Thermal-electrical-mechanical combined testing system for submarine cable

Abstract

The present invention relates to a system capable of simultaneously performing thermal testing, electrical testing, and mechanical testing in an environment similar to a dynamic cable installation environment. The present invention comprises: a seawater tank module for forming a seawater atmosphere for a test cable; a mechanical testing module in which a fixing end and an operating end are provided on the test cable, and mechanical aging is performed on the test cable in accordance with the operation of an actuator; an electrical testing module in which voltage is applied to both ends of the test cable, and electrical aging is performed; a thermal testing module in which current is applied to a dummy cable, independently provided from the test cable, and thermal aging is performed; and a control module which carries out data input, control processing, monitoring, and storage with respect to the seawater tank module, mechanical testing module, thermal testing module, and electrical testing module. The technical purpose of the present invention is to simultaneously perform mechanical, thermal, and electrical testing on a dynamic cable.

Description

Submarine Cable Thermal-Electro-Mechanical Composite Test System

[0001] The present invention relates to a submarine cable thermal-electrical-mechanical composite test system, and more particularly, to a system capable of simultaneously performing thermal tests, electrical tests, and mechanical tests in an environment similar to the installation of a dynamic cable.

[0002] For submarine cables applied to offshore wind power, performance verification is required through evaluation tests for mechanical stress, electrical stress, and thermal stress before installation.

[0003] Traditionally, the representative submarine cable applied to offshore wind power is a static cable, which is installed on the seabed and does not move when installed in fixed offshore wind turbines, etc., as it is laid inside a J-tube metal pipe.

[0004] Therefore, since the above static cable is subjected to mechanical stress only during production, transportation, and installation, it is acceptable to separately conduct mechanical tests to evaluate the mechanical stress occurring in land and marine environments and electrical and thermal tests to evaluate the electrical and thermal stress occurring in the submarine environment during operation.

[0005] Looking at this in detail, as shown in Fig. 1(a), the type test process for static cables is conducted in the following order: tensile stress tests, tensile-bending tests, etc. are conducted to verify whether mechanical stress generated during production, transportation, and installation has an effect on the performance of submarine cables, and then electrical tests are conducted separately.

[0006] That is, after each mechanical test for mechanical stress applied during production, transportation, and installation on one sample, the cable is visually inspected for breakage and damage, and if no abnormalities are found, an electrical test is conducted on this sample.

[0007] However, recently, floating offshore wind turbines designed to float underwater are expanding in line with the floating offshore wind power generation project plan.

[0008] At this time, a dynamic cable floating underwater is applied to the floating offshore wind turbine. Unlike the static cable fixed to the seabed, the dynamic cable experiences continuous tension and bending due to underwater environmental factors such as waves, buoyancy, currents, and cable weight.

[0009] In other words, dynamic cables are subjected to continuous mechanical stress not only in the terrestrial environment during production, transportation, and installation, but also in the marine environment after installation.

[0010] Accordingly, the test of the dynamic cable is currently conducted independently on two samples, as in the type test of Fig. 1(b). One sample is subjected to a test for mechanical stress in the production, transportation, and installation environments, similar to a static cable, followed by an electrical test, and the other sample is subjected to an electrical and thermal test and a mechanical stress test in a marine environment sequentially.

[0011] However, in the case of dynamic cables, mechanical stress due to the marine environment and electrical and thermal stress are simultaneously formed underwater, but the test to measure this is performed separately on land for electrical, thermal and mechanical stress, and therefore there is a problem in that it produces results that are different from the stress due to the actual use environment.

[0012] In the same context as the conventional method, Korean Patent No. 10-2508559, 'Floating offshore wind power dynamic cable power core tensile-bending rotation fatigue test structure' and Korean Patent No. 10-2282208, 'Floating offshore wind power dynamic cable bending stiffness test facility', which test the characteristics of dynamic cables, are disclosed, but they contain the problems pointed out above.

[0013] That is, since the mechanical, electrical, and thermal stresses of an actual dynamic cable occur simultaneously in the usage environment, it is desirable to conduct the type test of the dynamic cable simultaneously in an underwater environment to solve the above-mentioned problem.

[0014] Below, we will examine research papers on mechanical, electrical, and thermal stresses on dynamic cables in underwater environments.

[0015] The papers 'Remnant Static Mechanical Stresses and Water Tree Ageing of XLPE Power Cables' and 'Water Tree Ageing of High Voltage XLPE Cable Insulation System under Combined Dynamic Mechanical and AC Electrical Stress' tested the possibility of improving water tree due to residual mechanical stresses generated during the manufacturing process of extruded XLPE power cables.

