A monitoring device and a monitoring method for a permanent magnet synchronous traction machine

Abstract

The present invention discloses a monitoring device and a monitoring method for a permanent magnet synchronous traction machine, comprising: a mounting plate, a temperature sensor and a magnetic field sensor are arranged on the mounting plate, and the mounting plate is connected and fixed to the shell of the permanent magnet synchronous traction machine; the temperature sensor is used to sense the temperature of the braking surface of the rotor of the permanent magnet synchronous traction machine and generate a temperature signal; the magnetic field sensor is used to sense the magnetic field of the permanent magnet of the permanent magnet synchronous traction machine and generate a magnetic field signal; a processing module is connected to the temperature sensor and the magnetic field sensor signal and receives the temperature signal and the magnetic field signal, and judges the fault condition to generate a fault signal and send it to an external Internet of Things system. The beneficial effect of the present invention is that the temperature of the rotor braking surface and the magnetic field change of the permanent magnet are detected by the temperature sensor and the magnetic field sensor respectively, and a relatively accurate fault judgment result is generated by comprehensive judgment, with high accuracy and good detection effect. At the same time, it is also connected to the external Internet of Things system, which is convenient for reporting the fault condition and performing fault repair.

Description

Technical Field

[0001] The present invention relates to the technical field of elevator traction machine monitoring, and in particular to a monitoring device and a monitoring method for a permanent magnet synchronous traction machine. Background Art

[0002] As the core component of the elevator system, the permanent magnet synchronous traction machine plays a decisive role in the safe and stable operation of the elevator. Once the traction machine's working state is abnormal and is not discovered in time, it may bury a major safety hazard to the safe and stable operation of the elevator, and in serious cases, a major safety accident will occur.

[0003] At present, some patents also provide devices and methods for monitoring traction machines. For example, a temperature sensor is used to monitor the temperature of the stator winding of a permanent magnet synchronous traction machine to determine whether the temperature reaches the demagnetization temperature of the permanent magnet, and an alarm is triggered when the demagnetization temperature is maintained for a certain period of time (application number: CN201510017111.8). Although this patent monitors the demagnetization of the permanent magnet in real time, the monitoring function of this device is relatively single and cannot monitor the traction machine well. Summary of the invention

[0004] In view of the above problems existing in the prior art, a monitoring device and a monitoring method for a permanent magnet synchronous traction machine are now provided.

[0005] The specific technical solutions are as follows:

[0006] A monitoring device for a permanent magnet synchronous traction machine, comprising:

[0007] A mounting plate, on which a temperature sensor and a magnetic field sensor are arranged, and the mounting plate is connected and fixed to a housing of the permanent magnet synchronous traction machine;

[0008] The temperature sensor is used to sense the temperature of the braking surface of the rotor of the permanent magnet synchronous traction machine and generate a temperature signal;

[0009] The magnetic field sensor is used to sense the magnetic field of the permanent magnet of the permanent magnet synchronous traction machine and generate a magnetic field signal;

[0010] A processing module is connected to the temperature sensor and the magnetic field sensor signal and receives the temperature signal and the magnetic field signal, and determines the fault condition of the permanent magnet synchronous traction machine to generate a fault signal and send it to an external Internet of Things system.

[0011] Preferably, the mounting plate has a temperature sensor bracket, which is vertically arranged on the mounting plate and extends from the mounting plate to a gap between the braking device of the permanent magnet synchronous traction machine and the rotor of the permanent magnet synchronous traction machine;

[0012] The temperature sensor is arranged on a side of the temperature sensor bracket facing the braking surface of the rotor.

[0013] Preferably, the braking device is arranged on the inner side of the rotor or on the outer side of the rotor.

[0014] Preferably, the magnetic field sensor is vertically arranged on the mounting plate, extending from the mounting plate to the gap between the coil of the permanent magnet synchronous traction machine and the rotor;

[0015] The permanent magnet is arranged on the rotor.

[0016] Preferably, the processing module also has an alarm submodule, which is connected to the external Internet of Things system and generates a fault signal according to the fault condition of the permanent magnet synchronous traction machine and sends it to the external Internet of Things system.

