A control method, system and device of a brushless direct current motor for a diaphragm pump

Abstract

The application relates to the technical field of motor control, and provides a control method, system and device of a brushless direct-current motor for a diaphragm pump, the method comprising the following steps: acquiring first weight coefficients of multiple different dimensions of diaphragm pump characteristics and corresponding first compatibility scores; acquiring second weight coefficients of multiple different dimensions of brushless direct-current motor characteristics and corresponding second compatibility scores; acquiring system compatibility according to the first weight coefficients, the first compatibility scores, the second weight coefficients and the second compatibility scores; and dynamically adjusting a control strategy based on the system compatibility, so as to realize the control of the brushless direct-current motor for the diaphragm pump. The application comprehensively considers multiple-dimensional characteristic elements of the diaphragm pump and the brushless direct-current motor, can dynamically adjust and optimize the control strategy based on the system compatibility, realizes good matching between the brushless direct-current motor control and the system, and thus improves the reliability of the control of the brushless direct-current motor for the diaphragm pump.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor control, in particular to a control method, system and device of a brushless direct current motor for a diaphragm pump. BACKGROUND

[0002] In a diaphragm pump operation system, a brushless direct current motor is widely used due to its advantages of high efficiency and low maintenance, and its control method directly affects the stability and working efficiency of the diaphragm pump. At present, the control technology for the brushless direct current motor for the diaphragm pump mainly focuses on single-dimensional control of motor speed and torque. For example, some solutions use conventional algorithms such as PID control to achieve motor speed regulation, but ignore the compatibility of the motor control system with the mechanical structure of the diaphragm pump, the characteristics of the working medium, and external working conditions. Since the control strategy is not dynamically optimized according to the system compatibility, when the diaphragm pump faces scenarios such as changes in medium viscosity, sudden changes in load, or wear of mechanical parts, the existing control method cannot ensure good matching of the motor and the system, which may lead to increased energy consumption, decreased control accuracy, and even system failure, exposing significant application limitations.

[0003] Therefore, it is necessary to improve the existing control technology for the brushless direct current motor for the diaphragm pump to improve the reliability of system control. SUMMARY

[0004] To solve the problems existing in the prior art, the present application provides a control method, system and device of a brushless direct current motor for a diaphragm pump, which obtains first weight coefficients of diaphragm pump characteristics in multiple different dimensions and corresponding first compatibility scores, and second weight coefficients of brushless direct current motor characteristics and corresponding second compatibility scores, and comprehensively considers the element compatibility of the diaphragm pump and the brushless direct current motor in multiple different dimensions. The control strategy can be dynamically adjusted according to the system compatibility, which improves the reliability of the control of the brushless direct current motor for the diaphragm pump. The specific technical solutions are as follows:

[0005] A control method of a brushless direct current motor for a diaphragm pump, comprising:

[0006] obtaining first weight coefficients of diaphragm pump characteristics in multiple different dimensions and corresponding first compatibility scores;

[0007] obtaining second weight coefficients of brushless direct current motor characteristics in multiple different dimensions and corresponding second compatibility scores;

[0008] obtaining system compatibility according to the first weight coefficients, the first compatibility scores, the second weight coefficients and the second compatibility scores;

[0009] dynamically adjusting the control strategy based on the system compatibility to control the brushless direct current motor for the diaphragm pump.

[0010] The control method of the brushless direct current motor for the diaphragm pump considers the multi-dimensional characteristic elements of the diaphragm pump and the brushless direct current motor by obtaining the first weight coefficient, the first compatibility score, the second weight coefficient, and the second compatibility score, and obtaining the system compatibility degree based on the first weight coefficient, the first compatibility score, the second weight coefficient, and the second compatibility score. The control strategy can be dynamically adjusted and optimized based on the system compatibility degree, the brushless direct current motor control is well matched with the system, and the reliability of the brushless direct current motor control for the diaphragm pump is improved.

[0011] Preferably, the method of obtaining the system compatibility degree specifically comprises:

[0012] obtaining a diaphragm pump compatibility factor Σ(W 1i ·S 1i ) and a direct current motor compatibility factor Σ(W 2i ·S 2i );

[0013] obtaining the system compatibility degree based on the diaphragm pump compatibility factor and the direct current motor compatibility factor;

[0014] wherein W 1i i represents the first weight coefficient of the i-th dimension, S 1i i represents the first compatibility score of the i-th dimension, W 2i i represents the second weight coefficient of the i-th dimension, and S 2i i represents the second compatibility score of the i-th dimension.

[0015] Preferably, the plurality of different dimensions of the brushless direct current motor characteristics include interface characteristics, and the control method further comprises obtaining the number of interfaces of the brushless direct current motor, and obtaining an interface complexity for suppressing the system compatibility degree based on the number of interfaces.

[0016] wherein the method of obtaining the system compatibility degree based on the diaphragm pump compatibility factor and the direct current motor compatibility factor specifically comprises: obtaining the system compatibility degree based on the interface complexity, the diaphragm pump compatibility factor, and the direct current motor compatibility factor.

[0017] Preferably, the control method further comprises obtaining a control signal matching degree, a power supply system compatibility, an environmental protection level, and a temperature compensation term.

[0018] wherein the method of obtaining the system compatibility degree based on the diaphragm pump compatibility factor and the direct current motor compatibility factor specifically comprises: obtaining the system compatibility degree based on the interface complexity, the diaphragm pump compatibility factor, the direct current motor compatibility factor, the signal matching degree C s , the power supply system compatibility P s , the environmental protection level E s , and the temperature compensation term T cSystem compatibility is acquired.

[0019] Preferably, the system compatibility

[0020] Wherein, 1+ln(N interface ) represents interface complexity, N interface represents the number of interfaces.

[0021] Preferably, the specific method of acquiring the temperature compensation term comprises:

[0022] Acquiring the actual working temperature T of the system and the maximum allowable working temperature T max ;

[0023] Acquiring the temperature compensation term according to the actual working temperature T and the maximum allowable working temperature T max

[0024] Wherein, e represents the natural constant, and k represents the preset temperature attenuation coefficient.

[0025] A control system of a brushless direct current motor for a diaphragm pump, for realizing the control method of the brushless direct current motor for the diaphragm pump, comprising:

[0026] A first acquisition module is configured to acquire first weight coefficients of a plurality of different dimensions of diaphragm pump features and corresponding first compatibility scores;

[0027] A second acquisition module is configured to acquire second weight coefficients of a plurality of different dimensions of brushless direct current motor features and corresponding second compatibility scores;

[0028] A compatibility acquisition module is configured to acquire system compatibility according to the first weight coefficients, the first compatibility scores, the second weight coefficients, and the second compatibility scores;

[0029] A control module is configured to dynamically adjust a control strategy based on the system compatibility, so as to realize the control of the brushless direct current motor for the diaphragm pump.

[0030] Preferably, the compatibility acquisition module comprises:

[0031] A diaphragm pump compatibility factor acquisition unit is configured to acquire a diaphragm pump compatibility factor according to the first weight coefficients and the first compatibility scores;

[0032] A direct current motor compatibility factor acquisition unit is configured to acquire a direct current motor compatibility factor according to the second weight coefficients and the second compatibility scores;

[0033] A system compatibility acquisition unit is configured to acquire system compatibility according to the diaphragm pump compatibility factor and the direct current motor compatibility factor.

