An explosion-proof high-voltage high-power high-speed permanent magnet motor

Abstract

This invention proposes an explosion-proof high-voltage, high-power, high-speed permanent magnet motor, belonging to the field of industrial special explosion-proof motors. It solves the problems of low efficiency and poor carbon reduction and energy saving effects in traditional steam turbine-driven units used in the energy and petrochemical industries. It includes a stator, rotor, sliding bearings, hexagonal bolts, spring washers, cooler, fixed support, extended bolts, fastening washers, fastening nuts, positive pressure explosion-proof enclosure and piping assembly, high-voltage junction box, temperature measuring junction box, and heater junction box. After the stator, rotor, and sliding bearings of the high-speed permanent magnet motor are assembled, the cooler is fixed above the stator. The positive pressure explosion-proof enclosure and piping assembly are installed on one side of the cooler and connect the inner cavity of the stator and the cooler to ensure the motor has explosion-proof functionality. It is mainly used for directly driving compressor units in the petrochemical industry.

Description

Technical Field

[0001] This invention belongs to the field of industrial special explosion-proof motors, and in particular relates to an explosion-proof high-voltage high-power high-speed permanent magnet motor. Background Technology

[0002] As the energy industry, petrochemical industry, mining, and special equipment industries develop towards higher efficiency, intensification, and intelligence, permanent magnet synchronous motors, due to their high power density, high efficiency, and excellent dynamic response capabilities, are gradually replacing traditional asynchronous motors as the core drive equipment for high-power power systems. Especially in flammable and explosive environments (such as natural gas compression, refineries, and underground coal mines), explosion-proof motors have become a mandatory requirement for ensuring production safety. However, existing explosion-proof motors face multiple technical bottlenecks when simultaneously meeting the requirements of high voltage (≥6kV), high power (≥1MW), high linear speed (≥100m / s), and explosion-proof performance.

[0003] Currently, explosion-proof motors generally adopt flameproof (Ex d) or increased safety (Ex e) designs, which suppress the propagation of internal explosions by thickening the shell, adding explosion-proof joint surfaces, and heat dissipation fins. However, such structures result in a large motor size and significantly increased weight, severely limiting the improvement of power density. Taking a typical 10MW compressor drive motor as an example, the flameproof shell thickness needs to reach 20-30mm, and the overall weight increases by more than 40% compared to ordinary motors, greatly limiting its application in space-constrained scenarios (such as offshore platforms and underground tunnels).

[0004] The centrifugal stress of the rotor in a high-speed permanent magnet motor can reach over 300 MPa. Traditional surface-mounted permanent magnets suffer from problems such as binding failure and eddy current losses in the sheath, while built-in magnet structures are difficult to optimize for magnetic circuit design due to space limitations in the explosion-proof cavity. Meanwhile, the dramatic increase in AC copper and iron losses under high-power conditions increases the difficulty of heat dissipation, but the explosion-proof enclosure hinders efficient heat dissipation paths. Existing air-cooling solutions prohibit direct contact between high-speed airflow and heat-generating components due to explosion-proof requirements, while forced water-cooling systems introduce complex sealing structures, increasing the risk of leakage and failing to meet international explosion-proof certification requirements.

[0005] High-voltage stator windings (6-10kV) require multi-layer insulation, but the compact internal space of explosion-proof motors makes it difficult to balance slot fill factor and insulation thickness. Traditional mica tape and VPI processes are prone to partial discharge under high-speed frequency conversion power supply, accelerating insulation aging. Furthermore, the common-mode voltage generated by IGBT high-frequency switching is coupled to the casing through parasitic capacitance, potentially triggering spark discharge in the explosion-proof gap, posing an explosion hazard. Existing solutions mostly rely on adding filters, further increasing size and reducing system efficiency.

