A magnetoelectric displacement detection device for a hydro-generator and a method of using the same

Abstract

The present invention relates to the field of vibration measurement technology and discloses a magnetoelectric displacement detection device for a hydro-turbine generator, comprising: a protective constant-voltage mechanism, an isolation constant-voltage mechanism disposed on top of the protective constant-voltage mechanism, a resonator mechanism and a quasi-zero stiffness mechanism installed within the protective constant-voltage mechanism, the quasi-zero stiffness mechanism being located below the resonator mechanism, and the resonator mechanism being located between the support protective mechanism and the isolation constant-voltage mechanism. The magnetoelectric displacement detection device for a hydro-turbine generator and its method of use, through the provision of the protective constant-voltage mechanism, the isolation constant-voltage mechanism, the resonator mechanism, and the quasi-zero stiffness mechanism, can achieve quasi-zero stiffness of the system by controlling the currents of the upper and lower electromagnets, thereby expanding the effective detection bandwidth of the system to the low-frequency band, thereby achieving the purpose of collecting low-frequency signals.

Description

Technical Field

[0001] The present invention relates to the field of vibration measurement technology, and in particular to a magnetoelectric displacement detection device for a hydro-generator and a method for using the same. Background Art

[0002] A hydro-turbine generator is a generator that uses a turbine as the prime mover to convert water energy into electrical energy. When water flows through the turbine, it converts water energy into mechanical energy. The turbine's rotating shaft drives the generator's rotor, converting mechanical energy into electrical energy for output. It is the main power equipment for hydropower stations to produce electricity. When the hydro-turbine generator is in operation, low-frequency vibrations may occur on the turbine shaft due to uneven water flow, bearing failure, and other reasons. These problems not only affect the stability and reliability of the unit, but also increase maintenance costs, shorten equipment life, and may even lead to long-term shutdowns. Therefore, timely monitoring and processing of low-frequency vibrations are crucial.

[0003] Due to the internal mechanical structure of general sensors, their natural frequency is relatively high, and the amplitude-frequency characteristic curve is severely attenuated below the natural frequency. In addition, the response curve has overshoot within the effective frequency band and is not flat enough. The above reasons make it difficult for such sensors to pick up signals below the natural frequency. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention provides a magnetoelectric displacement detection device for a hydro-generator and a method for using the same, which solves the problems mentioned in the above background.

[0005] The present invention provides the following technical solution: a magnetoelectric displacement detection device for a hydro-generator, comprising: a protective constant-pressure mechanism, an isolation constant-pressure mechanism provided on top of the protective constant-pressure mechanism, a resonator mechanism and a quasi-zero stiffness mechanism installed inside the protective constant-pressure mechanism, the quasi-zero stiffness mechanism being located below the resonator mechanism, and the resonator mechanism being located between the support protective mechanism and the isolation constant-pressure mechanism.

[0006] Preferably, the protective constant pressure mechanism includes a main shell, a sub-shell, a support block, a first sealing ring, a constant pressure hole, a mounting ring groove and a mounting head, the sub-shell is fixedly installed on the bottom of the main shell by bolts, the support block is fixedly connected to the inside of the sub-shell, the first sealing ring is fixedly connected to the surface of the sub-shell, and the first sealing ring is located between the main shell and the sub-shell, the constant pressure hole is opened through the upper surface of the main shell, the mounting ring groove is arranged on the inner wall of the main shell, and the mounting head is integrally arranged on the top of the main shell.

[0007] Preferably, the isolation constant pressure mechanism includes a constant pressure cover, an elastic diaphragm, a second sealing ring and a top block. The constant pressure cover is fixedly mounted on the top of the main shell by bolts, and a constant pressure gap is provided between the constant pressure cover and the mounting head, and the constant pressure gap is connected to the main shell through a constant pressure hole. The elastic diaphragm is fixedly mounted on the top of the constant pressure cover, the second sealing ring is fixedly connected to the bottom end of the constant pressure cover, and the second sealing ring is located between the constant pressure cover and the main shell, and the top block is fixedly connected to the inner wall of the top of the elastic diaphragm.

