voltage source is determined based on the rated voltage of the constant voltage source and the resistance value of the equalizing circuit of the valve module. The specific selection criteria for the DC voltage excitation source have been described in detail in the method implementation, and will not be repeated here.

[0077] The failure determination module is used to determine the failure rate of the voltage equalization electrode based on the current in the first leakage current loop and the current in the second leakage current loop. The calculation formula is as follows:

[0078]

[0079] Determine whether the equalizing electrode has failed based on its failure rate.

[0080] Device Implementation Method 2

[0081] This invention discloses a failure detection device for the equalizing electrode of a converter valve, comprising a DC voltage excitation source, a measurement module, and a failure determination module. The DC voltage excitation source is connected to the metal portion where the equipotential lines of the equalizing electrodes at both ends of the converter valve tower module are connected, forming a first leakage current loop from the equalizing electrode to deionized water and a second leakage current loop from the metal water pipe to deionized water. The measurement module (e.g., a current transformer) measures the current in the first leakage current loop on the scaling side and the current in the first leakage current loop on the non-scaling side, or the measurement module (e.g., a voltmeter) measures the voltage drop across the equipotential line of the equalizing electrode on the scaling side and the voltage drop across the equipotential line of the equalizing electrode on the non-scaling side. The failure determination module calculates the failure rate of the equalizing electrode on the scaling side by combining the calibrated failure rate of the equalizing electrode on the non-scaling side and the measurement data from the measurement module, and determines whether the equalizing electrode has failed based on the failure rate. The equalizing electrodes on the scaling side and the non-scaling side are symmetrically arranged in the water pipe of the converter valve tower. The calibrated failure rate of the equalizing electrode on the non-scaling side is determined based on the current in the first and second leakage current loops on the non-scaling side.

[0082] Among them, when the failure determination module calculates the failure rate of the equalizing electrode on the scaling side based on the current of the first leakage current loop on the scaling side, the current of the first leakage current loop on the non-scaling side, and the calibrated failure rate of the equalizing electrode on the non-scaling side, the calculation formula is as follows:

[0083]

[0084] When the failure determination module calculates the failure rate of the scaling-side equalizing electrode based on the equipotential line voltage drop of the scaling-side equalizing electrode, the equipotential line voltage drop of the non-scaling-side equalizing electrode, and the calibrated failure rate of the non-scaling-side equalizing electrode, the calculation formula is as follows:

[0085]

[0086] This invention utilizes the specific function of the equalizing electrode in shunting the current flowing through the metal water pipe via the equipotential line. Based on the principle of shunting detection, a DC voltage excitation source is connected to the metal connection point between the equalizing electrodes and the equipotential lines at both ends of the converter valve module. The leakage current from the equalizing electrode to deionized water and from the metal water pipe to deionized water are tested. Based on these two leakage currents, a failure index for the equalizing electrode is established, resulting in a more accurate assessment of failure. Electrode failure can be determined without disassembling the equalizing electrode and the electrode equipotential line. Non-destructive testing is performed without altering the electrical connections of the valve tower itself, resulting in higher testing efficiency and no damage to the equalizing electrode. Error theory analysis yields the accuracy requirements of the current transformer under the most stringent operating conditions. A current transformer meeting these accuracy requirements is selected to measure the leakage current and shunting current, ensuring the accuracy of the measurement results.

Claims

1. A method for detecting the failure of a pressure equalization electrode in a converter valve, characterized in that, include: A DC voltage excitation source is connected to the metal where the equipotential lines of the equalizing electrodes at both ends of the converter valve tower valve module are connected, forming the first leakage current loop from the equalizing electrodes to the deionized water, and the second leakage current loop from the metal water pipe to the deionized water. Measure the current in the first leakage current loop and the second leakage current loop respectively; The failure rate of the equalizing electrode is determined based on the current in the first leakage current loop and the current in the second leakage current loop, and the failure rate of the equalizing electrode is used to determine whether the equalizing electrode has failed.

2. The method for detecting the failure of the equalizing electrode in a converter valve according to claim 1, characterized in that, The formula for calculating the failure rate of the equalizing electrode is as follows: Where η is the failure rate of the equalizing electrode, I1 is the current in the first leakage current loop, and I2 is the current in the second leakage current loop.

