An accelerator ground wire system and design method based on EMC

Abstract

The present invention relates to an accelerator ground wire system and design method based on EMC, which includes: a universal ground network, which is arranged on the universal equipment side and is the main ground network of the universal equipment. The universal equipment is connected to the universal ground network through the low-voltage power distribution system of the power distribution room to achieve safe grounding; a process ground network, which is laid near the process power distribution equipment and is the main ground network of the process power distribution equipment. The process equipment is connected to the process ground network through a grounding box, and the process ground network achieves differentiated grounding through the grounding box; a grounding well is used to connect the universal ground network with the process ground network, realize high-frequency isolation and power frequency combination between the universal ground network and the process ground network, and serve as a grounding test point. The present invention can take into account both safety protection and electromagnetic compatibility performance, and can be applied in the field of electromagnetic compatibility and grounding of accelerators.

Description

Technical Field

[0001] The invention relates to the technical field of accelerator electromagnetic compatibility and grounding, and in particular to an accelerator ground wire system based on EMC and a design method thereof. Background Art

[0002] With the development of technology, the electromagnetic interference problem of large scientific facilities such as accelerators has become increasingly prominent. The system failure rate and electromagnetic noise level are high, which affects the quality of beam and scientific research experiments. The ground wire is one of the important electromagnetic interference pathways, which is related to the safety protection and electromagnetic compatibility performance of the accelerator device. The accelerator device generally adopts the TN-S power distribution system. The equipment is connected to the PE line. When a grounding fault occurs, the overcurrent device operates and protects. However, from the perspective of electromagnetic compatibility performance analysis, this ground wire structure will cause serious common ground impedance interference problems between devices due to the long PE line and high ground wire impedance. For this reason, the accelerator device is usually equipped with a dedicated ground grid. According to the TN-S repeated grounding method, the grounding is carried out nearby on the equipment side, which alleviates the problem of high ground wire impedance, but will cause ground loop interference; if only a dedicated ground grid is used, that is, the TT power distribution system, although the equipment is grounded nearby and the ground loop problem is alleviated, it does not meet the requirements of power distribution safety specifications. In addition, the accelerator device system is huge and the equipment composition is complex. Due to the lack of a reasonable grounding solution, it has become an important interference channel - transient high-voltage and high-frequency noise such as surges and pulse groups cause equipment malfunctions or even damage through the grounding wire; at the same time, conducted emission noise is crosstalked through the grounding wire, affecting weak signal detection and increasing the difficulty of scientific research experiments.

[0003] In summary, it is very important to study how to achieve grounding differentiation and reasonable ground wire structure design based on the load characteristics of accelerator equipment, while taking into account electrical safety protection and electromagnetic compatibility performance. Summary of the invention

[0004] In view of the above problems, the object of the present invention is to provide an EMC-based accelerator ground wire system and design method, which can take into account both safety protection and electromagnetic compatibility performance.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an EMC-based accelerator grounding system, which includes: a universal grounding network, which is arranged on the universal equipment side and is the main grounding network of the universal equipment. The universal equipment is connected to the universal grounding network via the low-voltage distribution system of the distribution room to achieve safe grounding; a process grounding network, which is laid near the process distribution equipment and is the main grounding network of the process distribution equipment. The process equipment is connected to the process grounding network via a grounding box, and the process grounding network achieves differentiated grounding through the grounding box; a grounding well, which is used to connect the universal grounding network and the process grounding network to achieve high-frequency isolation and power frequency combination between the universal grounding network and the process grounding network, and serves as a grounding test point.

[0006] Furthermore, the universal grounding grid is composed of a plurality of horizontal grounding electrodes and a plurality of vertical grounding electrodes, and a grounding lead-out point is formed at the connection between the horizontal grounding electrode and the vertical grounding electrode. The leads extending from the connection of each grounding lead-out point are connected to one end of the grounding well.

[0007] Furthermore, the grounding wells connected to the process grounding grid are respectively provided at least at the beginning, the end and the middle of the universal grounding grid.

