Deep-cone thickener rake frame driving method and system based on permanent magnet motor

Abstract

The invention discloses a deep-cone thickener rake frame driving method and system based on a permanent magnet motor, and belongs to the technical field of mine solid waste disposal and filling, and the method comprises the following steps: collecting real-time operation parameters of the permanent magnet motor, the real-time operation parameters including stator current, voltage, rotating speed and output torque; based on the output torque, whether the deep-cone thickener is in a rake pressing state or not is recognized, and when the deep-cone thickener is in the rake pressing state, the reference rotating speed of the permanent magnet motor is controlled to be reduced; the real-time temperature of a stator winding and a rotor permanent magnet area in the permanent magnet motor is obtained, and when the real-time temperature is higher than a preset threshold value, the output power of the permanent magnet motor is controlled; acquiring historical load data of the deep-cone thickener, and modeling the historical load data and the output torque to obtain a historical load-torque model; and constructing a torque change prediction model based on the historical load-torque model, predicting future torque data by using the torque change prediction model, and identifying an impending rake pressing risk.

Description

Technical Field

[0001] The present invention belongs to the technical field of mine solid waste disposal and filling, and in particular relates to a deep cone thickener rake driving method and system based on a permanent magnet motor. Background Art

[0002] The deep-cone thickener is a key piece of equipment for tailings slurry thickening. Its primary function is to increase slurry concentration, form a high-concentration underflow, and achieve continuous, deep dehydration in one stage. This equipment is widely used in mine backfill systems, directly impacting filling efficiency and operational continuity.

[0003] During thickener operation, the rake system plays an important role, primarily for removing free water trapped in flocs, promoting floc sedimentation, and clearing bottom material, ensuring a smooth and stable slurry thickening process. Currently, there are two mainstream rake drive methods: the first is hydraulic drive, which uses a hydraulic motor to drive the rake rotation. However, this method has a complex structure, poor operational stability, and high maintenance costs and is prone to leakage in the hydraulic system. The second is asynchronous motor + reducer drive, which uses an ordinary three-phase asynchronous motor with a reduction mechanism to achieve low-speed, high-torque output. Although this method has a simple structure, it has low operating efficiency under low-speed and heavy-load conditions, resulting in high heat loss and slow response, making it difficult to meet the requirements for stable operation under complex load conditions.

[0004] In actual production, traditional drive systems are more prone to "rake crushing" accidents under the following two typical operating conditions: This occurs when the rake frame is unable to rotate normally despite the resistance of the mud layer. First, when the deep-cone thickener stores tailings slurry for an extended period without filling, the mud layer gradually hardens and the resistance increases dramatically. Second, improper flocculant selection or a sudden increase in the thickener feed concentration or flow rate disrupts the coordinated flocculation and settling process of coarse and fine particles in the tailings, forming a heterogeneous mud layer and increasing local resistance. When equipment faces the risk of "rake crushing," failure to take timely action can result in equipment downtime or even thickening system failure, seriously impacting the continuity and safety of mine filling operations.

[0005] Therefore, it is urgent to propose a new rake drive method with high energy efficiency, fast dynamic response and low-speed high torque output capability, so as to improve the operating stability and automation control level of the deep cone thickener under complex working conditions, effectively reduce the risk of rake pressure, and ensure the efficient and continuous operation of the filling system. Summary of the Invention

[0006] The present invention aims to solve the deficiencies of the prior art and provides the following solutions:

[0007] A method for driving a deep cone thickener rake frame based on a permanent magnet motor comprises the following steps:

[0008] Collecting real-time operating parameters of the permanent magnet motor, the real-time operating parameters including: stator current, voltage, speed and output torque;

[0009] identifying, based on the output torque, whether the deep cone thickener is in a rake pressure state, and controlling to reduce a reference speed of the permanent magnet motor when in the rake pressure state;

[0010] Acquiring real-time temperatures of the stator winding and the rotor permanent magnet region of the permanent magnet motor, and controlling the output power of the permanent magnet motor when the real-time temperatures are higher than a preset threshold;

[0011] Acquiring historical load data of a deep cone thickener, and modeling the historical load data and the output torque to obtain a historical load-torque model;

[0012] Based on the historical load-torque model, a torque change prediction model is constructed, and the torque change prediction model is used to predict future torque data to identify the impending raking risk.

