A multi-dimensional coupling evaluation test system for grounding grid conductor materials

Abstract

The present invention belongs to the technical field of electrical equipment, and particularly relates to a multi-dimensional coupling evaluation test system for grounding grid conductor materials. The structure of this system is simple and reasonable, the operation is simple, it is easy to implement, the effect is obvious, and it has extremely high popularization and application value. It is the only multi-dimensional coupling corrosion system that can simulate the grounding grid conductors in complex electromagnetic environments in AC substations and DC converter stations. Experiments in multiple soil environments can be realized at one time. By studying their interactions with current, magnetic field, etc., the corrosion effects on the grounding grid conductors can be investigated. The method of conducting experiments using this system is relatively easy to implement, and the conclusions obtained through research can guide the differential design of grounding grid anti-corrosion and the comprehensive evaluation of service life.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrical equipment, and particularly relates to a multi-dimensional coupling evaluation test system for grounding grid conductor materials. Background Art

[0002] A grounding grid is a device that provides a theoretically zero potential for electrical equipment. When a short circuit occurs in an electrical equipment, or there is an induced voltage on the outer shell of the electrical equipment, or the electrical equipment is struck by lightning, etc., the grounding grid can reliably conduct the voltage and current on the electrical equipment into the ground through the grounding lead wire, thereby ensuring the safety of personnel and equipment. The grounding grid mainly consists of a grounding lead wire and a grounding grid conductor. Among them, the grounding lead wire is a conductor connecting the power equipment and the grounding grid conductor, and its materials are copper, copper-clad steel, steel, composite materials, etc.; the grounding grid conductor is laid in a grid shape by conductors, and is used to disperse the current conducted down by the grounding lead wire.

[0003] The grounding grid is buried underground. Affected by the soil environment and the external electrical environment, chemical reactions will occur in the grounding grid conductor, resulting in metal corrosion loss. In severe cases, the grounding grid conductor will break, affecting the safe and stable operation of power equipment. At present, the research on the corrosion of the grounding grid is mainly based on the corrosion of the soil, without considering the influence of the current on the grounding body. And there is no effective conclusion on what kind of influence the magnitude of the current flowing into the grounding grid conductor (hereinafter referred to as the in-ground current) can have on the corrosion of the grounding body. Through excavation inspection, it is found that the corrosion degree of each part of the grounding grid is not the same. Near the equipment, the corrosion is severe, and farther away from the equipment, the corrosion is lighter or even no corrosion occurs. Therefore, assuming that the characteristics of the soil are equal everywhere, the magnitude of the in-ground current is of great significance to the corrosion of the grounding grid.

[0004] The in-ground current is divided into alternating current, direct current and harmonic current. In an open substation, the magnetic field generated by the busbar and other lead conductors will also pass through the grounding grid conductor, accelerating the influence on the corrosion degree of the grounding grid conductor. The chemical environment of the soil is mainly reflected in the pH value. Therefore, the in-ground current, magnetic field and chemical environment of the soil constitute the multi-dimensional coupling corrosion factors of the grounding grid conductor.

[0005] At present, neither the power industry nor other industries have conducted research on the coupling corrosion of grounding grid conductors under multi-dimensional factors such as in-ground current, magnetic field and chemical environment of the soil, nor have corresponding test devices or systems. Summary of the Invention

[0006] In view of the deficiencies in the above-mentioned existing technologies, the present invention provides a multi-dimensional coupling evaluation test system for grounding grid conductor materials. Its purpose is to explore the corrosion mechanism of grounding grid conductors by the in-ground current, magnetic field, and chemical environment of the soil, and thus an invention purpose of a test system with a reasonable system structure, easy-to-understand principle, easy implementation, and suitable for the laboratory to study the multi-dimensional coupling corrosion mechanism of grounding bodies is proposed.

[0007] The technical solution adopted by the present invention to achieve the above object is as follows:

[0008] A multi-dimensional coupling evaluation test system for grounding grid conductor materials, wherein a test metal electrode is connected to a test container, the other end of the test metal electrode is connected to a current transformer through a line, and the other end of the current transformer is connected to a through-core current transformer, a voltmeter, a variable transformer, a test power supply, and a ground wire in sequence through a line; another lead-out line on the through-core current transformer is connected to the terminal of the test metal electrode at the bottom of the test container; a magnetic field generator is connected through the side of the test container, and the other end of the magnetic field generator is connected to a second current transformer, a second voltmeter, a second variable transformer, and a ground wire in sequence through a line; connected; the other end of the second voltmeter is connected to a harmonic generator through a line.