[0006] The global explosion-proof motor market exceeded US$12 billion in 2024, with high-voltage, high-power, high-speed models experiencing an annual growth rate of over 15%. The main demand is concentrated in liquefied natural gas compression, hydrogen storage and transportation, and deep well drilling. However, products from major domestic and international manufacturers are still primarily low-pressure and low-to-medium speed (<6,000 rpm), with high-speed models generally having a maximum power output below 5MW. Therefore, there is an urgent need for an innovative explosion-proof high-voltage, high-power, high-speed permanent magnet motor that can overcome these limitations through optimization and innovation in topology, materials, and heat dissipation. Summary of the Invention

[0007] In view of this, in order to solve the problem that there is currently no explosion-proof high-voltage high-power high-speed permanent magnet motor, this invention proposes an explosion-proof high-voltage high-power high-speed permanent magnet motor.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: an explosion-proof high-voltage high-power high-speed permanent magnet motor, comprising a stator, a rotor, a sliding bearing, a cooler, and an explosion-proof enclosure and piping assembly. The stator is connected to the sliding bearing, the rotor is supported by the sliding bearing, the cooler is fixed above the stator, and the positive pressure explosion-proof enclosure and piping assembly are installed on one side of the cooler and connect the inner cavity of the stator and the cooler.

[0009] Preferably, the stator includes a frame and a stator core, the stator core is segmented, and the segments are spaced apart by toothed pressure plates to form a duct path.

[0010] Preferably, the stator further includes a wind deflector, which is fixed to the inner side of one end of the base and is used to guide the flow direction of the cooling medium.

[0011] Preferably, the stator further includes end pressure plates, copper conductors, and high-voltage slot insulation. The two ends of the stator core are pressed and fixed by end pressure plates. The copper conductors are wrapped around the high-voltage slot insulation and then embedded in the rectangular slots of the stator core. After being connected according to a specified path, a circuit is formed.

[0012] Preferably, the rotor includes an alloy shaft and a multi-layer carbon fiber protective sleeve, wherein a magnet is disposed on the outer surface of the alloy shaft, and the multi-layer carbon fiber protective sleeve is wrapped around the outer periphery of the magnet.

[0013] Preferably, the rotor further includes pole spacer blocks and magnetic isolation rings. The magnets are pasted in sections along the axial direction, with the sections separated by magnetic isolation rings and the poles separated by pole spacer blocks to form a constant magnetic field.

[0014] Preferably, the rotor further includes a magnetic shielding plate, which blocks the outermost end of the magnet and is fixed inside the slot of the alloy shaft. The outer surfaces of the magnetic shielding plate, the magnet, the interpole magnetic block and the magnetic shielding ring are wrapped with a multi-layer carbon fiber protective sleeve to overcome the centrifugal force generated during high-speed rotation.

[0015] Preferably, the multi-layer carbon fiber protective sleeve adopts a multi-layer winding structure, which enables the rotor to operate stably under the condition that the surface linear velocity is not less than 180m / s.

[0016] Preferably, the sliding bearing includes a tilting pad bearing housing and a thrust pad, the thrust pad being installed on one side of the tilting pad bearing housing to bear axial thrust, and the rotor being supported by the guide pad and the tilting pad bearing housing; the sliding bearing also has an inner atmospheric balance tube assembly to balance the pressure between the motor cavity and the bearing cavity.

[0017] Preferably, it also includes a high-voltage junction box, which includes a high-voltage junction box base, a lower cover plate and a sealing gasket. The lower cover plate is provided with a wiring hopper, and a sealing gasket is installed at the joint surface to ensure sealing.

[0018] Compared with existing technologies, the beneficial effects of the explosion-proof high-voltage high-power high-speed permanent magnet motor of the present invention are: 1. This invention has outstanding advantages such as high efficiency, compact structure and large capacity. Through optimization research and experimental implementation of physical topology such as stress and heat dissipation, it also meets the requirements of explosion-proof certification. It replaces the function of steam turbine driving load in energy, petrochemical and other fields with a more precise installation method, achieving better energy saving effect and reducing carbon emission indicators. 2. The stator section of this invention effectively reduces the operating temperature rise of the winding by more than 15K through differentiated segmented size design and guiding the flow path of the cooling working fluid; 3. This invention is the first to adopt a segmented skewed pole arrangement of magnets on a long-shaft rotor, which effectively reduces torque pulsation during motor operation and improves working stability. The ventilation groove below the magnetic shielding block enhances the heat exchange capacity of the rotor and effectively reduces the risk of demagnetization caused by the temperature rise of the permanent magnet. In addition, the innovative multi-layer sheath winding design increases the stress that the carbon fiber material can withstand and can increase the linear velocity of the rotor surface by more than 20%. 4. The bearing of this invention adopts a tilting pad sliding bearing. Through the new pad and reasonable oil circuit design, it can achieve reliable and stable operation with low vibration level in a wider range of rotation, effectively improving the service life of high-speed permanent magnet motor. 5. This invention effectively reduces the complexity of the drive system by directly driving the explosion-proof high-voltage high-power high-speed permanent magnet motor with loads in various application scenarios. At the same time, through the design of a high-voltage insulation system, a high-strength rotor sheath, and a high-performance bearing lubrication system, it not only improves the output power of the permanent magnet motor but also effectively breaks through its limit operating speed, combining outstanding advantages such as explosion-proof reliability, high power density, and high operating speed.