[0008] Preferably, the resonator mechanism includes an upper limit cylinder, a lower limit cylinder and a limit ring, the upper limit cylinder and the lower limit cylinder are fixedly connected to the inside of the mounting head, and the upper limit cylinder and the lower limit cylinder are relatively distributed, and the limit ring is slidably connected between the upper limit cylinder and the lower limit cylinder.

[0009] Preferably, the resonator mechanism also includes a top rod, a mass block and a resonance beam. The top rod is fixedly inserted into the interior of the limit ring, and the surface of the top rod is slidingly connected to the inner wall of the top end of the upper limit cylinder and the inner wall of the bottom end of the lower limit cylinder respectively. The number of the mass blocks and the number of the resonance beams are both two, and the two mass blocks are slidingly connected to the interior of the top rod. The resonance beams are respectively fixedly inserted into one end of the two mass blocks, and each mass block and each resonance beam form a group, and the two groups of mass blocks and resonance beams constitute two resonance structures respectively.

[0010] Preferably, the resonator mechanism also includes an anti-deflection ring, an anti-deflection frame, a guide slide and a guide groove. The anti-deflection ring is fixedly sleeved on the surface of the bottom end of the top rod, the anti-deflection frame is fixedly connected to the inner wall of the main shell, the guide slide is integrally arranged on the inner wall of the anti-deflection frame, and the guide groove is opened on the inner wall of the anti-deflection ring, and the surface of the guide groove is slidably connected to the surface of the guide slide.

[0011] Preferably, the resonator mechanism further includes a connecting ring, a spring sheet, a connecting frame and a sleeve ring, the connecting ring and the connecting frame are both fixedly sleeved on the surface of the top rod, the spring sheet is fixedly connected between the connecting ring and the main shell, and the sleeve ring is integrally arranged at the bottom of the connecting frame.

[0012] Preferably, the quasi-zero stiffness mechanism includes an induction coil, a magnet mounting seat, a connecting bar, an upper electromagnet, a lower electromagnet, a guide rod, an intermediate permanent magnet, a sliding hole, an upper pre-stress spring and a lower pre-stress spring, the induction coil is fixedly mounted inside the mounting ring groove, the connecting bar is fixedly inserted into the inner wall of the support block, the magnet mounting seats are respectively integrally arranged on the surfaces at both ends of the connecting bar, the upper electromagnet and the lower electromagnet are respectively fixedly connected to the inside of the two magnet mounting seats, the guide rod is fixedly inserted between the two magnet mounting seats, the intermediate permanent magnet is slidably connected to the surface of the guide rod through the sliding hole, and the intermediate permanent magnet is fixedly connected to the inside of the sleeve ring, the upper pre-stress spring and the lower pre-stress spring are respectively located at the top and the bottom of the intermediate permanent magnet, and the upper pre-stress spring and the lower pre-stress spring are both movably sleeved on the surface of the guide rod.

[0013] Preferably, the upper electromagnet, the lower electromagnet and the middle permanent magnet form a negative stiffness structure, and the middle permanent magnet, the guide rod, the upper preload spring and the lower preload spring form a positive stiffness structure.

[0014] A method for using a magnetoelectric displacement detection device for a hydro-generator, comprising:

[0015] Step S1: The device is fixedly mounted on the surface base of the turbine generator, ensuring that the mandrel is vertically placed on the turbine shaft;

[0016] Step S2: In the working state, the mandrel is excited by the vibration transmitted by the turbine shaft. The mass block and resonant beam inside the resonator mechanism respond, making the frequencies of the two resonant structures consistent, further amplifying the vibration signal to facilitate the subsequent collection of weak low-frequency signals;

[0017] Step S3: adjusting the currents of the upper and lower electromagnets to achieve quasi-zero stiffness of the system, thereby expanding the effective detection bandwidth of the system to a low frequency band;

[0018] Step S4: In the quasi-zero stiffness system, the middle permanent magnet moves up and down under the action of the magnetic force, and the induction coil cuts the magnetic lines to generate an induced electromotive force. The current fluctuation signal generated by the induced electromotive force is the detected low-frequency vibration signal.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The magnetoelectric displacement detection device for a hydro-generator and its use method, by providing a protective constant-voltage mechanism, an isolation constant-voltage mechanism, a resonator mechanism, and a quasi-zero stiffness mechanism, can achieve quasi-zero stiffness of the system by controlling the magnitude of the current in the upper electromagnet and the lower electromagnet, thereby expanding the effective detection bandwidth of the system to the low-frequency band, thereby achieving the purpose of collecting low-frequency signals.

