Grounding system and design method for a marine rotary electrical device

Abstract

The present application relates to the technical field of ship lightning protection design, in particular to a kind of ground system and design method of shipborne rotary electrical device.The present application adopts segmented multi-stage grounding structure design, by dividing device body and base outer circle, base inner and outer circle dynamic conduction, base inner circle and ship base three-section ground connection unit, both can ensure the original movement performance and working accuracy of shipborne electrical device rotary part, also can ensure reliable ground connection between electrical device and ship body, while cooperating accurate, efficient ground resistance accounting design process, can effectively guarantee the working stability of ground system;The present application adopts the multi-parameter correction ground resistance design method adapted to the harsh working conditions of ship, can accurately match ground parameters for different sea areas, different installation positions, different working conditions, adapt to the extreme operating environment of ship open-air salt spray, high humidity, high and low temperature alternation, high-frequency vibration, effectively improve the long-term operation stability and service life of ground system.

Description

Technical Field

[0001] This invention relates to the field of marine lightning protection design technology, specifically to a grounding system and design method for a shipborne rotary electrical device. Background Technology

[0002] According to the design requirements for ship lightning protection, the metal casings of all electrical devices installed in the open areas of a ship must be reliably grounded to discharge lightning-induced currents and equipment leakage currents, ensuring the safe operation of ship electrical equipment and the personal safety of crew members. The mounting bases for conventional fixed shipboard electrical devices are made of metal, as are the hull and hull base. The mounting bases of the electrical devices are directly connected to the hull base using bolts or screws. To further reduce grounding resistance, a metal grounding wire is added between the mounting bases of the electrical devices and the hull base to ensure good contact between the electrical devices and the hull.

[0003] However, the mounting base for the shipborne rotary electrical device is a split rotary structure, mainly consisting of an inner ring fixed to the hull and an outer ring that rotates with the equipment. The entire equipment is mounted on the outer ring structure. If the traditional integrated grounding wire bridging scheme is used, the grounding wire will directly block and restrict the rotation stroke of the outer ring of the base, causing hard interference with the rotating moving parts, resulting in the equipment being unable to rotate 360° normally, which seriously affects the functionality of the equipment.

[0004] Currently, there is no specific grounding design solution for rotary equipment in the industry. Some simplified modification solutions directly eliminate the jumper grounding wire and rely solely on bolt contact grounding, which has problems such as large contact gaps, poor contact after oxidation and corrosion, and excessive grounding resistance. In thunderstorms, there are safety hazards such as poor current discharge, equipment breakdown and damage, and ship hull electrification. It cannot meet the long-term stable grounding requirements of ships under harsh working conditions. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a grounding system and design method for a shipborne rotary electrical device. The system adopts a segmented cross-connection grounding method, which can ensure that the rotary part of the electrical device can rotate normally and that the electrical device is reliably grounded to the ship. At the same time, through a precise and efficient grounding resistance calculation and design process, the working stability of the grounding system can be effectively guaranteed.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: I. A grounding system for a shipborne rotary electrical device The present invention provides a grounding system for a shipborne rotary electrical device, which mainly includes: a device body 1 and a rotary base. The rotary base includes an outer ring 2 and an inner ring 3. The inner ring 3 is fixedly installed on a hull base 5. The device body 1 is fixedly installed on the outer ring 2, and the outer ring 2 and the inner ring 3 are rotatably connected. The device body 1 is connected to the outer ring 2 of the base via grounding wire 6 to form a first grounding connection unit; the outer ring 2 of the base is connected to the inner ring 3 of the base via a rotating bearing 4 to form a second grounding connection unit; the inner ring 3 of the base is connected to the hull base 5 via grounding wire 8 to form a third grounding connection unit.

[0007] Preferably, one end of the grounding wire 6 is fixedly installed on the outer ring 2 of the base by a connecting screw 7, and the other end is fixedly connected to the outer shell of the device body 1 by welding or screwing.

[0008] Preferably, one end of the grounding wire 8 is fixedly installed on the inner ring 3 of the base by connecting screw 9, and the other end is fixedly connected to the hull base 5 by welding or screwing.

[0009] Preferably, both grounding wire 6 and grounding wire 8 are made of pure copper strip.

