A method, device, equipment and medium for calculating the rotor flux of an induction motor

Abstract

The present invention discloses a method, device, equipment, and medium for calculating the rotor flux of an induction motor, relating to the field of motor technology. The method comprises: determining a first rotor flux calculation result based on a current model, and determining a second rotor flux calculation result based on a voltage model; determining a switching coefficient based on the angular velocity of the induction motor; determining a rotor flux difference between the second rotor flux calculation result and the first rotor flux calculation result, and obtaining a third rotor flux calculation result based on the switching coefficient and the rotor flux difference; and determining the rotor flux calculation result of the induction motor based on the first rotor flux calculation result and the third rotor flux calculation result. The present invention comprehensively utilizes the current model and the voltage model to mix and output the calculation results of the two models, thereby improving the accuracy of the flux calculation result and avoiding the use of a single model, which causes the flux calculation result to be affected by changes in motor parameters and reduce its accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a method, device, equipment and medium for calculating the rotor flux of an induction motor. Background Art

[0002] (Asynchronous) induction motors can be controlled via vector control, where the accuracy of the rotor flux calculation determines the quality of the motor control performance.

[0003] Currently, rotor flux calculations typically use voltage models or current models. However, the voltage model is significantly affected by the stator resistance voltage drop when the motor is running at low speed, which can easily cause distortion and affect the accuracy of the calculation results.

[0004] Therefore, how to more accurately obtain the rotor flux of the induction motor to perform relevant control on the induction motor is a technical problem that needs to be solved urgently in the industry. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a method, device, equipment and medium for calculating the rotor flux of an induction motor to solve the problem that the voltage model is greatly affected by the stator resistance voltage drop when the motor is at low speed, which easily causes distortion and affects the accuracy of the calculation results.

[0006] According to a first aspect, an embodiment of the present invention provides a method for calculating the rotor flux of an induction motor, the method comprising:

[0007] Determine a first rotor flux calculation result based on the current model, and determine a second rotor flux calculation result based on the voltage model;

[0008] Determining a switching coefficient based on the angular velocity of the induction motor; wherein the switching coefficient corresponds to the angular velocity one by one, and each angular velocity corresponds to one switching coefficient;

[0009] determining a rotor flux difference between the second rotor flux calculation result and the first rotor flux calculation result, and obtaining a third rotor flux calculation result based on the switching coefficient and the rotor flux difference;

[0010] The induction motor rotor flux calculation result is determined based on the first rotor flux calculation result and the third rotor flux calculation result.

[0011] In combination with the first aspect, in a first implementation of the first aspect, determining the switching coefficient based on the angular velocity of the induction motor specifically includes:

[0012] determining an angular velocity of the induction motor and a first domain range of the angular velocity;

[0013] Determine the second domain range of the initial switching coefficient;

[0014] Taking the angular velocity and the switching parameter as input parameters, establishing a membership relationship between the input parameters and the fuzzy value;

[0015] Based on the first domain range and the membership relationship, fuzzy processing is performed on the angular velocity to establish a fuzzy relationship between the angular velocity and the corresponding fuzzy value of the angular velocity;

[0016] Based on the second domain range and the membership relationship, the initial switching coefficient is fuzzified to establish a fuzzy relationship between the initial switching coefficient and the corresponding fuzzy value of the switching coefficient;

[0017] Establish fuzzy rules based on the motor temperature rise characteristics and electromagnetic characteristics of induction motors;

[0018] determining an error component of the initial switching coefficient, and determining a control output value based on the fuzzified relationship, the fuzzy rule, and the error component;

[0019] Determining a fuzzy output value corresponding to the control output value;

[0020] The switching coefficient is determined based on the second domain range, the membership relationship and the fuzzified output value.

[0021] In combination with the first implementation of the first aspect, in the second implementation of the first aspect, determining the fuzzy output value corresponding to the control output value specifically includes:

[0022] Defuzzification is performed on the control output value based on a center of gravity method to determine a fuzzy output value corresponding to the control output value.