[0019] 6. In existing flammable and explosive environments such as energy and petrochemical industries, steam turbines are often used to drive loads. This results in problems such as large space occupation of drive equipment and low transmission efficiency. The present invention replaces the steam turbine with an explosion-proof high-voltage high-power high-speed permanent magnet motor, which has a significant advantage in drive efficiency, and the system efficiency is improved by more than 13%.

[0020] 7. Existing explosion-proof technologies suffer from limitations in explosion-proof structures, resulting in low power density. Furthermore, the reliability and heat dissipation of permanent magnets are constrained by the explosion-proof cavity when the centrifugal stress of the high-speed rotor exceeds 300MPa. Traditional high-voltage insulation is also prone to partial discharge, posing safety hazards. This invention, through analysis and research on electromagnetics, structural layout, temperature field, manufacturing process, and materials, innovatively overcomes the bottleneck of discharge risk in high-voltage insulation systems reaching 10kV level frequency conversion power supply. It achieves stable operation at a linear speed of 180m / s with a high-strength rotor sheath combined with a multi-layered wrapping structure. While meeting Ex d IIC T4 explosion-proof certification, the short-time peak power-to-speed ratio reaches 1.61kW / rpm@12MW, and vibration is controlled below 1.5mm / s during stable operation. This effectively improves the voltage level and capacity of high-voltage, high-speed explosion-proof motors. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a front view of an explosion-proof high-voltage high-power high-speed permanent magnet motor according to the present invention. Figure 2 This is a cross-sectional view of the stator and rotor of the high-speed permanent magnet motor described in this invention; Figure 3 This is a front view of the sliding bearing described in this invention; Figure 4 This is a cross-sectional view of the sliding bearing described in this invention; Figure 5 This is a front view of the high-voltage junction box described in this invention; In the picture: Stator 101; Rotor 102; Sliding bearing 103; Hex bolt 104; Spring washer 105; Cooler 106; Fixed support 107; Extended bolt 108; Fastening washer 109; Fastening nut 110; Positive pressure explosion-proof box and piping assembly 111; High-voltage junction box 112; Temperature measuring junction box 113; Heater junction box 114; Frame 201; Stator core 202; Tooth pressure plate 203; End pressure plate 204; Copper conductor 205; High-voltage slot insulation 206; Wind shield 207; Alloy shaft 301; Magnetic shielding pressure plate 302; Magnet 303; Pole spacer magnetic block 304; Magnetic shielding ring 305; Multi-layer carbon fiber protective sleeve 306; Bearing support seat 401; Eye bolt 4 02; 403; 404; 405; 406; 407; 408; 409; 410; 411; 412; 413; 414; 415; 416; 417; 418; 419; 420; 421; 422; 423; 401; 502; 503; 504; 505; 506; 507; 508; 509; 500; Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the drawings, and not all of them. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the invention.

[0023] See Figure 1This embodiment describes an explosion-proof high-voltage high-power high-speed permanent magnet motor, comprising a stator 101, a rotor 102, a sliding bearing 103, hexagonal bolts 104, spring washers 105, a cooler 106, a fixed support 107, extension bolts 108, fastening washers 109, fastening nuts 110, a positive pressure explosion-proof box and piping assembly 111, a high-voltage junction box 112, a temperature measuring junction box 113, and a heater junction box 114. The stator 101 is connected to the sliding bearing 103, and the rotor 102 is connected via... Supported by sliding bearing 103, after the stator 101 and rotor 102 of the high-speed permanent magnet motor and sliding bearing 103 are assembled, the cooler 106 is fixed above the stator 101 by a fixed support 107 welded to the lower end using hexagonal bolts 104, spring washers 105, extension bolts 108, fastening washers 109, and fastening nuts 110. The positive pressure explosion-proof box and pipeline assembly 111 are installed on one side of the cooler 106 and connect the inner cavity of the stator 101 and the cooler 106 to ensure that the motor has explosion-proof function.