[0010] Preferably, the resistance values ​​of the first grounding connection unit, the second grounding connection unit, and the third grounding connection unit are specifically calculated and determined and the overall resistance value is checked by adopting a multi-parameter correction grounding resistance design method based on the actual operating conditions of the ship and the installation environment of the device.

[0011] Preferably, the resistance R1 of the first grounding connection unit is calculated as follows:

[0012] In the formula, The resistivity of pure copper strip at room temperature; S is the effective laying length of grounding wire one; S is the initial effective cross-sectional area of ​​the pure copper strip. The salt spray corrosion correction factor for the device body is 0.85~0.95 for open-air ship conditions and 0.95~1.0 for closed compartment conditions. The value is the correction factor for the ambient temperature of the water area. The value is 1.1 to 1.2 for low temperature conditions of -20℃ to 0℃, 1.0 for normal temperature conditions of 0℃ to 40℃, and 1.05 to 1.1 for high temperature conditions of 40℃ to 60℃.

[0013] Preferably, the resistance R2 of the second grounding connection unit is calculated as follows:

[0014] In the formula, C is the material contact coefficient of the rotating bearing; n is the effective rolling contact point of the bearing; and F is the static assembly preload pressure of the bearing. The value is 0.85~0.95 for normal navigation vibration conditions and 0.7~0.85 for strong turbulence vibration conditions. This is the bearing salt spray oxidation correction factor, with a value of 1.1~1.2 for open-air conditions and 1.0 for closed conditions without salt spray. This is the air humidity correction factor. The value is 1.05~1.1 for high humidity conditions (humidity > 90%) and 1.0 for normal humidity conditions.

[0015] Preferably, the resistance R3 of the third grounding connection unit is calculated as follows:

[0016] In the formula, This refers to the effective laying length of the grounding wire. The salt spray corrosion correction factor for the hull base is determined based on the degree of salt spray attack at the installation location of the hull base. The value is 0.85~0.9 for the exposed location on the outer side of the hull and 0.9~0.98 for the semi-shrouded location on the inner side of the hull.

[0017] Preferably, the overall resistance verification includes: Determine the total resistance R of the grounding system 总 Does it meet the requirements? If not, adjust the total resistance value R by increasing the cross-sectional area of ​​the copper strip, shortening the grounding wire length, replacing the high-conductivity rotating bearing, and adjusting the bearing preload. 总 Continue until the total resistance meets the specifications.

[0018] II. A design method for a grounding system of a shipborne rotary electrical device Based on the same inventive concept, the present invention also provides a design method for the grounding system of the shipborne rotary electrical device as described above, comprising the following steps: S1, On-site working conditions and equipment parameter acquisition: Collect the rotation angle, rotation speed and the size parameters of the inner and outer rings of the base of the shipborne rotary electrical device, and record the ship's operating conditions, hull base material and installation environment parameters to determine the grounding system design reference parameters. S2, Segmented multi-level grounding structure division and layout: Based on the rotation range and movement trajectory of the electrical device, determine the layout positions of each connection point of the first grounding connection unit, the second grounding connection unit, and the third grounding connection unit respectively; S3, Grounding component selection and parameter matching: Based on the rated power and lightning protection level of the electrical device, select the material and cross-sectional area of ​​the grounding wire, match the appropriate specifications of the conductive rotating bearing, and determine the laying length of grounding wire one and grounding wire two according to the layout position of each connection point. S4, Grounding resistance graded design and verification: Based on the actual operating conditions of the ship and the installation environment of the equipment, the resistance values ​​of the first grounding connection unit, the second grounding connection unit and the third grounding connection unit are calculated and determined respectively using the multi-parameter modified grounding resistance design method, and the total grounding resistance of the system is verified. S5, Grounding system assembly and construction: Grind, remove rust and deoxidize all grounding connection contact surfaces to ensure that the contact surfaces are flat and clean, and connect and fix the connection points of the first grounding connection unit, the second grounding connection unit and the third grounding connection unit in sequence to ensure good contact and conductivity.