[0009] Further, one end of the magnetic field generator extends out of the test container and is connected to a straight conductor.

[0010] Further, the other end of the magnetic field generator is connected to the second current transformer through a line with a switch K8, and a line with a switch K9 is also connected to the test container, and the other end of the line is connected to the line between the switch K8 and the second current transformer; another line at the other end of the second variable transformer is connected to the ground wire, and another line passes through a line with a switch K12 and is connected to the switch K6; one end of the second voltmeter is connected to one end of the second variable transformer through a line with a switch K14, and the other end of the second voltmeter is connected to the harmonic generator through a line with a switch K11.

[0011] Further, switches K4, K5, and K6 are connected to the line between the through-core current transformer and the test power supply, a voltmeter and a variable transformer are connected to the line between the switch K5 and the switch K6, and the other end line of the variable transformer is respectively connected to the lead of the voltmeter and the ground wire; the lead-out wires of the switch K4 and the switch K5 are respectively connected to the lead-out wires at both ends of the switch K10, and a rectifier is connected between the two lead-out wires.

[0012] Further, the test metal electrode is composed of a test metal material and a fastener, wherein the fastener is sleeved on the test metal material and tightened by the thread on the test metal material; the fastener is a nut that matches the metal material.

[0013] Further, both the current transformer and the second current transformer are equipped with instantaneous trip protection.

[0014] Further, the test container is made of polyethylene transparent material. The upper part of the test container is provided with a container cover plate with holes. The inside of the test container is divided into multiple small containers by partitions. The bottom of each small container is inlaid with a graphite electrode, and the graphite electrode is grounded through a grounding wire; a test metal electrode is provided in each small container, and the other end of each test metal electrode is respectively connected to the current transformer through a circuit provided with a switch.

[0015] Further, the magnetic field generator is an Ampere loop. When current is passed through it, a transverse magnetic field will be generated in the loop.

[0016] Further, the test method for the multi-dimensional coupling evaluation test system of the grounding grid conductor material includes the following steps:

[0017] Step 1. Select three soil samples or equivalent solutions with different acid-base degrees;

[0018] Step 2. Pass the test metal material through the hole on the container cover plate and fix the test metal material on the container cover plate with nuts;

[0019] Step 3. Corrosion evaluation of the test metal material by alternating current;

[0020] Step 4. Corrosion evaluation of the test metal material by harmonic current and alternating current;

[0021] Step 5. Corrosion evaluation of the test metal material by alternating magnetic field, harmonic current and alternating current;

[0022] Step 6. Corrosion evaluation of the metal electrode by direct current;

[0023] Step 7. Corrosion evaluation of the test metal material by direct current magnetic field and direct current.

[0024] Further, the selection of three soil samples or equivalent solutions with different acid-base degrees in Step 1 includes:

[0025] The pH of the first soil sample is 7, the pH of the second soil sample is > 7, and the pH of the third soil sample is < 7. They are respectively placed in three small containers in the test container. The test metal material is buried in the soil sample. When the soil sample or equivalent solution is different, the test metal material is of the same material; when the soil sample or equivalent solution is the same, three different materials of the test metal material are taken for comparative analysis;

[0026] The corrosion evaluation of the test metal material by alternating current in Step 3 includes:

[0027] Close switches K6, K5, K4, K1 - K3, adjust the adjustable transformer, and the alternating current forms a loop through the metal electrode and the graphite electrode at the bottom of the container to simulate the current dissipation of the grounding grid conductor in the substation; adjust the phase shifter to make the phase of the current change into capacitive current, inductive current or resistive current;

[0028] The corrosion evaluation of the test metal material by the harmonic current and alternating current described in step 4 includes:

[0029] On the basis of the corrosion evaluation of the test metal material by the alternating current, close switches K11 and K13, adjust the harmonic generator until the desired current waveform and frequency are obtained to simulate the harmonic corrosion of the grounding grid conductor in the substation by corona, etc.;

