Control method, system and device of brushless direct current motor for diaphragm pump

Abstract

The invention 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, and the method comprises the steps: obtaining a plurality of first weight coefficients of different dimensions of diaphragm pump features and corresponding first compatibility scores; obtaining second weight coefficients of the brushless direct current motor characteristics of multiple different dimensions and corresponding second compatibility scores; acquiring system compatibility according to the first weight coefficient, the first compatibility score, the second weight coefficient and the second compatibility score; based on the system compatibility, the control strategy is dynamically adjusted, and the brushless direct current motor for the diaphragm pump is controlled. According to the method, the multi-dimensional characteristic elements of the diaphragm pump and the brushless direct current motor are comprehensively considered, the control strategy can be dynamically adjusted and optimized based on the system compatibility, the brushless direct current motor control is well matched with the system, and therefore the control reliability of the brushless direct current motor for the diaphragm pump is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and more particularly, to a control method, system and device for a brushless DC motor used in a diaphragm pump. Background Art

[0002] In the diaphragm pump operation system, brushless DC motors are widely used due to their advantages such as high efficiency and low maintenance, and their control methods directly affect the stability and working efficiency of the diaphragm pump. Currently, the control technologies for brushless DC motors used in diaphragm pumps mostly focus on single-dimensional control such as motor speed and torque. For example, some solutions use conventional algorithms such as PID control to achieve motor speed regulation, but ignore the compatibility between the motor control system and system elements such as the mechanical structure of the diaphragm pump, the characteristics of the working medium, and the external working conditions. Due to the lack of dynamic optimization of the control strategy based on system compatibility, when the diaphragm pump faces scenarios such as changes in medium viscosity, sudden load changes, or wear of mechanical components, the existing control methods are difficult to ensure a good match between the motor and the system, easily leading to increased energy consumption, decreased control accuracy, and even system failures, revealing significant application limitations.

[0003] Therefore, it is necessary to improve the existing control technologies for brushless DC motors used in diaphragm pumps to improve the reliability of system control. Summary of the Invention

[0004] Based on this, in order to solve the problems existing in the prior art, the present invention provides a control method, system and device for a brushless DC motor used in a diaphragm pump. By obtaining the first weight coefficients and corresponding first compatibility scores of the diaphragm pump characteristics in multiple different dimensions, as well as the second weight coefficients and corresponding second compatibility scores of the brushless DC motor characteristics, and integrating the element compatibility degrees of the diaphragm pump and the brushless DC motor in multiple different dimensions, the control strategy can be dynamically adjusted according to the level of system compatibility, improving the reliability of the control of the brushless DC motor used in the diaphragm pump. The specific technical solutions are as follows:

[0005] A control method for a brushless DC motor used in a diaphragm pump, comprising:

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

[0007] Obtaining the second weight coefficients and corresponding second compatibility scores of the brushless DC motor characteristics in multiple different dimensions;

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

[0009] Based on the level of system compatibility, dynamically adjusting the control strategy to achieve the control of the brushless DC motor used in the diaphragm pump.

[0010] 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 degree according to the first weight coefficient, the first compatibility score, the second weight coefficient, and the second compatibility score. It comprehensively considers the multi-dimensional characteristic factors of the diaphragm pump and the brushless DC motor. It can dynamically adjust and optimize the control strategy based on the high or low system compatibility degree, realize the good matching between the control of the brushless DC motor and the system, and thus improve the reliability of the control of the brushless DC motor for the diaphragm pump.

[0011] Preferably, the method for obtaining the system compatibility degree specifically includes:

[0012] Obtain the diaphragm pump compatibility factor Σ(W 1i ·S 1i ) and the DC motor compatibility factor ∑(W 2i ·S 2i );

[0013] Obtain the system compatibility degree according to the diaphragm pump compatibility factor and the DC motor compatibility factor;

[0014] 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, and S 2i represents the second compatibility score of the i-th dimension.

[0015] Preferably, the characteristics of the brushless DC motor in multiple different dimensions include interface characteristics. The control method further includes obtaining the number of interfaces of the brushless DC motor and obtaining the interface complexity for suppressing the system compatibility degree according to the number of interfaces;

[0016] wherein, the method for obtaining the system compatibility degree according to the diaphragm pump compatibility factor and the DC motor compatibility factor specifically includes: obtaining the system compatibility degree according to the interface complexity, the diaphragm pump compatibility factor, and the DC motor compatibility factor.

[0017] Preferably, the control method further includes: obtaining the control signal matching degree, the power supply system compatibility, the environmental protection level, and the temperature compensation item;

[0018] wherein, the method for obtaining the system compatibility degree according to the diaphragm pump compatibility factor and the DC motor compatibility factor specifically includes: according to 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 item T cObtain the system compatibility.

[0019] Preferably, the system compatibility

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

[0021] Preferably, the specific method for obtaining the temperature compensation term includes:

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

[0023] According to the actual working temperature T and the maximum allowable working temperature T max Obtain the temperature compensation term

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

[0025] A control system for a brushless DC motor used in a diaphragm pump, which is used to implement the control method of the brushless DC motor for the diaphragm pump, and includes:

[0026] A first acquisition module, configured to acquire the first weight coefficient of the diaphragm pump characteristics in multiple different dimensions and the corresponding first compatibility score;

[0027] A second acquisition module, configured to acquire the second weight coefficient of the brushless DC motor characteristics in multiple different dimensions and the corresponding second compatibility score;

[0028] A compatibility acquisition module, configured to acquire the system compatibility according to the first weight coefficient, the first compatibility score, the second weight coefficient, and the second compatibility score;

[0029] A control module, configured to dynamically adjust the control strategy based on the level of the system compatibility to implement the control of the brushless DC motor for the diaphragm pump.