[0019] Compared with the prior art, the present invention has the following main advantages: 1. This invention adopts a segmented multi-level grounding structure design. By dividing the device body into three grounding connection units: the outer ring of the base, the dynamic conduction between the inner and outer rings of the base, and the inner ring of the base and the ship hull base, it can not only ensure the original motion performance and working accuracy of the rotating part of the ship's electrical equipment, but also ensure the reliable grounding connection between the electrical equipment and the ship hull. At the same time, with a precise and efficient grounding resistance calculation and design process, it can effectively ensure the working stability of the grounding system.

[0020] 2. This invention adopts a multi-parameter modified grounding resistance design method adapted to harsh ship operating conditions. It can accurately match grounding parameters for different sea areas, different installation locations, and different operating conditions, adapting to the extreme operating environment of ships such as open-air salt spray, high humidity, alternating high and low temperatures, and high frequency vibration, effectively improving the long-term operational stability and service life of the grounding system. Attached Figure Description

[0021] Figure 1 This is an overall schematic diagram of the grounding system of the shipborne rotary electrical device in an embodiment of the present invention; Figure 2 This is a flowchart illustrating the grounding system design method in an embodiment of the present invention.

[0022] In the diagram: 1-device body, 2-outer ring of base, 3-inner ring of base, 4-rotating bearing, 5-hull base, 6-grounding wire one, 7-connecting screw one, 8-grounding wire two, 9-connecting screw two. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0024] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0025] In this invention, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly and specifically limited.

[0026] Example 1: This example provides a grounding system for a shipborne rotary electrical device, such as... Figure 1 As shown, it mainly includes: device body 1 and rotary base. The rotary base includes an outer ring 2 and an inner ring 3. The inner ring 3 is fixedly installed on the hull base 5. The device body 1 is fixedly installed on the outer ring 2, and the outer ring 2 and the inner ring 3 are rotatably connected. The device body 1 is connected to the outer ring 2 of the base via grounding wire 6 to form a first grounding connection unit; the outer ring 2 of the base is connected to the inner ring 3 of the base via a rotating bearing 4 to form a second grounding connection unit; the inner ring 3 of the base is connected to the hull base 5 via grounding wire 8 to form a third grounding connection unit.

[0027] In this embodiment, one end of the grounding wire 6 is fixedly installed on the outer ring 2 of the base by connecting screw 7, and the other end is fixedly connected to the outer shell of the device body 1 by welding or screwing.

[0028] In this embodiment, one end of the grounding wire 8 is fixedly installed on the inner ring 3 of the base by connecting screw 9, and the other end is fixedly connected to the hull base 5 by welding or screwing.

[0029] In this embodiment, both grounding wire 6 and grounding wire 8 are made of pure copper strip.

[0030] This invention uses a segmented grounding method consisting of a first grounding connection unit, a second grounding connection unit, and a third grounding connection unit. The grounding resistance is composed of the above three parts, and the combined resistance of the three parts meets the grounding resistance requirements (the grounding resistance requirement for shipborne electrical equipment is no more than 10mΩ). This ensures that the rotating part of the electrical device can rotate normally, and also ensures good contact and reliable grounding between the electrical device and the ship hull.

[0031] Furthermore, this application addresses the complex and harsh operating conditions of ships exposed to salt spray, alternating high and low temperatures, high humidity, and high-frequency vibration. It abandons the traditional single-theoretical resistance calculation formula and fully considers interference factors such as environmental corrosion, temperature deformation, and vibration contact attenuation. The resistance calculation formula for each grounding connection unit is optimized and improved, and a shipboard environment correction coefficient is adopted to achieve high-precision verification of the grounding resistance, ensuring it closely matches actual operating conditions. The specific optimized calculation formula and parameter definitions are as follows: 1) Resistor R1 of the first grounding connection unit (outer ring of the device body and the base)

[0032] In the formula, The resistivity of the pure copper strip at room temperature is 0.0175 Ω·mm² / m in this embodiment; S is the effective laying length of grounding wire 1, in meters; S is the initial effective cross-sectional area of ​​the pure copper strip, in mm². The salt spray corrosion correction factor for the device body is 0.85~0.95 for open-air ship conditions and 0.95~1.0 for closed compartment conditions. The value is the correction factor for the ambient temperature of the water area. The value is 1.1 to 1.2 for low temperature conditions of -20℃ to 0℃, 1.0 for normal temperature conditions of 0℃ to 40℃, and 1.05 to 1.1 for high temperature conditions of 40℃ to 60℃.