[0008] Furthermore, the process grounding network is formed by connecting the construction steel bars and artificial grounding electrodes between the process equipment room and the accelerator tunnel to form a cage-type grounding network, and process grounding lead-out points are formed at the connection points. The leads extending from the connection of each process grounding lead-out point are connected to the other end of the grounding well.

[0009] Furthermore, the grounding box adopts a process distribution cabinet or a process distribution box;

[0010] In addition to the original components, the process distribution cabinet or the process distribution box is also provided with a process ground bar and a filter unit; the process ground bar is insulated and installed on the cabinet or box; one end of the process ground bar is connected to the process ground network, and the other end of the process ground bar is connected to one end of the first PE bar in the process distribution cabinet or the process distribution box through the filter unit; the other end of the first PE bar is connected to the second PE bar in the power cabinet in the distribution room.

[0011] Further, the grounding well includes a filter unit and a fastener;

[0012] The filter unit is fixed at the location to be installed via the fasteners, and the grounding well is led out into the foundation well.

[0013] Further, the filtering unit includes a magnetic ring and a grounding cable;

[0014] The grounding cable is wound around the magnetic ring, and the grounding cable on the magnetic ring forms a winding cable, and both ends of the grounding cable extend to the outside of the magnetic ring to form connecting ends for connecting the universal ground grid and the process ground grid.

[0015] A design method for implementing the above-mentioned EMC-based accelerator ground wire system comprises:

[0016] Classify the accelerator equipment into general equipment, general process equipment and sensitive process equipment;

[0017] The grounding grid is laid according to the equipment classification results. The process grounding grid is laid along the accelerator beam line and between the process equipment. The general grounding grid is laid along the periphery of the building and at a distance not less than the preset distance from the edge of the process grounding grid.

[0018] The universal ground grid and the process ground grid are connected via a filter unit in the grounding well to achieve joint grounding and isolate the high-frequency noise between the universal ground grid and the process ground grid.

[0019] Furthermore, each PE bar in the power distribution room is connected to a universal ground grid via a universal ground bar MEB, and the universal equipment is connected to the universal ground grid via the PE bar in the power distribution room;

[0020] When the process equipment is in normal working condition, it is connected to the process ground grid nearby through the process ground bar in the grounding box, wherein the general process equipment and the sensitive process equipment are connected to the process ground grid through different grounding boxes respectively;

[0021] When a grounding fault occurs in the process equipment, the process ground grid is connected in a repeated grounding manner on the equipment side according to TN-S.

[0022] Furthermore, a plurality of independent grounding lead wires are arranged on the process ground network, and each grounding lead wire is used to connect each grounding box to achieve differentiated and nearby grounding of process equipment.

[0023] The present invention adopts the above technical solution, which has the following advantages:

[0024] 1. The present invention adopts the method of laying the ground grid in different zones, and realizes the combined power frequency grounding and the independent high frequency grounding through the grounding well and its filtering unit, thereby alleviating the influence of the general grounding system on the process equipment.

[0025] 2. The filtering unit adopted by the present invention is simple, economical, and has high engineering applicability. It has a good suppressive effect on high-frequency interference on the ground line and has no effect on the grounding protection of the distribution system.

[0026] 3. The present invention adopts a solution of equipment classification and differentiated grounding, and realizes the nearby grounding of process equipment through process grounding boxes and filtering units, which relatively reduces the ground impedance and alleviates the interference problem caused by common ground impedance of different equipment; special grounding lead-out points are set according to the sensitivity of process equipment to realize differentiated grounding and alleviate the ground interference problem between equipment; at the same time, the grounding method is repeated on the equipment side according to TN-S to improve the safety protection performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of a grounding system in one embodiment of the present invention;

[0028] Figure 2 It is a structural diagram of a process power distribution cabinet (box) in one embodiment of the present invention;

[0029] Figure 3 is a schematic diagram of a filter unit in one embodiment of the present invention;