[0030] Preferably, the compatibility acquisition module includes:

[0031] A diaphragm pump compatibility factor acquisition unit, configured to acquire the diaphragm pump compatibility factor according to the first weight coefficient and the first compatibility score;

[0032] A DC motor compatibility factor acquisition unit, configured to acquire the DC motor compatibility factor according to the second weight coefficient and the second compatibility score;

[0033] A system compatibility acquisition unit, configured to acquire the system compatibility according to the diaphragm pump compatibility factor and the DC motor compatibility factor.

[0034] Preferably, the system compatibility acquisition unit obtains the system compatibility according to the formula to obtain the system compatibility;

[0035] where 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 for a brushless DC motor of a diaphragm pump, comprising:

[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 of the diaphragm pump. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0040] Figure 1 is an overall flowchart of a control method for a brushless DC motor of a diaphragm pump in an embodiment of the present invention;

[0041] Figure 2 is a flowchart of a specific method for obtaining system compatibility in an embodiment of the present invention;

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

[0043] Figure 4It is a schematic diagram of the overall structure of a brushless DC motor for a diaphragm pump. Specific embodiments

[0044] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with its embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not limit the protection scope of the present invention.

[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 may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only embodiments.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0047] The "first" and "second" described in the present invention do not represent specific quantities and sequences, but are only used for name distinction.

[0048] Before elaborating on the embodiments of the present invention, a brief introduction to the prior art will be given first.

[0049] A diaphragm pump, also known as a control pump, is a main type of actuator. By receiving a control signal output by a regulating control unit, it changes the fluid flow rate by means of power operation. The role of the diaphragm pump in the control process is to receive the control signal of a regulator or a computer, change the flow rate of the medium to be regulated, and keep the regulated parameter within the required range, so as to achieve the automation of the production process. The diaphragm pump separates the liquid to be transported from the piston rod and the pump cylinder by means of a diaphragm, thereby protecting the piston rod and the pump cylinder. The parts on the left side of the diaphragm in contact with the liquid are all made of corrosion-resistant materials or coated with a layer of corrosion-resistant substances, and the right side of the diaphragm is filled with water or oil.

[0050] An electric diaphragm pump is a new type of pump. In recent years, due to breakthroughs in diaphragm materials, it has been applied to industries such as petrochemical, ceramics, and metallurgy. Its features include no need for priming water, strong self-priming ability. It directly separates the conveyed medium from the driving mechanical parts, so the medium will not leak outwards, and the pump itself has no shaft seal, greatly extending its service life. The medium-flow part of the pump body can be classified as cast iron, stainless steel, rubber-lined, aluminum alloy, fluorine-lined, etc. according to user requirements. Different pump body materials are suitable for different scenarios. For example, cast iron is suitable for non-corrosive materials, stainless steel is used in corrosive environments, PP (polypropylene) and PVDF (fluoroplastic) are used for strongly corrosive liquids. According to the different media pumped by the electric diaphragm pump, the diaphragm can be classified as fluorobutadiene rubber, fluororubber, nitrile rubber, polytetrafluoroethylene, etc. Thus, different pump bodies and diaphragm materials have different application scenarios. In addition, the materials of the motor also have different adaptabilities in different scenarios. For example, the cast iron shell is prone to corrosion and rust in environments with high temperature and humidity or in chemical workshops. Cast iron bearings are prone to fatigue fracture under high speed and high load conditions. The aluminum alloy shell motor has better heat dissipation performance, can operate stably at a wider ambient temperature range, and the formed oxide film on the surface can also prevent the motor from getting damp and rusting, but its wear resistance and hardness are weaker than those of cast iron.

[0051] The material selection of the diaphragm pump (such as cast iron, stainless steel, plastic) affects the medium adaptability. Material compatibility may affect the pump body temperature rise, and then affect the heat dissipation strategy of the control algorithm. If the material compatibility is high (such as stainless steel being corrosion-resistant), a higher working temperature or a more aggressive control strategy can be allowed without excessive derating protection. In addition, in practical applications, the algorithm complexity can be adjusted according to compatibility. For example, a high-compatibility system may integrate more sensor data and adopt advanced algorithms such as model predictive control (MPC), while a low-compatibility system may need to simplify the control to reduce the requirements for interfaces and processing capabilities.

[0052] Different control methods such as PID, vector control, fuzzy control, etc. have an impact on aspects such as speed regulation accuracy and service life. Considering the balance between efficiency and life, a high-compatibility motor and pump combination may allow a higher operating efficiency because the motor or diaphragm pump materials are heat-resistant, which can reduce the heat dissipation demand, and thus a higher-frequency PWM control can be adopted. In the case of low compatibility, the load may need to be reduced to avoid premature wear, and a more conservative control strategy is used. Specifically, for example, when conveying corrosive media through a stainless steel pump, the motor can adopt high-efficiency vector control, combined with temperature compensation to reduce derating and extend the operating time. On the contrary, plastic pumps may be sensitive to temperature and need to adopt soft start and soft stop strategies to avoid overheating, reduce mechanical shock, and extend the life.

[0053] It can be seen that different electric diaphragm pumps have different compatibilities based on the different material characteristics when the diaphragm pump is combined with the motor. To improve the reliability of system operation, it is necessary to dynamically adjust the control strategy by combining the high and low compatibilities of the diaphragm pump and the motor.

[0054] After searching, the applicant found some relevant prior arts. For example, the "High-performance Brushless Motor Control System, Method and Medium Based on ROS2" with application number CN202411784737.7, the "Intelligent Control Method and System for Motors of Permanent Magnet Synchronous Water Pumps" with application number CN202311625130.X, and the "Remote Control Method for High-pressure Water Pump Motors Based on Data Acquisition" with application number CN202411803502.8 all involve the dynamic adjustment and optimization of motor control strategies. However, the above three motor control methods do not adjust and optimize the control strategy by comprehensively considering the compatibility degrees of the diaphragm pump and the brushless DC motor in multiple different dimensions, and there is further room for optimizing the reliability of system operation.