[0023] In combination with the first embodiment of the first aspect, in the third embodiment of the first aspect, determining the switching coefficient based on the second domain range, the membership relationship, and the fuzzified output value specifically includes:

[0024] Determine the maximum and minimum values of the second domain;

[0025] Determine the sum and difference between the maximum value and the minimum value;

[0026] The switching coefficient is determined based on the sum value, the difference value, the membership relationship and the fuzzified output value.

[0027] In combination with the first aspect, in a fourth implementation of the first aspect, determining the first rotor flux calculation result based on the current model, and determining the second rotor flux calculation result based on the voltage model, specifically include:

[0028] Determine the first coordinate axis component of the stator current and the second coordinate axis component of the stator current in the two-phase stationary coordinate system, the first coordinate axis component of the stator voltage and the second coordinate axis component of the stator voltage in the two-phase stationary coordinate system, the angular velocity, rotor resistance, rotor inductance, rotor mutual inductance, rotor electromagnetic time constant, pole pair number, stator resistance, stator inductance, and leakage flux coefficient of the induction motor; the electronic current of the induction motor is synthesized by the first coordinate axis component of the stator current and the second coordinate axis component of the stator current, and the electronic voltage of the induction motor is synthesized by the first coordinate axis component of the stator voltage and the second coordinate axis component of the stator voltage;

[0029] Determine, based on the first coordinate axis component of the stator current, the second coordinate axis component of the stator current, the angular velocity, the rotor resistance, the rotor inductance, the rotor mutual inductance, the rotor electromagnetic time constant, and the number of pole pairs, a first rotor flux first component result and a first rotor flux second component result of the induction motor in a two-phase stationary coordinate system output by a current model; the first rotor flux calculation result is obtained by synthesizing the first rotor flux first component result and the first rotor flux second component result;

[0030] Based on the first coordinate axis component of the stator current, the second coordinate axis component of the stator current, the first coordinate axis component of the stator voltage, the second coordinate axis component of the stator voltage, the rotor inductance, the rotor mutual inductance, the stator resistance, the rotor resistance and the leakage magnetic coefficient, the second rotor flux first component result and the second rotor flux second component result of the induction motor output by the voltage model in the two-phase stationary coordinate system are determined; the second rotor flux calculation result is obtained by synthesizing the second rotor flux first component result and the second rotor flux second component result.

[0031] In combination with the fourth embodiment of the first aspect, in the fifth embodiment of the first aspect, determining a rotor flux difference between the second rotor flux calculation result and the first rotor flux calculation result, and obtaining a third rotor flux calculation result based on the switching coefficient and the rotor flux difference, specifically includes:

[0032] determining a rotor flux first component difference between the first rotor flux first component result and the second rotor flux first component result;

[0033] determining a rotor flux second component difference between the first rotor flux second component result and the second rotor flux second component result;

[0034] The product between the difference between the first component of the rotor flux and the switching coefficient is calculated to obtain the first component result of the third rotor flux, and the product between the difference between the second component of the rotor flux and the switching coefficient is calculated to obtain the second component result of the third rotor flux; the third rotor flux calculation result is obtained by synthesizing the third rotor flux first component result and the third rotor flux first component result.

[0035] In combination with the fifth embodiment of the first aspect, in the sixth embodiment of the first aspect, determining the induction motor rotor flux calculation result based on the first rotor flux calculation result and the third rotor flux calculation result specifically includes:

[0036] Accumulating the first rotor flux first component result and the third rotor flux first component result to obtain the induction motor rotor flux first component result;

[0037] The first rotor flux second component result and the third rotor flux second component result are accumulated to obtain the induction motor rotor flux second component result; the induction motor rotor flux calculation result is obtained by synthesizing the induction motor rotor flux first component result and the induction motor rotor flux second component result.

