An electric valve actuator capable of adapting to different rated driving torques and its driving current setting method

Abstract

An electric valve actuator that can adapt to different rated torques, including an actuator. The actuator includes a stepper motor driver, a stepper motor, and a speed reducer connected in sequence. The power output terminal of the stepper motor driver is connected to the power input terminal of the stepper motor through a wire. The power output terminal of the stepper motor is connected to the power input terminal of the speed reducer. The power output terminal of the speed reducer is connected to the valve shaft of the valve. Different ports of the stepper motor driver are connected to corresponding ports of the valve controller. Under the conditions of the same specification and model of the stepper motor and the speed reducer, by adjusting the set value of the drive current of the electric valve actuator, the same specification and model of the stepper motor and the speed reducer can adapt to multiple rated output torques, having the advantages of simple structure, convenient operation, and practical and high efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of fluid machinery, and particularly relates to an electric valve actuator capable of adapting to different rated driving torques and a driving current setting method thereof. Background Art

[0002] An electric valve is an important terminal actuator in the process industry. It is usually composed of an electric actuator and a valve body. The actuator drives the valve core in the valve body to move, thereby regulating the fluid flow rate in the pipeline. With the continuous progress and improvement of the production process, higher requirements are put forward for the positioning accuracy of the electric valve actuator. In order to achieve precise flow regulation, a new type of electric valve actuator driven by a stepper motor has emerged. The stepper motor can drive the valve core to rotate according to the control pulse, realizing more precise positioning control, and is suitable for application occasions with high flow regulation accuracy. The valve structure refers to electric valves driven by stepper motors such as the patent "Closed-loop High-precision Quantitative Valve" (ZL20131009466.1) and "A Dilution Water Valve Actuator" (ZL201420553135.6).

[0003] The rated driving torque of an electric valve is an important technical index. When designing and manufacturing the valve, it is necessary to make the driving torque generated by the valve driving motor through the speed reduction mechanism match the rated value. If the generated driving torque or thrust is too large, it is easy to cause excessive load on the valve driving device or the valve body and cause damage; if the generated driving torque or thrust is insufficient, it is easy to cause missed steps and cause positioning errors. The stepper motor belongs to a standardized and serialized product, and its rated current and rated torque are fixed. In order to make the output torque of the actuator consistent with the rated torque value of the valve, it is necessary to select a reducer with a specific reduction ratio. Taking the rated torque of the valve driving stepper motor as 1.25 N·m and the rated output torque of the actuator as 125 N·m as an example, the reduction ratio of the reducer should be 100:1; if the rated output torque of the actuator is 250 N·m, the reduction ratio of the reducer should be 200:1. It can be seen that for electric valve actuators with different rated torques, reducers with different reduction ratios need to be configured, resulting in a large variety of reducer types and models in the inventory of electric valve manufacturers, high procurement and inventory costs, and increasing the burden on enterprises.

[0004] There are a wide variety of reduction ratios for the actuator reducers, which brings another problem. Actuators with different reduction ratios will have different numbers of operation steps. Taking an actuator with a rated output torque of 125 N·m and a reduction ratio of 100:1 as an example, assuming that the stepping motor rotates 200 control pulses per revolution and the angular stroke range of the valve actuator is 0 to 90°, then when the valve moves from fully open to fully closed, the stepping motor rotates 25 full revolutions, and the number of control pulses required is 5000. If the actuator has a rated output torque of 250 N·m and a reduction ratio of 200:1, then when the valve moves from fully open to fully closed, the stepping motor rotates 50 full revolutions. Assuming that the model of the stepping motor remains unchanged and it still rotates 200 control pulses per revolution, the number of control pulses required for the valve to move from fully open to fully closed is 10000. Electric valve actuators with different rated torques have different numbers of control pulses, which is not conducive to forming products with unified specifications and is not beneficial to the standardization and serialization of products.