[0016] Single-core extruded XLPE power cables are largely divided into a core and an insulation layer. During production, after the extrusion and curing processes, internal residual stress remains due to the difference in cooling rates between the inside and outside of the insulation layer during rapid cooling. This internal residual stress causes water treeing, a polymer fracture behavior, due to the combined effects of mechanical and electrical stress when used in an underwater environment.

[0017] The above papers are tests that artificially create a harsh environment that cannot occur in an actual cable use environment by extracting a core from a single-core extruded XLPE power cable, filling the inside and outside of the insulation layer with water, applying mechanical stress, and then observing the water tree in order to observe the water tree.

[0018] Such studies generally have the problem that they cannot be applied to observing underwater stress in dynamic cables, as the test subjects and test purposes are different in that dynamic cables generally use three-core extruded XLPE power cables and an armor layer is formed on the outer layer to resist underwater mechanical stress.

[0019] That is, although the study for water tree observation is conducted in an underwater environment, the core is extracted from a single-core extruded XLPE power cable and only the insulation layer is tested, so there is an extreme difference from the actual dynamic cable installation environment experiment.

[0020] In addition, the experimental object of the above study is a single-core extruded XLPE power cable, and a metal tube is inserted inside the insulation layer to apply mechanical stress while maintaining the shape of the insulation layer and is fixed to the actuator. Therefore, stress unrelated to the mechanical stress applied to an actual dynamic cable is applied, and a thermal test that applies current to the cable is not performed, so there is a problem that it is only a laboratory-level study unrelated to the installation environment of an actual dynamic cable.

[0021] The present invention was invented to solve the above-mentioned problem, and the technical task of the present invention is to provide a submarine cable thermal-electrical-mechanical composite test system that can simultaneously apply mechanical, electrical, and thermal stresses to a dynamic cable after forming an environment similar to the actual installation environment of the dynamic cable.

[0022] In order to solve the above technical problem, the present invention provides a submarine cable test system comprising: a seawater tank module for forming a seawater atmosphere in a test cable; a mechanical test module in which a fixed end and an operating end are formed in the test cable and mechanical aging of the cable is performed according to the operation of an actuator; an electrical test module in which electrical aging is performed by applying voltage to both ends of the test cable; a thermal test module in which current is applied to a dummy cable formed independently of the test cable, heat generation of the dummy cable is measured, and this is monitored as heat generation of the test cable while applying current to the test cable; and a control module in which data input, control processing, monitoring, and storage of the seawater tank module, the mechanical test module, the thermal test module, and the electrical test module are performed, thereby simultaneously performing mechanical, thermal, and electrical tests on a dynamic cable. The technical gist of the present invention is a submarine cable thermal-electrical-mechanical composite test system.

[0023] In the present invention, it is preferable that the seawater tank module be a submarine cable thermal-electrical-mechanical composite test system characterized by comprising: a seawater tank for submerging a test cable; and a storage tank connected to a pipe controlled by a control valve.

[0024] In addition, it is preferable that the above-mentioned fixed end and the working end be a submarine cable thermal-electrical-mechanical composite test system characterized in that they fix and clamp an armor layer that protects the inner wire of the test cable.

[0025] In addition, it is preferable that the mechanical test module be a submarine cable thermal-electrical-mechanical composite test system characterized in that a vertical actuator formed on the top of the submarine tank module to press the test cable and a horizontal actuator performing horizontal movement on the action side are linked to simulate mechanical aging due to water current.

[0026] In addition, it is preferable that the above-mentioned vertical actuator be formed with a pressing member that pressurizes the test cable, and the pressing member is formed in a semicircular shape in the longitudinal direction of the test cable, and a semicircular inner groove that conforms to the test cable is formed on the contact surface of the test cable, which is a submarine cable thermal-electrical-mechanical composite test system.

[0027] In addition, it is preferable that the above-mentioned horizontal actuator be a submarine cable thermal-electrical-mechanical composite test system characterized in that it is driven on a rail formed in the longitudinal direction of the test cable and the direction of movement is constrained in the longitudinal direction of the test cable.

[0028] In addition, it is preferable that the control module be a submarine cable thermal-electrical-mechanical composite test system, characterized in that it comprises: an input unit for inputting necessary information for performing the submarine cable thermal-electrical-mechanical composite test; a current control unit for monitoring the current and heat generation applied to the dummy cable and applying current to the test cable based on the heat generation amount; a voltage control unit for controlling the voltage applied to the test cable; a motion control unit for controlling the actuator operation; a seawater control unit for controlling the water level of the seawater tank module; and a memory unit for storing data acquired from the input unit, the current control unit, the voltage control unit, the motion control unit, and the seawater control unit.