[0055] To solve the technical problems existing in the above-mentioned prior arts, an embodiment of the present invention provides a control method for a brushless DC motor used in a diaphragm pump, as Figure 1 shown, which includes:

[0056] S1, obtaining the first weight coefficients and the corresponding first compatibility scores of the diaphragm pump characteristics in multiple different dimensions.

[0057] Specifically, the diaphragm pump characteristics in multiple different dimensions include but are not limited to pump body material characteristics (such as plastic, aluminum alloy, cast iron, stainless steel, and ceramic, etc.) and diaphragm material characteristics (such as fluorobutyl rubber, fluororubber, nitrile rubber, polytetrafluoroethylene, etc.).

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

[0059] S2, obtaining the second weight coefficients and the corresponding second compatibility scores of the brushless DC motor characteristics in multiple different dimensions.

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

[0061] For the first weight coefficient of the characteristics of diaphragm pumps in multiple different dimensions and the second weight coefficient of the characteristics of brushless DC motors in multiple different dimensions, they can be preset by technicians according to experience. Preferably, the first weight coefficient can be set according to the aging and / or wear of the materials of different dimensions of the corresponding diaphragm pump. For the second weight coefficient corresponding to the material characteristics of the brushless DC motor, it can be set according to the aging and / or wear of the materials of different dimensions of the corresponding brushless DC motor. One method is to first quantify the quality standard values of the materials of different dimensions of the diaphragm pump and the brushless DC motor when they leave the factory (such as quantifying the quality standard values through indicators such as the surface flatness, color uniformity, and the number of defects of the material), and set the corresponding first weight preset value and second weight preset value. Then, by collecting the current quality values of the materials of different dimensions of the diaphragm pump and the brushless DC motor after a preset period of use in the same application scenario, finally, the first weight coefficient and the second weight coefficient are obtained based on the quality standard values, the current quality values, the first weight preset value, and the second weight preset value. Generally speaking, the lower the current quality value and the greater the difference from the quality standard value, the more serious the aging and wear of the material, 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 Among them, CQ 1i 、QS 1i respectively represent the current quality value and the quality standard value corresponding to the material of the diaphragm pump in the i-th dimension. CQ 2i 、QS 2i respectively represent the current quality value and the quality standard value corresponding to the material of the brushless DC motor in the i-th dimension. W 1i ', W 2i ' respectively represent the first weight preset value corresponding to the material of the diaphragm pump in the i-th dimension and the second weight preset value corresponding to the material of the brushless DC motor in the i-th dimension.

[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 scenario. 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 existing in presetting the weight coefficient by relying on the experience of technicians be avoided, but also the first weight coefficient and the second weight coefficient can be dynamically adjusted according to the actual application, making the system compatibility more in line with the actual application situation. It should be noted that for the first weight preset value corresponding to the diaphragm pump material in the i-th dimension and the second weight preset value corresponding to the brushless DC motor material in the i-th dimension, they can be allocated according to the importance of the material in the actual application. For example, 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. Obtain the system compatibility based on 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 obtained by weighted summation or weighted average calculation 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 Figure 2 shown, in step S3, the method for obtaining the system compatibility specifically includes:

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

[0068] S32. Obtain the system compatibility based on the diaphragm pump compatibility factor and the DC motor compatibility factor.

[0069] Among them, W 1i represents the first weight coefficient in the i-th dimension, S 1i represents the first compatibility score in the i-th dimension, W 2i represents the second weight coefficient in the i-th dimension, and S 2iRepresents the second compatibility score for the i-th dimension.

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

[0071] S4. Based on the level of system compatibility, dynamically adjust the control strategy to achieve the control of the brushless DC motor for the diaphragm pump.

[0072] For dynamically adjusting the control strategy based on the level of system compatibility, one understanding is to dynamically adjust the complexity of the brushless DC motor control algorithm according to the level of system compatibility. For example, when the system compatibility is high, model predictive control (MPC, Model Predictive Control) is used to achieve high-precision flow regulation. When the system compatibility is low, a simplified PID control is used to simplify the control to reduce the requirements for interfaces and processing capabilities, prevent the motor from overloading, improve the reliability of system operation, or use a soft start and soft stop strategy to reduce mechanical shock and extend the life.

[0073] Based on the different specific application scenarios of the brushless DC motor for the diaphragm pump, dynamically adjust the control strategy according to the level of system compatibility. Overall, it avoids problems such as unstable system operation and reduced efficiency and life of the diaphragm pump and the motor caused by the mismatch between the control strategy and the system compatibility, and can improve the 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. It can dynamically adjust and optimize the control strategy based on the level of system compatibility, achieve a good match between 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 characteristics of the brushless DC motors in multiple different dimensions include interface characteristics. The control method further includes obtaining the number of interfaces of the brushless DC motor and obtaining the interface complexity for suppressing the system compatibility degree according to the number of interfaces. Among them, the method for obtaining the system compatibility degree according to the diaphragm pump compatibility factor and the DC motor compatibility factor specifically includes: obtaining the system compatibility degree according to the interface complexity, the diaphragm pump compatibility factor, and the DC motor compatibility factor.

[0076] For the brushless DC motor used in the diaphragm pump, in addition to the materials of the diaphragm pump and the brushless DC motor, the number of motor interfaces also affects the system compatibility degree. Generally speaking, the more types of motor interfaces there are, the more brands of sensors it can support and the wider its compatibility range.