[0005] Therefore, to solve this problem, there is an urgent need to invent an electric valve actuator that can adapt to different rated torques, enabling the same specification of stepping motor and reducer to meet the requirements of different rated output torques, reducing the number of specifications of the stepping motor and reducer required for producing electric valves, and being able to unify the number of pulses required for the electric valve to move from fully open to fully closed, thereby improving the standardization and serialization level of products. Summary of the Invention

[0006] In order to overcome the defects of the above-mentioned existing technologies, the purpose of the present invention is to provide an electric valve actuator mechanism that can adapt to different rated torques and its drive current setting method, which can reduce the number of specifications of the stepping motor and reducer required for producing electric valve actuators, and can make the produced electric valve actuators have unified operation steps, facilitating the management and maintenance of products, improving the standardization and serialization level of products, and having the advantages of simple structure, convenient operation, practicality and high efficiency.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] An electric valve actuator mechanism that can adapt to different rated torques, including an actuator 4, and the actuator 4 includes a stepping motor driver 1, a stepping motor 2, and a reducer 3 that are connected in sequence. The power output end of the stepping motor driver 1 is connected to the power input end of the stepping motor 2 through a wire, the power output end of the stepping motor 2 is connected to the power input end of the reducer 3, and the power output end of the reducer 3 is connected to the valve shaft 5 of the valve 6;

[0009] The Power+ and Power- ports of the stepper motor driver 1 are respectively connected to the power output ports of the valve controller 7 to provide the DC power required for the operation of the stepper motor driver 1. The common anode port of the valve controller 7 is connected to the OPTO port of the stepper motor driver 1 as the common anode of the control signal. The enable control port of the valve controller 7 is connected to the ENA port of the stepper motor driver 1 to provide the enable control signal required for the operation of the stepper motor 2. The direction control port of the valve controller 7 is connected to the DIR port of the stepper motor driver 1 to provide the direction control signal required for the operation of the stepper motor 2. The pulse control port of the valve controller 7 is connected to the PLS port of the stepper motor driver 1 to provide the pulse control signal required for the operation of the stepper motor 2. There is a DIP switch on the stepper motor driver 1, which can set the magnitude of the drive current value for the operation of the stepper motor 2.

[0010] The stepper motor 2 is a two-phase stepper motor, namely phase A and phase B. The A+, A-, B+, and B- ports of the stepper motor 2 are respectively connected to the A+, A-, B+, and B- drive current output ports of the stepper motor driver 1.

[0011] When the torque output by the stepper motor 2 is greater than the driving torque requirement of the valve 6, the speed reducer 3 can be not configured.

[0012] Based on the above method for setting the drive current of the electric valve actuator adaptable to different rated torques, it includes the following steps:

[0013] Step 1: Obtain the functional relationship between the drive current of the stepper motor 2 and the driving torque that can be provided:

[0014] The functional relationship of the drive current value of the stepper motor 2 required under different driving torque conditions is obtained by interpolation as T = f (Is) ;

[0015] Step 2: Collect the basic technical parameters of the actuator 4 according to the specifications and models of the current stepper motor 2 and the speed reducer 3, including the reduction ratio n of the speed reducer 3 (the rotational speed ratio of the input shaft to the output shaft of the speed reducer);

[0016] Step 3: Select the model of the stepper motor 2 according to the current actuator 4. On the basis of Step 1, substitute the output current range (Imin ~ Imax) of the stepper motor driver 1 into the formula T = f(Is) to calculate the torque value range (Tmin ~ Tmax) that the current stepper motor 2 can provide;

[0017] Step 4: According to the reduction ratio n of the speed reducer 3, calculate the range of the output torque Tau that the actuator 4 can provide according to the proportional relationship as n·(Tmin ~ Tmax);

[0018] Step 5: Determine the value of the expected target rated output torque Ten of the actuator 4 according to the requirements of the designed product sequence of the actuator 4;