[0024] Detailed Implementation Method 2: See Figure 2 In this embodiment, the stator 101 includes a frame 201, a stator core 202, a toothed pressure plate 203, an end pressure plate 204, a copper conductor 205, a high-voltage slot insulation 206, and a wind shield 207. The stator core 202 is divided into several segments, which are separated by the toothed pressure plate 203 to form a wind tunnel path. The two ends of the stator core 202 are pressed and fixed by the end pressure plate 204. The copper conductor 205 wraps around the high-voltage slot insulation 206 and is embedded in the rectangular slot of the stator core 202. After being connected according to a specified path, a circuit is formed. The wind shield 207 is fixed to the inner side of one end of the frame 201 and its function is to guide the flow direction of the cooling working fluid entering the stator 101.

[0025] The rotor 102 includes an alloy shaft 301, a magnetic shielding plate 302, magnets 303, pole spacing magnetic blocks 304, a magnetic shielding ring 305, and a multi-layer carbon fiber protective sleeve 306. The alloy shaft 301 is processed so that segmented magnets 303 are glued to the outer surface of the alloy shaft 301 with epoxy adhesive. The segments are separated by magnetic shielding rings 305. The poles are separated by stainless steel pole spacing magnetic blocks 304 to generate a constant magnetic field. The magnetic shielding plate 302 blocks the outermost end of the magnets 303 and is fixed inside the slot of the alloy shaft 301. The outer surfaces of the magnetic shielding plate 302, magnets 303, pole spacing magnetic blocks 304, and magnetic shielding ring 305 are completely wrapped with a multi-layer carbon fiber protective sleeve 306 to overcome the centrifugal force generated during high-speed rotation.

[0026] The multi-layer carbon fiber protective sleeve 306 adopts a multi-layer winding structure, which enables the rotor 102 to operate stably under the condition that the surface linear velocity is not less than 180m / s.

[0027] Detailed implementation method 3: See Figure 3-4In this embodiment, the sliding bearing 103 includes a bearing support 401, eye bolts 402, hexagonal socket head cap screws 403, tapered pins 404, tilting pad bearing housing 405, thrust bearing 406, guide bearing 407, inner atmospheric balance pipe assembly 408, air seal cover 409, copper teeth 410, oil return pipe assembly 411, observation window 412, oil flange 413, oil inlet pipe 414, pressure gauge 415, regulating valve 416, tee connector 417, outer atmospheric balance pipe assembly 418, ball valve 419, cover plate 420, screw plug 421, connecting pipe assembly 422, and breather 423. The stator 101 is connected to the sliding bearing 103 on both sides by hexagonal bolts 104 and spring washers 105. The rotor is connected to the guide bearing 407 and tilting pad bearing housing 405. The bearing support 401 is supported and filled with lubricating oil for lubrication. It is connected to the oil station through the oil inlet pipe 414, the oil return pipe group 411, and the oil flange 413 for circulation and heat dissipation. The oil pressure and oil quantity are monitored by the pressure gauge 415, the observation window 412, and the regulating valve 416. The upper and lower parts of the bearing support 401 are connected and fixed by the hexagonal screws 403 and the tapered pins 404 to ensure the integrity of the sliding bearing 103. The thrust bearing 406 is installed on one side of the tilting pad bearing 405 to prevent damage to the rotor caused by external mechanical transmission. The copper teeth 410 are fixed to the inner surface of the air seal cover 409 to ensure the sealing of the lubricating oil during rotor rotation. The inner atmospheric balance pipe group 408 can balance the pressure between the motor cavity and the bearing cavity.

[0028] Detailed implementation method 4: See Figure 5 In this embodiment, the high-voltage junction box 112 includes a high-voltage junction box base 501, a lifting ring 502, a high-voltage junction box cover 503, a handle 504, a lower cover plate 505, a wiring hopper 506, a wire clamping hopper 507, a wire clamping plate 508, and a sealing gasket 509. The lifting ring 502 is welded to the top of the junction box base 501, and the handle 504 is welded to the outside of the high-voltage junction box cover 503. The lower cover plate 505 is fixed to the opening on the lower side of the junction box base 501 and two sets of wiring hoppers 506 are installed thereon. The high-voltage cable is connected to the inside of the high-voltage junction box 112 through the wire clamping hopper 507 and the wire clamping plate 508 and fixed to the terminal block. The sealing gasket 509 installed on the joint surface ensures the overall sealing of the high-speed permanent magnet motor.