[0017] Preferably, the processing module calculates the rotation speed of the permanent magnet synchronous traction machine according to the magnetic field signal.

[0018] A monitoring method for a permanent magnet synchronous traction machine, which is applicable to the above-mentioned monitoring device, wherein the temperature sensor of the monitoring device continuously monitors the temperature of the braking surface of the rotor and generates a temperature signal, and the magnetic field sensor of the monitoring device continuously monitors the magnetic field of the permanent magnet and generates a magnetic field signal. The monitoring method specifically comprises:

[0019] Step S1: generating a rotation state parameter according to the magnetic field signal;

[0020] The rotation state parameter is used to indicate whether the rotor is in a rotation state or a stationary state;

[0021] Step S2: judging whether the temperature of the braking surface is within a safe temperature range according to the temperature signal, and judging whether there is a sudden change in the strength of the permanent magnet according to the magnetic field signal;

[0022] When the temperature is within a safe range and there is no sudden change in the strength of the permanent magnet, proceed to step S3;

[0023] When the temperature is not within the safe range and there is no sudden change in the strength of the permanent magnet, proceed to step S6;

[0024] When the temperature is within the safe range and the permanent magnet has a sudden change in strength, go to step S7;

[0025] When the temperature is not within the safe range and the permanent magnet has a sudden change in strength, go to step S8;

[0026] Step S3: judging whether the rotor is in a rotating state according to the rotation state parameter;

[0027] If yes, go to step S4;

[0028] If not, output the shutdown status signal and the temperature signal to the external Internet of Things system, and then return to step S1;

[0029] Step S4: outputting the temperature signal to an external IoT system and calculating the rotation speed of the rotor;

[0030] Step S5: determining whether the rotation speed exceeds a threshold value;

[0031] If yes, output an overspeed fault signal to the external IoT system, and then return to step S1;

[0032] If not, output the speed signal to the external IoT system and then return to step S1.

[0033] Step S6: Determine the temperature fault type according to the temperature signal, output the temperature fault signal to the external Internet of Things system, and then return to step S1.

[0034] Step S7: Output a permanent magnet fault signal to the external Internet of Things system, and then return to the step S1.

[0035] Step S8: Determine the temperature fault type according to the temperature signal, output the temperature fault signal to the external Internet of Things system, and simultaneously output the permanent magnet fault signal to the external Internet of Things system, and then return to step S1.

[0036] Preferably, the step S4 further includes:

[0037] Step S41: outputting the temperature signal to the external Internet of Things system;

[0038] Step S42: obtaining the number of permanent magnets of the permanent magnet synchronous traction machine;

[0039] Step S43: calculating the period of the magnetic field signal;

[0040] Step S44: Calculate the rotation speed according to the number of permanent magnets and the magnetic field signal period.

[0041] Preferably, the step S6 further includes:

[0042] Step S61: determining whether the braking surface is heated up rapidly;

[0043] If so, output an abnormal temperature fault signal to the external IoT system;

[0044] If not, go to step S62;

[0045] Step S62: judging whether the rotor is in a rotating state according to the rotation state parameter;

[0046] If yes, output a brake fault signal to the external IoT system, and then return to step S1;

[0047] If not, output a stator over-temperature fault signal to the external Internet of Things system, and then return to step S1.

[0048] The above technical solution has the following advantages or beneficial effects: the temperature of the rotor braking surface and the magnetic field change of the permanent magnet are detected respectively by the temperature sensor and the magnetic field sensor, and a more accurate fault judgment result is generated by comprehensive judgment, which has high accuracy and good detection effect. At the same time, it is also connected to the external Internet of Things system to facilitate reporting of fault conditions for fault inspection and repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The embodiments of the present invention will be described more fully with reference to the attached drawings, which are provided for illustration and description only and are not intended to limit the scope of the present invention.