[0029] According to the submarine cable thermal-electrical-mechanical composite test system by means of solving the above problem, after creating an environment similar to the actual installation environment of a dynamic cable, a characteristic evaluation test is performed by simultaneously applying mechanical, electrical, and thermal stresses to the dynamic cable, and there is an effect of ensuring the reliability of the evaluation results.

[0030] Accordingly, it has the effect of ensuring the quality and improving the durability of submarine cables.

[0031] Fig. 1(a) shows the type test process of a static cable, and Fig. 1(b) is a flowchart showing the conventional type test process of a dynamic cable.

[0032] Figure 2 is a schematic diagram showing the configuration of a submarine cable thermal-electrical-mechanical composite test system of the present invention.

[0033] Figure 3 is a control module configuration diagram of the present invention.

[0034] FIG. 4 is a diagram of a submarine cable thermal-electrical-mechanical composite test system according to an embodiment of the present invention.

[0035] Figure 5 is a clamp drawing of a fixed end according to an embodiment.

[0036] Figure 6 is a drawing of a seawater tank module and a vertical actuator according to an embodiment.

[0037] Figure 7 is a drawing of a horizontal actuator of a mechanical test module according to an embodiment.

[0038] Figure 8 is a drawing of a dummy cable according to an embodiment.

[0039] The present invention will be described with reference to the drawings below. In explaining the present invention, if it is determined that a detailed description of a related known technology or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

[0040] And the terms described below are terms defined in consideration of their functions in the present invention, and may vary depending on the intention or custom of the user or operator, so their definitions should be made based on the contents throughout this specification explaining the present invention.

[0041]

[0042] Hereinafter, referring to the attached drawings, the configuration of the present invention will be examined. As shown in FIG. 2, in order to construct a cable testing system by forming an environment similar to an actual dynamic cable installation environment, the present invention is configured with a seawater tank module (10), a mechanical testing module (200), an electrical testing module (300), a thermal testing module (400), and a control module (500), thereby simultaneously performing mechanical, thermal, and electrical tests on a dynamic cable.

[0043] The seawater tank module (10) is intended to form a seawater atmosphere for the test cable (A), and may include seawater tanks (100) of various sizes and shapes in which the test cable (A) is submerged depending on the test conditions.

[0044] At this time, the seawater tank module (10) further includes a storage tank (110) so that the water level in the seawater tank (100) can be maintained at a constant level according to the movement of the test cable (A) during the test.

[0045] For example, since the water level in the seawater tank (100) varies depending on the operating status of the mechanical test module (200) described later, it is desirable to adjust the water level in conjunction with this.

[0046] The storage tank (110) is connected to the seawater tank (100) by a pipe (120) controlled by a control valve (130) to control the inflow and discharge of seawater into and out of the seawater tank (100), thereby allowing the water level of the seawater tank (100) to be adjusted to a certain height.

[0047] In this way, the test cable (A) forms a stable seawater atmosphere, thereby creating an environment similar to the installation environment of an actual dynamic cable.

[0048] The mechanical test module (200) is configured such that the test cable (A) is formed with a fixed end (210) and an operating end (220), and mechanical aging of the cable (A) is performed according to the actuator operation. More specifically, one side of the test cable (A) is fixed by the fixed end (210), and a horizontal actuator (230) is formed at the operating end (220), so that the other side of the test cable (A) can move horizontally. The horizontal actuator (230) is driven on a rail formed in the longitudinal direction of the test cable (A), so that the direction of movement can be constrained in the longitudinal direction of the test cable (A). Accordingly, the test cable (A) can perform a tensile stress test that applies mechanical stress.

[0049] In addition, a vertical actuator (240) is formed at the top of the subsea tank module (100) to press the test cable (A). Accordingly, the horizontal actuator (230) and the vertical actuator (240) are linked to simulate mechanical aging due to water currents, thereby enabling a tensile bending test to be performed.

[0050] At this time, the fixed end (210) and the operating end (220) in the mechanical test module (200) have a technical point of fixing and clamping the armor layer that protects the internal wires of the test cable (A). In general, the armor layer is a steel wire formed on the outside to protect the internal wires of a dynamic cable, and serves to minimize mechanical stress caused by waves, buoyancy, currents, cable weight, etc. from being applied to the internal wires.