[0019] Step 6: Compare the expected target rated output torque Ten of the actuator 4 with the range of the output torque Tau that the actuator 4 can provide. If the expected target rated output torque Ten of the actuator 4 is within the range of Tau, go to Step 7; if the expected target rated output torque Ten of the actuator 4 is not within the range of Tau, it means that the current stepping motor 2 and reducer 3 of the current specification model cannot meet the requirements of the rated driving torque of the current valve 6, then it is necessary to change the specification model of the stepping motor 2 or the reducer 3, return to Step 2, and re - set;

[0020] Step 7: Calculate the value of the driving torque T that the stepping motor 2 needs to provide according to the expected target rated output torque Ten of the actuator 4 and the reduction ratio n of the reducer 3 M , as shown in formula (1):

[0021]

[0022] Step 8: Substitute the value of the driving torque T that the stepping motor 2 needs to provide M into the functional relationship T = f(Is) between the driving torque of the stepping motor and the driving current, and inversely calculate the value of the driving current Iset of the stepping motor driver 1 that needs to be set under the current driving torque condition;

[0023] Step 9: Set the driving current of the stepping motor 2 at the gear position closest to Iset by adjusting the current setting switch of the stepping motor driver 1; or use the setting software of the stepping motor driver 1 through a computer to set the driving current of the stepping motor 2 to Iset;

[0024] Step 10: Check the driving torque output by the actuator 4. If the output driving torque cannot meet the accuracy requirements of the rated torque, return to Step 9 and adjust the driving current value of the stepping motor 2 until the accuracy requirements are met; if the output driving torque can meet the accuracy requirements of the rated torque, go to Step 11;

[0025] Step 11: Determine whether other rated output torque values need to be matched under the current hardware conditions of the actuator 4. If so, change the target rated torque value of the actuator 4, enter Step 5, and perform the setting process of the driving current value of the stepping motor 2 under other rated torque conditions, and adapt to other different rated torque values under the condition of keeping the current specification models of the actuator 4, stepping motor 2, and reducer 3 unchanged; if other rated output torque values do not need to be matched under the current hardware conditions of the actuator 4, end the driving current setting process of the actuator 4.

[0026] The beneficial effects of the present invention are as follows:

[0027] According to the rated output torque specification of the actuator 4 and in combination with the specification models of the stepper motor 2 and the speed reducer 3, the drive current setting values for the full series of actuators 4 can be obtained. Under the condition of the same specification model of the stepper motor 2 and the speed reducer 3, by adjusting the drive current setting value of the actuator 4, the same specification model of the stepper motor 2 and the speed reducer 3 can be made to adapt to multiple rated output torques; using a smaller number of specification types of stepper motors and speed reducers to achieve multiple specifications of rated output torques is conducive to reducing the number of parts required for the production and manufacturing of the actuator 4 and reducing production costs; moreover, it can solve the problem that in order to match the rated output torque, speed reducers with different reduction ratios are used, resulting in a large number of operation step specifications for the actuator 4, inconsistent operation step numbers for different actuators 4, and too many operation step specifications, which is not conducive to forming a unified product specification; it has the advantages of simple structure, convenient operation, and practical and high efficiency. Description of the Drawings

[0028] Figure 1 is the mechanical structure schematic diagram of the present invention.

[0029] Figure 2 is the structural principle block diagram of the present invention.

[0030] Figure 3 is the rated drive torque setting flow chart of the electric valve actuator of the present invention.

[0031] Figure 4 is the control system connection diagram of the present invention.

[0032] Figure 5 is the structural schematic diagram of the test device for the relationship between the drive torque of the stepper motor and the required drive current setting value of the present invention.

[0033] Figure 6 is the test flow chart of the functional relationship between the drive torque of the stepper motor and the required drive current of the present invention.