[0050] Figure 1 A front view of an embodiment of the present invention;

[0051] Figure 2 is an oblique view of an embodiment of the present invention;

[0052] Figure 3 A partial view of an embodiment of the present invention;

[0053] Figure 4 A schematic diagram of a mounting plate according to an embodiment of the present invention;

[0054] Figure 5 is a cross-sectional view of an embodiment of the present invention;

[0055] Figure 6 A schematic diagram of a magnetic field sensor according to an embodiment of the present invention;

[0056] Figure 7 A schematic diagram of the magnetic field monitoring principle of an embodiment of the present invention;

[0057] Figure 8 is a schematic diagram of a fault-free magnetic field signal in an embodiment of the present invention;

[0058] Fig. 9 A schematic diagram of a magnetic field signal with a fault in an embodiment of the present invention;

[0059] Fig.10 It is an overall schematic diagram of an embodiment of the present invention;

[0060] Fig.11 Schematic diagram of a monitoring method according to a real-time example of the present invention;

[0061] Fig.12 This is a schematic diagram of sub-steps of step S4 of an embodiment of the present invention;

[0062] Fig.13 Schematic diagram of sub-steps of step S6 of an embodiment of the present invention.

[0063] Explanation of the reference numerals: 1-coil, 2-first monitoring device, 3-second monitoring device, 4-rotor, 5-braking device, 6-permanent magnet, 7-processing module, 8-external Internet of Things system, 201-temperature sensor, 201A-temperature sensor bracket, 202-magnetic field sensor, 203-mounting plate, 701-alarm submodule. DETAILED DESCRIPTION

[0064] 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.

[0065] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0066] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0067] The present invention comprises:

[0068] A monitoring device for a permanent magnet synchronous traction machine, such as Figure 1-5 As shown, including:

[0069] A mounting plate 203, on which a temperature sensor 201 and a magnetic field sensor 202 are disposed, and the mounting plate 203 is connected and fixed to a housing of the permanent magnet synchronous traction machine;

[0070] The temperature sensor 201 is used to sense the temperature of the braking surface of the rotor 4 of the permanent magnet synchronous traction machine and generate a temperature signal;

[0071] The magnetic field sensor 202 is used to sense the magnetic field of the permanent magnet 6 of the permanent magnet synchronous traction machine and generate a magnetic field signal;

[0072] The processing module 7 is connected to the temperature sensor 201 and the magnetic field sensor 202 and receives the temperature signal and the magnetic field signal, and determines the fault condition of the permanent magnet synchronous traction machine to generate a fault signal and send it to the external Internet of Things system 8.

[0073] In a preferred embodiment, Figure 1As shown, the monitoring devices disclosed in the present invention can be used in combination, such as a first monitoring device 2 and a second monitoring device 3. By adding multiple groups of monitoring devices, timely fault judgment can be effectively performed on some larger traction machines, or in partial fault situations, such as when an abnormal temperature condition exists at a certain point of the stator winding when the traction machine is shut down, the fault situation can be judged in time.

[0074] In a preferred embodiment, the monitoring device can also be used in a single group, and its installation method is consistent with the method of using multiple groups of monitoring devices in combination. By setting at least one monitoring device, fault detection of the traction machine can be realized, which expands the scope of use of the traction machine and facilitates monitoring of the traction machine in various situations, such as when the traction machine is small in size and the internal space of the shell is compact.

[0075] In a preferred embodiment, the mounting plate 203 has a temperature sensor bracket 201A, which is vertically arranged on the mounting plate 203 and extends from the mounting plate 203 to the gap between the brake device 5 of the permanent magnet synchronous traction machine and the rotor 4 of the permanent magnet synchronous traction machine;

[0076] The temperature sensor 201 is arranged on a side of the temperature sensor bracket facing the braking surface of the rotor 4 .

[0077] Specifically, the temperature sensor 201 is preferably a non-contact infrared sensor, which can effectively monitor the temperature of the braking surface without contacting the braking surface of the rotor 4, thereby avoiding the influence of the contact sensor on the rotor 4. At the same time, the utility model preferably installs the monitoring device in conjunction with the braking device, but the advantage of the utility model is that it can also achieve the required monitoring effect when installed at other air gap positions.

[0078] In a preferred embodiment, the braking device 5 is disposed on the inner side of the rotor 4 or on the outer side of the rotor 4 .