[0021] The magnetoelectric displacement detection device for a hydro-generator and its use method facilitate the disassembly, assembly, and maintenance of the main housing and the auxiliary housing, as well as the production and installation of the device, by providing a main housing, an auxiliary housing, a support block, a first sealing ring, a constant pressure hole, a mounting ring groove, and a mounting head, and facilitate the replacement of internal components of the device.

[0022] The magnetoelectric displacement detection device for a hydro-generator and the method for using the same can ensure air pressure balance on both sides of the limit ring when the push rod continuously expands and contracts due to vibration detection by the constant pressure cover, elastic diaphragm, second sealing ring and push block. At the same time, the change in air pressure inside the device caused by the expansion and contraction of the push rod can be compensated by the expansion and contraction of the elastic diaphragm, ensuring that the air pressure inside and outside the device approaches equilibrium.

[0023] The magnetoelectric displacement detection device for a hydro-generator and its use method, through the provision of a top rod, a mass block and a resonance beam, when the resonance structure is subjected to vibration excitation, the two resonance beams will simultaneously respond to the vibration of the excitation source and can achieve resonance superposition, further amplifying the vibration signal.

[0024] The magnetoelectric displacement detection device for a hydro-generator and its use method, through the provided induction coil, magnet mounting seat, connecting bar, upper electromagnet, lower electromagnet, guide rod, middle permanent magnet, sliding hole, upper preload spring and lower preload spring, can control the magnitude and direction of the magnetic force of the upper electromagnet and the lower electromagnet by electric current. By controlling the magnitude and direction of the magnetic force of the upper electromagnet and the lower electromagnet, the magnitude of the resistance during movement of the middle permanent magnet can be controlled, thereby controlling the magnitude of the negative stiffness, and further achieving total stiffness adjustment aligned with zero stiffness. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the present invention;

[0026] Figure 2 It is a cross-sectional view of the present invention;

[0027] Figure 3 It is a structural schematic diagram of the positions of the resonator mechanism and the quasi-zero stiffness mechanism of the present invention;

[0028] Figure 4 Schematic diagram of the explosion structure at the location of the resonator mechanism and the quasi-zero stiffness mechanism of the present invention;

[0029] Figure 5 This is a schematic diagram of the connection structure between the resonator mechanism and the intermediate permanent magnet of the present invention;

[0030] Figure 6 This is a schematic diagram of the explosion structure at the position of the push rod of the present invention;

[0031] Figure 7 This is a schematic diagram of the quasi-zero stiffness mechanism structure of the present invention.

[0032] In the figure: 101, main housing; 102, auxiliary housing; 103, support block; 104, first sealing ring; 105, constant pressure hole; 106, mounting ring groove; 107, mounting head; 201, constant pressure cover; 202, elastic diaphragm; 203, second sealing ring; 204, top block; 301, upper limit cylinder; 302, lower limit cylinder; 303, limit ring; 304, top rod; 305, mass block; 306, resonance beam; 307, Anti-deflection ring; 308, anti-deflection frame; 309, guide slide; 310, guide groove; 311, connecting ring; 312, spring sheet; 313, connecting frame; 314, sleeve ring; 401, induction coil; 402, magnet mounting seat; 403, connecting strip; 404, upper electromagnet; 405, lower electromagnet; 406, guide rod; 407, middle permanent magnet; 408, sliding hole; 409, upper preload spring; 410, lower preload spring. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] See also Figure 1-7 A magnetoelectric displacement detection device for a hydro-generator comprises: a protective constant-voltage mechanism, an isolation constant-voltage mechanism disposed on the top of the protective constant-voltage mechanism, a resonator mechanism and a quasi-zero stiffness mechanism installed inside the protective constant-voltage mechanism, the quasi-zero stiffness mechanism being located below the resonator mechanism, and the resonator mechanism being located between the supporting protective mechanism and the isolation constant-voltage mechanism. By configuring the protective constant-voltage mechanism, the isolation constant-voltage mechanism, the resonator mechanism and the quasi-zero stiffness mechanism, the stiffness of the system can be changed to quasi-zero stiffness by controlling the currents of the upper electromagnet 404 and the lower electromagnet 405, thereby expanding the effective detection bandwidth of the system to a low-frequency band, thereby achieving the purpose of collecting low-frequency signals.