[0034] ​Preferably, the system compatibility acquisition unit acquires the system compatibility according to the formula

[0035] wherein W 1i represents the first weight coefficient of the i-th dimension, S 1i represents the first compatibility score of the i-th dimension, W 2i represents the second weight coefficient of the i-th dimension, S 2i represents the second compatibility score of the i-th dimension, Σ(W 1i ·S 1i ) represents the diaphragm pump compatibility factor, Σ(W 2i ·S 2i ) represents the DC motor compatibility factor, C s , P s , E s respectively represent the signal matching degree, the power supply system compatibility, and the environmental protection level, 1+ln(N interface ) represents the interface complexity, N interface represents the number of interfaces, represents the temperature compensation term, T represents the actual working temperature of the system, T max represents the maximum allowable working temperature, e represents the natural constant, and k represents the preset temperature attenuation coefficient.

[0036] A control device of a brushless DC motor for a diaphragm pump comprises:

[0037] a memory for storing a computer program;

[0038] a processor for executing the computer program to implement the control method of the brushless DC motor for the diaphragm pump. BRIEF DESCRIPTION OF DRAWINGS

[0039] The present application can be further understood from the following description in conjunction with the accompanying drawings. The components in the drawings are not necessarily drawn to scale, but emphasis is instead placed on illustrating the principles of the embodiments. In different views, the same reference numerals designate corresponding parts.

[0040] Figure 1 is a schematic diagram of the overall flow of a control method of a brushless DC motor for a diaphragm pump in an embodiment of the present application;

[0041] Figure 2 is a schematic diagram of the flow of a specific method for acquiring system compatibility in an embodiment of the present application;

[0042] Figure 3 is a schematic diagram of the overall structure of a control system of a brushless DC motor for a diaphragm pump in an embodiment of the present application;

[0043] Figure 4 ​It is the whole structure schematic diagram of brushless DC motor for diaphragm pump. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with its embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the protection scope of the present application.

[0045] It should be noted that when an element is referred to as being "fixed" to another element, it can be directly on the other element or there can be intervening elements. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can be present. As used herein the terms "vertical", "horizontal", "left", "right" and similar terms are used for explanation only and are not intended to limit the present application to only specific embodiments.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0047] The "first", "second" in the present application do not represent the specific number and order, but only for the name of the distinction.

[0048] Before the embodiment of the present application is described in detail, the prior art is briefly introduced.

[0049] The diaphragm pump, also known as control pump, is the main type of actuator, which changes the flow of fluid by receiving the control signal output by the adjustment control unit and through power operation. The role of the diaphragm pump in the control process is to accept the control signal of the regulator or computer, change the flow of the medium to be adjusted, and maintain the parameter to be adjusted within the required range, so as to achieve the automation of the production process. The diaphragm pump separates the liquid to be pumped from the piston and the pump cylinder by means of a diaphragm, thereby protecting the piston and the pump cylinder. The part on the left side of the diaphragm in contact with the liquid is made of corrosion-resistant material or coated with a layer of corrosion-resistant material, and the right side of the diaphragm is filled with water or oil.

[0050] Electric diaphragm pump is a new type of pump, in recent years, due to the breakthrough in the diaphragm material is made, to be applied to petrochemical, ceramic, metallurgical industry, the characteristics of no need to fill the water, strong self-priming ability, it directly to the delivery medium and transmission mechanical parts are separated, so the medium will not leak, and the pump itself without shaft seal, the service life is greatly extended. Pump body medium flow part, can be according to the user requirements of difference, classification for cast iron, stainless steel, rubber, aluminum alloy, fluorine lining and so on, different pump body material is suitable for different scene, such as cast iron is suitable for no corrosive material, stainless steel for corrosive environment, PP (polypropylene) and PVDF (fluorine plastic) for strong corrosive liquid. And according to the electric diaphragm pump pumping of different medium, diaphragm can be classified as fluorine butyl rubber, fluorine rubber, but the Qing rubber, polytetrafluoroethylene and so on. As can be seen, different pump body and diaphragm material, its application scene has some difference. In addition, the motor material in different scene, its adaptability is also different, such as cast iron shell in the temperature and humidity is larger or chemical workshop, easy to rust, cast iron bearing in high speed, high load condition is easy to fatigue fracture, aluminum alloy shell motor heat dissipation performance is better, can be in more extensive environmental temperature stable operation, the surface of the oxide film can also prevent the motor from being damp and rust, but its wear resistance and hardness is weaker than cast iron.

[0051] The material selection of diaphragm pump (such as cast iron, stainless steel, plastic) will affect the medium adaptability, and the material compatibility may affect the pump body temperature rise, and then affect the heat dissipation strategy of control algorithm. If the material compatibility is high (such as stainless steel corrosion resistance), higher working temperature or more aggressive control strategy can be allowed without excessive derating protection. In addition, in practical application, the algorithm complexity can be adjusted according to the compatibility, for example, high compatibility system may integrate more sensor data and use advanced algorithm such as model predictive control (MPC), while low compatibility system may need to simplify the control to reduce the requirement of interface and processing capacity.

[0052] Different control methods such as PID, vector control, fuzzy control have influence on speed regulation accuracy and life. Considering the balance between efficiency and life, high compatibility motor and pump combination may allow higher operating efficiency, because the motor or diaphragm pump material can resist high temperature, which can reduce the heat dissipation demand, so as to use higher frequency PWM control. In the case of low compatibility, the load may need to be reduced to avoid premature wear, and more conservative control strategy is used. Specifically, for example, through the stainless steel pump to transport corrosive medium, at this time the motor can use high efficiency vector control combined with temperature compensation to reduce the derating and prolong the running time. On the contrary, plastic pump may be sensitive to temperature, and soft start and soft stop strategy is needed to avoid overheating and reduce mechanical impact to prolong the life.

[0053] Therefore, based on the different material characteristics of the diaphragm pump combined with the motor, different electric diaphragm pumps have different compatibility. In order to improve the system operation reliability, it is necessary to dynamically adjust the control strategy combined with the compatibility of the diaphragm pump and the motor.

[0054] The applicant found some related prior art through retrieval, such as "High-performance brushless motor control system, method and medium based on ROS2", "Intelligent control method and system of permanent magnet synchronous water pump motor", and "High-pressure water pump motor remote control method based on data acquisition", all of which involve dynamic adjustment and optimization of motor control strategy. However, the above three motor control methods do not comprehensively adjust and optimize the control strategy based on the compatibility of the diaphragm pump and the brushless DC motor in multiple different dimensions, and the system operation reliability has further optimization space.

[0055] In order to solve the technical problems existing in the prior art mentioned above, an embodiment of the present application provides a control method for a brushless DC motor for a diaphragm pump, as shown in Figure 1 , which comprises:

[0056] S1, obtaining a first weight coefficient of a plurality of different dimensions of diaphragm pump characteristics and a corresponding first compatibility score.

[0057] Specifically, the plurality of different dimensions of diaphragm pump characteristics include but are not limited to pump body material characteristics (such as plastic, aluminum alloy, cast iron, stainless steel, and ceramic, etc.) and diaphragm membrane material characteristics (such as fluoro-butyl rubber, fluoro rubber, nitrile rubber, polytetrafluoroethylene, etc.).

[0058] For the first compatibility score, the matching degree between different diaphragm pump materials and media can be assigned. For example, when the pump body material is cast iron, the first compatibility score for weak acid is set to 3.0, and the first compatibility score for strong acid is set to 2.0; when the diaphragm material is polytetrafluoroethylene, the first compatibility score for weak acid is set to 5.0, and the first compatibility score for strong acid is set to 4.5 or 4.0, etc.