3. A method for detecting the failure of a pressure equalization electrode in a converter valve, characterized in that, include: A DC voltage excitation source is connected to the metal where the equipotential lines of the equalizing electrodes at both ends of the converter valve tower valve module are connected, forming the first leakage current loop from the equalizing electrodes to the deionized water, and the second leakage current loop from the metal water pipe to the deionized water. A pressure equalization electrode symmetrically arranged in the water pipe of the converter valve tower is selected, namely the scaling side and the non-scaling side. The failure rate of the pressure equalization electrode on the non-scaling side is calibrated based on the current of the first leakage current loop and the current of the second leakage current loop on the non-scaling side. Measure the current in the first leakage current loop on the scaling side and the first leakage current loop on the non-scaling side, and calculate the failure rate of the equalizing electrode on the scaling side based on the calibrated failure rate of the equalizing electrode on the non-scaling side; or measure the equipotential line voltage drop of the equalizing electrode on the scaling side and the equipotential line voltage drop of the equalizing electrode on the non-scaling side, and calculate the failure rate of the equalizing electrode on the scaling side based on the calibrated failure rate of the equalizing electrode on the non-scaling side; determine whether the equalizing electrode has failed based on the failure rate of the equalizing electrode.

4. The method for detecting the failure of the equalizing electrode of the converter valve according to claim 3, characterized in that, The failure rate of the scaling-side equalizing electrode is calculated using the following formula: Where, η 结垢 For the failure rate of the equalizing electrode on the scaling side, η 标定 For the failure rate of the equalizing electrode on the non-scaling side, I 1结垢 I is the current in the first leakage current loop on the scaling side. 1非结垢 U is the current in the first leakage current loop on the non-scaling side; 1结垢 U is the voltage drop across the equipotential line of the equalizing electrode on the scaling side. 1非结垢 The voltage drop of the equipotential line of the equalizing electrode on the non-scaling side.

5. The method for detecting the failure of the equalizing electrode of the converter valve according to claim 3 or 4, characterized in that, The DC voltage excitation source is a constant voltage source. The rated current of the constant voltage source is determined based on the rated voltage of the constant voltage source and the resistance value of the valve module's equalization circuit. The rated voltage of the constant voltage source is determined based on the maximum resistance value of the water circuit where the equalization electrode is located and the measurement accuracy.

6. The method for detecting the failure of the equalizing electrode of the converter valve according to claim 5, characterized in that, The rated current of the constant voltage source satisfies the following formula: Where I3 is the rated current of the constant voltage source, U is the rated voltage of the constant voltage source, and R1 is the resistance of the valve module equalization circuit.

7. A device for detecting the failure of a pressure equalization electrode in a converter valve, characterized in that, It includes a DC voltage excitation source, a current measurement module, and a failure determination module. The DC voltage excitation source is connected to the metal part where the equipotential lines of the equalizing electrodes at both ends of the converter valve tower valve module are connected, which is used to form a first leakage current loop from the equalizing electrode to the deionized water and a second leakage current loop from the metal water pipe to the deionized water. The current measurement module is used to measure the current in the first leakage current loop and the second leakage current loop. The failure determination module is used to determine the failure rate of the equalizing electrode based on the current in the first leakage current loop and the current in the second leakage current loop, and to determine whether the equalizing electrode has failed based on the failure rate.

8. The converter valve equalizing electrode failure detection device according to claim 7, characterized in that, The formula for calculating the failure rate of the equalizing electrode is as follows: Where η is the failure rate of the equalizing electrode, I1 is the current in the first leakage current loop, and I2 is the current in the second leakage current loop.

9. A device for detecting the failure of a pressure equalization electrode in a converter valve, characterized in that, It includes a DC voltage excitation source, a measurement module, and a failure determination module; the DC voltage excitation source is connected to the metal part where the equipotential lines of the equalizing electrodes at both ends of the converter valve tower valve module are connected, which is used to form a first leakage current loop from the equalizing electrode to the deionized water, and a second leakage current loop from the metal water pipe to the deionized water; the measurement module is used to measure the current of the first leakage current loop on the scaling side and the current of the first leakage current loop on the non-scaling side, or to measure the voltage drop of the equipotential line of the equalizing electrode on the scaling side and the voltage drop of the equipotential line of the equalizing electrode on the non-scaling side. The failure determination module is used to calculate the failure rate of the scaling-side equalizing electrode by combining the calibrated failure rate of the non-scaling side equalizing electrode and the measurement data of the measurement module, and to determine whether the equalizing electrode has failed based on the failure rate. The scaling-side equalizing electrode and the non-scaling side equalizing electrode are symmetrically arranged in the water pipe of the converter valve tower. The calibrated failure rate of the non-scaling side equalizing electrode is determined based on the current of the first leakage current loop and the current of the second leakage current loop on the non-scaling side.

10. The converter valve equalization electrode failure detection device according to claim 9, characterized in that, The failure rate of the scaling-side equalizing electrode is calculated using the following formula: Where, η 结垢 For the failure rate of the equalizing electrode on the scaling side, η 标定 For the failure rate of the equalizing electrode on the non-scaling side, I 1结垢 I is the current in the first leakage current loop on the scaling side. 1非结垢 U is the current in the first leakage current loop on the non-scaling side; 1结垢 U is the voltage drop across the equipotential line of the equalizing electrode on the scaling side. 1非结垢 The voltage drop of the equipotential line of the equalizing electrode on the non-scaling side.

Images