[0079] Specifically, the brake device 5 may be a drum brake disposed on the inner side of the rotor, or an external brake disposed on the outer side of the rotor. It should be understood that, as the specific type of the brake device 5 changes, the relative position of the brake device 5 and the rotor 4 will also change, thereby causing a change in the braking surface of the rotor 4. However, regardless of the type of brake device 5 used, the temperature sensor 201 should be disposed on the side of the temperature sensor bracket 201A facing the braking surface of the rotor 4, and used to sense the real-time temperature value of the braking surface, and the real-time temperature value is processed by the processing module 7 to generate a temperature change value.

[0080] In a preferred embodiment, the magnetic field sensor 202 is vertically arranged on the mounting plate 203, and extends from the mounting plate 203 to the gap between the coil 1 and the rotor 4 of the permanent magnet synchronous traction machine;

[0081] Permanent magnets 6 are arranged on the rotor 4 .

[0082] Specifically, Figure 6 As shown, the magnetic field sensor 202 is preferably a Hall element, which extends into the gap between the coil 1 and the rotor 4 of the traction machine, senses the magnetic field emitted by the permanent magnet, and Figure 7 As shown, the excitation current I of the Hall element flows in from the a and b terminals, and generates an electromotive force E at the c and d terminals according to the Hall effect. When the excitation current I is constant, the stronger the magnetic field intensity B, the higher the Hall electromotive force E, and the direction of the magnetic field is opposite, the direction of the Hall electromotive force also changes.

[0083] In a preferred embodiment, the magnetic field strength B measured over time T under normal circumstances should be as follows: Figure 8 As shown, when the measured magnetic field strength is Fig. 9 When it is shown, it indicates that the local magnetic field is abnormal. It can be preliminarily determined that the permanent magnet 6 is defective or demagnetized. At this time, the machine is shut down to send out an alarm signal and contact the external Internet of Things system 8 to notify the maintenance personnel to maintain or replace the permanent magnet 6 in time. This can avoid major elevator accidents caused by the defect or demagnetization of the permanent magnet 6 and improve the safety of the elevator system operation.

[0084] In a preferred embodiment, Fig.10 As shown, the processing module 7 also has an alarm submodule 701, which is connected to the external Internet of Things system 8 and generates a fault signal according to the fault condition of the permanent magnet synchronous traction machine and sends it to the external Internet of Things system 8.

[0085] In a preferred embodiment, the processing module 7 calculates the rotation speed of the permanent magnet synchronous traction machine according to the magnetic field signal.

[0086] Specifically, when the magnetic field sensor 202 detects that the rotor 4 is in a rotating state and there is no sudden change in the magnetic field strength, the real-time speed of the traction machine can be calculated based on the number of permanent magnets 6 input in advance and the detected magnetic field change period, thereby realizing the monitoring of the real-time speed of the traction machine.

[0087] Furthermore, when the rotation speed exceeds the safe range, the detection device can also send out an alarm signal, shut down the machine and contact the external Internet of Things system 8 to notify relevant personnel to deal with the abnormal operating state of the traction machine to avoid major safety accidents.

[0088] A monitoring method for a permanent magnet synchronous traction machine is applicable to the above-mentioned monitoring device, wherein the temperature sensor of the monitoring device continuously monitors the temperature of the braking surface of the rotor 4 and generates a temperature signal, and the magnetic field sensor of the monitoring device continuously monitors the magnetic field of the permanent magnet 6 and generates a magnetic field signal, such as Fig.11 As shown, the monitoring method specifically includes:

[0089] Step S1: generating a rotation state parameter according to a magnetic field signal;

[0090] The rotation state parameter is used to indicate whether the rotor 4 is in a rotating state or a stationary state;

[0091] Specifically, the magnetic field sensor 202 detects the direction of the magnetic field intensity of the permanent magnet 6 in real time. When it is detected that the magnetic field intensity is changing in real time, it means that the rotor 4 is in a rotating state, otherwise it means that the rotor 4 is in a stationary state.

