A fault response type magnetic fluid injection permanent magnet motor and control method

Abstract

This invention relates to the field of fault-tolerant motor technology, and in particular to a fault-responsive magnetohydrodynamic (MHD) injection permanent magnet motor and its control method. The motor includes a drive system comprising a stator and a rotor for outputting power; a MHD injection cooling system comprising several axially spaced MHD cooling pipes, which are U-shaped and surround the upper and lower end faces of the stator; the inlet and outlet of the MHD cooling pipes are connected to a circulation assembly for storing and cooling MHD fluid; and a fault diagnosis system for real-time monitoring of the motor's electrical parameters and determining the type and location of short-circuit faults, and controlling the injection of MHD fluid into the corresponding MHD cooling pipes of the circulation assembly based on the detection results. This invention significantly improves the fault-tolerant operation capability of the motor by injecting high-permeability MHD fluid into a specific area of ​​the stator when a fault occurs, simultaneously increasing the leakage inductance of the fault circuit to suppress short-circuit current and rapidly cooling the fault area.

Description

Technical Field

[0001] This invention relates to the field of fault-tolerant motor technology, and in particular to a fault-responsive magnetohydrodynamic injection permanent magnet motor and its control method. Background Technology

[0002] Axial flux permanent magnet motors are widely used in numerous fields, including electric vehicles, wind power generation, ship propulsion, core pumps, and even aviation and marine applications. However, in harsh environments or high-overload applications, these motors are highly susceptible to short-circuit faults. Because permanent magnets are difficult to demagnetize once magnetized, the fault current during a short circuit is often substantial, potentially leading to component burnout, system shutdown, or even safety accidents. If a motor fault is not addressed promptly, it can cause irreversible damage. Therefore, timely fault handling techniques for axial flux permanent magnet motors are essential.

[0003] Currently, there are few active control methods for suppressing short-circuit current in axial flux permanent magnet motors. Existing research shows that short-circuit currents are usually very large. If suppression is achieved solely by controlling the demagnetizing current, the amplitude of the required demagnetizing current will be too high. The strong reverse magnetic field generated by this current will directly exacerbate the demagnetization risk of the permanent magnet, thus limiting the effectiveness and safety of this control method.

[0004] Therefore, this invention discloses a fault-responsive magnetohydrodynamic injection permanent magnet motor and its control method to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a fault-responsive magnetohydrodynamic injection permanent magnet motor and its control method, which aims to solve the problem of difficulty in suppressing short-circuit current when a short-circuit fault occurs in an axial flux permanent magnet motor.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a fault-responsive magnetohydrodynamic injection permanent magnet motor, comprising:

[0007] The drive system includes a stator and a rotor that are configured to output power.

[0008] A magnetohydrodynamic (MHD) injection cooling system includes a plurality of MHD cooling pipes arranged axially at equal intervals. The MHD cooling pipes are U-shaped and arranged around the upper and lower end faces of the stator. The inlet and outlet of the MHD cooling pipes are connected to a circulation assembly for storing and cooling the MHD.

[0009] The fault diagnosis system is used to monitor the electrical parameters of the motor in real time and determine the type and location of short circuit faults, and to control the injection of magnetic fluid into the magnetic fluid cooling pipe corresponding to the circulation component based on the detection results.

[0010] Preferably, the stator includes several modular stator cores, which are spliced ​​together along the circumferential direction to form a ring, and the stator cores are provided with windings; the magnetohydrodynamic cooling pipes are embedded between the teeth of adjacent stator cores.

[0011] Preferably, the magnetohydrodynamic cooling pipe extends through the axial length of the stator core, and the inlet and outlet of the magnetohydrodynamic cooling pipe are concentrated on the same outer end face of the motor.

[0012] Preferably, stator slots are provided between adjacent stator cores, and the magnetic fluid cooling pipes are arranged at intervals of one stator slot, and the magnetic fluid cooling pipes are arranged alternately along the circumference of the stator core.

[0013] Preferably, the number of magnetic fluid cooling pipes corresponds to the number of stator cores; when the number of stator cores is 2n, the number of magnetic fluid cooling pipes is n; when the number of stator cores is 2n+1, the number of magnetic fluid cooling pipes is n+1.

[0014] Preferably, the circulation component includes a solenoid valve disposed on the magnetofluid cooling pipe, and the fault diagnosis system is used to control the opening and closing of the solenoid valve to realize the injection of magnetofluid at the fault location.

