Magnetoelectric displacement detection device for hydro-generator and use method of magnetoelectric displacement detection device

Abstract

The invention relates to the technical field of vibration measurement, and discloses a magnetoelectric displacement detection device for a hydro-generator, which comprises a protection constant-pressure mechanism, an isolation constant-pressure mechanism is arranged at the top of the protection constant-pressure mechanism, a resonator mechanism and a quasi-zero stiffness mechanism are respectively arranged in the protection constant-pressure mechanism, and the isolation constant-pressure mechanism is arranged at the bottom of the protection constant-pressure mechanism. The quasi-zero stiffness mechanism is located below the resonator mechanism, and the resonator mechanism is located between the supporting protection mechanism and the isolation constant-pressure mechanism. According to the magnetoelectric displacement detection device for the hydro-generator and the use method of the magnetoelectric displacement detection device, through the arrangement of a protection constant-voltage mechanism, an isolation constant-voltage mechanism, a resonator mechanism and a quasi-zero stiffness mechanism, the stiffness of a system can be changed into quasi-zero stiffness by controlling the magnitude of currents of an upper-layer electromagnet and a lower-layer electromagnet, and the detection accuracy is improved. The effective detection bandwidth of the system is promoted to be expanded to a low-frequency band, so that the purpose of collecting low-frequency signals is achieved.

Description

Technical Field

[0001] The invention relates to the field of vibration measurement technology, in particular to a magnetoelectric displacement detection device for a hydro-generator and a use method thereof. 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 shaft drives the rotor of the generator to convert mechanical energy into electrical energy for output. It is the main power equipment for producing electricity in hydropower stations. When the hydro-turbine generator is in working condition, low-frequency vibration of the turbine shaft may occur 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 cause long-term shutdown. Therefore, timely monitoring and processing of low-frequency vibration is very important.

[0003] Due to the internal mechanical structure, general sensors have a high natural frequency, the amplitude-frequency characteristic curve is severely attenuated below the natural frequency, and 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 of 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-turbine generator, comprising: a protective constant-pressure mechanism, a top of which is provided with an isolation constant-pressure mechanism, a resonator mechanism and a quasi-zero stiffness mechanism are respectively 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 supporting 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 mounted 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 arranged between the constant pressure cover and the mounting head, and the constant pressure gap is connected with 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 at 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 both 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 push rod, a mass block and a resonance beam, the push rod is fixedly inserted in the interior of the limit ring, and the surface of the push rod is slidably 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 slidably connected in the interior of the push rod, the resonance beams are respectively fixedly inserted in 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, 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 also 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 in 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 of the intermediate permanent magnet 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: Step S1: The device is fixedly mounted on the surface base of the hydro-generator, and the top rod is ensured to be vertically placed on the turbine shaft; Step S2: In the working state, the mandrel is excited by the vibration transmitted by the turbine shaft, and the mass block and the resonance beam inside the resonator mechanism respond, so that the frequencies of the two resonant structures are consistent, further amplifying the vibration signal, so as to facilitate the subsequent collection of weak low-frequency signals; Step S3: adjusting the currents of the upper electromagnet and the lower electromagnet to make the stiffness of the system reach quasi-zero stiffness, thereby expanding the effective detection bandwidth of the system to the low frequency band; 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.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The magnetoelectric displacement detection device for a hydro-turbine generator and the use method thereof can realize that the stiffness of the system becomes quasi-zero stiffness by controlling the magnitude of the current of the upper electromagnet and the lower electromagnet through the provision of a protection constant voltage mechanism, an isolation constant voltage mechanism, a resonator mechanism and a quasi-zero stiffness mechanism, thereby expanding the effective detection bandwidth of the system to a low frequency band, thereby achieving the purpose of collecting low-frequency signals.

[0016] The magnetoelectric displacement detection device for a hydro-generator and the use method thereof are provided with a main housing, a sub-housing, a support block, a first sealing ring, a constant pressure hole, a mounting ring groove and a mounting head, so as to facilitate the disassembly and assembly of the main housing and the sub-housing for maintenance and the production and installation of the device, and facilitate the replacement of internal components of the device.

[0017] The magnetoelectric displacement detection device for a hydro-turbine generator and the use method thereof can ensure the air pressure balance on both sides of the limit ring when the push rod continuously expands and contracts due to vibration detection by means of the constant pressure cover, elastic diaphragm, second sealing ring and push block, and can also compensate for the change of the air pressure inside the device when the push rod expands and contracts by the expansion and contraction of the elastic diaphragm, thereby ensuring that the air pressure inside and outside the device approaches balance.

[0018] The magnetoelectric displacement detection device for a hydro-turbine generator and the use method thereof, 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 resonance superposition can be achieved to further amplify the vibration signal.

[0019] The magnetoelectric displacement detection device for a hydro-turbine generator and the use method thereof can control the magnitude and direction of the magnetic force of the upper electromagnet and the lower electromagnet by current through the induction coil, the magnet mounting seat, the connecting bar, the upper electromagnet, the lower electromagnet, the guide rod, the middle permanent magnet, the sliding hole, the upper preload spring and the lower preload spring. By controlling the magnitude and direction of the magnetic force of the upper electromagnet and the lower electromagnet, the magnitude of the resistance of the middle permanent magnet during movement can be controlled, thereby controlling the magnitude of the negative stiffness, and further realizing the total stiffness adjustment aligned with zero stiffness. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is a cross-sectional view of the present invention; Figure 3 It is a structural schematic diagram of the resonator mechanism and the quasi-zero stiffness mechanism of the present invention; Figure 4 It is a schematic diagram of the explosion structure at the position of the resonator mechanism and the quasi-zero stiffness mechanism of the present invention; Figure 5 It is a schematic diagram of the connection structure between the resonator mechanism and the intermediate permanent magnet of the present invention; Figure 6 This is a schematic diagram of the explosion structure at the position of the push rod of the present invention; Figure 7 It is a schematic diagram of the structure of the quasi-zero stiffness mechanism of the present invention.