[0092] Step S2: judging whether the temperature of the braking surface is within a safe temperature range according to the temperature signal, and judging whether the permanent magnet 6 has a sudden change in strength according to the magnetic field signal;

[0093] When the temperature is within the safe range and there is no sudden change in the strength of the permanent magnet 6, proceed to step S3;

[0094] When the temperature is not within the safe range and the permanent magnet 6 does not have a sudden change in strength, go to step S6;

[0095] When the temperature is within the safe range and the permanent magnet 6 has a sudden change in strength, go to step S7;

[0096] When the temperature is not within the safe range and the permanent magnet 6 has a sudden change in strength, go to step S8;

[0097] Step S3: judging whether the rotor 4 is in a rotating state according to the rotation state parameter;

[0098] If yes, go to step S4;

[0099] If not, output the shutdown status signal and the temperature signal to the external Internet of Things system 8, and then return to step S1;

[0100] Specifically, when the processing module 7 determines that the rotor 4 is in a stationary state through the real-time magnetic field strength output by the magnetic field sensor 202 and the temperature sensor 201 detects that the temperature is in a safe range, it can be determined that the traction machine is in a normal shutdown state at this time.

[0101] Step S4: outputting the temperature signal to the external IoT system 8 and calculating the rotation speed of the rotor 4;

[0102] Step S5: Determine whether the rotation speed exceeds the threshold value;

[0103] If yes, an overspeed fault signal is output to the external IoT system 8, and then the process returns to step S1;

[0104] If not, output the speed signal to the external IoT system 8 and then return to step S1.

[0105] Step S6: Determine the temperature fault type according to the temperature signal, output the temperature fault signal to the external Internet of Things system 8, and then return to step S1.

[0106] Step S7: Output a permanent magnet fault signal to the external Internet of Things system 8, and then return to step S1.

[0107] Specifically, if the permanent magnet 6 exists as Fig. 9 The sudden change in intensity shown indicates that the permanent magnet 6 is defective or demagnetized. At this time, the machine is shut down to send out an alarm signal and contact the external Internet of Things system 8 to notify the maintenance personnel to maintain or replace the permanent magnet 6 in time, which can avoid major elevator accidents caused by the defect or demagnetization of the permanent magnet 6 and improve the safety of the elevator system operation.

[0108] Step S8: Determine the temperature fault type according to the temperature signal, output the temperature fault signal to the external Internet of Things system 8, and simultaneously output the permanent magnet fault signal to the external Internet of Things system 8, and then return to step S1.

[0109] In a preferred embodiment, Fig.12 As shown, step S4 also includes:

[0110] Step S41: outputting a temperature signal to an external IoT system 8;

[0111] Step S42: obtaining the number of permanent magnets 6 of the permanent magnet synchronous traction machine;

[0112] Step S43: calculating the period of the magnetic field signal;

[0113] Step S44: Calculate the rotation speed according to the number of permanent magnets 6 and the magnetic field signal period.

[0114] Specifically, when the processing module 7 determines through the real-time magnetic field strength output by the magnetic field sensor 202 that the rotor 4 is in a rotating state and there is no sudden change in the magnetic field strength, the real-time speed of the traction machine can be output according to the number of permanent magnets 6 input in advance and the detected magnetic field change cycle, thereby realizing the monitoring of the real-time speed of the traction machine. When the speed exceeds the safe range, the detection device sends an alarm signal, shuts down and communicates to the outside, notifying relevant personnel to respond to the abnormal operating state of the traction machine to avoid major safety accidents.

[0115] In a preferred embodiment, Fig.13 As shown, step S6 also includes:

[0116] Step S61: determining whether the braking surface is heated up rapidly;

[0117] If so, output an abnormal temperature fault signal to the external IoT system 8;

[0118] If not, go to step S62;

[0119] Step S62: judging whether the rotor 4 is in a rotating state according to the rotation state parameter;

[0120] If yes, output a brake fault signal to the external IoT system 8, and then return to step S1;

[0121] If not, a stator over-temperature fault signal is output to the external Internet of Things system 8, and then the process returns to step S1.