[0015] Preferably, the circulation component further includes a storage tank, which is connected to the magnetic fluid cooling pipe and is used to store and cool the magnetic fluid. In the event of a fault, the magnetic fluid in the storage tank is injected into the corresponding magnetic fluid cooling pipe by an inflow pump and circulated. After the fault is cleared, the magnetic fluid in the magnetic fluid cooling pipe flows back into the storage tank.

[0016] Preferably, the circulation assembly further includes a main inflow pipe, a main outflow pipe, and a main return pipe that are respectively connected to the magnetofluid cooling pipe. The main inflow pipe is connected to the storage tank through the inflow pump, the main return pipe is connected to the storage tank through the return pump, and the main outflow pipe is connected to the storage tank.

[0017] This invention also discloses a control method for controlling the fault current of a fault-responsive magnetohydrodynamic injected permanent magnet motor, comprising the following steps:

[0018] The motor's operating status is monitored in real time through a fault diagnosis system;

[0019] When a short circuit fault is detected, the location of the fault is determined.

[0020] After locating the fault, the fault diagnosis system controls the start of the magnetic fluid injection cooling system to inject magnetic fluid into the corresponding magnetic fluid cooling pipe to cool the fault location.

[0021] After troubleshooting, the magnetic fluid in the magnetic fluid cooling pipes is recovered.

[0022] Preferably, in the fault location locating step, if a magnetic fluid cooling pipe is provided at the located fault location, the solenoid valve of the magnetic fluid cooling pipe is controlled to open; if no magnetic fluid cooling pipe is provided at the located fault location, the solenoid valves corresponding to one or two magnetic fluid cooling pipes that are closer to the short-circuit fault location are controlled to open.

[0023] Compared with existing technologies, this invention has the following advantages and technical effects: This invention discloses a fault-responsive magnetohydrodynamic (MHD) injection permanent magnet motor and its control method, comprising a drive system, a MHD injection cooling system, and a fault diagnosis system. The drive system, consisting of a stator and a rotor, is the core component of the permanent magnet motor, converting electricity into power output through the interaction between the stator and rotor. The MHD injection cooling system features U-shaped MHD cooling pipes that axially and equally spaced around the stator, with the pipe inlets and outlets connected to the circulation assembly. When a short-circuit fault occurs in the motor, MHD fluid is introduced into the MHD cooling pipes to actively change the motor's electromagnetic parameters. This results in a fast response, suppressing the short-circuit current within milliseconds. This increases the leakage inductance of the motor under short-circuit fault conditions, leading to increased impedance and effectively suppressing the short-circuit current. Simultaneously, the MHD fluid, as a cooling medium, cools the faulty area of ​​the motor, improving its fault-tolerant operation capability. The fault diagnosis system monitors electrical parameters, determines the type and location of the short-circuit fault, and then controls the circulation assembly to inject MHD fluid into the corresponding MHD cooling pipe. The injection strategy is highly targeted, accurately injecting fluid based on the fault type and location, avoiding impact on healthy phases. The magnetofluid is automatically recovered after the fault is cleared, and the system can be restored to its initial state, exhibiting repeatability and good applicability.

[0024] This invention significantly improves the fault-tolerant operation capability of the motor by injecting a high-permeability magnetic fluid into a specific area of ​​the stator when a fault occurs, thereby simultaneously increasing the leakage inductance of the fault circuit to suppress short-circuit current and rapidly cooling the fault area. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0026] Figure 1 The axial flux permanent magnet motor structure provided by this invention;

[0027] Figure 2This is an axial view of the magnetofluid cooling pipe of the present invention;

[0028] Figure 3 This is a schematic diagram of the stator core and magnetofluid cooling pipes of the present invention;

[0029] Figure 4 This is a schematic diagram of the control method of the present invention;

[0030] In the diagram: 1. Permanent magnet; 2. Stator core; 3. Magnetofluid cooling pipe; 4. Winding; 5. Rotor core; 6. Solenoid valve; 7. Storage tank; 8. Main inflow pipe; 9. Main outflow pipe; 10. Main return pipe; 11. Inflow pump; 12. Return pump; 13. Gear shoe; 14. Gear. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Reference Figures 1 to 4 As shown, this embodiment provides a fault-responsive magnetohydrodynamic injection permanent magnet motor, including:

[0034] The drive system includes a stator and a rotor, which are configured to output power.