[0030] Figure 4is a flow chart of grounding system design in one embodiment of the present invention;

[0031] Reference numerals:

[0032] 1-Universal ground grid; 1.1-Grounding lead-out point; 1.2-Horizontal grounding electrode; 1.3-Vertical grounding electrode;

[0033] 2-distribution room; 2.1-universal ground bar MEB; 2.2-power cabinet; 2.3-PE bar; 2.4-PE line;

[0034] 3- Grounding well;

[0035] 4-Filter unit; 4.1-Grounding cable; 4.2-High performance magnetic ring; 4.3-Winding cable;

[0036] 5-grounding box; 5.1-process grounding bar; 5.2-insulator; 5.3-crossbeam; 5.4-fastening bolts; 5.5-PE bar; 5.6-N bar;

[0037] 6-Technology ground grid. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0039] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0040] The EMC-based accelerator ground wire system and design method provided by the present invention include: a universal ground grid, which is arranged on the universal equipment side and is the main ground grid of the universal equipment. The universal equipment is connected to the universal ground grid through the low-voltage power distribution system of the power distribution room to achieve safe grounding; a process ground grid, which is laid nearby near the process power distribution equipment and is the main ground grid of the process power distribution equipment. The process equipment is connected to the process ground grid through a grounding box, and the process ground grid achieves differentiated grounding through the grounding box; a grounding well is used to connect the universal ground grid and the process ground grid to achieve high-frequency isolation and power frequency combination between the universal ground grid and the process ground grid, and serve as a grounding test point. The present invention can take into account both safety protection and electromagnetic compatibility performance.

[0041] In one embodiment of the present invention, an EMC-based accelerator ground wire system is provided. In this embodiment, Figure 1 As shown, the system includes:

[0042] Universal grounding grid 1 is set at the universal equipment side and is the main grounding grid for universal equipment. Universal equipment is connected to universal grounding grid 1 through the low-voltage power distribution system of power distribution room 2 to achieve safe grounding.

[0043] The process grounding network 6 is laid near the process power distribution equipment and is the main grounding network for the process power distribution equipment. The process equipment is connected to the process grounding network through the grounding box 5 to achieve repeated grounding and improve safety performance. The process grounding network achieves differentiated grounding through the grounding box 5.

[0044] The grounding well 3 is used to connect the universal grounding grid 1 and the process grounding grid 6 to achieve high-frequency isolation and power frequency connection between the universal grounding grid 1 and the process grounding grid 6, and serves as a grounding test point.

[0045] In the above embodiment, the universal grounding grid 1 is composed of a plurality of horizontal grounding electrodes 1.2 and a plurality of vertical grounding electrodes 1.3, and a grounding lead-out point 1.1 is formed at the connection between the horizontal grounding electrode 1.2 and the vertical grounding electrode 1.3. The leads extending from each grounding lead-out point 1.1 are connected to one end of the grounding well 3.

[0046] Among them, the general equipment is connected to the second PE row 2.3 in the power cabinet 2.2 in the distribution room 2, and the second PE row 2.3 in each power cabinet 2.2 is connected to the general ground bar MEB 2.1, and connected to the general ground network 1 through the general ground bar MEB 2.1.

[0047] In the above embodiment, grounding wells 3 connected to the process grounding grid 6 are respectively provided at least at the beginning, the end and the middle of the universal grounding grid 1 , and such grounding wells 3 are used for combined grounding and grounding performance testing.

[0048] In the above embodiment, the process ground network 6 is formed by connecting the construction steel bars and artificial grounding electrodes between the process equipment room and the accelerator tunnel to form a cage-type ground network, which effectively reduces the investment in the ground network and shields external interference; process grounding lead-out points are formed at the connection points, and the leads extending from the connection of each process grounding lead-out point are connected to the other end of the grounding well 3.