[0030] The corrosion evaluation of the test metal material by the alternating magnetic field, harmonic current and alternating current described in step 5 includes:

[0031] On the basis of the corrosion evaluation of the test metal material by the harmonic current, close switches K12, K14, K10, K8, K9, adjust the adjustable transformer, and the magnetic field generator will generate a transverse magnetic field and a longitudinal magnetic field to simulate the magnetic field generated by the busbar of an open - type substation, etc., and conduct a comprehensive multi - dimensional coupled corrosion evaluation of the test metal material together with the alternating current and harmonics;

[0032] The corrosion evaluation of the direct current on the metal electrode 14 described in step 6 includes:

[0033] On the basis of step 2, close switches K6, K5, K13, K7, K1 - K3, adjust the adjustable transformer, and the rectifier rectifies the original alternating current into direct current to simulate the corrosion of the test metal material by the direct current of the DC converter station;

[0034] The corrosion evaluation of the direct current magnetic field and direct current on the test metal material described in step 7 includes:

[0035] On the basis of the corrosion evaluation of the test metal material by the direct current, close switches K8 and K9, and the magnetic field generator will generate a constant transverse magnetic field and longitudinal magnetic field to simulate the magnetic field generated by the busbar of the DC converter station, etc., and conduct a comprehensive multi - dimensional coupled corrosion evaluation of the test metal material together with the direct current.

[0036] The present invention has the following beneficial effects and advantages:

[0037] The structure of this system is simple and reasonable, the operation is simple, it is easy to implement, the effect is obvious, and it has extremely high popularization and application value. It is the only multi - dimensional coupled corrosion system that can simulate the grounding grid conductor in a complex electromagnetic environment in AC substations and DC converter stations.

[0038] This system can achieve tests on multiple soil environments at one time. By studying their interaction with electric current, magnetic field, etc., the corrosion effect on the grounding grid conductor can be studied;

[0039] The method of using this system for testing is relatively easy to implement. The conclusions obtained through research can guide the differential design of grounding grid anti-corrosion and the comprehensive evaluation of service life. Brief Description of the Drawings

[0040] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0041] Figure 1 is the overall structure diagram of the test device of the present invention;

[0042] Figure 2 is the structural schematic diagram of the test metal electrode in the present invention;

[0043] Figure 3 is the structural schematic diagram of the container cover in the present invention.

[0044] In the figure:

[0045] Test metal electrode 1, test container 2, container cover 3, grounding wire 4, phase shifter 5, rectifier 6, adjustable transformer 7, test power supply 8, current transformer 9, voltmeter 10, magnetic field generator 11, harmonic generator 12, real-time monitoring system 13, test metal material 14, fastener 15, through-hole current transformer 16, second current transformer 99, second voltmeter 100, second adjustable transformer 77. Detailed Embodiments

[0046] In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be further described in detail below in conjunction with the drawings and specific embodiments. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

[0047] Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention may be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0048] The following refers to Figures 1 - 3 Describe the technical solutions of some embodiments of the present invention.

[0049] Embodiment 1

[0050] The present invention is a multi-dimensional coupling evaluation test system for grounding grid conductor materials, as Figure 1 shown, Figure 1This is the overall structure diagram of the test device of the present invention.

[0051] The system of the present invention includes a test metal electrode 1, a test container 2, a container cover plate 3, a ground wire 4, a phase shifter 5, a rectifier 6, an adjustable transformer 7, a test power supply 8, a current transformer 9, a voltmeter 10, a magnetic field generator 11, a harmonic generator 12, a real-time monitoring system 13, a through-core current transformer 16 and switches.

[0052] The test metal electrode 1 is connected to the test container 2. The other end of the test metal electrode 1 is connected to the current transformer 9 through a line with a switch. The other end of the current transformer 9 is connected to the through-core current transformer 16 through a line. The other end of the through-core current transformer 16 is connected to the test power supply 8 through a line, and the other end of the test power supply 8 is connected to the ground wire 4. The side of the test container 2 is connected to the magnetic field generator 11 in a penetrating manner. One end of the magnetic field generator 11 extends out of the test container 2 and is connected to a linear conductor. The other end of the magnetic field generator 11 is connected to a second current transformer 99 through a line with a switch K8. A line with a switch K9 is also connected to the test container 2, and the other end of the line is connected to the line between the switch K8 and the second current transformer 99. The other end of the second current transformer 99 is connected to a second voltmeter 100 and a second adjustable transformer 77 through a line. One line of the other end of the second adjustable transformer 77 is connected to the ground wire 4, and the other line is connected to the switch K6 through a line with a switch K12. One end of the second voltmeter 100 is connected to one end of the second adjustable transformer 77 through a line with a switch K14, and the other end of the second voltmeter 100 is also connected to the harmonic generator 12 through a line with a switch K11.