[0077] For the interfaces, 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 ) in addition to including the second weight coefficient and the second compatibility score corresponding to the brushless DC motor housing material characteristics, and the second weight coefficient and the second compatibility score corresponding to the bearing material characteristics, also includes the second weight coefficient and the second compatibility score corresponding to the interface characteristics. Generally speaking, the second weight coefficients corresponding to different types of interfaces can be set by technicians, and the second compatibility scores 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, its communication failure rate is extremely low, the data transmission rate is high, the communication distance can reach 10KM, and the network debugging is easy, and 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, and its second compatibility score can be set to 2.5 or 2.0, etc.

[0079] System compatibility degree Where I c represents the interface complexity, and I c can be 1 + ln(N interface ) or ln(1 + N interface ) and so on. Of course, other logarithmic function forms can also be used to process the number of interfaces to obtain the interface complexity, which is not specifically limited here. Generally speaking, the more motor interfaces there are, the higher the system compatibility degree, but too many interfaces may lead to an increase in system complexity. Since too many interfaces may increase system complexity, here the sensitivity of the system compatibility degree to the number of interfaces is adjusted through the number of interfaces and the logarithmic function. In the system compatibility degree formula The denominator uses I c Balance the impact brought by the number of interfaces, making the marginal benefit of increasing the number of interfaces decrease, so that the obtained DC motor compatibility factor and system compatibility 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 overestimation of the system compatibility.

[0080] When the first weight coefficient and the second weight coefficient are set by technicians, 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 fluoroplastics can be appropriately increased, and the second weight coefficient corresponding to interface characteristics can be decreased; in an intelligent and digital factory, 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 Taking the motor interface complexity into account, the logarithmic function ln(N interface ) is used to suppress the increase in system complexity that may be caused by too many interfaces and avoid overfitting. It can dynamically optimize the system compatibility and balance the functional expandability and reliability of the system.

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

[0083] Among them, the method for obtaining the system compatibility according to the diaphragm pump compatibility factor and the DC motor compatibility factor specifically includes: according to the interface complexity, diaphragm pump compatibility factor, DC motor compatibility factor, signal matching degree C s , power supply system compatibility P s , environmental protection level E s , and temperature compensation item T c to obtain the system compatibility.

[0084] System compatibility Among them, 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 item includes:[[]]

[0086] Obtain the actual working temperature T of the system and the maximum allowable working temperature T max ;

[0087] According to the actual working temperature T and the maximum allowable working temperature T max to obtain the temperature compensation item Among them, \(e\) represents the natural constant, and \(k\) represents a preset temperature decay coefficient.

[0088] The actual working temperature \(T\) represents the actual ambient temperature or the temperature of key components (such as the motor winding, the diaphragm material contact area, etc.) during the current operation of the diaphragm pump and the DC motor control system. For the diaphragm pump, its reference temperature range is -60°C to 150°C, and for the brushless DC motor, its 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 winding to dynamically correct the actual working temperature \(T\).

[0089] The maximum allowable working temperature \(T\) max represents the critical temperature for the safe operation of the system, which can be determined comprehensively according to the material and system design. For the diaphragm pump side, the maximum allowable working temperature \(T\) max is determined by the diaphragm material (for example, the upper limit of fluororubber is 150°C, and PTFE can reach 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 of the protection circuit (usually 80°C to 120°C). In actual applications, the smaller value of the two is taken as the overall threshold of the system, that is, the smaller value 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, \(T\) can be set according to the temperature resistance of the actual diaphragm material max (for example, 150°C for PTFE diaphragm and 100°C for fluororubber); for the motor side, \(T\) can be set comprehensively by combining the insulation class of the winding (such as 180°C for class H motor) and the threshold of the protection circuit max .

[0091] For \(k\), it is an adjustment parameter for controlling the temperature sensitivity, which affects the steepness of the function curve and represents the attenuation rate of the tolerance of the material or system to the increase in temperature. Its typical values are as follows:

[0092] \(k = 0.1\), which is suitable for a gentle transition in a wide temperature range (such as a laboratory environment).

[0093] \(k = 0.3\), which is suitable for a rapid response in an industrial scenario (such as a high-temperature workshop).

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

[0095] 1. High-temperature protection mechanism. When \(T\geq T\) max , as the actual working temperature \(T\) increases, the temperature compensation term rapidly becomes smaller, and the system compatibility drops sharply, triggering system protection (such as frequency reduction operation or shutdown) to prevent diaphragm aging and rupture or demagnetization of the motor permanent magnet.

[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 temperature, adapting to cold environments (such as -60°C operating conditions).

[0097] 3. Dynamic temperature rise suppression. When T is close to T max , by adjusting the k value, the compatibility attenuation rate can be controlled to match the requirements of different scenarios. For example, in high-reliability scenarios (such as chemical explosion-proof environments): by increasing the k value, early warning can be given, or in high-elasticity scenarios (such as intermittent short-term overheating): by decreasing the k value, temporary overlimit is allowed.

[0098] Here, the temperature compensation term uses an exponential decay function, which can meet the requirements of the wide temperature range of the diaphragm pump (such as -60°C to 150°C) and increase the temperature rise compensation coefficient of the motor winding. By quantifying the influence of thermal effects on material properties and signal stability, this temperature compensation term achieves precise adaptation to wide temperature range operating conditions and can significantly improve the reliability of the system in extreme environments.

[0099] Specifically, the signal matching degree Among them, ε PWM represents the duty cycle error of the drive 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 ε PWM reflects the duty cycle deviation of the PWM drive signal (such as the difference between the actual output and the theoretical value). Through 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 value of the signal matching degree C s decreases, thus automatically reducing the weight in the system compatibility formula and avoiding torque fluctuations of the motor 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 defect of the closed-loop control system. For example, when the motor runs at high speed, excessive delay will cause phase lag, and the signal matching degree C s directly reduces the system compatibility value through the denominator term, forcing the design to optimize the feedback path (such as shortening the wiring or upgrading the sensor).