[0013] Preferably, the method for calculating the output torque includes:

[0014]

[0015] Where T(t) represents the output torque, p represents the number of pole pairs, and Ψ f Represents the rotor flux constant, I q (t) represents the q-axis current component of the stator current.

[0016] Preferably, the method for identifying whether the deep cone thickener is in the rake pressure state includes:

[0017] Calculate the first derivative of the output torque

[0018] Three judgment conditions are constructed based on the output torque and the first-order derivative:

[0019]

[0020] Among them, δ1 represents the preset sudden increase threshold, T max γ represents the rated torque upper limit, γ represents the over-limit proportional coefficient, Δt represents the duration of the torque change, t represents the current time, τ represents a time within the time interval starting from the current time t, and Δt0 represents the minimum duration threshold;

[0021] When the three judgment conditions are met at the same time, it is determined that the deep cone thickener is in the rake pressure state.

[0022] Preferably, the method for controlling and reducing the reference speed of the permanent magnet motor includes:

[0023] ω ref (t+1)=ω ref(t)·β (β<1),

[0024] Among them, ω ref (t+1) represents the reference speed after adjustment, ω ref (t) represents the reference speed before adjustment, and β represents the deceleration factor.

[0025] Preferably, the method for obtaining the historical load-torque model includes:

[0026] Obtain the historical load data L(t) of the deep cone thickener;

[0027] The historical load data L(t) is used as input, and the output torque T(t) is used as output. The historical load data and the output torque are modeled using a polynomial fitting method to obtain a historical load-torque model:

[0028] T(t)=a0+a1L(t)+a2L 2 (t)+…+a n L n (t)+ε(t),

[0029] i=0,1,2,...,n,

[0030] Among them, ε(t) represents the model error term, a i Represents the coefficients of the polynomial.

[0031] The present invention also provides a deep cone thickener rake drive system based on a permanent magnet motor, wherein the system applies any of the above methods and comprises: a parameter acquisition module, a speed control module, a power control module, a model building module and a risk prediction module;

[0032] The parameter acquisition module is used to acquire real-time operating parameters of the permanent magnet motor, and the real-time operating parameters include: stator current, voltage, speed and output torque;

[0033] The speed control module identifies whether the deep cone thickener is in a rake pressure state based on the output torque, and controls to reduce a reference speed of the permanent magnet motor when the deep cone thickener is in the rake pressure state.

[0034] The power control module is used to obtain the real-time temperature of the stator winding and the rotor permanent magnet area in the permanent magnet motor, and when the real-time temperature is higher than a preset threshold, control the output power of the permanent magnet motor;

[0035] The model building module is used to obtain historical load data of the deep cone thickener, model the historical load data and the output torque, and obtain a historical load-torque model;

[0036] The risk prediction module constructs a torque change prediction model based on the historical load-torque model, and uses the torque change prediction model to predict future torque data to identify impending raking risks.

[0037] Preferably, in the parameter acquisition module, the calculation process of the output torque includes:

[0038]

[0039] Where T(t) represents the output torque, p represents the number of pole pairs, and Ψ f Represents the rotor flux constant, I q (t) represents the q-axis current component of the stator current.