[0059] S2, obtaining a second weight coefficient of a plurality of different dimensions of brushless DC motor characteristics and a corresponding second compatibility score.

[0060] The multiple different dimensions of brushless DC motor features include, but are not limited to, brushless DC motor shell material features (such as aluminum alloy, stainless steel, plastic, glass fiber reinforced plastic, etc.) and bearing material features (such as stainless steel, ceramic, titanium alloy, cast iron, etc.). For the second compatibility score, the matching degree between different brushless DC motor features and the application environment can be assigned. For example, when the shell material is cast iron, its second compatibility score in a chemical environment or a coastal environment with high temperature and humidity can be set to 2.5 points, and its second compatibility score in a dry or inland environment can be set to 3.5 or 4.3 points, etc. The second compatibility score of cast iron bearing in a high load operating environment can be set to 1.5 or 1.8, etc. If in a low load and low speed working condition, the second compatibility score is relatively high, set to 3.5 or 4.5, etc.

[0061] For the first weight coefficients of multiple different dimensions of diaphragm pump features and the second weight coefficients of multiple different dimensions of brushless DC motor features, they can be pre-set by technicians according to experience. Preferably, the first weight coefficient can be set according to the aging and / or wear of the corresponding diaphragm pump material of different dimensions, and the second weight coefficient corresponding to the brushless DC motor material feature can be set according to the aging and / or wear of the corresponding brushless DC motor material of different dimensions. One method is to first quantify the quality standard value of the material of different dimensions of the diaphragm pump and the brushless DC motor when they leave the factory (such as quantifying the quality standard value by the material surface flatness, color uniformity, flaw number, etc.), and set the corresponding first weight preset value and second weight preset value, then collect the current quality value of the material of different dimensions of the diaphragm pump and the brushless DC motor after a pre-set time in the same application scenario, and finally obtain the first weight coefficient and the second weight coefficient according to the quality standard value, the current quality value, the first weight preset value and the second weight preset value. In general, the lower the current quality value, the greater the difference from the quality standard value, the more serious the material aging and wear, and the lower the matching degree between the material and the current application scenario.

[0062] Specifically, the first weight coefficient of the i-th dimension The second weight coefficient of the i-th dimension Wherein, CQ 1i , QS 1i respectively represent the current quality value and the quality standard value of the i-th dimension of the diaphragm pump material, CQ 2i , QS 2i respectively represent the current quality value and the quality standard value of the i-th dimension of the brushless DC motor material, W 1i , W 2i respectively represent the first weight preset value of the i-th dimension of the diaphragm pump material and the second weight preset value of the i-th dimension of the brushless DC motor material.

[0063] According to the formula and It can be seen that the lower W 1i ' and W 2i ', the lower the matching degree between the material and the current application scene. Therefore, according to the formula and By quantifying the quality value of the material to calculate the first weight coefficient and the second weight coefficient, not only can the instability and error deviation caused by relying on the experience of technical personnel to preset the weight coefficient be avoided, but also the first weight coefficient and the second weight coefficient can be dynamically adjusted according to the actual application, so that the system compatibility is more in line with the actual application. It should be pointed out that the first weight preset value corresponding to the diaphragm pump material of the ith dimension and the second weight preset value corresponding to the brushless DC motor material of the ith dimension can be allocated according to the importance of the material in the actual application, such as in a chemical environment, the first weight preset value corresponding to the corrosion-resistant diaphragm pump material and the second weight preset value corresponding to the corrosion-resistant brushless DC motor material are relatively higher.

[0064] S3, obtaining the system compatibility according to the first weight coefficient, the first compatibility score, the second weight coefficient and the second compatibility score.

[0065] For the system compatibility, it can be calculated by weighted summation or weighted average based on the first weight coefficient, the first compatibility score, the second weight coefficient and the second compatibility score, or a corresponding function formula can be set. Generally speaking, the higher the product of the first weight coefficient and the first compatibility score and the product of the second weight coefficient and the second compatibility score, the higher the system compatibility.

[0066] Preferably, as shown in Figure 2 , in step S3, the method for obtaining the system compatibility specifically comprises:

[0067] S31, obtaining the diaphragm pump compatibility factor Σ(W 1i ·S 1i ) and the DC motor compatibility factor Σ(W 2i ·S 2i );

[0068] S32, obtaining the system compatibility according to the diaphragm pump compatibility factor and the DC motor compatibility factor.

[0069] Wherein, W 1i represents the first weight coefficient of the ith dimension, S 1i represents the first compatibility score of the ith dimension, W 2i represents the second weight coefficient of the ith dimension, and S 2ia second compatibility score of the i-th dimension.

[0070] Specifically, the system compatibility CS = ∑(W 1i · S 1i )·∑(W 2i · S 2i ) or CS = (∑(W 1i · S 1i )+∑(W 2i · S 2i )) / 2. Of course, based on actual conditions, the final system compatibility calculation formula can be adjusted appropriately based on the diaphragm pump compatibility factor ∑(W 1i · S 1i ) and the DC motor compatibility factor ∑(W 2i · S 2i ).

[0071] S4, based on the system compatibility, dynamically adjusting the control strategy to realize the control of the brushless DC motor for the diaphragm pump.

[0072] For dynamically adjusting the control strategy based on the system compatibility, one understanding is that the complexity of the brushless DC motor control algorithm is dynamically adjusted according to the system compatibility. For example, when the system compatibility is high, model predictive control (MPC) is used to realize high-precision flow regulation, and when the system compatibility is low, simplified PID control is used to reduce the requirements for interfaces and processing capabilities, prevent motor overload, and improve system operation reliability, or soft start and soft stop strategies are used to reduce mechanical impact and prolong service life.

[0073] Based on the different specific application scenarios of the brushless DC motor for the diaphragm pump, the control strategy is dynamically adjusted according to the system compatibility, which overall avoids problems such as system instability, reduced efficiency and service life of the diaphragm pump and motor caused by mismatching of the control strategy and the system compatibility, and can improve overall production efficiency.

[0074] In summary, the control method of the brushless DC motor for the diaphragm pump obtains the first weight coefficient, the first compatibility score, the second weight coefficient, and the second compatibility score, and obtains the system compatibility according to the first weight coefficient, the first compatibility score, the second weight coefficient, and the second compatibility score. When controlling the brushless DC motor for the diaphragm pump, it comprehensively considers the multi-dimensional characteristic elements of the diaphragm pump and the brushless DC motor, and can dynamically adjust and optimize the control strategy based on the system compatibility, realize good matching of the brushless DC motor control and the system, and thus improve the reliability of the control of the brushless DC motor for the diaphragm pump.

[0075] As a preferred technical solution, the plurality of different dimensions of the brushless DC motor features include interface features, and the control method further comprises obtaining an interface quantity of the brushless DC motor, and obtaining an interface complexity for suppressing system compatibility according to the interface quantity; wherein the method for obtaining the system compatibility according to the diaphragm pump compatibility factor and the DC motor compatibility factor specifically comprises: obtaining the system compatibility according to the interface complexity, the diaphragm pump compatibility factor and the DC motor compatibility factor.

[0076] For the brushless DC motor for the diaphragm pump, factors affecting the system compatibility include not only the material of the diaphragm pump and the brushless DC motor, but also the interface quantity of the motor. Generally speaking, the more the types of motor interface quantity, the more brands of sensors it can support, and the more compatibility range it has.