[0035] Preferably, the protective constant pressure mechanism includes a main housing 101, a sub-housing 102, a support block 103, a first sealing ring 104, a constant pressure hole 105, a mounting ring groove 106 and a mounting head 107, the sub-housing 102 is fixedly mounted on the bottom of the main housing 101 by bolts, the support block 103 is fixedly connected to the inside of the sub-housing 102, the first sealing ring 104 is fixedly connected to the surface of the sub-housing 102, and the first sealing ring 104 is located between the main housing 101 and the sub-housing 102, and the constant pressure hole 105 is fixedly mounted on the bottom of the main housing 101 by bolts, the support block 103 is fixedly connected to the inside of the sub-housing 102, and the first sealing ring 104 is fixedly connected to the surface of the sub-housing 102, and the first sealing ring 104 is located between the main housing 101 and the sub-housing 102. The pressure hole 105 is opened through the upper surface of the main shell 101, the mounting ring groove 106 is set on the inner wall of the main shell 101, and the mounting head 107 is integrally set on the top of the main shell 101. Through the arrangement of the main shell 101, the auxiliary shell 102, the support block 103, the first sealing ring 104, the constant pressure hole 105, the mounting ring groove 106 and the mounting head 107, the main shell 101 and the auxiliary shell 102 are convenient for disassembly and maintenance and the production and installation of the device, and the replacement of internal components of the device is convenient.

[0036] Preferably, the isolation constant pressure mechanism includes a constant pressure cover 201, an elastic diaphragm 202, a second sealing ring 203 and a top block 204. The constant pressure cover 201 is fixedly mounted on the top of the main housing 101 by bolts, and a constant pressure gap is provided between the constant pressure cover 201 and the mounting head 107, and the constant pressure gap is connected to the main housing 101 through the constant pressure hole 105. The elastic diaphragm 202 is fixedly mounted on the top of the constant pressure cover 201, the second sealing ring 203 is fixedly connected to the bottom end of the constant pressure cover 201, and the second sealing ring 203 is fixedly connected to the bottom end of the constant pressure cover 201. The sealing ring 203 is located between the constant pressure cover 201 and the main shell 101, and the top block 204 is fixedly connected to the inner wall of the top of the elastic diaphragm 202. Through the arrangement of the constant pressure cover 201, the elastic diaphragm 202, the second sealing ring 203 and the top block 204, the air pressure balance on both sides of the limit ring 303 can be ensured when the top rod 304 detects vibration and continuously expands and contracts. At the same time, the change in the internal air pressure of the device when the top rod 304 expands and contracts can be compensated by the expansion and contraction of the elastic diaphragm 202, thereby ensuring that the air pressure inside and outside the device is close to balance.

[0037] Preferably, the resonator mechanism includes an upper limit cylinder 301, a lower limit cylinder 302 and a limit ring 303. The upper limit cylinder 301 and the lower limit cylinder 302 are fixedly connected to the inside of the mounting head 107, and the upper limit cylinder 301 and the lower limit cylinder 302 are relatively distributed, and the limit ring 303 is slidably connected between the upper limit cylinder 301 and the lower limit cylinder 302.

[0038] Preferably, the resonator mechanism also includes a top rod 304, a mass block 305 and a resonance beam 306. The top rod 304 is fixedly inserted into the interior of the limit ring 303, and the surface of the top rod 304 is slidingly connected to the inner wall of the top end of the upper limit cylinder 301 and the inner wall of the bottom end of the lower limit cylinder 302 respectively. The number of mass blocks 305 and the number of resonance beams 306 are both two, and the two mass blocks 305 are slidingly connected to the interior of the top rod 304. The resonance beams 306 are respectively fixedly inserted into one end of the two mass blocks 305, and each mass block 305 and each resonance beam 306 form a group, and the two groups of mass blocks 305 and resonance beams 306 respectively constitute two resonance structures. By setting the top rod 304, mass blocks 305 and resonance beams 306, when the resonance structure is subjected to vibration excitation, the two resonance beams 306 will respond to the vibration of the excitation source at the same time, and can realize resonance superposition to further amplify the vibration signal.