[0040] Preferably, in the speed control module, the process of identifying whether the machine is in the rake pressing state includes:

[0041] Calculate the first derivative of the output torque

[0042] Three judgment conditions are constructed based on the output torque and the first-order derivative:

[0043]

[0044] Among them, δ1 represents the preset sudden increase threshold, T max γ represents the rated torque upper limit, γ represents the over-limit proportional coefficient, Δt represents the duration of the torque change, t represents the current time, τ represents a time within the time interval starting from the current time t, and Δt0 represents the minimum duration threshold;

[0045] When the three judgment conditions are met at the same time, it is determined that the deep cone thickener is in the rake pressure state.

[0046] Preferably, in the speed control module, the process of controlling the reduction of the reference speed includes:

[0047] ω ref (t+1)=ω ref (t)·β (β<1),

[0048] Among them, ω ref (t+1) represents the reference speed after adjustment, ω ref (t) represents the reference speed before adjustment, and β represents the deceleration factor.

[0049] Preferably, the model building module constructs the historical load-torque model in a process that includes:

[0050] Obtain the historical load data L(t) of the deep cone thickener;

[0051] The historical load data L(t) is used as input, and the output torque T(t) is used as output. The historical load data and the output torque are modeled using a polynomial fitting method to obtain a historical load-torque model:

[0052] T(t)=a0+a1L(t)+a2L 2 (t)+…+a n L n (t)+ε(t),

[0053] i=0,1,2,...,n,

[0054] Among them, ε(t) represents the model error term, a i Represents the coefficients of the polynomial.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] The present invention introduces two configurations: a permanent magnet synchronous motor and a permanent magnet direct drive motor. The permanent magnet synchronous motor achieves high torque output through a reducer, which is suitable for situations where there are certain restrictions on the structural layout space but high driving capacity must be guaranteed. The permanent magnet direct drive motor omits the reduction mechanism, has a simpler and more compact structure, and has higher transmission efficiency. It is particularly suitable for application scenarios with ample space and higher requirements for response speed and system maintenance convenience. Both methods can be flexibly selected according to specific on-site working conditions to improve system adaptability and engineering versatility. The permanent magnet motor system has better dynamic response and control accuracy. Through the matching servo control system, precise speed regulation and real-time torque control are achieved, and the operating parameters can be intelligently adjusted according to the rake frame load status. When the initial signs of "rake pressure" appear during the operation of the thickener, the system can quickly respond and execute deceleration or shutdown instructions, significantly reducing the risk of accidents and improving the safety of the entire machine operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0058] Figure 1 Schematic diagram of a method flow in an embodiment of the present invention. DETAILED DESCRIPTION

[0059] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0060] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0061] Example 1

[0062] In this embodiment, the permanent magnet motor is a permanent magnet synchronous motor with a rated power of 315kW, an output speed of 750r / min, and a rated torque of approximately 4000N·m. The output end of the motor is connected to the rake center transmission device through a planetary-worm gear composite reducer with a reduction ratio of approximately 1:3000. After multi-stage transmission, the final output meets the working requirements of 0.25r / min and 1.8 million N·m. The reducer adopts a reinforced support structure that can effectively withstand the resistance load generated by high-concentration slurry. The motor is equipped with a servo drive control system for real-time acquisition of the operating parameters of the permanent magnet motor, including current, voltage, speed and output torque, and adaptive adjustment based on the load change trend of the thickener rake. The servo system can establish a load-torque model based on historical data, predict future torque change trends, identify impending rake pressure risks in advance, automatically slow down and issue an early warning to avoid equipment damage.

[0063] Specifically, such as Figure 1 As shown, a method for driving a deep cone thickener rake frame based on a permanent magnet motor includes the following steps:

[0064] S1. Collect real-time operating parameters of the permanent magnet synchronous motor, including stator current I(t), voltage V(t), speed ω(t), and output torque T(t).

[0065] The calculation method of output torque includes:

[0066]

[0067] Where T(t) represents the output torque, p represents the number of pole pairs, and Ψ f Represents the rotor flux constant, I q (t) represents the q-axis current component of the stator current.