[0034] Among them, 1. Stepper motor driver; 2. Stepper motor; 3. Speed reducer; 4. Actuator; 5. Valve rotating shaft; 6. Valve; 7. Valve controller; 11. Stepper motor driver Q; 12. Magnetic powder brake controller; 13. Magnetic powder brake; 14. Stepper motor M; 15. Angular displacement sensor. Detailed Embodiments

[0035] The following further describes the present invention in detail with reference to the drawings and embodiments:

[0036] See Figure 1, An electric valve actuator adaptable to different rated torques, comprising an actuator 4. The actuator 4 includes a stepper motor driver 1, a stepper motor 2 and a speed reducer 3 connected in sequence. The power output terminal of the stepper motor driver 1 is connected to the power input terminal of the stepper motor 2 through a wire. The power output terminal of the stepper motor 2 is connected to the power input terminal of the speed reducer 3. The power output terminal of the speed reducer 3 is connected to the valve shaft 5 of the valve 6.

[0037] See Figure 4 , The Power+ and Power- ports of the stepper motor driver 1 are respectively connected to the power output ports of the valve controller 7 to provide the DC power required for the operation of the stepper motor driver 1. The common anode port of the valve controller 7 is connected to the OPTO port of the stepper motor driver 1 as the common anode of the control signal. The enable control port of the valve controller 7 is connected to the ENA port of the stepper motor driver 1 to provide the enable control signal required for the operation of the stepper motor 2. The direction control port of the valve controller 7 is connected to the DIR port of the stepper motor driver 1 to provide the direction control signal required for the operation of the stepper motor 2. The pulse control port of the valve controller 7 is connected to the PLS port of the stepper motor driver 1 to provide the pulse control signal required for the operation of the stepper motor 2. There is a DIP switch on the stepper motor driver 1, and the driving current value for the operation of the stepper motor 2 can be set.

[0038] The stepper motor 2 is a two-phase stepper motor, namely phase A and phase B. The A+, A-, B+ and B- ports of the stepper motor 2 are respectively connected to the A+, A-, B+ and B- driving current output ports of the stepper motor driver 1.

[0039] When the torque output by the stepper motor 2 is greater than the driving torque requirement of the valve 7, the speed reducer 3 can be not configured.

[0040] See Figure 3 , Based on the driving current setting method of the above-mentioned electric valve actuator adaptable to different rated torques, the following steps are included:

[0041] Step 1: Obtain the functional relationship between the driving current of the stepper motor 2 and the driving torque that can be provided:

[0042] The functional relationship of the driving current value of the stepper motor 2 required under different driving torque conditions is obtained by interpolation as T = f (Is) ;

[0043] Step 2: Collect the basic technical parameters of the actuator 4 according to the current specifications and models of the stepper motor 2 and the speed reducer 3, including the reduction ratio n of the speed reducer 3 (the rotation speed ratio of the input shaft to the output shaft of the speed reducer);

[0044] Step 3: Select the model of the stepper motor 2 according to the current actuator 4. On the basis of Step 1, substitute the output current range (Imin~Imax) of the stepper motor driver 1 into the formula T = f(Is) to calculate the torque value range (Tmin~Tmax) that the current stepper motor 2 can provide;

[0045] Step 4: According to the reduction ratio n of the reduction gear 3, calculate the range of the output torque Tau that the actuator 4 can provide according to the proportional relationship as n·(Tmin~Tmax);

[0046] Step 5: Determine the value of the expected target rated output torque Ten of the actuator 4 according to the design product sequence requirements of the actuator 4;

[0047] Step 6: Compare the expected target rated output torque Ten of the actuator 4 with the range of the output torque Tau that the actuator 4 can provide. If the expected target rated output torque Ten of the actuator 4 is within the range of Tau, go to Step 7; if the expected target rated output torque Ten of the actuator 4 is not within the range of Tau, it means that the current specifications and models of the stepper motor 2 and the reduction gear 3 cannot meet the requirements of the rated driving torque of the current valve 6, then it is necessary to change the specifications and models of the stepper motor 2 or the reduction gear 3, and return to Step 2 to re - set;