[0035] The magnetic fluid injection cooling system includes several magnetic fluid cooling pipes 3 arranged axially at equal intervals. The magnetic fluid cooling pipes 3 are U-shaped and arranged around the upper and lower end faces of the stator. The inlet and outlet of the magnetic fluid cooling pipes 3 are connected to a circulation component for storing and cooling magnetic fluid.

[0036] The fault diagnosis system is used to monitor the electrical parameters of the motor in real time and determine the type and location of short circuit faults. Based on the detection results, it controls the injection of magnetic fluid into the corresponding magnetic fluid cooling pipe 3 of the circulation component.

[0037] This invention discloses a fault-responsive magnetohydrodynamic (MHD) injected permanent magnet motor and its control method, comprising a drive system, a MHD injection cooling system, and a fault diagnosis system. The drive system, consisting of a stator and a rotor, is the core component of the permanent magnet motor, converting electricity into power output through the interaction between the stator and rotor. The MHD injection cooling system features U-shaped MHD cooling pipes that axially and equally spaced around the stator. The pipe inlets and outlets are connected to the circulation assembly. When a short-circuit fault occurs in the motor, MHD fluid is introduced into the MHD cooling pipes to actively change the motor's electromagnetic parameters. This fast response time can suppress the short-circuit current within milliseconds, increasing the leakage inductance of the motor under short-circuit fault conditions, thereby increasing impedance and effectively suppressing the short-circuit current. Simultaneously, the MHD fluid, as a cooling medium, can cool the faulty area of ​​the motor, improving the motor's fault-tolerant operation capability. The fault diagnosis system monitors electrical parameters, determines the type and location of the short-circuit fault, and then controls the circulation assembly to inject MHD fluid into the corresponding MHD cooling pipe. The injection strategy is highly targeted, accurately injecting fluid based on the fault type and location, avoiding impact on healthy phases. The magnetofluid is automatically recovered after the fault is cleared, and the system can be restored to its initial state, exhibiting repeatability and good applicability.

[0038] In one embodiment of the present invention, the axial flux permanent magnet motor of the present invention adopts a classic dual-rotor single-stator topology.

[0039] In one embodiment of the present invention, the magnetic fluid used to handle the fault is preferably a liquid magnetic material with high magnetic permeability. Its injection can significantly reduce the magnetic resistance of the original air magnetic circuit, increase the leakage inductance of the fault circuit, thereby suppressing the short-circuit current and cooling the fault area.

[0040] Further optimization of the design involves a stator comprising several modular stator cores 2, which are joined together circumferentially to form a ring. Windings 4 are installed on each stator core 2. Magnetorheological fluid cooling pipes 3 are embedded between the toothed shoes 13 of adjacent stator cores 2. The ring-shaped stator is divided into several modular stator cores 2, with the magnetorheological fluid cooling pipes corresponding to the toothed shoes 13 of the stator cores 2. This arrangement of the magnetorheological fluid cooling pipes is more rational and facilitates effective injection of magnetorheological fluid in case of a fault.

[0041] In one embodiment of the present invention, the toothed shoe is a conventional design in the mechanical field and is a key extension of the toothed component in a mechanical structure. It is usually located at the end of the tooth and its core function is to optimize the contact performance of the tooth, enhance the structural stability, and adapt to specific working conditions.

[0042] In one embodiment of the present invention, reference is made to the appendix. Figure 1 As shown, the stator consists of a stator core 2 and windings 4, and the rotor includes a rotor core 5 and a permanent magnet 1.

[0043] In one embodiment of the present invention, reference is made to the appendix. Figure 3As shown, the stator core includes a toothed shoe 13 and teeth 14 disposed between the toothed shoes 13.

[0044] Further optimization of the design involves extending the magnetic fluid cooling pipe 3 along the axial length of the stator core 2, with its inlet and outlet concentrated on the same outer end face of the motor. A U-shaped magnetic fluid cooling pipe is positioned between the toothed shoes of adjacent stator modules, extending along the axial length of the stator core 2, with both its inlet and outlet concentrated on the same outer end face of the motor, facilitating integration with external circulation components.