[0033] In this application, the salt spray correction coefficient is used to compensate for the attenuation of the effective conduction cross-sectional area caused by slight corrosion and oxidation of the copper strip surface by seawater salt spray, and the temperature correction coefficient is used to adapt to the metal resistivity deformation deviation caused by the day and night of the ship and the temperature difference in the sea area.

[0034] 2) Resistor R2 of the second grounding connection unit (dynamically connected between the inner and outer rings of the base)

[0035] In the formula, C is the material contact coefficient of the rotating bearing, with a value of 0.8 for steel conductive bearings and 0.4 for copper conductive bearings; n is the number of effective rolling contact points of the bearing; F is the static assembly preload pressure of the bearing, in N; This is the ship vibration correction factor. The value is 0.85~0.95 for normal navigation vibration conditions and 0.7~0.85 for strong turbulence vibration conditions. It is used to compensate for the attenuation of bearing contact pressure caused by hull vibration. This is the bearing salt spray oxidation correction factor, with a value of 1.1~1.2 for open-air conditions and 1.0 for closed conditions without salt spray. This is an air humidity correction factor. The value is 1.05~1.1 for high humidity conditions (humidity > 90%) and 1.0 for normal humidity conditions. It is used to adapt to the problem of increased contact resistance caused by the thickening of the oxide film on the bearing contact surface in high humidity environments.

[0036] 3) Resistor R3 of the third grounding connection unit (inner ring of the base and the hull base)

[0037] In the formula, The effective laying length of the grounding wire is in meters. The salt spray corrosion correction factor for the hull base is determined based on the degree of salt spray attack at the installation location of the hull base; the value is 0.85~0.9 for exposed locations on the outer side of the hull and 0.9~0.98 for semi-sheltered locations on the inner side of the hull. S The definition and value standards of the parameters are completely consistent with those of the first grounding connection unit to ensure the consistency of the working condition correction of grounding components of the same material.

[0038] 4) Total resistance R of the grounding system 总

[0039] The total resistance verification standard of this application is adapted to the operating requirements of ships. Each environmental correction factor is based on the ship electrical grounding design specifications and marine atmospheric environment test standards. It can accurately simulate the actual grounding resistance of equipment under long-term operation conditions such as salt spray, temperature change, vibration, and high humidity, thus avoiding the problem of excessive deviation between traditional theoretical calculations and actual operating conditions.

[0040] Example 2: This example provides a grounding system for a shipborne rotary electrical device. One end of the grounding wire 6 (pure copper strip) is fixedly installed on the outer ring 2 of the base by connecting screw 7, and the other end is fixedly connected to the outer shell of the device body 1 by welding or screwing (if the grounding wire is fixed by screwing, the grounding bolt hole needs to be designed and reserved in advance during the research and development and production stage of the electrical equipment) to ensure that both ends of the grounding wire are well fixed and rotate together with the device body 1 and the outer ring 2 of the rotary base. Furthermore, one end of the grounding wire 2 8 (pure copper strip 2) is fixedly installed on the inner ring 3 of the base by connecting screw 2 9, and the other end is fixedly connected to the hull base 5 by welding or screwing, thereby making the inner ring of the electrical device base reliably connected to the hull structure.

[0041] Furthermore, the outer ring 2 and the inner ring 3 of the base are reliably connected through their own structure (such as ball bearings).

[0042] Example 3: Based on the same inventive concept, this example also provides a design method for the grounding system of the shipborne rotary electrical device as described above, such as... Figure 2 As shown, it includes the following steps: Step S1: On-site working conditions and equipment parameters are collected. The rotation angle, rotation speed, and inner and outer ring dimensions of the base of the shipborne rotary electrical device are collected. At the same time, the material of the hull base and the installation environment (open-air salt spray, humid conditions) are recorded to clarify the total grounding resistance threshold (≤10mΩ) of the grounding system specified in the ship's regulations and to determine the design reference parameters of the grounding system.