[0053] Three switches K4, K5, and K6 are connected to the line between the through-core current transformer 16 and the test power supply 8. A voltmeter 10 and an adjustable transformer 7 are connected to the line between the switch K5 and the switch K6. The other lines of the adjustable transformer 7 are respectively connected to the lead wire of the voltmeter 10 and the ground wire 4. Another lead-out line on the through-core current transformer 16 is connected to the terminal of the test metal electrode 1 at the bottom of the test container 2.

[0054] The lead-out wires of the switches K4 and K5 are respectively connected to the lead-out wires at both ends of the switch K10, and a rectifier 6 is connected between the two lead-out wires.

[0055] Among them, the test metal electrode 1 is composed of a test metal material 14 and a fastener 15.

[0056] Both the current transformer 9 and the second current transformer 99 are equipped with instantaneous tripping protection.

[0057] The switches are high-power switches K1-K14.

[0058] As Figure 2 shown Figure 2 is a schematic structural view of the test metal electrode in the present invention. The test metal electrode 1, i.e., the simulated grounding grid conductor, is a metal material with the same material as the actual grounding body, and the material can be galvanized steel, copper-clad steel, pure copper, steel, composite conductor, etc. The cross-sectional diameter of the metal material is 18 mm, and the surface has threads. The fastener 15 is a nut with a diameter of 18 mm, and the nut can cooperate with the metal material. The nut is sleeved on the test metal material 14 and tightened through the threads on the test metal material 14.

[0059] The test container 2 is made of polyethylene transparent material, which is not affected by acid-base corrosion, and at the same time, the test situation inside the container can be observed with the naked eye. Its interior can be divided into two or three small containers according to the test requirements, and the partition is also made of polyethylene material. The bottom of each small container is composed of a graphite electrode. The diameter of the graphite electrode is 30 mm, and the thickness is the same as that of the test container 2. It is embedded in the middle of the bottom of the test container 2 and is waterproofed. Each graphite electrode is grounded through a grounding lead wire, i.e., a grounding wire 4.

[0060] As Figure 3 shown Figure 3 is a schematic structural view of the container cover in the present invention. The container cover 3 is also made of transparent hard insulating material for easy observation of the test situation. There are holes on it for inserting the test metal material 14 into the test container 2. A real-time monitoring system 13 is connected in each small container inside the test container 2 for real-time monitoring of the pH value, temperature, humidity, timing, etc. inside the container. The sensors for testing the pH value, temperature, and humidity inside the container are connected to the monitoring system 13 through data lines passing through the holes on the side of the test container 2. The holes are waterproofed, and the display part of the monitoring system 13 is adhered to the outer side of the test container 2. The shape of the container cover 3 is rectangular, and the length and width are the same as those of the test container 2. During the test, the metal electrode 1 should be first passed through the cover plate and then covered on the test container 2. After the test is completed, the cover plate is removed, and then the test metal electrode 1 is pulled out.

[0061] The grounding wire 4 can be a flexible grounding wire. The purpose of setting a separate grounding wire for each small container is to ensure the accuracy of the test and reduce the influence between each other.

[0062] The phase shifter 5 can shift the phase of the original current to make the nature of the current become capacitive current, inductive current or resistive current, and is used to simulate the influence of different nature currents on the grounding grid conductor.

[0063] The rectifier 6 can rectify the original alternating current into direct current and is used to simulate the situation of a DC converter station.

[0064] The magnetic field generator 11 is an Ampere loop. When current is passed through it, a transverse magnetic field will be generated in the loop and a longitudinal magnetic field will be generated around the straight conductor, which is used to simulate the magnetic field generated by an open substation busbar, etc.