[0045] Further optimization involves setting stator slots between adjacent stator cores 2, with magnetic fluid cooling pipes 3 arranged every other stator slot, and the magnetic fluid cooling pipes 3 alternately arranged around the circumference of the stator cores 2; the number of magnetic fluid cooling pipes 3 corresponds to the number of stator cores 2; when the number of stator cores 2 is 2n, the number of magnetic fluid cooling pipes 3 is n; when the number of stator cores 2 is 2n+1, the number of magnetic fluid cooling pipes 3 is n+1. To optimize the layout of the magnetic fluid cooling pipes, this embodiment adopts an alternating arrangement scheme. The specific number N of magnetic fluid cooling pipes is determined by the total number M of stator modules: when the total number of stator modules M=2n is even, the required number of magnetic fluid cooling pipes N=n; when the total number of stator modules M=2n+1 is odd, the required number of magnetic fluid cooling pipes N=n+1. Under the premise of ensuring effective coverage of any potential fault location, this embodiment provides an optimization scheme that minimizes the number of pipes, significantly simplifying the mechanical complexity of the motor body structure and the complexity of the fluid system, while improving manufacturing process and economy.

[0046] Further optimization of the scheme includes a circulation component comprising a solenoid valve 6 mounted on the magnetic fluid cooling pipe 3, with a fault diagnosis system controlling the opening and closing of the solenoid valve 6 to inject magnetic fluid into the fault location; the circulation component also includes a storage tank 7, connected to the magnetic fluid cooling pipe 3, for storing and cooling magnetic fluid; in the event of a fault, the inflow pump 11 injects the magnetic fluid from the storage tank 7 into the corresponding magnetic fluid cooling pipe 3; after the fault is cleared, the magnetic fluid in the magnetic fluid cooling pipe 3 flows back into the storage tank 7; the circulation component also includes a main inflow pipe 8, a main outflow pipe 9, and a main return pipe 10, all connected to the magnetic fluid cooling pipe 3 respectively. The main inflow pipe 8 is connected to the storage tank 7 via the inflow pump 11, and the main return pipe 10 is connected to the storage tank 7 via the return pump 12. See appendix. Figure 4As shown, the circulation assembly includes a storage tank 7, a solenoid valve 6, a main inflow pipe 8, a main outflow pipe 9, a main return pipe 10, an inflow pump 11, and a return pump 12. The magnetofluid is normally stored in the storage tank 7, which integrates an active cooling device for forced cooling before and after magnetofluid injection, ensuring it always maintains optimal fluid characteristics and cooling capacity. Each U-shaped magnetofluid cooling pipe inlet is connected to an independently controlled solenoid valve 6. By default, solenoid valve 6 connects the magnetofluid cooling pipe inlet to the main return pipe 10. When an injection command is received, the connection is switched so that the main inflow pipe 8 connects to the magnetofluid cooling pipe 3 inlet. The inflow pump 11 drives the magnetofluid to be injected into the magnetofluid cooling pipe 3. At the same time, the heated magnetofluid flows into the main outflow pipe 9 and returns to the storage tank 7 to cool down, maintaining a stable circulation of the magnetofluid. After the fault is cleared, solenoid valve 6 is adjusted to the return state. The magnetofluid remaining in the magnetofluid cooling pipe 3 enters the main return pipe 10 and is then drawn into the storage tank 7 by the return pump 12, completing the recovery and facilitating subsequent use.

[0047] In one embodiment of the present invention, the three ports of the solenoid valve 6 are respectively connected to the main inflow pipe 8, the inlet of the motor's magnetohydrodynamic cooling pipe 3, and the main return pipe 10.

[0048] In one embodiment of the present invention, the fault diagnosis system accurately diagnoses the type of short circuit fault (divided into inter-turn short circuit fault and phase-to-phase short circuit fault) and locates the faulty phase within milliseconds after the fault occurs. The controller executes a pre-programmed differentiated injection strategy based on the diagnosis results.

[0049] Inter-turn short circuit fault: When an inter-turn short circuit is diagnosed in a certain phase winding 4, the fault diagnosis system immediately triggers commands. The first command controls the magnetic fluid injection cooling system of the storage box 7 to pre-cool the magnetic fluid; the second command turns on the inflow pump to continuously inject the magnetic fluid in the box into the main inflow pipe 8; the third command queries the U-shaped magnetic fluid cooling pipe 3 closest to the phase winding 4 and sends an opening command to the solenoid valve 6.