[0048] Step 7: According to the expected target rated output torque Ten of the actuator 4 and the reduction ratio n of the reduction gear 3, calculate the value of the driving torque T that the stepper motor 2 needs to provide M , as shown in formula (1):

[0049]

[0050] Step 8: Substitute the value of the driving torque T that the stepper motor 2 needs to provide M into the functional relationship T = f(Is) between the driving torque and the driving current of the stepper motor, and calculate the driving current value Iset that needs to be set under the current driving torque condition by inverse calculation;

[0051] Step 9: By adjusting the current setting switch of the stepper motor driver 1, set the driving current of the stepper motor 2 at the gear position closest to Iset; or through a computer, use the setting software of the stepper motor driver 1 to set the driving current of the stepper motor 2 to Iset;

[0052] Step 10: Check the driving torque output by the actuator 4. If the output driving torque cannot meet the accuracy requirements of the rated torque, return to Step 9 to adjust the driving current value of the stepper motor 2 until the accuracy requirements are met; if the output driving torque can meet the accuracy requirements of the rated torque, go to Step 11;

[0053] Step Eleven: Determine whether it is necessary to match other rated output torque values under the current actuator 4 hardware conditions. If so, change the target rated torque value of the actuator 4 and enter Step Five to perform the setting process of the drive current value of the stepper motor 2 under other rated torque conditions, and adapt to other different rated torque values while keeping the specifications and models of the current actuator 4, stepper motor 2, and reducer 3 unchanged. If it is not necessary to match other rated output torque values under the current actuator 4 hardware conditions, end the drive current setting process of the actuator 4.

[0054] The method for obtaining the functional relationship between the stepper motor drive current and the drive torque that can be provided in Step One is as follows:

[0055] See Figure 5 , obtain the functional relationship between the stepper motor drive current and the drive torque that can be provided through a test device for the relationship between the drive torque of the stepper motor and the set value of the required drive current. The device includes a stepper motor driver Q11, the stepper motor driver Q11 is connected to the stepper motor M14 through a wire, the output shaft of the stepper motor M14 is connected to the output shaft of the magnetic powder brake 13, the control end of the magnetic powder brake controller 12 is connected to the power input end of the magnetic powder brake 13, and the power output shaft of the stepper motor M14 is connected to the angular displacement sensor 15;

[0056] To ensure the consistency of the test results, it is necessary to make the stepper motor driver Q11 to be tested and the stepper motor M14 have the same model and specifications as the stepper motor driver 1 and the stepper motor 2 actually used in the actuator 4. See Figure 6 , the process of testing the functional relationship between the drive torque of the stepper motor M14 and the required drive current:

[0057] First Step: Set the drive current of the stepper motor driver Q11 to I in ascending order n ;

[0058] Second Step: Adjust the current value of the magnetic powder brake controller 12 so that the braking torque provided by the magnetic powder brake 13 is equal to T n ;

[0059] Third Step: Set the microstep resolution of the stepper motor driver Q11 to be the same as that of the stepper motor driver 1 in the actuator 4, and send N positioning control pulses to the stepper motor driver Q11. Assume that under the current setting mode of the stepper motor driver Q11, the step angle of the stepper motor M14 is θ 0 , then the theoretical rotation angle θ 1 of the stepper motor M14 is equal to N·θ 0 ;

[0060] Step 4: Compare the actual rotation angle θ of the stepping motor M14 detected by the angular displacement sensor 15 with θ 2 If θ 1 is less than θ 2 , it indicates that the set current value I of the current stepping motor driver Q11 cannot overcome the braking torque T of the magnetic powder brake 13 1 , and a stepping loss phenomenon occurs. It is necessary to increase the set value of the driving current of the stepping motor driver Q11 and retest from the first step; until θ n is equal to θ n or within the allowable error range, it indicates that the set value of the driving current of the current stepping motor driver Q11 can overcome the braking torque of the magnetic powder brake 13, ensuring the positioning accuracy of the stepping motor M14, and obtaining the set value I of the driving current of the stepping motor M14 required under the condition of satisfying the driving torque T 2 1 ; n sn