[0077] For the interface, it includes but is not limited to CAN, Modbus, I2C, USB and RS232 / 485.

[0078] At this time, the DC motor compatibility factor ∑(W 2i ·S 2i ) includes not only the second weight coefficient and the second compatibility score corresponding to the brushless DC motor housing material feature, but also the second weight coefficient and the second compatibility score corresponding to the bearing material feature, and further includes the second weight coefficient and the second compatibility score corresponding to the interface feature. Generally speaking, the second weight coefficient corresponding to different types of interfaces can be set by technical personnel, and the second compatibility score corresponding to different types of interfaces can be assigned according to the interface function integrity, such as protocol stability (communication failure rate), transmission rate compliance rate, communication distance, network debugging difficulty, etc. For example, for the CAN interface, the communication failure rate is very low, the data transmission rate is high, the communication distance can reach 10KM, and the network debugging is easy, so its second compatibility score can be set to 8. For RS485, the communication failure rate is high, the data transmission rate is low, the communication distance is less than 1.5KM, and the network debugging is difficult, so its second compatibility score can be set to 2.5 or 2.0, etc.

[0079] System compatibility Wherein I c represents the interface complexity, I c may be 1+ln(N interface ) or ln(1+N interface ) and the like. Of course, other logarithmic function forms can also be used to process the interface quantity to obtain the interface complexity, which is not specifically limited here. Generally speaking, the more the motor interface quantity, the higher the system compatibility, but too many interfaces may increase the system complexity. Since too many interfaces may increase the system complexity, the sensitivity of the system compatibility to the interface quantity is adjusted by the interface quantity and the logarithmic function here. In the system compatibility formula The denominator of I c balances the impact of the number of interfaces, the marginal benefit of increasing the number of interfaces, and the DC motor compatibility factor and system compatibility obtained in this way are more reasonable. Specifically, when the number of interfaces increases from 3 to 10, the denominator I c increases from 2.1 to 3.3, which can suppress the virtual high system compatibility.

[0080] When the first weight coefficient and the second weight coefficient are set by the technician, different first weight coefficients and second weight coefficients can be matched based on different application scenarios. For example, in a chemical environment, the first weight coefficient and the second weight coefficient corresponding to materials such as ceramics and fluoroplastic can be appropriately increased, and the second weight coefficient corresponding to the interface feature can be reduced; in a smart digital chemical plant, the second weight coefficient of industrial protocol interfaces such as CAN and EtherCAT can be increased to optimize multi-device collaboration.

[0081] Based on the formula , the complexity of the motor interface is considered, and the logarithmic function ln(N interface ) is used to suppress the system complexity that may be caused by too many interfaces, thereby avoiding overfitting. The system compatibility can be dynamically optimized, and the functional expansibility and reliability of the system can be balanced.

[0082] As a preferred technical solution, the control method further comprises: obtaining a control signal matching degree, a power supply system compatibility, an environmental protection level, and a temperature compensation term.

[0083] The method for obtaining the system compatibility based on the diaphragm pump compatibility factor and the DC motor compatibility factor specifically comprises: obtaining the system compatibility based on the interface complexity, the diaphragm pump compatibility factor, the DC motor compatibility factor, the signal matching degree C s , the power supply system compatibility P s , the environmental protection level E s , and the temperature compensation term T c .

[0084] The system compatibility , wherein 1+ln(N interface ) represents the interface complexity, and N interface represents the number of interfaces.

[0085] Preferably, the specific method for obtaining the temperature compensation term comprises:

[0086] obtaining the actual working temperature T and the maximum allowable working temperature T max .

[0087] obtaining the temperature compensation term based on the actual working temperature T and the maximum allowable working temperature T max . wherein e represents a natural constant, and k represents a preset temperature attenuation coefficient.

[0088] The actual working temperature T represents the actual environmental temperature or the temperature of key components (such as motor windings, diaphragm material contact areas, etc.) of the diaphragm pump and the DC motor control system during current operation. For the diaphragm pump, the reference temperature range is -60°C to 150°C, and for the brushless DC motor, the reference temperature range is -20°C to 80°C. Temperature sensors are deployed at key points such as the diaphragm contact surface of the diaphragm pump and the motor windings to dynamically correct the actual working temperature T.

[0089] The maximum allowable working temperature T max represents the critical temperature for safe operation of the system, which can be determined comprehensively according to the materials and system design. For the diaphragm pump side, the maximum allowable working temperature T max is determined by the diaphragm material (such as fluororubber upper limit 150°C, PTFE up to 200°C); for the motor side, the maximum allowable working temperature T max is determined by the demagnetization temperature of the permanent magnet and the threshold value of the protection circuit (usually 80°C to 120°C). The smaller of the two is taken as the overall threshold value of the system, i.e. the smaller of the two is taken as the maximum allowable working temperature T max .

[0090] Furthermore, for the maximum allowable working temperature T max , on the diaphragm pump side, T max may be set according to the actual temperature resistance of the diaphragm material (for example, PTFE diaphragm 150°C, fluororubber 100°C); for the motor side, T max may be set comprehensively in combination with the winding insulation class (such as H-class motor 180°C) and the protection circuit threshold.

[0091] For k, which is an adjustment parameter for controlling temperature sensitivity, affects the steepness of the function curve, and represents the decay rate of the material or system's tolerance to temperature rise, its typical values are as follows:

[0092] k = 0.1, suitable for wide temperature range smooth transition (such as laboratory environment).

[0093] k = 0.3, suitable for rapid response in industrial scenarios (such as high-temperature workshops).

[0094] For the temperature compensation term, it has the following three characteristics:

[0095] 1. High temperature protection mechanism. When T ≥ T max , as the actual working temperature T rises, the temperature compensation term rapidly decreases, the system compatibility rapidly decreases, triggering system protection (such as running at a lower frequency or shutting down), preventing diaphragm aging and rupture or motor permanent magnet demagnetization.

[0096] 2. Low-temperature adaptability optimization. When T << T max , the temperature compensation term approaches 1, and the compatibility evaluation is not affected by low temperatures, adapting to cold environments (e.g., -60°C working conditions).

[0097] 3. Dynamic temperature rise suppression. When T approaches T max , the compatibility decay rate can be controlled by adjusting the k value to match different scenarios, such as high-reliability scenarios (e.g., chemical explosion-proof environments): by increasing the k value, early warning is provided, or high-elasticity scenarios (e.g., intermittent short-term over-temperature): by reducing the k value, temporary over-limiting is allowed.

[0098] Here, the temperature compensation term uses an exponential decay function to adapt to the wide temperature range of the diaphragm pump (e.g., -60°C to 150°C) and increase the motor winding temperature rise compensation coefficient. This temperature compensation term quantifies the impact of thermal effects on material performance and signal stability, achieving precise adaptation to wide temperature range conditions and significantly improving system reliability in extreme environments.

[0099] Specifically, the signal matching degree C where ε PWM represents the duty cycle error of the driving signal, τ feedback represents the Hall / encoder feedback delay, f PWM represents the actual PWM frequency, f base represents the reference frequency (recommended 8-20 kHz), and sinh -1 represents the inverse hyperbolic sine function.