[0101] Nonlinear frequency matching evaluation is achieved through the inverse hyperbolic sine function: when f PWM is close to f base , sinh -1 (1) ≈ 0.86, indicating a relatively high degree of matching; when f PWM significantly deviates from the reference frequency, the function value decays rapidly. For example, when f PWM = 2f base , sinh -1 (2) ≈ 0.28, but the denominator grows even faster, overall reducing the system compatibility value. Therefore, this function formula can effectively avoid structural damage caused by resonance between the PWM frequency and the natural frequency of the mechanical system, such as the fatigue failure of a 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 (such as the power supply system compatibility P s , the environmental protection level E s , etc.). Its dynamic characteristics directly affect the robustness of the overall system, which is manifested in the following two aspects:

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

[0104] Second, cooperation with the motor mechanical interface: High-frequency PWM signals (the C s term) may cause harmonic vibrations in the flange connection. The geometric matching degree can be evaluated through the cosine similarity measure to assess its impact on signal stability.

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

[0106] Power supply system compatibility Among them, 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, and I peak is the peak current of the pump load. Tanh represents the hyperbolic tangent function.

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

[0108] 1. Non-linear smooth transition: The hyperbolic tangent function is used to normalize the voltage difference, restricting the voltage matching degree to the interval [0,1), avoiding the compatibility jump problem caused by the mutation of 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 approaches the lower limit, the function value decays rapidly, triggering the protection mechanism.

[0110] 3. Suppress the influence of voltage fluctuation: By dynamically correcting the matching degree between the power supply voltage and the equipment demand, the influence of voltage fluctuation on the stroke accuracy of the diaphragm pump is reduced.

[0111] Power supply system compatibility formula It includes the ratio of the rated current to the peak current, which quantifies the ability of the motor to withstand sudden changes in the pump load through The higher the ratio, the greater the margin of the system under peak operating conditions; when the peak current of the pump load exceeds the rated current of the motor, this parameter triggers a frequency reduction or current limiting strategy to avoid overheating of the winding. In this way, by restricting the duration of the peak current, the thermal aging of the insulating material can be reduced and the motor life can be extended.

[0112] In the optimized system compatibility Among them, the power supply system compatibility directly affects the overall system compatibility as a product factor, and it has a weight amplification effect (when P s decreases due to voltage / current mismatch, the overall compatibility score decays exponentially, forcing the designer to prioritize optimizing the power supply system parameters) and a multi-parameter coupling verification effect (interacts with parameters such as signal matching degree, for example, low P s may expose the problem of out-of-sync control signals caused by CAN bus communication delay). Generally speaking, P s achieves the balance between the safety and energy efficiency of the power supply system and becomes the core control parameter of the system compatibility .

[0113] Environmental protection level Among them, IP motor represents the motor protection level value (such as IP motor =IP67 corresponding to the motor protection level value of 67, IP motor =IP65 corresponding to the motor protection level value of 65), IP pump represents the diaphragm pump protection level value (such as IP pump =IP54 corresponding to the diaphragm pump protection level value of 54, IP pump =IP67 corresponding to the diaphragm pump protection level value of 67), δ sealIndicates the aging coefficient of the seal.

[0114] For the aging coefficient of the seal, it can be obtained based on the accelerated aging test method, which specifically includes the following steps:

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

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

[0117] Record the material property decay curve (such as elastic modulus, tensile strength), and calculate the aging coefficient of the seal through the formula where S represents the key performance parameter of the sealing material.

[0118] Of course, the aging coefficient of the seal can also be obtained through the fatigue cycle test method. In the fatigue cycle test method, first conduct a dynamic seal test according to the working frequency of the diaphragm pump (such as 3000 times / hour), and then count the actual number of cycles N before the seal fails 实际 , and define the aging coefficient as or where N 标准 represents the standard number of cycles of the standard diaphragm pump.

[0119] Generally speaking, the longer the seal is used, the more serious the aging degree, and the corresponding aging coefficient is smaller. By combining the motor protection level, the diaphragm pump protection level, and the seal aging coefficient to obtain the environmental protection level, it has the following advantages:

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

[0121] 2. Couple material characteristics with environmental factors. By incorporating the material compatibility (such as the corrosion resistance of fluororubber) into a unified evaluation system through δ seal , the problem of "high protection level ≠ long-term reliability" caused by simply relying on the IP level can be avoided (such as the IP67 motor fails due to seal aging in an acid mist environment).

[0122] 3. Quantify the impact of attenuation on the system. The system compatibility and reliability can be directly correlated through the environmental protection level. Specifically, a decrease in the aging coefficient will reduce the system compatibility.

[0123] In practical applications, compared with the static IP level assessment, the dynamic seal aging coefficient can be used to early warn of the risk of seal failure and formulate a differential maintenance plan according to the attenuation rate of the seal aging coefficient. For example, when the seal aging coefficient > 0.8, check the diaphragm pump and the brushless DC motor every 6 months; when the seal aging coefficient < 0.5, monitor the health status of the diaphragm pump and the brushless DC motor weekly.

[0124] Signal matching degree C s The design can achieve dynamic frequency adaptation and avoid the resonance risk caused by a fixed PWM frequency; the power supply system compatibility P s In the formula, it takes into account the impact of voltage fluctuations on the diaphragm stroke and can achieve double closed-loop control of voltage / current; the environmental protection level E s can correct dynamically based on the seal aging coefficient to overcome the defect of simple superposition of IP levels.

[0125] Sometimes, for the compatibility between the diaphragm pump and the brushless DC motor control, in addition to the diaphragm pump material, the brushless DC motor material and the interface, factors such as the matching degree of the motor control signal (involving PWM frequency and feedback type), the power supply system compatibility (such as matching corresponding current and voltage parameters for different scenarios), and the environmental protection level (such as IP67) also need to be considered. By comprehensively considering factors such as the interface complexity, the diaphragm pump compatibility factor, the DC motor compatibility factor, the matching degree of the motor control signal, the power supply system compatibility, and the environmental protection level, obtaining the system compatibility and dynamically adjusting the control strategy based on the system compatibility can further improve the reliability of the system.