[0039] Preferably, the resonator mechanism also includes an anti-deflection ring 307, an anti-deflection frame 308, a guide slide 309 and a guide groove 310. The anti-deflection ring 307 is fixedly sleeved on the surface of the bottom end of the top rod 304, the anti-deflection frame 308 is fixedly connected to the inner wall of the main shell 101, the guide slide 309 is integrally arranged on the inner wall of the anti-deflection frame 308, and the guide groove 310 is opened on the inner wall of the anti-deflection ring 307, and the surface of the guide groove 310 is slidably connected to the surface of the guide slide 309, so as to ensure that the top rod 304 can detect its axial vibration and reduce the interference caused by its radial vibration.

[0040] Preferably, the resonator mechanism also includes a connecting ring 311, a spring sheet 312, a connecting frame 313 and a sleeve ring 314. The connecting ring 311 and the connecting frame 313 are both fixedly sleeved on the surface of the top rod 304. The spring sheet 312 is fixedly connected between the connecting ring 311 and the main shell 101. The sleeve ring 314 is integrally arranged at the bottom of the connecting frame 313.

[0041] Preferably, the quasi-zero stiffness mechanism includes an induction coil 401, a magnet mounting seat 402, a connecting bar 403, an upper electromagnet 404, a lower electromagnet 405, a guide rod 406, an intermediate permanent magnet 407, a sliding hole 408, an upper preload spring 409 and a lower preload spring 410. The induction coil 401 is fixedly mounted inside the mounting ring groove 106, the connecting bar 403 is fixedly plugged into the inner wall of the support block 103, the magnet mounting seats 402 are respectively integrally arranged on the surfaces of both ends of the connecting bar 403, the upper electromagnet 404 and the lower electromagnet The iron 405 is fixedly connected to the inside of the two magnet mounting seats 402, the guide rod 406 is fixedly inserted between the two magnet mounting seats 402, the middle permanent magnet 407 is slidably connected to the surface of the guide rod 406 through the sliding hole 408, and the middle permanent magnet 407 is fixedly connected to the inside of the sleeve ring 314, the upper pre-stress spring 409 and the lower pre-stress spring 410 are respectively located at the top of the middle permanent magnet 407 and the bottom of the middle permanent magnet 407, and the upper pre-stress spring 409 and the lower pre-stress spring 410 are both movably sleeved on the surface of the guide rod 406.

[0042] Preferably, the upper electromagnet 404, the lower electromagnet 405 and the middle permanent magnet 407 form a negative stiffness structure, and the middle permanent magnet 407, the guide rod 406, the upper pre-stress spring 409 and the lower pre-stress spring 410 form a positive stiffness structure. By setting the induction coil 401, the magnet mounting seat 402, the connecting bar 403, the upper electromagnet 404, the lower electromagnet 405, the guide rod 406, the middle permanent magnet 407, the sliding hole 408, the upper pre-stress spring 409 and the lower pre-stress spring 410, the upper electromagnet 404, the lower electromagnet 405, the guide rod 406, the middle permanent magnet 407, the sliding hole 408, the upper pre-stress spring 409 and the lower pre-stress spring 410, the upper electromagnet 404 can be controlled by current. The magnitude and direction of the magnetic force of the magnet 404 and the lower electromagnet 405 can be controlled by controlling the magnitude and direction of the magnetic force of the upper electromagnet 404 and the lower electromagnet 405, so as to control the magnitude of the resistance of the middle permanent magnet 407 during movement, thereby controlling the magnitude of the negative stiffness, and further achieving the total stiffness adjustment to quasi-zero stiffness. The magnetic force of the upper electromagnet 404 and the lower electromagnet 405 is nonlinear. By controlling the current, more complex stiffness control can be achieved. Further, under a specific current, the system can achieve a quasi-zero stiffness structure to collect low-frequency signals.