[0029] The high-speed permanent magnet motor in this embodiment of the invention has a rated power of 6800kW, a rated frequency of 253.33Hz, 4 poles, a rated voltage of 10kV, and an insulation class of 180 H. Under the Exd IIC T4 explosion-proof certification standard, the short-time peak power-to-speed ratio reaches 1.61kW / rpm@12MW, and the vibration is controlled below 1.5mm / s during stable operation.

[0030] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. An explosion-proof high-voltage high-power high-speed permanent magnet motor, characterized in that: The device includes a stator (101), a rotor (102), a sliding bearing (103), a cooler (106), and an explosion-proof enclosure and piping assembly (111). The stator (101) is connected to the sliding bearing (103), the rotor (102) is supported by the sliding bearing (103), the cooler (106) is fixed above the stator (101), and the positive pressure explosion-proof enclosure and piping assembly (111) is installed on one side of the cooler (106) and connects the stator (101) and the inner cavity of the cooler (106).

2. The explosion-proof high-voltage high-power high-speed permanent magnet motor according to claim 1, characterized in that: The stator (101) includes a frame (201) and a stator core (202). The stator core (202) is segmented, and the segments are spaced apart by toothed pressure plates (203) to form a wind tunnel path.

3. The explosion-proof high-voltage high-power high-speed permanent magnet motor according to claim 2, characterized in that: The stator (101) also includes a windshield (207), which is fixed to the inner side of one end of the base (201) and is used to guide the flow direction of the cooling medium.

4. The explosion-proof high-voltage high-power high-speed permanent magnet motor according to claim 2, characterized in that: The stator (101) also includes an end plate (204), a copper conductor (205) and a high-voltage slot insulation (206). The two ends of the stator core (202) are pressed and fixed by the end plate (204). The copper conductor (205) wraps around the high-voltage slot insulation (206) and is embedded in the rectangular slot of the stator core (202). After being connected according to the specified path, a circuit is formed.

5. The explosion-proof high-voltage high-power high-speed permanent magnet motor according to claim 1, characterized in that: The rotor (102) includes an alloy shaft (301) and a multi-layer carbon fiber protective sleeve (306). The outer surface of the alloy shaft (301) is provided with a magnet (303), and the multi-layer carbon fiber protective sleeve (306) is wrapped around the outer periphery of the magnet (303).

6. The explosion-proof high-voltage high-power high-speed permanent magnet motor according to claim 5, characterized in that: The rotor (102) also includes pole spacer magnetic blocks (304) and magnetic isolation rings (305). The magnets (303) are pasted in segments along the axial direction, with the segments separated by pole spacer magnetic rings (305) and the poles separated by pole spacer magnetic blocks (304) to form a constant magnetic field.

7. The explosion-proof high-voltage high-power high-speed permanent magnet motor according to claim 5, characterized in that: The rotor (102) also includes a magnetic shielding plate (302), which blocks the outermost end of the magnet (303) and is fixed inside the slot of the alloy shaft (301). The outer surfaces of the magnetic shielding plate (302), the magnet (303), the interpole magnetic block (304) and the magnetic shielding ring (305) are wrapped with a multi-layer carbon fiber protective sleeve (306) to overcome the centrifugal force generated during high-speed rotation.

8. The explosion-proof high-voltage high-power high-speed permanent magnet motor according to claim 1, characterized in that: The multi-layer carbon fiber protective sleeve (306) adopts a multi-layer winding structure, which enables the rotor (102) to operate stably under the condition that the surface linear velocity is not less than 180m / s.

9. The explosion-proof high-voltage high-power high-speed permanent magnet motor according to claim 1, characterized in that: The sliding bearing (103) includes a tilting pad bearing housing (405) and a thrust pad (406). The thrust pad (406) is installed on one side of the tilting pad bearing housing (405) to bear axial thrust. The rotor (102) is supported by the guide pad (407) and the tilting pad bearing housing (405). The sliding bearing (103) is also provided with an inner atmospheric balance tube assembly (408) to balance the pressure between the motor cavity and the bearing cavity.

10. The explosion-proof high-voltage high-power high-speed permanent magnet motor according to claim 1, characterized in that: It also includes a high-voltage junction box (112), which includes a lower cover plate (505) and a sealing gasket (509). The lower cover plate (505) is provided with a wiring hopper (506), and the sealing gasket (509) is installed at the joint surface to ensure sealing.

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