[0126] As a preferred technical solution, the above cosine similarity metric can be expressed as Based on the cosine similarity metric Introduce the mechanical interface standardization value formula where, N nonstd represents the number of non-standard interfaces, such as special-shaped flanges, etc., D flange represents the actual flange diameter, D standard represents the flange industry standard diameter.

[0127] As a non-standard interface penalty factor, this factor reflects the negative impact of the number of non-standard interfaces on the system compatibility in the form of a reciprocal. For example, for each additional special-shaped flange (non-standard interface), the denominator increases, resulting in a decrease in the M s value; adding a constant 0.1 to the denominator can avoid a zero denominator (when N nonstdWhen it is 0), while weakening the penalty for a small number of non-standard interfaces, it better meets the actual engineering requirements.

[0128] In the cosine similarity metric when the actual flange diameter D flange is close to the industry standard D standard the cosine value approaches 1, maximizing M s ; when the actual flange diameter D flange deviates from the standard, the cosine function decays non-linearly, quantifying the degree of geometric mismatch.

[0129] Flexible adaptation can be achieved by adjusting D standard to support other industry standards outside the ISO standard (such as DIN, ANSI), thus being compatible with multiple standard systems.

[0130] For the standardized value of the mechanical interface, the standardized interface reduces the need for customized adaptation and improves the mechanical connection efficiency between the diaphragm pump and the motor control system. By monitoring the change trend of the M s value (such as the decay of the cosine value), the mechanical wear of the interface can be predicted in advance. By quantifying the standardization degree of the mechanical interface and introducing the cosine similarity metric of the flange diameter, the problem of ignoring the geometric matching degree existing in only counting the number of interfaces in the existing technology can be overcome, and the integratability and long-term operation stability can be improved.

[0131] Based on the system mechanical interface standardized value formula the system compatibility can be further optimized. The optimized system compatibility

[0132] formula By coupling multi-dimensional parameters, the 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 the improvement of system-level reliability under complex working conditions.

[0133] Of course, to match the actual situation, for the system compatibility formula the signal matching degree C s the power supply system compatibility P s the environmental protection level E s the mechanical interface standardized value M s and the temperature compensation term T c corresponding weight coefficients can be set, and by adjusting the weight coefficients, the importance degrees of the signal matching degree C s the power supply system compatibility P s the environmental protection level E s the mechanical interface standardized value M s and the temperature compensation term T c in the system compatibility can be adjusted.

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

[0135] Construct a neural network model, and construct a loss function of the neural network model according to the system compatibility formula

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

[0137] represents the noise factor, I n represents the amplitude of the 6k±1 harmonic current (unit: A), which is caused by the switching action of the motor driver resulting in current waveform distortion. These harmonics will cause electromagnetic vibration and be transmitted as audible noise (such as high-frequency whistling) through the pump body structure. The brushless motor generates specific sub-current harmonics due to PWM modulation or square wave control during the commutation process. For example, when k = 1, n = 5, 7th harmonics; when k = 2, n = 11, 13th harmonics, etc. n represents the harmonic order, and the purpose is to attenuate and weight the high-order harmonics. The logarithmic operation 20lg is used to convert the current harmonic amplitude into sound pressure level (dB), reflecting its contribution to noise. represents the current change rate term, represents the instantaneous current change rate (unit: A / s), which can be understood as the sudden change of the magnetic field force caused by the sudden change of the current (such as at the moment of commutation or load mutation), triggering the instantaneous impact vibration between the stator and rotor of the motor and generating "click" - like transient noise, K v represents the current change rate weight coefficient (unit: dB·s / A), which is used to quantify the sensitivity of the current change rate to noise and 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 value between the actual speed and the target speed when the motor is in a stable operating state) and the dynamic response time T resp (the time required for the system to reach a new steady state from receiving the speed regulation instruction, including the transition process of the acceleration / deceleration stage), and suppress the Hall position detection error θ err ) through sinc(θ err (the deviation between the rotor position signal output by the Hall sensor and the actual mechanical angle), which can improve the accuracy of the control algorithm.

[0139] β·softplus(T - T 0) represents the temperature compensation term, T represents the actual temperature during motor operation, which can be monitored in real time through a temperature sensor. T 0 represents the preset upper limit of safe temperature (for example, the diaphragm pump can withstand a temperature of 150 °C). When the threshold is exceeded, derating protection is triggered. In this case, the softplus function is used to smooth the impact of temperature rise on the lifespan, achieving adaptive thermal management.

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

[0141] α, β, and γ represent weight coefficients, which are used to adjust the optimization priorities of the main loss term, the temperature compensation term, and the variance term of speed regulation accuracy. For example, when α is increased, the system focuses on efficiency, noise, compatibility, and speed regulation accuracy. When β is increased, the system strengthens the temperature rise constraint. When γ is increased, the speed regulation stability of the system can be improved.

[0142] In the loss function, by introducing the temperature penalty term Softplus function, when the temperature rise ΔT exceeds the threshold T 0 an exponential loss increase occurs, strengthening the thermal protection mechanism; by adding the control parameter variance term Var(θ), the oscillation risk of the control strategy is suppressed.

[0143] The training dataset can be constructed and the neural network model can be trained by collecting the historical operation data of the system, such as the mechanical output power of the motor, the electrical input power, the noise parameters, the temperature / voltage / current parameters during motor operation, the motor speed error information, the dynamic response time, and the system parameters related to the system compatibility. Since obtaining the training dataset to train the neural network model belongs to the conventional technical means in this field, it will not be elaborated here.