[0065] The harmonic generator 12 is a device for generating various harmonics, and the current waveform and frequency are adjustable, which is used to simulate the harmonic interference generated by substation corona, etc. on the grounding conductor.

[0066] The through-type current transformer 16 is a device for generating large current, which converts the primary current of the adjustable transformer 7 into the large current required for the test.

[0067] The test power supply 8, current transformer 9, voltmeter 10 and high-power switches K1 - K14 are auxiliary devices of the test system. Among them, the test power supply 8 can take the commercial power of 220V and the power should be sufficient; the current transformer 9 and voltmeter 10 read the current value and voltage value during the test, and can disconnect the circuit in time when a ground short circuit occurs in the system; there are 14 high-power switches K1 - K14 in total.

[0068] During the test, different soil samples are taken, and the acidity and alkalinity of the soil samples can be selected according to the test purpose. For example, three soil samples are taken. The pH of the first soil sample is 7, the pH of the second soil sample is > 7, and the pH of the third soil sample is < 7. They are respectively placed in three small containers. Then the test metal material 14 is inserted into the soil sample through the container cover plate 3 and fixed with the fixing nut. Then the test metal material 14 is connected to the current source, and different influencing factors are loaded, such as the nature of the current, harmonics, magnetic field, etc., and then the multi-dimensional coupling study of the influence of current on the corrosion of the grounding body can be carried out.

[0069] Embodiment 2

[0070] The present invention also provides an embodiment. In specific implementation, a test method for a test system for multi-dimensional coupling evaluation of grounding grid conductor materials is as follows:

[0071] Step 1. Select three soil samples or equivalent solutions with different acid-base degrees.

[0072] The pH of the first soil sample is 7, the pH of the second soil sample is > 7, and the pH of the third soil sample is < 7. They are respectively loaded into three small containers in the test container 2. At the same time, the test metal material 14 is buried in the soil sample in the Figure 1 way. When the soil samples or equivalent solutions are different, the test metal material 14 is of the same material. When the soil samples or equivalent solutions are the same, the test metal material 14 can take three different materials for comparative analysis;

[0073] Step 2. Pass the test metal material 14 through the hole on the container cover plate 3 and fix the test metal material 14 on the container cover plate 3 with a nut;

[0074] Step 3. Corrosion evaluation of the test metal material 14 by alternating current.

[0075] Close switches K6, K5, K4, K1 - K3, and adjust the adjustable transformer 7. At this time, the alternating current forms a loop through the metal electrode and the graphite electrode at the bottom of the container, simulating the current dissipation situation of the substation grounding grid conductor. Adjust the phase shifter 5 to make the phase of the current change into capacitive current, inductive current, or resistive current.

[0076] Step 4. Corrosion evaluation of the test metal material 14 by harmonic current and alternating current.

[0077] On the basis of the corrosion evaluation of the test metal material 14 by alternating current, close switches K11, K13, and adjust the harmonic generator 12 until the desired current waveform and frequency are obtained, simulating the harmonic corrosion of the substation grounding grid conductor by corona, etc.

[0078] Step 5. Corrosion evaluation of the test metal material 14 by alternating magnetic field, harmonic current, and alternating current.

[0079] On the basis of the corrosion evaluation of the test metal material 14 by harmonic current, close switches K12, K14, K10, K8, K9, and adjust the adjustable transformer 7. The magnetic field generator 11 will generate a transverse magnetic field and a longitudinal magnetic field, simulating the magnetic field generated by the busbars of an open - type substation, etc., and conduct a comprehensive multi - dimensional coupling corrosion evaluation of the test metal material 14 together with the alternating current and harmonics.

[0080] Step 6. Corrosion evaluation of the metal electrode 14 by direct current.

[0081] On the basis of Step 2, close switches K6, K5, K13, K7, K1 - K3, and adjust the adjustable transformer 7. At this time, the rectifier 6 rectifies the original alternating current into direct current, which is used to simulate the corrosion situation of the test metal material 14 by the direct current of a DC converter station.

[0082] Step 7. Corrosion evaluation of the test metal material 14 by direct magnetic field and direct current.