[0068] S2. Based on the output torque, identify whether the deep cone thickener is in the rake pressing state. When in the rake pressing state, control to reduce the reference speed of the permanent magnet synchronous motor.

[0069] The method for identifying whether the deep cone thickener is in the rake state includes: calculating the first derivative of the output torque Three judgment conditions are constructed based on the output torque and the first-order derivative:

[0070]

[0071] Among them, δ1 represents the preset sudden increase threshold, T max γ represents the rated torque upper limit, γ represents the over-limit ratio coefficient, Δt represents the duration of the torque change, t represents the current time, τ represents a time in the time interval starting from the current time t, and Δt0 represents the minimum duration threshold; when all three judgment conditions are met at the same time, that is, if the derivative is greater than the preset sudden increase threshold δ1, and the current torque T(t) exceeds the rated torque upper limit T max γ (where γ is the over-limit proportional coefficient, usually 1.1 to 1.3), and it lasts for a period of time Δt, then the deep cone thickener is determined to be in the rake pressure state.

[0072] The method of controlling and reducing the reference speed of a permanent magnet synchronous motor includes:

[0073] ω ref (t+1)=ω ref (t)·β (β<1),

[0074] Among them, ω ref (t+1) represents the reference speed after adjustment, ω ref (t) represents the reference speed before adjustment, and β represents the deceleration factor.

[0075] S3. Acquire the real-time temperature of the stator winding and the rotor permanent magnet region in the permanent magnet synchronous motor. When the real-time temperature is higher than a preset threshold, control the output power of the permanent magnet synchronous motor.

[0076] In this embodiment, in order to prevent the permanent magnet from demagnetizing under high temperature conditions, the motor is internally integrated with temperature monitoring modules, which are respectively arranged in the stator winding and the rotor permanent magnet area to collect the real-time temperature T of the stator winding. s (t), real-time temperature T of the rotor permanent magnet area r (t). The system has built-in high temperature threshold judgment logic: when the temperature exceeds T lim When the servo system is in operation, the driver will automatically limit the motor output and trigger shutdown protection when necessary. The servo system has built-in judgment logic:

[0077] T s (t)>T lim or T r (t)>T lim ,

[0078] Among them, T limIt is usually set to 100°C. If the limit is exceeded, the system limits the motor output power and triggers a shutdown if necessary.

[0079] S4. Obtain historical load data of the deep cone thickener, model the historical load data and output torque, and obtain a historical load-torque model.

[0080] The method for obtaining the historical load-torque model includes: obtaining historical load data L(t) of the deep cone thickener. In this embodiment, the historical load data L(t) is a function of multi-dimensional parameters such as mud layer height, underflow concentration, and rake resistance; using the historical load data L(t) as input and the output torque T(t) as output, a polynomial fitting method is used to model the historical load data and the output torque to obtain the historical load-torque model:

[0081] T(t)=a0+a1L(t)+a2L 2 (t)+…+a n L n (t)+ε(t),

[0082] i=0,1,2,...,n,

[0083] Among them, ε(t) represents the model error term, a i Represents the coefficients of the polynomial.

[0084] S5. Based on the historical load-torque model, a torque change prediction model is constructed. The torque change prediction model is used to predict future torque data and identify the impending rake pressure risk.

[0085] In this embodiment, taking the LSTM neural network as an example, a torque change prediction model is constructed based on the historical load-torque model:

[0086]

[0087] If the predicted value Significantly different from the current value, that is:

[0088]

[0089] If this condition is met for multiple consecutive cycles, the impending harrowing risk can be identified in advance and active warning can be achieved.

[0090] Example 2

[0091] In this embodiment, a deep cone thickener rake drive system based on a permanent magnet motor includes: a parameter acquisition module, a speed control module, a power control module, a model building module and a risk prediction module.

[0092] The parameter acquisition module is used to collect the real-time operating parameters of the permanent magnet motor, which include: stator current, voltage, speed and output torque.