[0061] Step 5: Determine whether the current driving torque T n reaches the rated driving torque of the stepping motor M14. If the driving torque T n is less than the rated driving torque of the stepping motor M14, enter the second step, further increase the current value of the magnetic powder brake controller 12 to make the magnetic powder brake 13 generate a greater braking torque, and test the set value of the driving current of the stepping motor required under the condition of satisfying a greater driving torque; until the magnetic powder brake 13 reaches the rated driving torque of the stepping motor M14, thereby obtaining a series of numerical relationships between the driving torque T n and the required driving current value I of the stepping motor sn ;

[0062] Step 6: Calculate the functional relationship T = f of the required driving current value of the stepping motor under different driving torque conditions through interpolation calculation (Is) , and end the test.

[0063] It should be noted here that the purpose of the above-mentioned preparatory work is to determine the functional relationship of the required driving current value of the stepping motor under different driving torque conditions. The present invention provides one of the determination methods, and in the subsequent implementation steps of the present invention, it is not limited to the method described above and the test device for the relationship between the driving torque of the stepping motor and the required set value of the driving current.

[0064] The working principle of the present invention is as follows:

[0065] Refer to Figure 2 ​​​, the stepper motor driver 1 provides the current for the operation of the stepper motor 2. According to the different magnitudes of the driving current provided by the stepper motor driver 1, the stepper motor 2 can generate driving torques of different magnitudes. The speed reducer 3 amplifies the torque output by the stepper motor 2 and provides the output torque to the valve 6; the stepper motor driver 1 can set the driving current through a switch or software, thereby adjusting the driving torque that the stepper motor 2 can provide.

[0066] According to steps one to eleven, it is possible to obtain a method for setting the driving current value of the driver that meets the requirements of multiple rated output torques under the condition that the specifications and models of the stepper motor 2 and the speed reducer 3 in the actuator 4 remain unchanged; according to the rated output torque specifications of the electric valve actuator and in combination with the adjustment of the specifications and models of the stepper motor 2 and the speed reducer 3, it is possible to obtain the driving current setting values of the full series of electric valve actuators. Under the condition of the same specification and model of the stepper motor 2 and the speed reducer 3, by adjusting the driving current setting value of the actuator 4, the same specification and model of the stepper motor 2 and the speed reducer 3 can be made to adapt to multiple rated output torques; by using a smaller number of specifications of the stepper motor 2 and the speed reducer 3, multiple specifications of rated output torques can be achieved.