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

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

[0146]

[0147] It can be seen that after optimizing the control parameters through the constructed neural network model, the comprehensive performance indicators of the system are better than those of the traditional PID fuzzy control algorithm. That is to say, by constructing a neural network model, the dimensional parameters such as noise factor, system compatibility, efficiency factor, and speed regulation accuracy are designed and integrated, realizing the collaborative optimization and dynamic balance of parameters such as efficiency, noise, and accuracy, improving the comprehensive performance of system control, and being applicable to high-reliability industrial scenarios.

[0148] An embodiment of the present invention further provides a control system for a brushless DC motor used in a diaphragm pump, which is used to implement the control method of the brushless DC motor used in the diaphragm pump, as Figure 3 shown, and it includes a first acquisition module, a second acquisition module, a compatibility acquisition module, and a control module.

[0149] The first acquisition module is used to acquire the first weight coefficients of the diaphragm pump characteristics in multiple different dimensions and the corresponding first compatibility scores; the second acquisition module is used to acquire the second weight coefficients of the brushless DC motor characteristics in multiple different dimensions and the corresponding second compatibility scores.

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

[0151] Preferably, the compatibility acquisition module includes 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 to acquire the diaphragm pump compatibility factor according to the first weight coefficients and the first compatibility scores; the DC motor compatibility factor acquisition unit is used to acquire the DC motor compatibility factor according to the second weight coefficients and the second compatibility scores; the system compatibility acquisition unit is used to acquire the system compatibility according to the diaphragm pump compatibility factor and the DC motor compatibility factor.

[0153] As Figure 4As shown in the figure, the overall structure of the brushless DC motor for diaphragm pumps includes parts such as the pump body 1, the diaphragm 2, the motor housing 3, the motor bearings 4, the liquid inlet 5, and the liquid outlet 6. Since the structure of the electric diaphragm pump based on the brushless DC motor belongs to the conventional technical means in this field, it will not be elaborated here.

[0154] Specifically, assuming that after obtaining the system compatibility degree according to the compatibility factor of the diaphragm pump and the compatibility factor of the DC motor and performing normalization processing, its value range is 0 - 1.0. In one application scenario, the pump body material of the diaphragm pump 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 the CAN / Modbus protocol, the medium is a low-viscosity liquid, and the finally calculated system compatibility degree is greater than 0.8, indicating a high-compatibility system. Then its control strategy can be set as follows: Adopt model predictive control (MPC), combine multi-sensor data of temperature, flow rate, and pressure to optimize the motor output torque in real time, and achieve the Pareto optimal solution of efficiency and life; Enable dynamic PWM frequency adjustment, automatically switch between SVPWM (low speed) and optimized six-step commutation (high speed) according to the change of the medium viscosity, and reduce the switching loss and the flow control error. If the pump body material is plastic, the medium also contains particles, the motor housing and bearings are both cast iron, and the finally calculated system compatibility degree is less than 0.5, then the following control strategy can be adopted: Adopt simplified PID control, discard the complex observer, and only estimate the rotational speed through the Hall sensor to reduce the dependence of the algorithm on the interface bandwidth; Adopt a load balancing mechanism, dynamically limit the peak current according to the temperature resistance threshold of the material (such as ≤60°C) to avoid the risk of jamming caused by particulate media.

[0155] Of course, when the system compatibility degree is greater than 0.9, a model predictive control (MPC) strategy can also be adopted to achieve high-precision flow regulation (such as in the pharmaceutical filling scenario); when the system compatibility degree is greater than or equal to 0.6 and less than or equal to 0.9, a control strategy of PID + feedforward compensation is adopted; when the system compatibility degree is less than 0.6, a control strategy of switch control + timeout protection is adopted. This situation can generally be understood as an emergency mode in a harsh environment, such as mine sludge discharge, etc.

[0156] It should be noted that based on the high or low system compatibility degree, the control strategy is dynamically adjusted. For the upper and lower limits of the numerical range of the system compatibility degree corresponding to different control strategies, fine-tuning can also be carried out according to the actual situation, which will not be elaborated here.

[0157] Based on the differences in the specific application scenarios of the brushless DC motor for diaphragm pumps, the control strategy is dynamically adjusted according to the high or low system compatibility. Overall, it avoids problems such as unstable system operation and reduced efficiency and life of the diaphragm pump and the motor caused by the mismatch between the control strategy and the system compatibility, and can improve 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 controlling the brushless DC motor for the diaphragm pump, it comprehensively considers the multi-dimensional characteristic factors of the diaphragm pump and the brushless DC motor. It can dynamically adjust and optimize the control strategy based on the high or low system compatibility degree, realize a good match between the control of the brushless DC motor and the system, and thus improve the reliability of the control of the brushless DC motor for the diaphragm pump.

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

[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 the signal matching degree, the power supply system compatibility, and the environmental protection level, 1 + ln(N interface ) represents the 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] Among them, the signal matching degree Among them, ε PWM represents the duty cycle error of the drive 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), 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] Dynamic PWM frequency modulation can be performed 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, 20kHz adaptive PWM is adopted, and the duty cycle is dynamically adjusted through the fuzzy PID algorithm.

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

[0165] Specific example: In the scenario of transporting high-viscosity media by a diaphragm pump, when τ feedback increases, it automatically switches to the 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, 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, and I peak is the peak current of the pump load, and tanh represents the hyperbolic tangent function.

[0167] Here, the weights of the voltage / current closed-loop control can be adjusted according to the value of the 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 the output efficiency through the 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 the peak current and protect the motor winding.

[0170] Specific example: When the pump load soars due to a sudden increase in the medium viscosity (such as transporting high-viscosity oil), if I peak soars, and if (that is, the peak current exceeds twice the rated current), it may trigger overheating and even burning of the motor winding. At this time, the current closed-loop current limiting can be triggered to prevent the motor from overloading. By monitoring this ratio in real time, the system can dynamically adjust the power supply strategy (such as reducing the frequency or cutting off the power supply).