[0021] 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

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0023] See also Figure 1-7 A magnetoelectric displacement detection device for a hydro-turbine generator comprises: a protective constant-pressure mechanism, an isolation constant-pressure mechanism is arranged on the top of the protective constant-pressure mechanism, a resonator mechanism and a quasi-zero stiffness mechanism are respectively 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 supporting protective mechanism and the isolation constant-pressure mechanism. By setting the protective constant-pressure mechanism, the isolation constant-pressure 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 current of the upper electromagnet 404 and the lower electromagnet 405, so as to expand the effective detection bandwidth of the system to the low-frequency band, thereby achieving the purpose of collecting low-frequency signals.

[0024] Preferably, the protective constant pressure mechanism comprises 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 installed 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. The pressure hole 105 is opened through the upper surface of the main shell 101, the mounting 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. 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 groove 106 and the mounting head 107, the main shell 101 and the auxiliary shell 102 are convenient for disassembly, assembly and maintenance, and the production and installation of the device, so as to facilitate the replacement of internal components of the device.

[0025] Preferably, 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 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 at the top of the elastic diaphragm 202. By setting the constant pressure cover 201, elastic diaphragm 202, second sealing ring 203 and top block 204, the air pressure balance on both sides of the limit ring 303 can be guaranteed when the top rod 304 detects vibration and continuously expands and contracts. At the same time, the change of 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 approaches balance.

[0026] 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.

[0027] 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 in the interior of the limit ring 303, and the surface of the top rod 304 is slidably 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 slidably connected in the interior of the top rod 304, the resonance beams 306 are respectively fixedly inserted in one end of the two mass blocks 305, and each mass block 305 and each resonance beam 306 are a group, and the two groups of mass blocks 305 and resonance beams 306 constitute two resonance structures respectively, 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.

[0028] 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.

[0029] 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, and the sleeve ring 314 is integrally arranged at the bottom of the connecting frame 313.

[0030] 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.

[0031] 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 preload spring 409 and the lower preload 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 preload spring 409 and the lower preload 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 preload spring 409 and the lower preload 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 realizing 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 realized, and further, under a specific current, the system can achieve a quasi-zero stiffness structure to collect low-frequency signals.

[0032] A method for using a magnetoelectric displacement detection device for a hydro-generator, comprising: Step S1: The device is fixedly mounted on the surface base of the hydro-turbine generator, and the top rod 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, and the vibration signal is further amplified to facilitate the subsequent collection of weak low-frequency signals; Step S3: Adjust the current 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: is the natural frequency, is the stiffness, is the mass. Under the condition of a certain damping ratio, the magnitude of the negative stiffness of the device is changed by adjusting the magnitude of the 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 stiffness is unchanged, so the reduction of its natural frequency decreases, which makes the effective detection bandwidth of the device expand to the low frequency band and can detect low-frequency vibrations. Step S4: In the quasi-zero stiffness system, the middle permanent magnet 407 moves up and down under the action of magnetic force, and a relative motion is formed between the induction coil 401 and the middle permanent magnet 407. 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.

[0033] Although 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 the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present 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 arranged on the top of the protective constant pressure mechanism, a resonator mechanism and a quasi-zero stiffness mechanism are respectively 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 supporting protective mechanism and the isolation constant pressure mechanism.

2. A magnetoelectric displacement detection device for a hydro-generator according to claim 1, characterized in that: 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 means of 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).

3. A magnetoelectric displacement detection device for a hydro-generator according to claim 2, characterized in that: 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) via 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), and the top block (204) is fixedly connected to the inner wall at the top of the elastic diaphragm (202).

4. A magnetoelectric displacement detection device for a hydro-generator according to claim 3, characterized in that: The resonator mechanism comprises 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 both fixedly connected inside the mounting head (107); 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).

5. A magnetoelectric displacement detection device for a hydro-generator according to claim 4, characterized in that: The resonator mechanism further comprises 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 slidably 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), the number of the mass blocks (305) and the number of the resonance beams (306) are both two, and the two mass blocks (305) are slidably connected to the interior of the top rod (304), the resonance beams (306) are 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.

6. A magnetoelectric displacement detection device for a hydro-generator according to claim 5, 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); 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); 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).

7. A magnetoelectric displacement detection device for a hydro-generator according to claim 6, 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).

8. The magnetoelectric displacement detection device for a hydro-generator according to claim 7, characterized in that: 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 (405) are respectively integrally mounted on the surfaces of the upper electromagnet (404) and the lower electromagnet (410), and the upper electromagnet (404) and the lower electromagnet (410) are respectively integrally mounted on the surfaces of the upper electromagnet (404) and the lower electromagnet (410). The iron (405) is respectively 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-compression spring (409) and the lower pre-compression 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-compression spring (409) and the lower pre-compression spring (410) are both movably sleeved on the surface of the guide rod (406).

9. A magnetoelectric displacement detection device for a hydro-generator according to claim 8, 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 pre-stress spring (409) and the lower pre-stress spring (410) form a positive stiffness structure.

10. A method for using a magnetoelectric displacement detection device for a hydro-generator according to claims 1 to 9, characterized in that: include: Step S1: The device is fixedly mounted on a surface base of a hydro-turbine generator, and the top rod (304) is ensured to be 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 resonance structures are consistent, and the vibration signal is further amplified 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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