[0049] In the above embodiment, if Figure 2As shown, the grounding box 5 adopts a process distribution cabinet or a process distribution box. In addition to the original components, the process distribution cabinet or the process distribution box is also provided with a process ground bar 5.1 and a filter unit 4; the process ground bar 5.1 is insulated and installed on the cabinet or the box; one end of the process ground bar 5.1 is connected to the process ground network 6, and the other end of the process ground bar 5.1 is connected to one end of the first PE bar 5.5 in the process distribution cabinet or the process distribution box through the filter unit 4; the other end of the first PE bar 5.5 is connected to the second PE bar 2.3 in the power cabinet 2.2 in the distribution room 2.

[0050] The two ends of the process ground row 5.1 are respectively installed on the crossbeam 5.3 of the cabinet or box through insulators 5.2; they are also installed on the crossbeam 5.3 of the first PE row 5.5, and the two ends of the crossbeam 5.3 are fixed to the cabinet or box through fastening bolts 5.4. An N row 5.6 is arranged on the adjacent crossbeam 5.3.

[0051] Preferably, the general process equipment and the sensitive process equipment in the process equipment are respectively connected to different grounding boxes 5 to achieve differentiated grounding and improve safety performance.

[0052] In the above embodiment, the grounding well 3 includes a filter unit 4 and a fastener; the filter unit 4 is fixed at the position to be installed by the fastener; and the grounding well 3 is led out to the foundation well. The foundation well refers to the civil engineering part (including the well cover) of the grounding well (commonly seen as an electric well or water well on the road), which is built with bricks, stones and cement.

[0053] In the above embodiment, the grounding well 3 is used for "power frequency equipotential and high frequency isolation" processing between the general grounding grid 1 and the process grounding grid 6; it can also be used for grounding grid resistance testing, grounding function expansion, etc.

[0054] In the above embodiment, the filtering unit 4 is used to implement filtering between ground grids and between ground wires. Figure 3 As shown, the filter unit 4 includes a magnetic ring 4.2 and a grounding cable 4.1. The grounding cable 4.1 is wound around the magnetic ring 4.2, and the grounding cable 4.1 on the magnetic ring 4.2 forms a winding cable 4.3, and both ends of the grounding cable 4.1 extend to the outside of the magnetic ring 4.2 to form connection ends for connecting the universal ground grid 1 and the process ground grid 6.

[0055] Preferably, the grounding cable 4.1 is a grounding soft copper cable with an insulating sheath. To ensure the feasibility of the project, the conductor cross-section is not greater than 10mm. 2 , the current carrying capacity of the grounding cable 4.1 can be increased by connecting multiple groups of filter units 4 in parallel. In this example, the magnetic ring 4.2 adopts a high-performance magnetic ring, for example, an amorphous magnetic ring with a large aperture can be selected.

[0056] In the above embodiments, all components in the process grounding system are connected at the same potential to improve safety performance.

[0057] In the above embodiments, the process grounding lead-out points can be independently led out at multiple points near the process distribution cabinet or process distribution box, general process equipment, sensitive process equipment, etc. to achieve differentiated grounding.

[0058] In the above embodiment, the grounding well 3 is arranged according to the position of the power distribution room 2. To further reduce interference, general equipment and process equipment are powered by different power cabinets 2.2; preferably, the power cabinets of different types of equipment can be powered by dedicated transformers respectively.

[0059] In one embodiment of the present invention, a design method for an accelerator ground wire system based on EMC is provided, and the method is used to implement the accelerator ground wire system in the above embodiments. Figure 4 As shown, the method comprises the following steps:

[0060] 1) Classify the accelerator equipment into general equipment, general process equipment and sensitive process equipment;

[0061] Among them, general equipment includes water cooling systems, ventilation and air-conditioning systems, building electricity, etc.; general process equipment includes magnets and their power supplies, vacuum, high frequency, ion sources and other functional systems; sensitive process equipment includes beam diagnosis, control and network and other weak signal control and detection systems.