[0050] Phase-to-phase short circuit fault: When a phase-to-phase short circuit is diagnosed, the fault diagnosis system immediately triggers commands. The first command controls the magnetic fluid injection cooling system of the storage tank 7 to pre-cool the magnetic fluid. The second command turns on the inflow pump 11 to continuously inject the magnetic fluid in the tank into the main inflow pipe 8. The third command queries the pre-fabricated fault diagnosis system layout diagram. If a magnetic fluid cooling pipe is directly arranged at that location, only the solenoid valve 6 corresponding to the magnetic fluid cooling pipe 3 is opened. If the short circuit point is not directly arranged with a magnetic fluid cooling pipe 3, the two solenoid valves 6 closest to it are opened simultaneously for coordinated injection.

[0051] In one embodiment of the present invention, the fault diagnosis system intelligently adjusts the pressure and flow parameters of the magnetohydrodynamic injection process in a closed loop according to the initial rising slope or amplitude of the fault current, so as to achieve graded and adaptive suppression of faults of different severity.

[0052] In one embodiment of the present invention, after the fault is cleared, the circulation component immediately stops injecting magnetic fluid into the magnetic fluid cooling pipe and switches all operating solenoid valves 6 to reflux mode, starts the recovery program, and after the magnetic fluid in the magnetic fluid cooling pipe is recovered and cooled, the system automatically resets and enters the standby state.

[0053] In one embodiment of the present invention, by injecting a high-permeability magnetic fluid into the fault region, the local magnetic field path and magnetic circuit parameters can be dynamically changed. The specific mechanism is as follows.

[0054] Mechanism explanation: Magnetic circuit reluctance The formula for calculating inductance is: The inductive reactance component of the motor impedance is In the formula, L is the inductance, N is the number of turns in the winding, R is the magnetic reluctance, l is the length of the magnetic path, μ is the permeability of the magnetic path, A is the cross-sectional area of ​​the magnetic path, f represents the frequency, and Lσ represents the leakage inductance; before the magnetofluid is injected, the medium of the magnetic path is air, μ _air Extremely low leakage magnetic reluctance R _normal Extremely high, resulting in leakage inductance L σ_normal Minimal; after magnetofluid injection, the magnetofluid replaces air, μ _fluid Alternate μ _air This makes the magnetic reluctance R of the magnetic circuit in this path... _fluid The leakage inductance L of the faulty circuit can be calculated using the inductance calculation formula. σ_fluid Significantly increased. The motor circuit impedance includes the inductive reactance, which increases with the increase of leakage inductance, ultimately leading to a significant increase in the total impedance of the entire fault circuit, thereby suppressing the short-circuit current.

[0055] This invention also discloses a control method for controlling the fault current of a fault-responsive magnetohydrodynamic injected permanent magnet motor, comprising the following steps:

[0056] The fault diagnosis system monitors the motor's operating status in real time and identifies short-circuit fault signals.

[0057] When a short-circuit fault is detected, the fault location is determined. Once a short-circuit fault is detected, the fault type and location are immediately determined. Fault types include inter-turn short circuits and phase-to-phase short circuits. Then, the corresponding magnetofluid injection strategy is executed according to the fault type. If the fault is an inter-turn short circuit, the stator core 2 area where the faulty phase winding 4 is located is located, and the solenoid valve 6 corresponding to the nearest magnetofluid cooling pipe 3 is opened. If the fault is a phase-to-phase short circuit, the stator core 2 area where the short-circuit winding 4 is located is located. If there is a magnetofluid cooling pipe 3 directly covering the area, the corresponding solenoid valve 6 is opened. If there is no magnetofluid cooling pipe 3 directly covering the area, the solenoid valves 6 of the two nearest magnetofluid cooling pipes 3 are opened simultaneously.

[0058] After locating the fault, the fault diagnosis system controls the start of the magnetic fluid injection cooling system to inject magnetic fluid into the corresponding magnetic fluid cooling pipe 3 to cool the fault location. At the same time as opening the selected solenoid valve 6, the magnetic fluid cooling and injection program of the storage tank 7 is started. The pre-cooled high permeability magnetic fluid is injected into the target magnetic fluid cooling pipe 3 within milliseconds. During the injection process, the injection parameters of the magnetic fluid, including flow rate, pressure and duration, are dynamically adjusted according to the severity of the fault.

[0059] After troubleshooting, the magnetic fluid in the magnetic fluid cooling pipe 3 is recovered; after the fault is cleared, the solenoid valve 6 is adjusted to the reflux state so that the magnetic fluid in the magnetic fluid cooling pipe 3 is collected into the main reflux pipe 10, and then the magnetic fluid is recovered into the storage tank 7 for cooling and storage, in preparation for the next use.