[0038] In a second aspect, an embodiment of the present invention further provides a device for calculating the rotor flux of an induction motor, the device comprising:

[0039] a first calculation module, configured to determine a first rotor flux calculation result based on a current model, and to determine a second rotor flux calculation result based on a voltage model;

[0040] A second calculation module is used to perform fuzzy processing on the angular velocity of the induction motor to obtain a switching coefficient;

[0041] a third calculation module, configured to determine a rotor flux difference between the second rotor flux calculation result and the first rotor flux calculation result, and obtain a third rotor flux calculation result based on the switching coefficient and the rotor flux difference;

[0042] The fourth calculation module is used to determine the induction motor rotor flux calculation result based on the first rotor flux calculation result and the third rotor flux calculation result.

[0043] In a third aspect, an embodiment of the present invention further provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the induction motor rotor flux calculation method as described above are implemented.

[0044] In a fourth aspect, an embodiment of the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the above-described methods for calculating the rotor flux of an induction motor.

[0045] The induction motor rotor flux calculation method, device, equipment and medium provided by the present invention comprehensively utilize the current model and the voltage model to mix the calculation results of the two models for output, thereby improving the accuracy of the flux calculation results and avoiding the use of a single model, which causes the flux calculation results to be affected by changes in motor parameters and reduce the accuracy. In addition, fuzzy control is used in the mixed output, and parameter characteristic data can be formulated into corresponding fuzzy control strategies for different motors. The switching coefficient can be applied to different working conditions, and smooth adjustment of the flux mixing results between different working conditions can be achieved, further improving the accuracy of the flux calculation results. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0047] Figure 1 A schematic diagram showing a method for calculating the rotor flux of an induction motor in the prior art is shown;

[0048] Figure 2 A schematic diagram showing a flow chart of a method for calculating the rotor flux of an induction motor provided by the present invention is shown;

[0049] Figure 3 A schematic diagram showing a method for calculating the rotor flux of an induction motor provided by the present invention is shown;

[0050] Figure 4 FIG2 is a flow chart showing step S20 in the method for calculating the rotor flux of an induction motor provided by the present invention;

[0051] Figure 5 A schematic diagram showing the establishment of a membership relationship in the induction motor rotor flux calculation method provided by the present invention is shown;

[0052] Figure 6 A schematic diagram showing the establishment of fuzzy rules in the induction motor rotor flux calculation method provided by the present invention is shown;

[0053] Figure 7 FIG2 is a flow chart showing step S29 in the method for calculating the rotor flux of an induction motor provided by the present invention;

[0054] Figure 8 1 is a flow chart showing step S10 of the method for calculating the rotor flux of an induction motor provided by the present invention;

[0055] Figure 9FIG4 is a flow chart showing step S30 of the method for calculating the rotor flux of an induction motor provided by the present invention;

[0056] Figure 10 FIG4 is a flow chart showing step S40 in the method for calculating the rotor flux of an induction motor provided by the present invention;

[0057] Figure 11 The figure shows a schematic structural diagram of the induction motor rotor flux calculation device provided by the present invention;

[0058] Figure 12 The figure shows a schematic structural diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0059] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0060] At present, (asynchronous) induction motors are widely used in various fields of production and life, and relevant control of induction motors can be achieved through vector control. The accuracy of rotor flux calculation determines the quality of motor control performance.

[0061] like Figure 1 As shown, the commonly used flux calculation method in the prior art is to calculate the rotor flux using a flux model 100. The flux model 100 generally uses a voltage model or a current model. However, the voltage model is significantly affected by the stator resistance voltage drop at low motor speeds, which can easily cause distortion in the rotor flux calculation results and affect the accuracy of the calculation results. The current model is significantly affected by the motor winding temperature and magnetic flux saturation at high motor speeds and is less stable than the voltage model.

[0062] The following combination Figure 2 and Figure 3 The method for calculating the rotor flux of an induction motor of the present invention is described. It can be understood that it is specifically for an asynchronous induction motor. The method includes the following steps:

[0063] S10 . Determine a first rotor flux calculation result based on a current model, and determine a second rotor flux calculation result based on a voltage model.