[0093] In the parameter acquisition module, the calculation process of the output torque includes:

[0094]

[0095] Where T(t) represents the output torque, p represents the number of pole pairs, and Ψ f Represents the rotor flux constant, I q (t) represents the q-axis current component of the stator current.

[0096] The speed control module identifies whether the deep cone thickener is in a rake pressing state based on the output torque, and controls to reduce the reference speed of the permanent magnet motor when in the rake pressing state.

[0097] In the speed control module, the process of identifying whether it is in the rake pressure state includes: calculating the first-order derivative of the output torque Three judgment conditions are constructed based on the output torque and the first-order derivative:

[0098]

[0099] Among them, δ1 represents the preset sudden increase threshold, T max γ represents the rated torque upper limit, γ represents the over-limit proportional coefficient, Δt represents the duration of the torque change, t represents the current time, τ represents a time within the time interval starting from the current time t, and Δt0 represents the minimum duration threshold. When all three judgment conditions are met at the same time, the deep cone thickener is determined to be in the rake state.

[0100] In the speed control module, the process of controlling the reduction of the reference speed includes:

[0101] ω ref (t+1)=ω ref (t)·β (β<1),

[0102] Among them, ω ref (t+1) represents the reference speed after adjustment, ω ref (t) represents the reference speed before adjustment, and β represents the deceleration factor.

[0103] The power control module is used to obtain the real-time temperature of the stator winding and rotor permanent magnet area in the permanent magnet motor. When the real-time temperature is higher than a preset threshold, the output power of the permanent magnet motor is controlled.

[0104] The model building module is used to obtain the historical load data of the deep cone thickener, model the historical load data and output torque, and obtain a historical load-torque model.

[0105] The model building module constructs the historical load-torque model through the following steps: obtaining the historical load data L(t) of the deep cone thickener; using the historical load data L(t) as input and the output torque T(t) as output, modeling the historical load data and output torque using polynomial fitting to obtain the historical load-torque model:

[0106] T(t)=a0+a1L(t)+a2L 2 (t)+…+a n L n (t)+ε(t),

[0107] i=0,1,2,...,n,

[0108] Among them, ε(t) represents the model error term, a i Represents the coefficients of the polynomial.

[0109] The risk prediction module builds a torque change prediction model based on the historical load-torque model, and uses the torque change prediction model to predict future torque data and identify the impending rake risk.

[0110] Example 3

[0111] In this embodiment, a deep cone thickener rake frame drive system based on a permanent magnet direct drive motor (PDD) is also provided, which is suitable for working conditions with a relatively open rake frame structure, good spatial layout conditions, and high requirements for drive response speed.

[0112] The permanent magnet direct-drive motor used has a customized outer rotor structure with a rated power of 500kW, a rated speed of 0.25r / min, and an output rated torque of 2.2 million N·m. It does not require any intermediate transmission mechanism. Its output shaft is directly connected to the thickener rake frame main shaft through a flexible coupling to achieve gapless direct transmission.

[0113] To meet the stringent thermal management requirements of high-torque density operation, this permanent magnet motor incorporates an active cooling system with embedded liquid cooling pipes. These cooling pipes are arranged in a spiral pattern around the stator core and rotor magnets, forming a closed-loop cooling circuit. Equipped with a variable-frequency water pump, a water-cooled radiator, and a temperature control controller, the system dynamically adjusts cooling intensity based on operating temperature, ensuring controlled temperature rise in the motor's core, preventing demagnetization of the permanent magnet material under high-temperature and high-load conditions, and significantly improving the motor's operating safety and service life.

[0114] The system control part adopts a high-performance servo drive controller and a three-level closed-loop control architecture of "current loop-speed loop-torque loop" to adapt to the low-speed, high-torque and no-intermediate-transmission operating characteristics of the permanent magnet direct-drive motor. The inner current loop is fed back in real time by the q-axis current I q With reference value Iq ref The error between them is PI regulated to achieve the electromagnetic torque T = k t I q Precise control; the intermediate speed loop is based on the actual angular velocity ω and the target speed ω ref The deviation between the reference current I q ref , which is further transmitted to the current loop to realize dynamic speed control; the outer torque loop takes the system load demand as input to adjust the speed target value, thereby achieving rapid response and steady-state stability control of the overall system operation status.