[0051] Unlike the conventional art paper, which inserts a metal tube inside the insulation layer and clamps it in order to test a model cable in which the conductor core is removed and only the insulation layer remains, the present invention cuts the same dynamic cable that is actually installed to a test length and clamps it fixedly to an armor layer that blocks mechanical stress, thereby creating an environment similar to the installation environment of an actual dynamic cable.

[0052] That is, since the mechanical stress occurring in the dynamic cable in an actual underwater environment is directly transmitted to the armor layer, the present invention has the advantage of being able to observe the dynamic cable state due to mechanical stress accumulation in an actual underwater environment by applying mechanical stress to the armor layer.

[0053] The electrical test module (300) applies voltage to the conductor of the test cable (A) to perform electrical aging.

[0054] The thermal test module (400) measures heat generation by applying current to a dummy cable (B) formed independently from the test cable (A), and applies the same current to the test cable while monitoring the heat generation.

[0055] That is, since high voltage is applied to the test cable, direct heat generation measurement is impossible, so an induced current is generated in the dummy cable (B) to generate heat as a result of the conductor resistance, and the temperature is measured with a temperature sensor formed in the dummy cable (B) to estimate the temperature of the test cable (A).

[0056] As shown in FIG. 3, the control module (500) performs data input, control processing, monitoring, and storage of the seawater tank module (10), mechanical test module (200), electrical test module (300), and thermal test module (400).

[0057] More specifically, the input unit (510) inputs necessary information for conducting a test through a PC linked to a submarine cable thermal-electrical-mechanical composite test, the current control unit (520) monitors the current and temperature applied to the dummy cable while applying current to the test cable, the voltage control unit (530) controls and monitors the voltage applied to the test cable, the motion control unit (540) controls the operation of the vertical actuator and the horizontal actuator, and the seawater control unit (550) controls the water level of the seawater tank module (10).

[0058] Additionally, the memory unit (560) stores data obtained from the input unit (510), current control unit (520), voltage control unit (530), motion control unit (540), and seawater control unit (550).

[0059]

[0060] Hereinafter, the present invention will be examined in more detail with reference to FIGS. 4 to 8.

[0061] As illustrated in FIG. 4, the submarine cable thermal-electrical-mechanical composite test system of the present invention has a technical purpose of constructing a test system capable of simultaneously conducting thermal-electrical-mechanical tests in an environment similar to an actual dynamic cable installation environment.

[0062] First, in order to conduct a mechanical test, a floor structure (1000) is formed in which a plurality of frame bars are assembled, a seawater tank module (10) is placed in the center of the floor structure (1000), and a pressing structure (2000) is formed on the seawater tank module (10). In addition, an operating section structure (3000) is formed in which a fixed section (210) for clamping a test cable (A) is placed at one end of the floor structure (1000), and an operating section (220) for clamping the test cable (A) is placed at the other end.

[0063] Additionally, a frame (4000) for cable terminal processing is formed at both ends of the test system to apply voltage to the cable core wire from which the armor layer has been removed.

[0064] And, in order to perform an electrical test, it is possible to check the pressure tester (310) and the pressure tester control device (320) that controls the pressure tester, and in order to perform a thermal test, it is possible to check that a dummy cable (B) that is formed independently from the regular test cable (A) is formed.

[0065] As shown in Fig. 5, it can be confirmed that the fixed end (210) and the operating end (220) fix and clamp the armor layer, which is the outer metal tube of the cable.

[0066] As shown in Fig. 6, cable support wheels (5000) are formed at both ends of the seawater tank module (10) to prevent excessive bending of the test cable and to form a cable curvature similar to an actual cable installation environment.

[0067] Additionally, a vertical actuator (240) is arranged at the top of the pressing structure (2000), and presses the test cable (A) located below by vertical movement. At this time, a pressing member (2100) is arranged to distribute the pressing force on the test cable (A).

[0068] The above-mentioned pressure member (2100) is formed in a semicircular shape so that the deformation of the test cable due to mechanical stress in an underwater environment can be similarly simulated, and the lower surface that comes into contact with the test cable is also formed with a semicircular groove so that the escape prevention and protection function of the test cable is performed.

[0069] The rings formed at both ends of the main body of the pressure member (2100) are connected to a test cable (A), and the main body shape can be formed into various shapes such as a pentahedron, a hexahedron, or a cylinder.

[0070] As shown in Fig. 7, it can be confirmed that an action section structure (3000) is formed in which an action section (220) is placed at the other end of a floor structure (1000).