Claims

1. A method for setting the drive current of an electric valve actuator adaptable to different rated torques, characterized in that: The actuator includes an actuator (4), and the actuator (4) includes a stepper motor driver (1), a stepper motor (2) and a speed reducer (3) connected in sequence. The power output end of the stepper motor driver (1) is connected to the power input end of the stepper motor (2) through a wire. The power output end of the stepper motor (2) is connected to the power input end of the speed reducer (3). The power output end of the speed reducer (3) is connected to the valve shaft (5) of the valve (6); the Power+ and Power- ports of the stepper motor driver (1) are respectively connected to the power output ports of the valve controller (7) to provide the DC power required for the operation of the stepper motor driver (1). The common anode port of the valve controller (7) is connected to the OPTO port of the stepper motor driver (1) as the common anode of the control signal. The enable control port of the valve controller (7) is connected to the ENA port of the stepper motor driver (1) to provide the enable control signal required for the operation of the stepper motor (2). The direction control port of the valve controller (7) is connected to the DIR port of the stepper motor driver (1) to provide the direction control signal required for the operation of the stepper motor (2). The pulse control port of the valve controller (7) is connected to the PLS port of the stepper motor driver (1) to provide the pulse control signal required for the operation of the stepper motor (2). There is a DIP switch on the stepper motor driver (1) to set the magnitude of the drive current value for the operation of the stepper motor (2); The drive current setting method includes the following steps: Step 1: Obtain the functional relationship between the drive current of the stepper motor (2) and the drive torque that can be provided; The drive current value function relationship T = f required for the stepping motor (2) under different drive torque conditions is obtained by interpolation (Is) ; Step 2: Collect the basic technical parameters of the actuator (4) according to the specifications of the current stepper motor (2) and speed reducer (3), including the reduction ratio n of the speed reducer (3) (the rotational speed of the input shaft of the speed reducer is compared with the rotational speed of the output shaft); Step 3: Select the model of the stepper motor (2) according to the current actuator (4). On the basis of Step 1, substitute the output current range (Imin~Imax) of the stepper motor driver (1) into the formula T = f(Is) to calculate the torque value range (Tmin~Tmax) that the current stepper motor (2) can provide; Step 4: According to the reduction ratio n of the speed reducer (3), calculate the range of the output torque Tau that the actuator (4) can provide according to the proportional relationship as n·(Tmin~Tmax); Step 5: Determine the value of the expected target rated output torque Ten of the actuator (4) according to the design product sequence requirements of the actuator (4); Step 6: Compare the expected target rated output torque Ten of the actuator (4) with the range of the output torque Tau that the actuator (4) can provide. If the expected target rated output torque Ten of the actuator (4) is within the range of Tau, proceed to Step 7; if the expected target rated output torque Ten of the actuator (4) is not within the range of Tau, it indicates that the current specifications of the stepper motor (2) and the speed reducer (3) cannot meet the requirements of the rated driving torque of the current valve (6). In this case, the specifications of the stepper motor (2) or the speed reducer (3) need to be changed, and return to Step 2 to re - set. Step Seven: Calculate the drive torque value T required by the stepper motor (2) according to the expected target rated output torque Ten of the actuator (4) and the reduction ratio n of the reduction gear (3), as shown in Formula (1): M , as shown in Equation (1): Step 8: Substitute the value of the driving torque T required by the stepper motor (2) M into the functional relationship T = f(Is) between the driving torque and the driving current of the stepper motor (2), and inversely calculate the set driving current value Iset of the stepper motor driver (1) required under the current driving torque condition; Step 9: By adjusting the current setting switch of the stepper motor driver (1), set the driving current of the stepper motor (2) to the gear position closest to Iset; or through a computer, use the setting software of the stepper motor driver (1) to set the driving current of the stepper motor (2) to Iset. Step 10: Check the driving torque output by the actuator (4). If the output driving torque cannot meet the accuracy requirements of the rated torque, return to Step 9 to adjust the driving current value of the stepper motor (2) until the accuracy requirements are met; if the output driving torque can meet the accuracy requirements of the rated torque, proceed to Step 11. Step 11: Determine whether other rated output torque values need to be matched under the current hardware conditions of the actuator (4). If so, change the target rated torque value of the actuator (4), and enter Step 5 to perform the setting process of the driving current value of the stepper motor (2) under other rated torque conditions, and adapt to other different rated torque values while keeping the specifications of the current actuator (4), stepper motor (2), and speed reducer (3) unchanged; if other rated output torque values do not need to be matched under the current hardware conditions of the actuator (4), end the driving current setting process of the actuator (4).

2. A method for setting the driving current of an electric valve actuator adaptable to different rated torques according to claim 1, characterized in that: The stepper motor (2) is a two - phase stepper motor, namely phase A and phase B. The A +, A -, B +, and B - ports of the stepper motor (2) are respectively connected to the A +, A -, B +, and B - driving current output ports of the stepper motor driver (1).

3. A method for setting the driving current of an electric valve actuator adaptable to different rated torques according to claim 1, characterized in that: When the torque output by the stepper motor (2) is greater than the driving torque requirement of the valve (6), the speed reducer (3) may not be configured.

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