[0100] The signal matching degree C ε PWM reflects the duty cycle deviation of the PWM driving signal (e.g., the difference between the actual output and the theoretical value). By introducing the denominator term ε PWM + τ feedback , the signal matching degree C s can dynamically suppress the distortion of the control signal caused by the duty cycle error. For example, when the duty cycle error increases, the signal matching degree C s value decreases, thereby automatically reducing the weight in the system compatibility formula and avoiding motor torque fluctuations caused by signal deviation. τ feedback characterizes the signal feedback delay of the Hall sensor or encoder. By introducing the τ feedback term, the signal matching degree C s can quantify the real-time defects of the closed-loop control system. For example, when the motor is running at high speed, excessive delay can cause phase lag, and the signal matching degree C s directly reduces the system compatibility value through the denominator term, forcing design optimization of the feedback path (e.g., shortening the wiring or upgrading the sensor).

[0101] Nonlinear frequency matching evaluation by hyperbolic sine inverse function: when f PWM is close to f base , sinh -1 (1) ≈ 0.86, the matching degree is high; when f PWM deviates from the reference frequency significantly, the function value decays rapidly, for example, f PWM = 2f base , sinh -1 (2) ≈ 0.28, but the denominator grows faster, and the overall system compatibility value decreases. Therefore, this function formula can effectively avoid structural damage caused by resonance of PWM frequency and mechanical system inherent frequency, such as fatigue failure of diaphragm pump under high-frequency vibration.

[0102] In the system compatibility formula, the signal matching degree C s forms a product relationship with other parameters (power supply system compatibility P s , environmental protection level E s , etc.), and its dynamic characteristics directly affect the robustness of the overall system, which is reflected in the following two aspects:

[0103] First, the coordination with the power supply system. The signal matching degree C s suppresses the duty cycle error, which may be caused by voltage fluctuations (P s term), and the combined effect can identify the coupling problem of power supply quality and control accuracy.

[0104] Second, the coordination with the motor mechanical interface: high-frequency PWM signal (C s term) may cause harmonic vibration of flange connection, and the cosine similarity measure can evaluate the influence of geometric matching degree on signal stability.

[0105] The signal matching degree C s quantifies the accuracy, real-time performance, and frequency matching degree of the control signal, and becomes the core correction term of the electrical-mechanical coupling problem in the system compatibility formula, and the mathematical formula design takes into account dynamic error suppression and frequency resonance avoidance.

[0106] Power supply system compatibility wherein, represents the voltage matching situation, V bus is the bus voltage, and V min is the minimum operating voltage of the diaphragm pump. represents the current tolerance, I rated is the rated current of the motor, I peak is the peak current of the pump load, and tanh represents the hyperbolic tangent function.

[0107] Power supply system compatibility formula It has the following advantages:

[0108] 1. Nonlinear smooth transition: The voltage difference is normalized by using a hyperbolic tangent function, and the voltage matching degree is limited to the [0,1) interval to avoid compatibility jump problems caused by abrupt changes in the linear function near the critical voltage.

[0109] 2. Wide voltage adaptability: When the bus voltage is much higher than the minimum operating voltage of the diaphragm pump, the tanh value approaches 1, and the system compatibility is optimal; when the voltage is close to the lower limit, the function value decays rapidly, triggering the protection mechanism.

[0110] 3. Suppress the impact of voltage fluctuations: By dynamically adjusting the matching degree between the power supply voltage and equipment requirements, the impact of voltage fluctuations on the stroke accuracy of the diaphragm pump is reduced.

[0111] Power supply system compatibility formula Includes the ratio of rated current to peak current, which is passed through This parameter quantifies the motor's ability to withstand sudden changes in pump load; a higher ratio indicates a greater system margin under peak operating conditions. When the peak pump load current exceeds the motor's rated current, this parameter triggers a frequency reduction or current limiting strategy to prevent winding overheating. By limiting the duration of peak current, thermal aging of the insulation material can be reduced, extending the motor's lifespan.

[0112] Optimized system compatibility In this context, power supply system compatibility, as a product factor, directly affects the overall system compatibility, exhibiting a weighting amplification effect (when P...). s When voltage / current mismatch decreases, the overall compatibility score decays exponentially, forcing designers to prioritize optimizing power supply system parameters. This also serves as a multi-parameter coupling verification mechanism (linked to parameters such as signal matching, for example, low P). s This may expose control signal asynchrony issues caused by CAN bus communication delays. In general, P s This achieves a balance between power supply system security and energy efficiency, resulting in improved system compatibility. The core control parameters.

[0113] Environmental protection level Among them, IP motor Indicates the motor protection rating (e.g., IP). motor =IP67 corresponds to a motor protection rating of 67, IP motor =IP65 corresponds to a motor protection rating of 65), IP pump Indicates the protection rating of the diaphragm pump (e.g., IP). pump =IP54 corresponds to a diaphragm pump protection rating of 54, IP pump =IP67 corresponds to a diaphragm pump protection rating of 67), δ sealdenotes the seal aging coefficient.

[0114] For the seal aging coefficient, an accelerated aging test method can be used, which includes the following steps:

[0115] Simulate actual working conditions (including but not limited to temperature, pressure, and medium corrosiveness) in the laboratory;

[0116] Place the sealing material (such as fluororubber, PTFE) in a high-temperature and high-pressure environment and run for a certain period of time, such as 100 hours, 500 hours, or 1000 hours, etc.

[0117] Record the material performance attenuation curve (such as elastic modulus, tensile strength), and calculate the seal aging coefficient by the formula where S denotes a key performance parameter of the sealing material.

[0118] Of course, the seal aging coefficient can also be obtained by a fatigue cycle test method. In the fatigue cycle test method, first, dynamic sealing test is performed according to the working frequency of the diaphragm pump (such as 3000 times / hour), and then the actual cycle number N 实际 before the seal fails is counted, and the aging coefficient is defined as or where N 标准 denotes the standard cycle number of the standard diaphragm pump.

[0119] In general, the longer the seal is used, the more serious the aging degree, and the smaller the corresponding aging coefficient. By combining the motor protection level, the diaphragm pump protection level, and the seal aging coefficient to obtain the environmental protection level, the following advantages are obtained:

[0120] 1. Dynamic correction of environmental protection level. The traditional IP level is generally a fixed value (such as IP67), and the introduction of the time dimension through the seal aging coefficient δ seal can reflect the protection performance attenuation caused by seal aging. For example, when the new seal δ seal = 0.98, after aging δ seal = 0.7, E s = 0.57, at which time the system can automatically trigger a maintenance warning.

[0121] 2. Coupling of material properties and environmental factors. By δ seal , the material compatibility (such as the corrosion resistance of fluororubber) is included in the unified evaluation system, which can avoid the problem of "high protection level ≠ long-term reliability" caused by simply relying on the IP level (such as the failure of an IP67 motor in an acid mist environment due to seal aging).

[0122] 3. Quantify the impact of the degradation on the system. The system compatibility and reliability can be directly linked to the environmental protection level, specifically, the reduction of the aging coefficient will reduce the system compatibility.

[0123] In practical applications, compared with static IP level evaluation, dynamic sealing aging coefficient can be used to early warning of sealing failure risk, and differential maintenance plan can be made according to the decay rate of the sealing aging coefficient, such as checking the diaphragm pump and brushless DC motor every 6 months when the sealing aging coefficient is greater than 0.8, and monitoring the health status of the diaphragm pump and brushless DC motor every week when the sealing aging coefficient is less than 0.5.

[0124] Signal matching degree C s The design can realize dynamic frequency adaptation and avoid resonance risk caused by fixed PWM frequency; power supply system compatibility P s The formula considers the influence of voltage fluctuation on diaphragm stroke, and can realize voltage / current double closed loop control; environmental protection level E s The IP level can be simply superimposed, and the dynamic correction is made based on the sealing aging coefficient.