[0062] 2) Lay the grounding grid according to the equipment classification results. The process grounding grid 6 is laid along the accelerator beam line and the process equipment (i.e., the accelerator main equipment installation area), and the grounding lead-out point is set nearby as needed; the general grounding grid 1 is laid along the periphery of the building and at a distance not less than the preset distance from the edge of the process grounding grid 6;

[0063] Among them, the pre-set spacing is preferably 10m in this embodiment; when the pre-set spacing cannot be met due to space limitations, the interference problem caused by "high voltage discharge" can be alleviated by replacing high resistivity soil between the two ground grids.

[0064] 3) Connect the universal grounding grid 1 and the process grounding grid 6 through the filter unit 4 in the grounding well 3 to achieve joint grounding and filter out high-frequency noise, so as to isolate the high-frequency noise of the universal grounding grid 1 from interfering with the high-frequency noise of the process grounding grid 6;

[0065] In the above embodiment, the horizontal grounding electrodes of the universal grounding grid 1 and the process grounding grid 6 are led to the grounding well 3. The specifications of the grounding well 3 are suitable for easy maintenance by personnel. The distribution of the grounding well 3 is set according to the number of distribution rooms 2 or as needed.

[0066] In the above embodiment, each second PE bar 2.3 in the power distribution room 2 is connected to the universal ground grid 1 via the universal ground bar MEB 2.1, and the universal equipment is connected to the universal ground grid 1 via the second PE bar 2.3 in the power distribution room 2.

[0067] When the process equipment is in normal working condition, it is connected to the process ground network 6 nearby through the process ground bar 5.1 in the grounding box 5, wherein the general process equipment and the sensitive process equipment are connected to the process ground network 6 through different grounding boxes 5 respectively;

[0068] When a ground fault occurs in the process equipment, the process ground grid 6 is connected in accordance with the TN-S repeated grounding method on the equipment side.

[0069] In the above embodiment, a plurality of independent grounding lead wires are arranged on the process grounding network 6, and each grounding lead wire is used to connect each grounding box 5, so as to realize differentiated and nearby grounding of process equipment.

[0070] In the above embodiment, the design of the filter unit 4 is as follows: the filter unit 4 is used for high frequency isolation, and includes a high performance magnetic ring 4.2 and a grounding cable 4.1 wound thereon. When high frequency interference passes through the local grid or ground line, the magnetic ring 4.2 absorbs the noise to reduce the noise level.

[0071] The filter unit 4 is composed of one or more sets of high-performance magnetic rings 4.2 connected in parallel and grounding cables 4.1. The material selection of the magnetic ring 4.2 is determined according to the suppression frequency and the size of the magnetic ring.

[0072] When the grounding cable 4.1 is wound on the magnetic ring 4.2, the relationship between the inductance L of the magnetic ring and the number of turns N is:

[0073]

[0074] Where μ0 is the vacuum magnetic permeability, μ0=4π×10 -7 (H / m), μ is the relative magnetic permeability, N is the number of coil turns, and c0 is the core constant. For a magnetic ring with an outer diameter of D, an inner diameter of d, and a length of h, its core constant is:

[0075]

[0076] When the magnetic ring 4.2 is put on the grounding cable 4.1, the impedance of the magnetic ring can be calculated as:

[0077]

[0078]

[0079] Magnetic ring specifications: N is the number of coil turns, outer diameter D, inner diameter d, length h, and Z is the required impedance.

[0080] In the above embodiment, the process equipment is grounded through the process ground bar 5.1. For sensitive process equipment or systems, dedicated grounding points and distribution cabinets (boxes) are provided as needed.