[0171] Regarding the temperature compensation term The temperature compensation and overheat protection can be linked to dynamically adjust the heat dissipation strategy. The specific implementation method is as follows:

[0172] 1. Low-temperature mode (T < -20°C): Increase the motor starting current to 150% to compensate for the resistance caused by the increased viscosity of the grease.

[0173] 2. High-temperature mode (T > 80°C): Enable the winding temperature observer, estimate the hot-spot temperature through Kalman filtering, and reduce the frequency in advance.

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

[0175] When the compatibility of the optimized system Mechanical interface standardization value formula is satisfied, fault-tolerant control based on mechanical interface feedback can also be implemented according to the mechanical interface standardization value. Since the flange matching degree will affect mechanical vibration, the load prediction model can be adjusted. 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, add a 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 mechanical vibration amplitude.

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

[0180] An embodiment of the present invention also provides a control device for a brushless DC motor used in a diaphragm pump, which includes: a memory for storing a computer program; a processor for executing the computer program to implement the control method of the brushless DC motor used in the diaphragm pump.

[0181] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0182] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A control method for a brushless DC motor for a diaphragm pump, characterized in that: The control method comprises: Obtaining first weight coefficients of diaphragm pump features of multiple different dimensions and corresponding first compatibility scores; Obtaining second weight coefficients of brushless DC motor features of multiple different dimensions and corresponding second compatibility scores; Obtaining system compatibility according to the first weight coefficient, the first compatibility score, the second weight coefficient, and the second compatibility score; Based on the system compatibility, the control strategy is dynamically adjusted to achieve the control of the brushless DC motor for the diaphragm pump.

2. A method for controlling a brushless DC motor for a diaphragm pump as claimed in claim 1, characterized in that: The methods for obtaining system compatibility specifically include: Get the diaphragm pump compatibility factor ∑(W 1i ·S 1i ) and DC motor compatibility factor ∑(W 2i ·S 2i ); Obtain system compatibility based on diaphragm pump compatibility factor and DC motor compatibility factor; Among them, 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.

3. A method for controlling a brushless DC motor for a diaphragm pump as claimed in claim 2, characterized in that: The brushless DC motor characteristics of multiple different dimensions include interface characteristics, and the control method further includes obtaining the number of interfaces of the brushless DC motor, and obtaining the interface complexity for suppressing system compatibility according to the number of interfaces; Among them, the method for obtaining system compatibility based on the diaphragm pump compatibility factor and the DC motor compatibility factor specifically includes: obtaining system compatibility based on interface complexity, the diaphragm pump compatibility factor and the DC motor compatibility factor.

4. A method for controlling a brushless DC motor for a diaphragm pump as claimed in claim 3, characterized in that: The control method further includes: obtaining control signal matching, power supply system compatibility, environmental protection level and temperature compensation items; The method for obtaining system compatibility based on the diaphragm pump compatibility factor and the DC motor compatibility factor specifically includes: according to the interface complexity, the diaphragm pump compatibility factor, the DC motor compatibility factor, the signal matching degree C s , Power supply system compatibility s 、Environmental protection level E s And the temperature compensation term T c Get system compatibility.

5. A method for controlling a brushless DC motor for a diaphragm pump as claimed in claim 4, characterized in that: System compatibility Among them, 1+ln(N interface ) represents the interface complexity, N interface Indicates the number of interfaces.

6. A method for controlling a brushless DC motor for a diaphragm pump as claimed in claim 5, characterized in that: The specific methods for obtaining the temperature compensation item include: Get the actual system operating temperature T and the maximum allowable operating temperature T max ; According to the actual working temperature T and the maximum allowable working temperature T max Get temperature compensation item Wherein, e represents a natural constant, and k represents a preset temperature attenuation coefficient.

7. A control system for a brushless DC motor for a diaphragm pump, used to implement the control method for a brushless DC motor for a diaphragm pump as claimed in any one of claims 1 to 6, characterized in that: include: A first acquisition module, used to acquire first weight coefficients of diaphragm pump characteristics of multiple different dimensions and corresponding first compatibility scores; A second acquisition module, used to acquire second weight coefficients of brushless DC motor characteristics of multiple different dimensions and corresponding second compatibility scores; A compatibility acquisition module, used to acquire system compatibility according to a first weight coefficient, a first compatibility score, a second weight coefficient and a second compatibility score; The control module is used to dynamically adjust the control strategy based on the system compatibility to achieve the control of the brushless DC motor for the diaphragm pump.

8. A control system for a brushless DC motor for a diaphragm pump as claimed in claim 7, characterized in that: The compatibility acquisition module includes: A diaphragm pump compatibility factor acquisition unit, used to acquire the diaphragm pump compatibility factor according to the first weight coefficient and the first compatibility score; A DC motor compatibility factor acquisition unit, configured to acquire the DC motor compatibility factor according to the second weight coefficient and the second compatibility score; The system compatibility acquisition unit is used to acquire the system compatibility according to the diaphragm pump compatibility factor and the DC motor compatibility factor.

9. A control system for a brushless DC motor for a diaphragm pump as claimed in claim 8, characterized in that: The system compatibility acquisition unit is based on the formula Obtain system compatibility; Among them, 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 signal matching, power supply system compatibility and environmental protection level, 1+ln(N interface ) represents the interface complexity, N interface Indicates the number of interfaces. represents the temperature compensation term, T represents the actual operating temperature of the system, T max represents the maximum allowable operating temperature, e represents the natural constant, and k represents the preset temperature attenuation coefficient.

10. A control device for a brushless DC motor for a diaphragm pump, characterized in that: include: Memory for storing computer programs; A processor, used for executing the computer program to implement the control method of the brushless DC motor for a diaphragm pump according to any one of claims 1 to 6.

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