[0115] In order to realize intelligent recognition and response to the complex rake resistance changes in the deep cone thickening process, the drive controller has a built-in Torque change rate and speed change trend The system dynamically constructs the operating characteristic curve F(t)=[I q (t), T(t), ω(t)], and perform window smoothing and mutation point identification on its first-order derivative sequence. When the judgment function satisfies:

[0116]

[0117] The system will immediately switch to deceleration buffer mode and actively reduce the reference speed:

[0118] ω ref (t+1)=β·ω ref (t) β∈(0.3, 0.8),

[0119] At the same time, an early warning signal is sent to the host computer platform. If the trend continues to intensify, the controller will enter safety protection mode and automatically perform a shutdown operation to avoid overload damage to the drive system caused by the rake. To achieve high-precision angular displacement control, the system uses a high-resolution absolute encoder to achieve micro-angle detection accuracy and support position closed-loop control and slow-speed drag operation mode. In terms of data interaction, the servo controller supports a variety of industrial communication protocols and can be seamlessly integrated into the mine's centralized control platform to achieve remote start-stop control, status monitoring, fault recording and historical data analysis, supporting the system's high-reliability operation in intelligent dense operations.

[0120] In addition, the control system reserves interfaces for data collection and model training, which can integrate a trend prediction model based on the long short-term memory network (LSTM). This model uses historical current, speed, and torque data sequences within a sliding time window for learning and modeling, enabling early identification of "rake pressure risks" within future short time intervals. The prediction model structure is as follows:

[0121]

[0122] When the predicted value meets the preset threshold The controller can proactively enter early warning mode to improve fault response speed and equipment safety redundancy.

[0123] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for driving a deep cone thickener rake frame based on a permanent magnet motor, characterized in that: The following steps are involved: Collecting real-time operating parameters of the permanent magnet motor, the real-time operating parameters including: stator current, voltage, speed and output torque; identifying, based on the output torque, whether the deep cone thickener is in a rake pressure state, and controlling to reduce a reference speed of the permanent magnet motor when in the rake pressure state; Acquiring real-time temperatures of the stator winding and the rotor permanent magnet region of the permanent magnet motor, and controlling the output power of the permanent magnet motor when the real-time temperatures are higher than a preset threshold; Acquiring historical load data of a deep cone thickener, and modeling the historical load data and the output torque to obtain a historical load-torque model; Based on the historical load-torque model, a torque change prediction model is constructed, and the torque change prediction model is used to predict future torque data to identify the impending raking risk.

2. The method for driving a deep cone thickener rake frame based on a permanent magnet motor according to claim 1, characterized in that: The method for calculating the output torque includes: Where T(t) represents the output torque, p represents the number of pole pairs, and Ψ f Represents the rotor flux constant, I q (t) represents the q-axis current component of the stator current.

3. The method for driving a deep cone thickener rake frame based on a permanent magnet motor according to claim 2, characterized in that: The method for identifying whether the deep cone thickener is in the rake pressing state includes: Calculate the first derivative of the output torque Three judgment conditions are constructed based on the output torque and the first-order derivative: Among them, δ1 represents the preset sudden increase threshold, T max γ represents the rated torque upper limit, γ represents the over-limit proportional coefficient, Δt represents the duration of the torque change, t represents the current time, τ represents a time within the time interval starting from the current time t, and Δt0 represents the minimum duration threshold; When the three judgment conditions are met at the same time, it is determined that the deep cone thickener is in the rake pressure state.