[0043] A method for using a magnetoelectric displacement detection device for a hydro-generator, comprising:

[0044] Step S1: The device is fixedly mounted on the surface base of the hydro-generator, ensuring that the mandrel 304 is vertically placed on the turbine shaft;

[0045] Step S2: In the working state, the mandrel 304 is excited by the vibration transmitted by the turbine shaft, and the mass block 305 and the resonant beam 306 inside the resonator mechanism respond, making the frequencies of the two resonant structures consistent, further amplifying the vibration signal to facilitate the subsequent collection of weak low-frequency signals;

[0046] Step S3: Adjust the currents of the upper electromagnet 404 and the lower electromagnet 405 to make the stiffness of the system reach quasi-zero stiffness. Since the natural frequency of the system is related to its own stiffness, the relationship between them is as follows:

[0047]

[0048] is the natural frequency, is the stiffness, For mass, under the condition of constant damping ratio, the magnitude of negative stiffness of the device is changed by adjusting the magnitude of current flowing through the upper electromagnet 404 and the lower electromagnet 405, so that the stiffness of the regulating device becomes quasi-zero stiffness. The decrease in stiffness reduces its natural frequency, which in turn expands the effective detection bandwidth of the device to the low frequency band and enables it to detect low-frequency vibrations.

[0049] Step S4: In the quasi-zero stiffness system, the middle permanent magnet 407 moves up and down under the action of the magnetic force, and relative motion is formed between the induction coil 401 and the middle permanent magnet 407. The induction coil 401 cuts the magnetic lines of force to generate an induced electromotive force. The current fluctuation signal generated by the induced electromotive force is the detected low-frequency vibration signal.

[0050] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A magnetoelectric displacement detection device for a hydro-generator, characterized in that: include: A protective constant pressure mechanism, wherein an isolation constant pressure mechanism is provided on top of the protective constant pressure mechanism, a resonator mechanism and a quasi-zero stiffness mechanism are installed inside the protective constant pressure mechanism, and the quasi-zero stiffness mechanism is located below the resonator mechanism, and the resonator mechanism is located between the support protective mechanism and the isolation constant pressure mechanism; The protective constant pressure mechanism comprises a main shell (101), a sub-shell (102), a support block (103), a first sealing ring (104), a constant pressure hole (105), a mounting ring groove (106) and a mounting head (107); the sub-shell (102) is fixedly mounted on the bottom of the main shell (101) by bolts; the support block (103) is fixedly connected to the inside of the sub-shell (102); the first sealing ring (104) is fixedly connected to the surface of the sub-shell (102); and the first sealing ring (104) is located between the main shell (101) and the sub-shell (102); the constant pressure hole (105) is opened through the upper surface of the main shell (101); the mounting ring groove (106) is arranged on the inner wall of the main shell (101); and the mounting head (107) is integrally arranged on the top of the main shell (101); The isolation constant pressure mechanism comprises a constant pressure cover (201), an elastic diaphragm (202), a second sealing ring (203) and a top block (204); the constant pressure cover (201) is fixedly mounted on the top of the main housing (101) by means of bolts, and a constant pressure gap is provided between the constant pressure cover (201) and the mounting head (107), and the constant pressure gap is connected to the main housing (101) through a constant pressure hole (105); the elastic diaphragm (202) is fixedly mounted on the top of the constant pressure cover (201), the second sealing ring (203) is fixedly connected to the bottom end of the constant pressure cover (201), and the second sealing ring (203) is located between the constant pressure cover (201) and the main housing (101); the top block (204) is fixedly connected to the inner wall of the top of the elastic diaphragm (202); The resonator mechanism comprises an upper limit cylinder (301), a lower limit cylinder (302) and a limit ring (303), wherein the upper limit cylinder (301) and the lower limit cylinder (302) are both fixedly connected to the interior of the mounting head (107), and the upper limit cylinder (301) and the lower limit cylinder (302) are relatively distributed, and the limit ring (303) is slidably connected between the upper limit cylinder (301) and the lower limit cylinder (302); The resonator mechanism further comprises a top rod (304), a mass block (305) and a resonance beam (306); the top rod (304) is fixedly plugged into the interior of the limiting ring (303); and the surface of the top rod (304) is slidably connected to the inner wall of the top end of the upper limiting cylinder (301) and the inner wall of the bottom end of the lower limiting cylinder (302); the number of the mass blocks (305) and the number of the resonance beam (306) are both two, and the two mass blocks (305) are slidably connected to the interior of the top rod (304); the resonance beam (306) is fixedly plugged into one end of the two mass blocks (305), and each mass block (305) and each resonance beam (306) form a group, and the two groups of mass blocks (305) and resonance beams (306) respectively constitute two resonance structures; The quasi-zero stiffness mechanism comprises an induction coil (401), a magnet mounting seat (402), a connecting bar (403), an upper electromagnet (404), a lower electromagnet (405), a guide rod (406), an intermediate permanent magnet (407), a sliding hole (408), an upper preload spring (409) and a lower preload spring (410), wherein the induction coil (401) is fixedly mounted inside the mounting ring groove (106), the connecting bar (403) is fixedly plugged into the inner wall of the support block (103), the magnet mounting seat (402) is integrally arranged on the surfaces of both ends of the connecting bar (403), the upper electromagnet (404) and the lower electromagnet (410) are ... connecting bar (403) is integrally mounted on the surfaces of the upper electromagnet (404) and the lower electromagnet (410) are fixedly mounted inside the mounting ring groove (106), the connecting bar (403) is fixedly plugged into the inner wall of the support block (103), the connecting bar (403) is fixedly plugged into the The iron (405) is fixedly connected to the inside of the two magnet mounting seats (402), the guide rod (406) is fixedly inserted between the two magnet mounting seats (402), the middle permanent magnet (407) is slidably connected to the surface of the guide rod (406) through the sliding hole (408), and the middle permanent magnet (407) is fixedly connected to the inside of the sleeve ring (314), the upper pre-stress spring (409) and the lower pre-stress spring (410) are respectively located at the top of the middle permanent magnet (407) and the bottom of the middle permanent magnet (407), and the upper pre-stress spring (409) and the lower pre-stress spring (410) are both movably sleeved on the surface of the guide rod (406).