[0064] It should be noted that if Figure 3 As shown, Figure 3 The current model 10 or the voltage model 20 in the embodiment can be adopted as follows: Figure 1The flux linkage model is the current model or voltage model used in the prior art. In step S10, the current model is used to calculate the first rotor flux linkage calculation result ψ IM , the voltage model can be used to calculate the second rotor flux calculation result ψ VM .

[0065] S20. Determine a switching coefficient based on the angular velocity of the induction motor. In the embodiment of the present invention, the switching coefficient corresponds to the angular velocity one-to-one, and each angular velocity corresponds to a switching coefficient. Therefore, it can be understood that the switching coefficient will change with the change of the input angular velocity ω and is not a fixed value.

[0066] like Figure 3 As shown in FIG. 1 , as a preferred implementation of the embodiment of the present invention, after calculating ψ IM and ψ VM Finally, in the embodiment of the present invention, the angular velocity ω of the induction motor is utilized, and a continuous switching coefficient k is outputted by performing fuzzy processing on ω.

[0067] Since the switching coefficient k is obtained based on the angular velocity ω, different operating conditions of the induction motor have different switching coefficients k. The switching coefficient k can be used to achieve smooth adjustment of the flux mixing results between different operating conditions.

[0068] S30 , determining a rotor flux difference between the second rotor flux calculation result and the first rotor flux calculation result, and obtaining a third rotor flux calculation result based on the switching coefficient and the rotor flux difference.

[0069] S40 : Determine a rotor flux calculation result of the induction motor based on the first rotor flux calculation result and the third rotor flux calculation result.

[0070] The switching coefficient k determines the output value of the flux mixture calculated by the current model 10 and the voltage model 20, that is, in the embodiment of the present invention, the switching coefficient k is based on ψ IM , ψ VM and k, and obtain the calculation result of the third rotor flux ψ.

[0071] The induction motor rotor flux calculation method of the present invention comprehensively utilizes the current model and the voltage model to mix the calculation results of the two models for output, thereby improving the accuracy of the flux calculation results and avoiding the use of a single model, which causes the flux calculation results to be affected by changes in motor parameters and reduce their accuracy. In addition, fuzzy control is used in the mixed output, and parameter characteristic data can be formulated into corresponding fuzzy control strategies for different motors. The switching coefficient can be applied to different working conditions, and smooth adjustment of the flux mixing results between different working conditions can be achieved, further improving the accuracy of the flux calculation results.

[0072] The following combination Figure 4 、 Figure 5 and Figure 6 The method for calculating the rotor flux of an induction motor according to the present invention is described. Step S20 specifically includes the following steps:

[0073] S21. Determine the angular velocity ω of the induction motor and a first domain range of the angular velocity ω. The first domain range is a range from a theoretical minimum value to a theoretical maximum value of the angular velocity ω. For example, for a certain induction motor, the first domain range of the angular velocity ω is (0-1500 rad / s), where the maximum value of the angular velocity ω in the domain is 1500 and the minimum value in the domain is 0.

[0074] S22, determine the initial switching coefficient k s The second domain of discourse.

[0075] Similar to step S21, in this embodiment of the present invention, the initial switching coefficient k is also determined. s The second domain range, the initial switching coefficient k s After fuzzy processing, the switching coefficient k is obtained, and the initial switching coefficient k s The domain range of is also the domain range of the switching coefficient k.

[0076] S23. Taking the angular velocity as an input parameter, establishing a membership relationship between the input parameter and the fuzzy value.

[0077] like Figure 5 As shown, Figure 5 In the formula, PB (Positive Big) indicates a large deviation in the positive direction, PS (Positive Small) indicates a small deviation in the positive direction, ZO (zero) indicates a deviation close to zero, NS (Negative Small) indicates a small deviation in the negative direction, and NB (Negative Big) indicates a large deviation in the negative direction. The above parameters are all qualitative descriptions of the fuzzy set, reflecting the range in which the fuzzified value obtained after fuzzification falls. That is, based on the establishment of the corresponding membership relationship, the fuzzified value obtained after fuzzification is qualitatively described to indicate the range in which the fuzzified value lies.