4. The method for driving a deep cone thickener rake frame based on a permanent magnet motor according to claim 1, characterized in that: The method for controlling and reducing the reference speed of the permanent magnet motor includes: oh ref (t+1)=ω ref (t)·β (β<1), Among them, ω ref (t+1) represents the reference speed after adjustment, ω ref (t) represents the reference speed before adjustment, and β represents the deceleration factor.

5. The method for driving a deep cone thickener rake frame based on a permanent magnet motor according to claim 2, characterized in that: The method for obtaining the historical load-torque model includes: Obtain the historical load data L(t) of the deep cone thickener; The historical load data L(t) is used as input, and the output torque T(t) is used as output. The historical load data and the output torque are modeled using a polynomial fitting method to obtain a historical load-torque model: T(t)=a0+a1L(t)+a2L 2 (t)+…+a n L n (t)+ε(t), i=0,1,2,...,n, Among them, ε(t) represents the model error term, a i Represents the coefficients of the polynomial.

6. A deep cone thickener rake drive system based on a permanent magnet motor, wherein the system applies the method according to any one of claims 1 to 5, characterized in that: include: Parameter acquisition module, speed control module, power control module, model building module and risk prediction module; The parameter acquisition module is used to acquire real-time operating parameters of the permanent magnet motor, and the real-time operating parameters include: stator current, voltage, speed and output torque; The speed control module identifies whether the deep cone thickener is in a rake pressure state based on the output torque, and controls to reduce a reference speed of the permanent magnet motor when the deep cone thickener is in the rake pressure state. The power control module is used to obtain the real-time temperature of the stator winding and the rotor permanent magnet area in the permanent magnet motor, and when the real-time temperature is higher than a preset threshold, control the output power of the permanent magnet motor; The model building module is used to obtain historical load data of the deep cone thickener, model the historical load data and the output torque, and obtain a historical load-torque model; The risk prediction module constructs a torque change prediction model based on the historical load-torque model, and uses the torque change prediction model to predict future torque data to identify impending raking risks.

7. The deep cone thickener rake drive system based on a permanent magnet motor according to claim 6, characterized in that: In the parameter acquisition module, the calculation process of the output torque includes: Where T(t) represents the output torque, p represents the number of pole pairs, and Ψ f Represents the rotor flux constant, I q (t) represents the q-axis current component of the stator current.

8. The deep cone thickener rake drive system based on a permanent magnet motor according to claim 7, characterized in that: In the speed control module, the process of identifying whether the machine is in the rake pressing state includes: Calculate the first derivative of the output torque Three judgment conditions are constructed based on the output torque and the first-order derivative: Among them, δ1 represents the preset sudden increase threshold, T max γ represents the rated torque upper limit, γ represents the over-limit proportional coefficient, Δt represents the duration of the torque change, t represents the current time, τ represents a time within the time interval starting from the current time t, and Δt0 represents the minimum duration threshold; When the three judgment conditions are met at the same time, it is determined that the deep cone thickener is in the rake pressure state.

9. The deep cone thickener rake drive system based on a permanent magnet motor according to claim 6, characterized in that: In the speed control module, the process of controlling the reduction of the reference speed includes: oh ref (t+1)=ω ref (t)·β (β<1), Among them, ω ref (t+1) represents the reference speed after adjustment, ω ref (t) represents the reference speed before adjustment, and β represents the deceleration factor.

10. The deep cone thickener rake drive system based on a permanent magnet motor according to claim 7, characterized in that: The model building module constructs the historical load-torque model in the following steps: Obtain the historical load data L(t) of the deep cone thickener; The historical load data L(t) is used as input, and the output torque T(t) is used as output. The historical load data and the output torque are modeled using a polynomial fitting method to obtain a historical load-torque model: T(t)=a0+a1L(t)+a2L 2 (t)+…+a n L n (t)+ε(t), i=0,1,2,...,n, Among them, ε(t) represents the model error term, a i Represents the coefficients of the polynomial.

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