2. A magnetoelectric displacement detection device for a hydro-generator according to claim 1, characterized in that: The resonator mechanism further comprises an anti-deflection ring (307), an anti-deflection frame (308), a guide slide (309) and a guide groove (310), wherein the anti-deflection ring (307) is fixedly sleeved on the surface of the bottom end of the top rod (304), the anti-deflection frame (308) is fixedly connected to the inner wall of the main shell (101), the guide slide (309) is integrally arranged on the inner wall of the anti-deflection frame (308), and the guide groove (310) is opened on the inner wall of the anti-deflection ring (307), and the surface of the guide groove (310) is slidably connected to the surface of the guide slide (309).

3. The magnetoelectric displacement detection device for a hydro-generator according to claim 2, characterized in that: The resonator mechanism further comprises a connecting ring (311), a spring sheet (312), a connecting frame (313) and a sleeve ring (314); the connecting ring (311) and the connecting frame (313) are both fixedly sleeved on the surface of the top rod (304); the spring sheet (312) is fixedly connected between the connecting ring (311) and the main housing (101); and the sleeve ring (314) is integrally arranged at the bottom of the connecting frame (313).

4. The magnetoelectric displacement detection device for a hydro-generator according to claim 1, characterized in that: The upper electromagnet (404), the lower electromagnet (405) and the middle permanent magnet (407) form a negative stiffness structure, and the middle permanent magnet (407), the guide rod (406), the upper preload spring (409) and the lower preload spring (410) form a positive stiffness structure.

5. A method for using the magnetoelectric displacement detection device for a hydro-generator according to claim 4, characterized in that: include: Step S1: The device is fixedly mounted on the surface base of the hydro-generator, ensuring that the mandrel (304) is vertically placed on the turbine shaft; Step S2: In the working state, the top rod (304) is excited by the vibration transmitted by the turbine shaft, and the mass block (305) and the resonance beam (306) inside the resonator mechanism respond, so that the frequencies of the two resonant structures are consistent, further amplifying the vibration signal to facilitate the subsequent collection of weak low-frequency signals; Step S3: adjusting the magnitude of the current of the upper electromagnet (404) and the lower electromagnet (405) so that the stiffness of the system reaches quasi-zero stiffness, thereby expanding the effective detection bandwidth of the system to a low frequency band; Step S4: In the quasi-zero stiffness system, the middle permanent magnet (407) moves up and down under the action of the magnetic force, and the induction coil (401) cuts the magnetic lines to generate an induced electromotive force. The current fluctuation signal generated by the induced electromotive force is the detected low-frequency vibration signal.

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