[0125] In some cases, the compatibility between the diaphragm pump and the brushless DC motor control needs to consider the matching degree of the motor control signal (involving PWM frequency and feedback type), power supply system compatibility (such as matching the corresponding current and voltage parameters for different scenes), environmental protection level (such as IP67), etc. in addition to the diaphragm pump material, brushless DC motor material and interface. By comprehensively considering the interface complexity, diaphragm pump compatibility factor, DC motor compatibility factor, motor control signal matching degree, power supply system compatibility, environmental protection level and other factors, the system compatibility is obtained, and the control strategy is dynamically adjusted based on the system compatibility, which can further improve the reliability of the system.

[0126] As a preferred technical solution, the cosine similarity measure can be represented as Based on the cosine similarity measure Introducing the mechanical interface standardization value formula Where N nonstd represents the number of non-standard interfaces, such as special flanges, D flange represents the actual flange diameter, D standard represents the flange industry standard diameter.

[0127] As a non-standard interface penalty factor, the factor reflects the negative impact of the number of non-standard interfaces on the system compatibility through the reciprocal form. For example, with the increase of one special flange (non-standard interface), the denominator increases, resulting in the decrease of M s value; adding a constant 0.1 to the denominator can avoid zero denominator (when N nonstd=0), while weakening the penalty for a small number of non-standard interfaces, which is more in line with the actual needs of engineering.

[0128] In cosine similarity measurement In the case of the actual flange diameter D flange Approaching industry standard D standard When the cosine value approaches 1, maximize M. s When the actual flange diameter D flange When deviating from the standard, the cosine function decays nonlinearly, quantifying the degree of geometric mismatch.

[0129] By adjusting D standard It enables flexible adaptation to support other industry standards (such as DIN and ANSI) in addition to ISO standards, thereby achieving compatibility with multiple standard systems.

[0130] Standardized mechanical interface values ​​reduce the need for customized adaptations and improve the mechanical connection efficiency between the diaphragm pump and the motor control system. This is achieved by monitoring M... s The trend of value changes (such as the decay of cosine value) can provide early warning of mechanical wear at the interface. By quantifying the standardization of mechanical interfaces and introducing a flange diameter cosine similarity metric, the problem of neglecting geometric matching due to simply counting the number of interfaces in existing technologies can be overcome, thereby improving integrability and long-term operational stability.

[0131] Based on the standardized value formula of the system mechanical interface The system compatibility can be further optimized, and the optimized system compatibility will be improved.

[0132] formula By coupling multidimensional parameters, deep compatibility between the mechanical characteristics of the diaphragm pump and the electrical / communication characteristics of the motor control system is achieved, which can support system-level reliability improvement under complex operating conditions.

[0133] Of course, in order to match the actual situation, the system compatibility formula The signal matching degree C can be used. s Power supply system compatibility P s Environmental protection level E s Mechanical interface standardization value M s and temperature compensation term T c Set appropriate weighting coefficients, and adjust the signal matching degree C by adjusting the weighting coefficients. s Power supply system compatibility P s Environmental protection level E s Mechanical interface standardization value M s and temperature compensation term T c The degree of importance in system compatibility.

[0134] As a preferred technical solution, the control method further comprises the following steps:

[0135] The neural network model is constructed, and a loss function of the neural network model is constructed according to the system compatibility formula

[0136] wherein, represents a main loss term, represents an efficiency factor, P mech represents a motor mechanical output power, P elec represents an electrical input power, K f represents a PWM frequency loss coefficient.

[0137] represents a noise factor, I n represents a 6k±1 harmonic current amplitude (unit: A), which is derived from the switching action of the motor driver causing current waveform distortion, and these harmonics can cause electromagnetic vibration, which is transmitted through the pump body structure to become audible noise (such as high-frequency whistling). The specific current harmonics generated by the brushless motor during commutation due to PWM modulation or square wave control. For example, when k = 1, n = 5, 7th harmonic; k = 2, n = 11, 13th harmonic, etc. n represents the harmonic order, and the purpose is to attenuate the high-order harmonic weighting. The logarithmic operation 20lg is used to convert the current harmonic amplitude into a sound pressure level (dB), reflecting its contribution to noise. represents a current rate of change term, represents a current instantaneous rate of change (unit: A / s), which can be understood as a sudden change in current (such as commutation or load mutation) causing a sudden change in magnetic field force, causing instantaneous impact vibration of the motor stator and rotor, producing "click" type transient noise, K v represents a current rate of change weight coefficient (unit: dB·s / A), which is used to quantify the sensitivity of the current rate of change to noise, which can be calibrated through experiments.

[0138] represents the speed regulation accuracy, which is used to comprehensively consider the steady-state speed error ε w (the deviation between the actual speed and the target speed of the motor in a stable running state) and the dynamic response time T resp (the time required for the system to reach a new steady state from receiving a speed regulation instruction, including the transition process of acceleration / deceleration), and the Hall position detection error θ err (sine(θ err (the deviation between the rotor position signal output by the Hall sensor and the actual mechanical angle) can improve the accuracy of the control algorithm.

[0139] β · softplus (T - T0) represents a temperature compensation term, T represents the actual temperature of the motor during operation, which can be monitored in real time by a temperature sensor. T0 represents a preset upper limit of the safety temperature (such as a diaphragm pump temperature resistance of 150℃), and the de-rating protection is triggered when the threshold is exceeded. In this case, the effect of temperature rise on service life is smoothed by the softplus function, and adaptive thermal management is achieved.

[0140] γ · Var (θ) represents a speed regulation accuracy variance term, Var (θ) represents the variance of the position detection error of the Hall sensor, reflecting the stability of the control system. Through the speed regulation accuracy variance term, the variance can be reduced to improve the speed regulation consistency.

[0141] α, β, γ represent weight coefficients for adjusting the optimization priority of the main loss term, the temperature compensation term, and the speed regulation accuracy variance term. For example, increasing α, the system focuses on efficiency, noise, compatibility, and speed regulation accuracy, increasing β, the system strengthens the temperature rise constraint, and increasing γ, the system can improve the speed regulation stability.

[0142] In the loss function, by introducing the temperature penalty term Softplus function, when the temperature rise ΔT exceeds the threshold T0, the exponential loss increases, and the thermal protection mechanism is strengthened; by adding the control parameter variance term Var (θ), the oscillation risk of the control strategy is suppressed.

[0143] The system historical operation data such as motor mechanical output power, electrical input power, noise parameters, temperature / voltage / current parameters of the motor during operation, motor speed error information, dynamic response time, and system parameters related to system compatibility can be collected to construct a training data set and train the neural network model. Since obtaining the training data set to train the neural network model belongs to the conventional technical means in the art, it will not be repeated here.

[0144] The neural network model is trained based on the training data set, and the control parameters of the brushless direct current motor control system for the diaphragm pump are obtained through the trained neural network model. The control parameters include but are not limited to PWM frequency, current loop bandwidth, field weakening compensation coefficient, and harmonic injection amplitude. The optimization range of PWM frequency can be set to 8-25kHz, the physical meaning can be understood as the balance point of switching loss and noise, the optimization range of current loop bandwidth can be set to 200-1200Hz, the physical meaning can be understood as the dynamic response and stability threshold, the optimization range of field weakening compensation coefficient can be set to 0.6-1.2, the physical meaning can be understood as the high-speed area efficiency optimization parameter, and the optimization range of harmonic injection amplitude can be set to 0-15% fundamental wave, the physical meaning can be understood as the active vibration suppression adjustment amount.