[0043] Step S2: Divide and lay out the segmented multi-level grounding structure. Based on the equipment's rotation range, determine the layout positions of the three-level grounding units to avoid the equipment's movement trajectory; determine the connection point of the first grounding connection unit to ensure that there is no dead angle of conduction between the device body and the outer ring of the base; the outer ring of the base and the inner ring of the base are connected by a rotating bearing as the second grounding connection unit to ensure dynamic rotation conduction; determine the connection point of the third grounding connection unit to ensure a reliable connection between the inner ring of the base and the ship's hull base.

[0044] Step S3: Select and match grounding components. Based on the equipment power and lightning protection level, select the cross-sectional area and thickness of the pure copper strip grounding wire, and match the appropriate conductive rotating bearing. Combined with the collected dimensional parameters, preliminarily determine the laying length of grounding wire one and grounding wire two, and complete the preliminary selection of components (adopt the principle of connection as close as possible to shorten the laying length of grounding wire and reduce the foundation resistance).

[0045] Step S4: Grounding resistance tiered design and verification. A multi-parameter corrected grounding resistance design method is used to calculate the resistance values ​​R1, R2, and R3 of the first, second, and third grounding connection units, respectively, and to verify the total system grounding resistance R. 总 If the total resistance is greater than the total grounding resistance threshold (10mΩ), the parameters are iteratively adjusted by increasing the cross-sectional area of ​​the copper strip, shortening the length of the grounding wire, replacing the high conductivity bearing, and optimizing the bearing preload pressure until the total resistance meets the specification requirements.

[0046] Step S5: Grounding system assembly and construction. Grind, remove rust, and deoxidize all grounding connection contact surfaces to ensure that the contact surfaces are flat and clean. Fix the two-stage grounding wires by screw tightening and welding to ensure that the connection is not loose. Precisely assemble the conductive bearings and control the bearing preload pressure to ensure flexible rotation and good contact conductivity.

[0047] Furthermore, all parts of this application that are not described in detail are the same as or implemented using existing technology.

[0048] In summary: 1. This invention adopts a segmented multi-level grounding structure design. By dividing the device body into three grounding connection units: the outer ring of the base, the dynamic conduction between the inner and outer rings of the base, and the inner ring of the base and the ship hull base, it can not only ensure the original motion performance and working accuracy of the rotating part of the ship's electrical equipment, but also ensure the reliable grounding connection between the electrical equipment and the ship hull. At the same time, with a precise and efficient grounding resistance calculation and design process, it can effectively ensure the working stability of the grounding system.

[0049] 2. This invention adopts a multi-parameter modified grounding resistance design method adapted to harsh ship operating conditions. It can accurately match grounding parameters for different sea areas, different installation locations, and different operating conditions, adapting to the extreme operating environment of ships such as open-air salt spray, high humidity, alternating high and low temperatures, and high frequency vibration, effectively improving the long-term operational stability and service life of the grounding system.

[0050] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0051] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0052] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A grounding system for a shipborne rotary electrical device, characterized in that: The device includes a main body (1) and a rotary base. The rotary base includes an outer ring (2) and an inner ring (3). The inner ring (3) is fixedly installed on the hull base (5). The main body (1) is fixedly installed on the outer ring (2), and the outer ring (2) and the inner ring (3) are rotatably connected. The device body (1) is connected to the outer ring (2) of the base via grounding wire one (6) to form a first grounding connection unit; the outer ring (2) of the base is connected to the inner ring (3) of the base via a rotating bearing (4) to form a second grounding connection unit; the inner ring (3) of the base is connected to the hull base (5) via grounding wire two (8) to form a third grounding connection unit.

2. The grounding system of a shipborne rotary electrical device according to claim 1, characterized in that, One end of the grounding wire (6) is fixedly installed on the outer ring (2) of the base by connecting screw (7), and the other end is fixedly connected to the outer shell of the device body (1) by welding or screwing.

3. The grounding system of a shipborne rotary electrical device according to claim 2, characterized in that, One end of the grounding wire 2 (8) is fixedly installed on the inner ring (3) of the base by connecting screw 2 (9), and the other end is fixedly connected to the hull base (5) by welding or screwing.

4. The grounding system of a shipborne rotary electrical device according to claim 3, characterized in that, Both grounding wire one (6) and grounding wire two (8) are made of pure copper strip.