[0081] The method provided in this embodiment is used to implement the above-mentioned system embodiments. Please refer to the above-mentioned embodiments for specific processes and detailed contents, which will not be repeated here.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An EMC-based accelerator ground wire system, characterized in that: include: The universal grounding grid is arranged on the universal equipment side and is the main grounding grid of the universal equipment. The universal equipment is connected to the universal grounding grid via the low-voltage power distribution system of the power distribution room to achieve safe grounding; The process grounding grid is laid near the process equipment and is the main grounding grid for the process equipment. The process equipment is connected to the process grounding grid via a grounding box, and the process grounding grid realizes differentiated grounding through the grounding box. A grounding well, used to connect the universal grounding network and the process grounding network, to achieve high-frequency isolation and power frequency combination between the universal grounding network and the process grounding network, and to serve as a grounding test point; The process grounding network is formed by connecting the construction steel bars and artificial grounding electrodes between the process equipment room and the accelerator tunnel to form a cage-type grounding network, and the connection points form process grounding lead-out points. The lead wires extending from the connection of the process grounding lead-out points are connected to the other end of the grounding well; The grounding box adopts a process distribution cabinet or a process distribution box; In addition to the original components, the process distribution cabinet or the process distribution box is also provided with a process ground bar and a filter unit; the process ground bar is insulated and installed on the cabinet or box; one end of the process ground bar is connected to the process ground network, and the other end of the process ground bar is connected to one end of the first PE bar in the process distribution cabinet or the process distribution box through the filter unit; the other end of the first PE bar is connected to the second PE bar in the power cabinet in the distribution room; Among them, the process equipment includes general process equipment and sensitive process equipment; general equipment includes water cooling system, ventilation and air-conditioning system and building electricity; general process equipment includes magnets and their power supplies, vacuum, high frequency and ion sources; sensitive process equipment includes beam diagnosis, control and network weak signal control and detection systems.

2. The EMC-based accelerator ground wire system according to claim 1, characterized in that: The universal grounding grid is composed of a plurality of horizontal grounding electrodes and a plurality of vertical grounding electrodes, and a grounding lead-out point is formed at the connection between the horizontal grounding electrode and the vertical grounding electrode. The lead wires extending from the connection of each grounding lead-out point are connected to one end of the grounding well.

3. The EMC-based accelerator ground wire system according to claim 1, characterized in that: The grounding wells connected to the process grounding grid are respectively arranged at least at the head end, the end end and the middle position of the universal grounding grid.

4. The EMC-based accelerator ground wire system according to claim 1, characterized in that: The grounding well includes a filter unit and a fastener; The filter unit is fixed at the location to be installed via the fasteners, and the grounding well is led out into the foundation well.

5. The EMC-based accelerator ground wire system according to claim 1 or 4, characterized in that: The filtering unit includes a magnetic ring and a grounding cable; The grounding cable is wound around the magnetic ring, and the grounding cable on the magnetic ring forms a winding cable, and both ends of the grounding cable extend to the outside of the magnetic ring to form connecting ends for connecting the universal ground grid and the process ground grid.

6. A design method for implementing an EMC-based accelerator ground wire system as claimed in any one of claims 1 to 5, characterized in that: include: Classify the accelerator equipment into general equipment, general process equipment and sensitive process equipment; The grounding grid is laid according to the equipment classification results. The process grounding grid is laid along the accelerator beam line and between the process equipment, and the general grounding grid is laid along the periphery of the building and at a distance not less than the preset distance from the edge of the process grounding grid; The universal ground grid and the process ground grid are connected via a filter unit in the grounding well to achieve joint grounding and isolate the high-frequency noise between the universal ground grid and the process ground grid.

7. The design method according to claim 6, characterized in that: Each PE bar in the power distribution room is connected to the universal ground grid via the universal ground bar MEB, and the universal equipment is connected to the universal ground grid via the PE bar in the power distribution room; Under normal working conditions, the general process equipment and the sensitive process equipment are connected to the process ground grid nearby through the process ground bar in the grounding box, wherein the general process equipment and the sensitive process equipment are connected to the process ground grid through different grounding boxes respectively; When a grounding fault occurs in the general process equipment and sensitive process equipment, the process ground grid is connected in a repeated grounding manner on the equipment side according to TN-S.

8. The design method according to claim 6, characterized in that: A plurality of independent grounding lead wires are arranged on the process ground network, and each grounding lead wire is used to connect each grounding box to realize differentiated and nearby grounding of process equipment.

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