[0060] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0061] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A fault-responsive magnetohydrodynamic injection permanent magnet motor, characterized in that, include: The drive system includes a stator and a rotor that are configured to output power. A magnetic fluid injection cooling system includes several magnetic fluid cooling pipes (3) arranged axially at equal intervals. The magnetic fluid cooling pipes (3) are U-shaped and arranged around the upper and lower end faces of the stator. The inlet and outlet of the magnetic fluid cooling pipes (3) are connected to a circulation component for storing and cooling magnetic fluid. The fault diagnosis system is used to monitor the electrical parameters of the motor in real time and determine the type and location of the short circuit fault, and to control the injection of magnetic fluid into the magnetic fluid cooling pipe (3) corresponding to the circulation component according to the detection results; The circulation component includes a solenoid valve (6) disposed on the magnetic fluid cooling pipe (3), and the fault diagnosis system is used to control the opening and closing of the solenoid valve (6) to realize the injection of magnetic fluid at the fault location; the circulation component also includes a storage tank (7), which is connected to the magnetic fluid cooling pipe (3) and is used to store and cool magnetic fluid; when a fault occurs, the magnetic fluid in the storage tank (7) is injected into the corresponding magnetic fluid cooling pipe (3) through the inflow pump (11) and circulates; after the fault is cleared, the magnetic fluid in the magnetic fluid cooling pipe (3) flows back into the storage tank (7); The fault current control method for a fault-responsive magnetohydrodynamic injected permanent magnet motor includes the following steps: The motor's operating status is monitored in real time through a fault diagnosis system; When a short circuit fault is detected, the location of the fault is determined. After locating the fault location, the magnetic fluid injection cooling system is started by controlling the fault diagnosis system to inject magnetic fluid into the magnetic fluid cooling pipe (3) at the corresponding location to cool the fault location; After troubleshooting, the magnetic fluid in the magnetic fluid cooling pipe (3) is recovered; In the fault location locating step, if a magnetic fluid cooling pipe (3) is provided at the located fault location, the solenoid valve (6) of the magnetic fluid cooling pipe (3) is controlled to open; if no magnetic fluid cooling pipe (3) is provided at the located fault location, the solenoid valve (6) corresponding to one or two magnetic fluid cooling pipes (3) that are closer to the short-circuit fault location is controlled to open.

2. The fault-responsive magnetohydrodynamic injection permanent magnet motor according to claim 1, characterized in that: The stator includes several modular stator cores (2), which are spliced ​​together along the circumferential direction to form a ring. The stator cores (2) are provided with windings (4); the magnetohydrodynamic cooling pipes (3) are embedded between the toothed shoes (13) of adjacent stator cores (2).

3. The fault-responsive magnetohydrodynamic injection permanent magnet motor according to claim 2, characterized in that: The magnetic fluid cooling pipe (3) extends through the axial length of the stator core (2), and the inlet and outlet of the magnetic fluid cooling pipe (3) are concentrated on the same outer end face of the motor.

4. The fault-responsive magnetohydrodynamic injection permanent magnet motor according to claim 2, characterized in that: Stator slots are provided between adjacent stator cores (2), and magnetic fluid cooling pipes (3) are arranged at intervals of one stator slot, and the magnetic fluid cooling pipes (3) are arranged alternately along the circumference of the stator cores (2).

5. The fault-responsive magnetohydrodynamic injection permanent magnet motor according to claim 2, characterized in that: The number of magnetic fluid cooling pipes (3) is set in correspondence with the number of stator cores (2); when the number of stator cores (2) is 2n, the number of magnetic fluid cooling pipes (3) is n; when the number of stator cores (2) is 2n+1, the number of magnetic fluid cooling pipes (3) is n+1.

6. The fault-responsive magnetohydrodynamic injection permanent magnet motor according to claim 1, characterized in that: The circulation assembly also includes a main inflow pipe (8), a main outflow pipe (9), and a main return pipe (10) that are respectively connected to the magnetic fluid cooling pipe (3). The main inflow pipe (8) is connected to the storage tank (7) through the inflow pump (11), the main return pipe (10) is connected to the storage tank (7) through the return pump (12), and the main outflow pipe (9) is connected to the storage tank (7).

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