[0145] When the system compatibility is between 0.6-0.9 and the control strategy adopts the fuzzy PID algorithm, the control parameters obtained based on the trained neural network model and the traditional PID fuzzy control method are compared in the performance index as shown in the following figure:

[0146]

[0147] Therefore, after the control parameters are optimized by the constructed neural network model, the comprehensive performance index of the system is better than that of the traditional PID fuzzy control algorithm. That is to say, by constructing the neural network model, the dimensions of noise factor, system compatibility, efficiency factor and speed regulation accuracy are designed to realize the collaborative optimization and dynamic balance of efficiency, noise and accuracy, improve the comprehensive performance of system control, and be suitable for high reliability industrial scene.

[0148] An embodiment of the present application also provides a control system of a brushless DC motor for a diaphragm pump for realizing the control method of the brushless DC motor for the diaphragm pump, as shown in the figure, which comprises a first acquisition module, a second acquisition module, a compatibility acquisition module and a control module. Figure 3

[0149] The first acquisition module is used for acquiring first weight coefficients of a plurality of different dimensions of diaphragm pump characteristics and corresponding first compatibility scores; and the second acquisition module is used for acquiring second weight coefficients of a plurality of different dimensions of brushless DC motor characteristics and corresponding second compatibility scores.

[0150] The compatibility acquisition module is used for acquiring a system compatibility according to the first weight coefficients, the first compatibility scores, the second weight coefficients and the second compatibility scores; and the control module is used for dynamically adjusting a control strategy based on the system compatibility to realize the control of the brushless DC motor for the diaphragm pump.

[0151] Preferably, the compatibility acquisition module comprises a diaphragm pump compatibility factor acquisition unit, a DC motor compatibility factor acquisition unit and a system compatibility acquisition unit.

[0152] The diaphragm pump compatibility factor acquisition unit is used for acquiring a diaphragm pump compatibility factor according to the first weight coefficients and the first compatibility scores; the DC motor compatibility factor acquisition unit is used for acquiring a DC motor compatibility factor according to the second weight coefficients and the second compatibility scores; and the system compatibility acquisition unit is used for acquiring a system compatibility according to the diaphragm pump compatibility factor and the DC motor compatibility factor.

[0153] As shown in the figure, the control system of the brushless DC motor for the diaphragm pump comprises a first acquisition module, a second acquisition module, a compatibility acquisition module and a control module. Figure 4 ​As shown, the overall structure of the brushless DC motor for the diaphragm pump includes a pump body 1, a diaphragm 2, a motor housing 3, a motor bearing 4, a liquid inlet 5, and a liquid outlet 6, etc. Since the structure of the electric diaphragm pump based on the brushless DC motor belongs to the conventional technical means in the art, it will not be described here.

[0154] Specifically, assuming that the system compatibility is obtained according to the diaphragm pump compatibility factor and the DC motor compatibility factor, and after normalization processing, its value range is 0-1.0. In one application scenario, the pump body material is stainless steel or ceramic, the diaphragm material is Teflon, the motor housing material is stainless steel or aluminum alloy, the bearing material is ceramic or titanium alloy, the motor supports CAN / Modbus protocol, and the medium is low viscosity liquid. The finally calculated system compatibility is greater than 0.8, indicating a high compatibility system, and its control strategy can be set as: using model predictive control (MPC), combining temperature, flow, pressure multi-sensor data to optimize motor output torque in real time, realizing Pareto optimal solution of efficiency and life; enabling dynamic PWM frequency adjustment, automatically switching SVPWM (low speed) and optimized six-step commutation (high speed) according to medium viscosity changes, reducing switching loss and flow control error. If the pump body material is plastic, the medium also has particles, and the motor housing and bearing are cast iron, the finally calculated system compatibility is less than 0.5, then the following control strategy can be used: using simplified PID control, discarding complex observer, estimating speed only through Hall sensor, reducing algorithm's dependence on interface bandwidth; using load balancing mechanism, dynamically limiting current peak value according to material temperature threshold (such as ≤60℃), avoiding the risk of locked-rotor caused by particle medium.

[0155] Of course, when the system compatibility is greater than 0.9, model predictive control (MPC) strategy can be used to realize high-precision flow regulation (such as in medical filling scenarios); when the system compatibility is greater than or equal to 0.6 and less than or equal to 0.9, PID+feedforward compensation control strategy is used; when the system compatibility is less than 0.6, switch control+timeout protection control strategy is used. This situation can be generally understood as an emergency mode in harsh environments, such as mine sludge discharge.

[0156] It should be noted that the control strategy is dynamically adjusted based on the system compatibility, and the upper and lower limits of the system compatibility corresponding to different control strategies can also be fine-tuned according to actual conditions, which will not be described here.

[0157] Based on the different application scenarios of the brushless DC motor for the diaphragm pump, the control strategy is dynamically adjusted according to the system compatibility, which avoids the problems of unstable system operation, reduced efficiency and life of the diaphragm pump and motor caused by mismatch between the control strategy and the system compatibility, and improves the overall production efficiency.

[0158] In summary, the control system of the brushless DC motor for the diaphragm pump obtains the first weight coefficient, the first compatibility score, the second weight coefficient, and the second compatibility score, and obtains the system compatibility degree according to the first weight coefficient, the first compatibility score, the second weight coefficient, and the second compatibility score. When the control of the brushless DC motor for the diaphragm pump is performed, the multi-dimensional characteristic elements of the diaphragm pump and the brushless DC motor are comprehensively considered. The control strategy can be dynamically adjusted and optimized based on the system compatibility degree, the brushless DC motor control and the system are well matched, and the reliability of the control of the brushless DC motor for the diaphragm pump is improved.

[0159] As a preferred technical solution, the system compatibility degree obtaining unit obtains the system compatibility degree according to the formula

[0160] Wherein, W 1i represents the first weight coefficient of the i-th dimension, S 1i represents the first compatibility score of the i-th dimension, W 2i represents the second weight coefficient of the i-th dimension, S 2i represents the second compatibility score of the i-th dimension, ∑(W 1i ·S 1i ) represents the diaphragm pump compatibility factor, ∑(W 2i ·S 2i ) represents the DC motor compatibility factor, C s , P s , E s respectively represent signal matching degree, power supply system compatibility, and environmental protection level, 1+ln(N interface ) represents interface complexity, c represents the number of interfaces, represents the temperature compensation term, T represents the actual working temperature of the system, T max represents the maximum allowable working temperature, e represents the natural constant, and k represents the preset temperature attenuation coefficient.

[0161] Wherein, the signal matching degree Wherein, ε PWM represents the drive signal duty cycle error, τ feedback represents the Hall / encoder feedback delay, f PWM represents the actual PWM frequency, f base represents the reference frequency (recommended 8-20kHz), sinh -1 represents the inverse hyperbolic sine function. When the system compatibility degree is high (such as greater than 0.8) and the signal matching degree is large (such as greater than 0.85 after normalization), the control signal error and delay are low, and the PWM frequency accuracy can be improved; otherwise, the frequency complexity needs to be reduced to avoid signal distortion.

[0162] ​The PWM frequency can be dynamically adjusted based on the control signal matching degree. The specific implementation method is as follows:

[0163] 1. High-frequency low-error mode: if ε PWM <5% and τ feedback <1ms, use 20kHz adaptive PWM, and dynamically adjust the duty cycle through fuzzy PID algorithm.