5. The grounding system of a shipborne rotary electrical device according to claim 1, characterized in that, The resistance values ​​of the first grounding connection unit, the second grounding connection unit, and the third grounding connection unit are calculated and determined separately based on the actual operating conditions of the ship and the installation environment of the equipment, and the overall resistance value is checked by adopting a multi-parameter correction grounding resistance design method.

6. The grounding system of a shipborne rotary electrical device according to claim 5, characterized in that, The resistance R1 of the first grounding connection unit is calculated as follows: In the formula, The resistivity of pure copper strip at room temperature; S is the effective laying length of grounding wire one; S is the initial effective cross-sectional area of ​​the pure copper strip. The salt spray corrosion correction factor for the device body is 0.85~0.95 for open-air ship conditions and 0.95~1.0 for closed compartment conditions. The value is the correction factor for the ambient temperature of the water area. The value is 1.1 to 1.2 for low temperature conditions of -20℃ to 0℃, 1.0 for normal temperature conditions of 0℃ to 40℃, and 1.05 to 1.1 for high temperature conditions of 40℃ to 60℃.

7. The grounding system of a shipborne rotary electrical device according to claim 6, characterized in that, The resistance R2 of the second grounding connection unit is calculated as follows: In the formula, C is the material contact coefficient of the rotating bearing; n is the effective rolling contact point of the bearing; and F is the static assembly preload pressure of the bearing. The value is 0.85~0.95 for normal navigation vibration conditions and 0.7~0.85 for strong turbulence vibration conditions. This is the bearing salt spray oxidation correction factor, with a value of 1.1~1.2 for open-air conditions and 1.0 for closed conditions without salt spray. This is the air humidity correction factor. The value is 1.05~1.1 for high humidity conditions (humidity > 90%) and 1.0 for normal humidity conditions.

8. The grounding system of a shipborne rotary electrical device according to claim 7, characterized in that, The resistance R3 of the third grounding connection unit is calculated as follows: In the formula, This refers to the effective laying length of the grounding wire. The salt spray corrosion correction factor for the hull base is determined based on the degree of salt spray intrusion at the installation location of the hull base. The value is 0.85~0.9 for the exposed location on the outer side of the hull and 0.9~0.98 for the semi-shrouded location on the inner side of the hull.

9. The grounding system of a shipborne rotary electrical device according to claim 8, characterized in that, The overall resistance value verification includes: Determine the total resistance R of the grounding system 总 Does it meet the requirements? If not, adjust the total resistance value R by increasing the cross-sectional area of ​​the copper strip, shortening the grounding wire length, replacing the high-conductivity rotating bearing, and adjusting the bearing preload. 总 Continue until the total resistance meets the specifications.

10. A design method for the grounding system of a shipborne rotary electrical installation as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1, On-site working conditions and equipment parameter acquisition: Collect the rotation angle, rotation speed and the size parameters of the inner and outer rings of the base of the shipborne rotary electrical device, and record the ship's operating conditions, hull base material and installation environment parameters to determine the grounding system design reference parameters. S2, Segmented multi-level grounding structure division and layout: Based on the rotation range and movement trajectory of the electrical device, determine the layout positions of each connection point of the first grounding connection unit, the second grounding connection unit, and the third grounding connection unit respectively; S3, Grounding component selection and parameter matching: Based on the rated power and lightning protection level of the electrical device, select the material and cross-sectional area of ​​the grounding wire, match the appropriate specifications of the conductive rotating bearing, and determine the laying length of grounding wire one and grounding wire two according to the layout position of each connection point. S4, Grounding resistance graded design and verification: Based on the actual operating conditions of the ship and the installation environment of the equipment, the resistance values ​​of the first grounding connection unit, the second grounding connection unit and the third grounding connection unit are calculated and determined respectively using the multi-parameter modified grounding resistance design method, and the total grounding resistance of the system is verified. S5, Grounding system assembly and construction: Grind, remove rust and deoxidize all grounding connection contact surfaces to ensure that the contact surfaces are flat and clean, and connect and fix the connection points of the first grounding connection unit, the second grounding connection unit and the third grounding connection unit in sequence to ensure good contact and conductivity.

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