[0122] Specifically, when the processing module 7 determines that the rotor 4 is rotating through the real-time magnetic field strength output by the magnetic field sensor 202, and at the same time the temperature sensor 201 detects that the temperature of the braking surface exceeds the safe range and is accompanied by a rapid temperature rise, that is, the temperature rise within the set duration ΔT exceeds the set threshold Δt, it can be preliminarily determined that the traction machine has a braking device 5 that is not lifted normally in the running state. At this time, the alarm submodule 701 sends an alarm signal, shuts down and contacts the external Internet of Things system 8, notifying the relevant maintenance personnel to turn to troubleshooting and repair the situation where the device 5 is not lifted normally, so as to avoid causing major safety accidents and eliminate safety hazards.

[0123] Furthermore, when the processing module 7 determines that the rotor 4 is stationary through the real-time magnetic field strength output by the magnetic field sensor 202, and at the same time the temperature sensor 201 detects that the temperature of the braking surface exceeds the safe range and is accompanied by a rapid temperature rise, that is, the temperature rise within the set duration ΔT exceeds the set threshold Δt, it can be preliminarily determined that the traction machine is in an abnormal shutdown state, and the temperature change is caused by the abnormal heating of the stator winding in the coil 1. At this time, an alarm signal is issued, the machine is shut down and the external Internet of Things system 8 is contacted to notify the maintenance personnel to promptly troubleshoot and respond to the abnormal heating of the stator winding, so as to avoid major elevator accidents caused by this and improve the safety of the elevator system operation.

[0124] The beneficial effects of the present invention are: the temperature of the rotor braking surface and the magnetic field change of the permanent magnet are respectively detected by the temperature sensor and the magnetic field sensor, and a relatively accurate fault judgment result is generated through comprehensive judgment, which has high accuracy and good detection effect. At the same time, it is also connected to an external Internet of Things system to facilitate reporting of fault conditions and turning to fault repair.

[0125] Those skilled in the art will appreciate that various aspects of the present invention, or possible implementations of various aspects, can be specifically implemented as systems, methods or computer program products. Therefore, various aspects of the present invention, or possible implementations of various aspects, can adopt the form of complete hardware embodiments, complete software embodiments (including firmware, resident software, etc.), or combined software and hardware embodiments, all collectively referred to as "circuit", "module" or "system" here. In addition, various aspects of the present invention, or possible implementations of various aspects, can adopt the form of computer program products, which refer to computer-readable program codes stored in computer-readable media.

[0126] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. The computer readable storage medium includes but is not limited to electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or apparatuses, or any suitable combination of the foregoing, such as random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable read-only memory (CD-ROM).

[0127] The processor in the computer reads the computer-readable program code stored in the computer-readable medium, so that the processor can execute the functional actions specified in each step or the combination of steps in the flowchart; and generate a device for implementing the functional actions specified in each block or the combination of blocks in the block diagram.

[0128] It should be understood that the processing module 7 can be understood as one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers (MCUs), microprocessors, or other electronic components, and is used to execute the aforementioned monitoring method, or execute computer-readable program codes for implementing the aforementioned monitoring method.

[0129] Computer readable program code can be executed completely on the local computer of the user, partially on the local computer of the user, as a separate software package, partially on the local computer of the user and partially on the remote computer, or executed completely on the remote computer or server.It should also be noted that in some alternative embodiments, the functions noted in each step in the flow chart or each block in the block diagram may not occur in the order noted in the figure.For example, depending on the function involved, two steps shown in succession or two blocks may actually be executed roughly simultaneously, or these blocks may sometimes be executed in reverse order.