[0164] 2. Low-frequency fault-tolerant mode: if ε PWM >10%, switch to 8kHz fixed frequency + dead zone compensation to reduce algorithm complexity.

[0165] Specific example: in the high-viscosity medium conveying scene of the diaphragm pump, τ feedback increases, automatically switches to low-frequency mode to avoid motor oscillation caused by feedback delay.

[0166] Power supply system compatibility Among them, represents the voltage matching situation, V bus is the bus voltage, V min is the minimum working voltage of the diaphragm pump. represents the current tolerance, I rated is the rated current of the motor, I peak is the peak current of the pump load, and tanh represents the hyperbolic tangent function.

[0167] Here, the weight of voltage / current closed-loop control can be adjusted according to the value of power supply system compatibility to balance energy efficiency and stability. The specific implementation method is as follows:

[0168] 1. When the normalized power supply system compatibility is greater than 0.8, voltage priority control is adopted to maximize output efficiency through bus voltage.

[0169] 2. When the normalized power supply system compatibility is less than 0.5, current-voltage double closed-loop control is enabled to limit peak current and protect motor windings.

[0170] Specific example: when the pump load causes the I peak to surge due to sudden increase of medium viscosity (such as conveying high-viscosity oil), if (i.e. the peak current exceeds 2 times the rated current), the motor winding may overheat or even burn out, at which time the current closed-loop current limiting can be triggered to prevent motor overload. By monitoring this ratio in real time, the system can dynamically adjust the power supply strategy (such as running at a lower frequency or cutting off the power supply).

[0171] For the temperature compensation term , dynamic adjustment of the heat dissipation strategy can be realized through the linkage of temperature compensation and overheat protection. The specific implementation method is as follows:

[0172] 1. Low temperature mode (T <-20℃): Increase motor start current to 150%, compensate for increased resistance due to increased grease viscosity.

[0173] 2. High temperature mode (T > 80℃): Enable winding temperature observer, estimate hot spot temperature through Kalman filter, reduce frequency in advance.

[0174] Specific example: In a high-temperature environment (T max = 120℃) in a refinery, the system calibrates the seal aging coefficient every 10 minutes, and synchronously adjusts the motor cooling fan speed.

[0175] When the optimized system compatibility Mechanical interface standardization value formula According to the mechanical interface standardization value, fault-tolerant control of mechanical interface feedback can also be implemented. Since the flange matching degree will affect mechanical vibration, the load prediction model can be adjusted, and the specific implementation method is as follows:

[0176] 1. For standard mechanical interfaces, when the normalized mechanical interface standardization value is greater than 0.9: enable minimum energy control to optimize the motor torque output curve.

[0177] 2. For non-standard interfaces, when the normalized mechanical interface standardization value is less than 0.7, increase the vibration suppression algorithm to correct the PWM waveform in real time through FFT analysis.

[0178] Specific example: When installing a special-shaped flange (N nonstd = 2), the system automatically injects reverse harmonic current to reduce the amplitude of mechanical vibration.

[0179] Through the above method, the value of the system compatibility formula is maximized, and the optimal solution of the diaphragm pump-motor system under complex working conditions is realized.

[0180] An embodiment of the present application also provides a control device for a brushless DC motor for a diaphragm pump, which comprises: a memory for storing a computer program; and a processor for executing the computer program to realize the control method for the brushless DC motor for the diaphragm pump.

[0181] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not contradict, they should be considered as within the scope of the present disclosure.

[0182] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A control method for a brushless DC motor used in a diaphragm pump, characterized in that, The control method includes: Obtain the first weight coefficients and corresponding first compatibility scores for multiple diaphragm pump features of different dimensions; Obtain the second weighting coefficients and corresponding second compatibility scores for multiple brushless DC motor features of different dimensions; The system compatibility is obtained based on the first weighting coefficient, the first compatibility score, the second weighting coefficient, and the second compatibility score. Based on the system's compatibility, the control strategy is dynamically adjusted to achieve control of the brushless DC motor used in the diaphragm pump. The specific methods for obtaining system compatibility include: Obtain the diaphragm pump compatibility factor and DC motor compatibility factor ; The system compatibility is obtained based on the diaphragm pump compatibility factor and the DC motor compatibility factor. in, Indicates the first The first weight coefficient of each dimension Indicates the first The first compatibility score across all dimensions Indicates the first The second weighting coefficient of each dimension Indicates the first The second compatibility score across all dimensions; Among them, the brushless DC motor features of multiple different dimensions include interface features, and the control method further includes obtaining the number of interfaces of the brushless DC motor and obtaining the interface complexity used to suppress system compatibility based on the number of interfaces. The control method further includes: acquiring control signal matching degree, power supply system compatibility, environmental protection level, and temperature compensation item; The method for obtaining system compatibility based on diaphragm pump compatibility factors and DC motor compatibility factors specifically includes: based on interface complexity, diaphragm pump compatibility factors, DC motor compatibility factors, and signal matching degree. Power supply system compatibility Environmental protection level and temperature compensation items Obtain system compatibility; Specific methods for obtaining temperature compensation terms include: Obtain the actual operating temperature of the system and maximum allowable operating temperature ; Based on actual operating temperature and maximum allowable operating temperature Obtain temperature compensation item ; in, Represents the natural constant. This indicates the preset temperature decay coefficient; System compatibility ; in, Indicates the complexity of the interface. Indicates the number of interfaces.

2. A control system for a brushless DC motor for a diaphragm pump, used to implement the control method for the brushless DC motor for a diaphragm pump as described in claim 1, characterized in that, include: The first acquisition module is used to acquire the first weight coefficients of multiple diaphragm pump features of different dimensions and the corresponding first compatibility scores; The second acquisition module is used to acquire the second weighting coefficients of multiple brushless DC motor features of different dimensions and the corresponding second compatibility scores; The compatibility acquisition module is used to acquire the system compatibility based on the first weight coefficient, the first compatibility score, the second weight coefficient, and the second compatibility score. The control module is used to dynamically adjust the control strategy based on the system's compatibility to control the brushless DC motor used in the diaphragm pump. The compatibility acquisition module includes: A diaphragm pump compatibility factor acquisition unit is used to acquire a diaphragm pump compatibility factor based on a first weighting coefficient and a first compatibility score. A DC motor compatibility factor acquisition unit is used to acquire a DC motor compatibility factor based on a second weighting coefficient and a second compatibility score. The system compatibility acquisition unit is used to obtain the system compatibility based on the diaphragm pump compatibility factor and the DC motor compatibility factor. The system compatibility acquisition unit obtains information based on the formula. Obtain system compatibility; in, Indicates the first The first weight coefficient of each dimension Indicates the first The first compatibility score across all dimensions Indicates the first The second weighting coefficient of each dimension Indicates the first The second compatibility score across multiple dimensions Indicates the diaphragm pump compatibility factor. This represents the DC motor compatibility factor. These represent signal matching degree, power supply system compatibility, and environmental protection level, respectively. Indicates the complexity of the interface. Indicates the number of interfaces. Indicates the temperature compensation term. Indicates the actual operating temperature of the system. Indicates the maximum allowable operating temperature. Represents the natural constant. This indicates the preset temperature decay coefficient.

3. A control device for a brushless DC motor used in a diaphragm pump, characterized in that, include: Memory, used to store computer programs; A processor is configured to execute the computer program to implement the control method for a brushless DC motor for a diaphragm pump as described in claim 1.

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