[0071] The working section structure (3000) is formed by a first structure (3100) formed at the other end of the floor structure (1000) and a plurality of second structures (3200) formed continuously and spaced apart from the first structure (3100), and a rail guide plate (3300) and a movable member (3400) are formed between the second structures (3200). At this time, an working section (220) for fixing and clamping a test cable (A) is formed on the movable member (3400), and the first structure (3100) and the movable member (3400) are connected to a horizontal actuator (230). The horizontal actuator (230) is driven on a rail of a rail guide plate (3300) formed in the longitudinal direction of the test cable (A), and the direction of movement is constrained in the longitudinal direction of the test cable (A), so that the working end (220) of the test cable (A) can move horizontally, and accordingly, a tensile stress test and a tensile bending test of the test cable (A) are performed.

[0072] As shown in Fig. 8, the dummy cable (B) is formed independently from the test cable (A), CTs are assigned to each phase, and busbars are installed on the R phase, S phase, and T phase.

[0073] When a three-phase current is applied to the dummy cable (B), heat is generated, and by measuring the temperature of the dummy cable (B) with a temperature sensor (not shown) and predicting the temperature of the test cable (A), the current applied to the test cable (A) can be adjusted.

[0074] Accordingly, the submarine cable thermal-electrical-mechanical composite test system of the present invention can perform tests by creating an environment similar to the actual installation environment of a dynamic cable by simultaneously applying mechanical, electrical, and thermal stresses to the dynamic cable in a seawater atmosphere.

[0075] The performance evaluation results of the dynamic cable obtained by the present invention have the advantage of ensuring reliability and promoting quality and durability improvement.

[0076]

[0077] The drawings shown for the purpose of explaining the present invention are one embodiment in which the present invention is embodied, and it can be seen that various combinations of forms are possible in order to realize the gist of the present invention as shown in the drawings.

[0078] Accordingly, the present invention is not limited to the above-described embodiments, and as claimed in the following claims, it is possible for anyone with ordinary skill in the art to make various modifications without departing from the spirit of the present invention, and it is said that the technical spirit of the present invention exists to the extent that it is possible to make various modifications without departing from the spirit of the present invention.

Claims

1. In the submarine cable test system, A seawater tank module that creates a seawater atmosphere for the test cable; A mechanical test module in which a fixed end and an operating end are formed on the test cable, and mechanical aging of the cable is performed according to the actuator operation; An electrical test module in which electrical aging is performed by applying voltage to both ends of the above test cable; A thermal test module that measures the heat generation of a dummy cable while applying current to a dummy cable formed independently of the test cable, and monitors this as the heat generation of the test cable while applying current to the test cable; A control module in which data input, control processing, monitoring and storage of the above seawater tank module, mechanical test module, thermal test module and electrical test module are performed; It consists of including A submarine cable thermal-electrical-mechanical composite test system characterized by simultaneously performing mechanical, thermal, and electrical tests on a dynamic cable.

2. In paragraph 1, The above seawater tank module A seawater tank for submerging the test cable; A storage tank connected to a pipe controlled by a control valve; A submarine cable thermal-electrical-mechanical composite test system characterized by comprising:

3. In paragraph 1, The above fixed and working ends are A submarine cable thermal-electrical-mechanical composite test system characterized by fixing and clamping an armor layer protecting the inner wires of the above-mentioned test cable.

4. In paragraph 1, The above mechanical test module A submarine cable thermal-electrical-mechanical composite test system characterized in that a vertical actuator formed on the top of the submarine tank module and pressing the test cable and a horizontal actuator performing horizontal movement on the action side are linked to simulate mechanical aging due to water current.

5. In paragraph 4, The above vertical actuator has A pressurizing member that pressurizes the test cable is formed. The above pressure member is formed in a semicircular shape in the length direction of the test cable, A submarine cable thermal-electrical-mechanical composite test system characterized in that a semicircular groove conforming to the test cable is formed on the contact surface of the test cable.

6. In the fourth paragraph, the horizontal actuator Driven on a rail formed in the longitudinal direction of the test cable A submarine cable thermal-electrical-mechanical composite test system characterized in that the direction of motion is constrained in the longitudinal direction of the test cable.

7. In paragraph 1, The above control module An input section for inputting necessary information for performing the above submarine cable thermal-electrical-mechanical composite test; A current control unit that monitors the current and heat generated by the dummy cable and applies current to the test cable based on the heat generated; A voltage control unit that controls the applied voltage of the above test cable; A motion control unit that controls the above actuator operation; A seawater control unit that controls the water level of the above seawater tank module; A memory unit that stores data obtained from the input unit, current control unit, voltage control unit, motion control unit, and seawater control unit; A submarine cable thermal-electrical-mechanical composite test system comprising:

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