[0130] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A monitoring method for a permanent magnet synchronous traction machine, characterized in that: A monitoring device applicable to a permanent magnet synchronous traction machine, wherein the temperature sensor of the monitoring device continuously monitors the temperature of the braking surface of the rotor and generates a temperature signal, and the magnetic field sensor of the monitoring device continuously monitors the magnetic field of the permanent magnet and generates a magnetic field signal. The monitoring method specifically includes: Step S1: generating a rotation state parameter according to the magnetic field signal; The rotation state parameter is used to indicate whether the rotor is in a rotation state or a stationary state; Step S2: judging whether the temperature of the braking surface is within a safe temperature range according to the temperature signal, and judging whether there is a sudden change in the strength of the permanent magnet according to the magnetic field signal; When the temperature is within a safe range and there is no sudden change in the strength of the permanent magnet, proceed to step S3; When the temperature is not within the safe range and there is no sudden change in the strength of the permanent magnet, proceed to step S6; When the temperature is within the safe range and the permanent magnet has a sudden change in strength, go to step S7; When the temperature is not within the safe range and the permanent magnet has a sudden change in strength, go to step S8; Step S3: judging whether the rotor is in a rotating state according to the rotation state parameter; If yes, go to step S4; If not, output the shutdown status signal and the temperature signal to the external Internet of Things system, and then return to step S1; Step S4: outputting the temperature signal to the external IoT system and calculating the rotation speed of the rotor; Step S5: determining whether the rotation speed exceeds a threshold value; If yes, output an overspeed fault signal to the external IoT system, and then return to step S1; If not, output the speed signal to the external IoT system, and then return to step S1; Step S6: determining the temperature fault type according to the temperature signal, outputting the temperature fault signal to the external Internet of Things system, and then returning to step S1; Step S7: outputting a permanent magnet fault signal to an external Internet of Things system, and then returning to step S1; Step S8: Determine the temperature fault type according to the temperature signal, output the temperature fault signal to the external Internet of Things system, and simultaneously output the permanent magnet fault signal to the external Internet of Things system, and then return to step S1.

2. The monitoring method according to claim 1, characterized in that: The step S4 further comprises: Step S41: outputting the temperature signal to the external Internet of Things system; Step S42: obtaining the number of permanent magnets of the permanent magnet synchronous traction machine; Step S43: calculating the period of the magnetic field signal; Step S44: Calculate the rotation speed according to the number of permanent magnets and the magnetic field signal period.

3. The monitoring method according to claim 1, characterized in that: The step S6 further comprises: Step S61: determining whether the braking surface is heated up rapidly; If so, output an abnormal temperature fault signal to the external IoT system; If not, go to step S62; Step S62: judging whether the rotor is in a rotating state according to the rotation state parameter; If yes, output a brake fault signal to the external IoT system, and then return to step S1; If not, output a stator over-temperature fault signal to the external Internet of Things system, and then return to step S1.

4. The monitoring method according to claim 1, characterized in that: The monitoring device comprises: A mounting plate, on which the temperature sensor and the magnetic field sensor are arranged, and the mounting plate is connected and fixed to a housing of the permanent magnet synchronous traction machine; The temperature sensor is used to sense the temperature of the braking surface of the rotor of the permanent magnet synchronous traction machine and generate a temperature signal; The magnetic field sensor is used to sense the magnetic field of the permanent magnet of the permanent magnet synchronous traction machine and generate a magnetic field signal; A processing module is connected to the temperature sensor and the magnetic field sensor signal and receives the temperature signal and the magnetic field signal, and determines the fault condition of the permanent magnet synchronous traction machine to generate a fault signal and send it to an external Internet of Things system.

5. The monitoring method according to claim 4, characterized in that: The mounting plate has a temperature sensor bracket, which is vertically arranged on the mounting plate and extends from the mounting plate to a gap between the brake device of the permanent magnet synchronous traction machine and the rotor of the permanent magnet synchronous traction machine; The temperature sensor is arranged on a side of the temperature sensor bracket facing the braking surface of the rotor.

6. The monitoring method according to claim 5, characterized in that: The braking device is disposed on the inner side of the rotor or on the outer side of the rotor.

7. The monitoring method according to claim 4, characterized in that: The magnetic field sensor is vertically arranged on the mounting plate, and extends from the mounting plate to the gap between the coil of the permanent magnet synchronous traction machine and the rotor; The permanent magnet is arranged on the rotor.

8. The monitoring method according to claim 4, characterized in that: The processing module also has an alarm submodule, which is connected to the external Internet of Things system and generates a fault signal according to the fault condition of the permanent magnet synchronous traction machine and sends it to the external Internet of Things system.

9. The monitoring method according to claim 5, characterized in that: The processing module calculates the rotation speed of the permanent magnet synchronous traction machine according to the magnetic field signal.

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