[0083] On the basis of the corrosion evaluation of the test metal material 14 by direct current, close switches K8, K9. The magnetic field generator 11 will generate a constant transverse magnetic field and a longitudinal magnetic field, simulating the magnetic field generated by the busbars of a DC converter station, etc., and conduct a comprehensive multi - dimensional coupling corrosion evaluation of the test metal material 14 together with the direct current.

[0084] The in - ground current, magnetic field, and chemical environment of the soil constitute the multi - dimensional coupling corrosion factors of the grounding grid conductor.

[0085] The corrosion factors of the soil described in the present invention include various ones, such as soil resistivity, acidity and alkalinity, instantaneous corrosion rate, average corrosion rate, water content, and so on.

[0086] The system of the present invention mainly considers the acidity and alkalinity of the soil, and divides the test container into three small containers, each of which corresponds to acidic soil, neutral soil, and alkaline soil respectively. Each small container has its own grounding point, so that the current forms a loop independently.

[0087] The selection of the grounding grid conductor material can be the same as the actual grounding grid material, such as galvanized steel, copper-clad steel, pure copper, etc. For the convenience of comparative analysis of test results, the size of the grounding grid conductor should be the same.

[0088] The power supply is given by an adjustable transformer and is connected to each grounding grid conductor through a switch, a phase shifter, and an ammeter.

[0089] Alternating current, direct current, harmonic current, and power frequency magnetic field can be loaded onto the grounding grid conductor alone or comprehensively to comprehensively evaluate the corrosion degree of the grounding grid conductor.

[0090] Embodiment 3

[0091] The present invention also provides an embodiment, a multi-dimensional coupling evaluation test system for grounding grid conductor materials, which uses a variety of different test metal materials 14 and different acid-base soils, and simultaneously simulates the comprehensive multi-dimensional coupling corrosion evaluation of the test metal materials 14 under the environment of alternating current, harmonic current, and alternating magnetic field.

[0092] The magnitude of the current flowing through the test metal material 14 can be visually adjusted, and the influence of different current values on the test metal material 14 can be studied, and the pH value, temperature, humidity, timing, etc. in the soil can be monitored in real time.

[0093] Others are the same as in Embodiments 1 and 2.

[0094] Embodiment 4

[0095] The present invention also provides an embodiment, a multi-dimensional coupling evaluation test system for grounding grid conductor materials, which uses a variety of different test metal materials 14 and different acid-base soils, and simultaneously simulates the comprehensive multi-dimensional coupling corrosion evaluation of the test metal materials 14 under the environment of direct current and direct magnetic field.

[0096] Others are the same as in Embodiments 1 and 2.

[0097] The magnitude of the current flowing through the test metal material 14 can be visually adjusted, and the influence of different current values on the test metal material 14 can be studied, and the pH value, temperature, humidity, timing, etc. in the soil can be monitored in real time.

[0098] In the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "connected" and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0099] In the description of the present invention, it should be understood that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention.

[0100] In the description of this specification, the descriptions of the terms "one embodiment", "some embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or instance. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0101] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A multi-dimensional coupling evaluation test system for grounding grid conductor materials, characterized in that: A test metal electrode is connected to the test container, and the other end of the test metal electrode is connected to a current transformer through a circuit. The other end of the current transformer is connected to a through-type current transformer, a voltmeter, a variable transformer, a test power supply, and a ground wire in sequence through a circuit; another lead-out circuit on the through-type current transformer is connected to the terminal of the test metal electrode at the bottom of the test container; a magnetic field generator is connected through the side of the test container, and the other end of the magnetic field generator is connected to a second current transformer, a second voltmeter, a second variable transformer, and a ground wire in sequence through a circuit; the other end of the second voltmeter is connected to a harmonic generator through a circuit; the harmonic generator is a device that generates various harmonics and is used to simulate the harmonic interference generated by substation corona on the grounding conductor; the test container is made of polyethylene transparent material, and the upper part of the test container is provided with a container cover with holes. The inside of the test container is divided into multiple small containers by partitions, and a graphite electrode is embedded at the bottom of each small container. The graphite electrode is grounded through a ground wire; a test metal electrode is provided in each small container, and the other end of each test metal electrode is respectively connected to a current transformer through a circuit provided with a switch; one end of the magnetic field generator extends out of the test container and is connected to a straight conductor; both the current transformer and the second current transformer are equipped with instantaneous trip protection.

2. A multi-dimensional coupling evaluation test system for grounding grid conductor materials according to claim 1, characterized in that: The other end of the magnetic field generator is connected to the second current transformer through a circuit provided with a switch K8, and a circuit provided with a switch K9 is also connected to the test container. The other end of the circuit is connected to the circuit between the switch K8 and the second current transformer. One circuit at the other end of the second variable transformer is connected to the ground wire, and the other circuit is connected to the switch K6 through a circuit provided with a switch K12; one end of the second voltmeter is connected to one end of the second variable transformer through a circuit provided with a switch K14, and the other end of the second voltmeter is connected to the harmonic generator through a circuit provided with a switch K11; the magnetic field generator is an Ampere loop, and when current is passed through it, a transverse magnetic field will be generated in the loop.

3. A multi-dimensional coupling evaluation test system for grounding grid conductor materials according to claim 1, characterized in that: Switches K4, K5, and K6 are connected to the circuit between the through-type current transformer and the test power supply. A voltmeter and a variable transformer are connected to the circuit between the switch K5 and the switch K6. The other end circuit of the variable transformer is respectively connected to the lead of the voltmeter and the ground wire; the lead-out wires of the switch K4 and the switch K5 are respectively connected to the lead-out wires at both ends of the switch K10, and a rectifier is connected between the two lead-out wires.

4. A multi-dimensional coupling evaluation test system for grounding grid conductor materials according to claim 1, characterized in that: The test metal electrode is composed of a test metal material and a fastener. The fastener is sleeved on the test metal material and tightened by the thread on the test metal material; the fastener is a nut that matches the metal material.

5. The test method of a multi-dimensional coupling evaluation test system for grounding grid conductor materials according to claim 1, characterized in that: It includes the following steps: Step 1. Select three soil samples or equivalent solutions with different acid-base levels; including: the pH of the first soil sample is 7, the pH of the second soil sample is >7, and the pH of the third soil sample is <7. Place them in three small containers in the test container respectively. Bury the test metal material in the soil sample. When the soil sample or equivalent solution is different, the test metal material is of the same material; when the soil sample or equivalent solution is the same, select three different materials for the test metal material for comparative analysis; Step 2. Pass the test metal material through the holes on the container cover plate and fix the test metal material on the container cover plate with nuts; Step 3. Corrosion evaluation of the test metal material by alternating current; including: Close switches K6, K5, K4, K1-K3, adjust the adjustable transformer, and the alternating current forms a loop through the metal electrode and the graphite electrode at the bottom of the container to simulate the current dissipation situation of the substation grounding grid conductor to the current; Adjust the phase shifter to make the phase of the current change into capacitive current, inductive current or resistive current; Step 4. Corrosion evaluation of the test metal material by harmonic current and alternating current; including: On the basis of the corrosion evaluation of the test metal material by alternating current, close switches K11, K13, and adjust the harmonic generator until the desired current waveform and frequency are obtained to simulate the harmonic corrosion of the substation grounding grid conductor by corona; Step 5. Corrosion evaluation of the test metal material by alternating magnetic field, harmonic current and alternating current; including: On the basis of the corrosion evaluation of the test metal material by harmonic current, close switches K12, K14, K10, K8, K9, adjust the adjustable transformer, and the magnetic field generator will generate a transverse magnetic field and a longitudinal magnetic field to simulate the magnetic field generated by the open substation busbar, and conduct a comprehensive multi-dimensional coupling corrosion evaluation of the test metal material together with alternating current and harmonics; On the basis of Step 2, close switches K6, K5, K13, K7, K1-K3, adjust the adjustable transformer, and the rectifier will rectify the original alternating current into direct current to simulate the corrosion situation of the test metal material by the direct current of the DC converter station; Step 6. Corrosion evaluation of the metal electrode by direct current; Step 7. Corrosion evaluation of the test metal material by direct current magnetic field and direct current, including: On the basis of the corrosion evaluation of the test metal material by direct current, close switches K8, K9, and the magnetic field generator will generate a constant transverse magnetic field and longitudinal magnetic field to simulate the magnetic field generated by the DC converter station busbar, and conduct a comprehensive multi-dimensional coupling corrosion evaluation of the test metal material together with direct current.

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