[0078] In the embodiment of the present invention, the preferred value of n during fuzzy processing is 4. The larger the value of n, the finer the fuzzy set division, and the more accurately the actual input angular velocity ω is reflected. The value of n can be adjusted accordingly according to actual conditions.

[0079] S24. Based on the first domain range and the membership relationship, perform fuzzy processing on the angular velocity, and establish a first fuzzy relationship between the angular velocity and the corresponding fuzzy value of the angular velocity.

[0080] In the embodiment of the present invention, the first fuzzy relationship between the angular velocity ω and the corresponding fuzzy value of the angular velocity is established by formula (1):

[0081]

[0082] Among them, x ω represents the input angular velocity ω; y ω Represents the angular velocity fuzzy value corresponding to the angular velocity ω; A represents the minimum value on the angular velocity ω domain; B represents the minimum value on the angular velocity ω domain; n represents the degree of membership.

[0083] S25. Based on the second domain range and the membership relationship, perform fuzzification processing on the initial switching coefficient, and establish a second fuzzy relationship between the initial switching coefficient and the corresponding fuzzy value of the switching coefficient.

[0084] In the embodiment of the present invention, the initial switching coefficient k is established by formula (2): s The second fuzzy relationship between and the corresponding switching coefficient fuzzy value:

[0085]

[0086] Among them, x k Indicates the initial switching coefficient k of the output s ;y ω Indicates the initial switching coefficient k s The corresponding switching coefficient fuzzy value; X represents the initial switching coefficient k s That is, the minimum value of the switching coefficient k domain; Y represents the initial switching coefficient k s That is, the minimum value of the switching coefficient k domain.

[0087] S26. Establish fuzzy rules based on the motor temperature rise characteristics and electromagnetic characteristics of the induction motor.

[0088] Since the capacity, winding material, and heat dissipation method of induction motors vary, the temperature rise characteristics and electromagnetic characteristics of different induction motors are not exactly the same. The flux linkage model 10 in the prior art cannot be adjusted according to the motor characteristics, which will also affect the accuracy of the results. However, the relationship between the temperature rise characteristics and electromagnetic characteristics of the induction motor and the influence of the rotor flux linkage is complex and difficult to express accurately.

[0089] like Figure 6 As shown, in the embodiment of the present invention, a number of fuzzy rules can be established based on the motor temperature rise characteristics and electromagnetic characteristics of the induction motor. It should be noted that in step S26, the fuzzy rules can also be established in combination with the operating experience of the technicians.

[0090] Finally, in step S26, one of the established fuzzy rules will be used to process the subsequent steps, such as Figure 6 Rule 1 in . Among them, NB in Indicates that the input is a large deviation in the negative direction, NB out Indicates that the output is a large deviation in the negative direction, NS in Indicates that the input is a small deviation in the negative direction, NS out Indicates that the output is a small deviation in the negative direction, ZO in Indicates that the input is a deviation close to zero, ZO out Indicates that the output is approximately zero deviation, PS in Indicates that the input is a small deviation in the positive direction, PS out Indicates that the output is a small deviation in the positive direction, PB in Indicates that the input is a large deviation in the positive direction, PB out Indicates that the output has a large deviation in the positive direction.

[0091] S27, determine the initial switching coefficient k s The error component of the control is obtained, and the control output value is determined based on the fuzzy relationship, fuzzy rules and error components.

[0092] In the embodiment of the present invention, the control output value out1 is calculated by formula (3):

[0093] out1=in*R (3)

[0094] Among them, out1 represents the control output value; in represents the initial switching coefficient k s The error component corresponding to ω is fuzzified to obtain the fuzzy value of the switching coefficient. When n is preferably 4, taking the fuzzy value of the switching coefficient falling into the PB interval as an example, in has a total of 2n+1 vectors; R represents the fuzzy rule.

[0095] In Rule 1:

[0096] R=(NB in ∩NB out )∪(NS in ∩NS out )∪(ZO in ∩ZO out )∪(PB in ∩PB out )∪(PS in ∩PS out )

[0097] S28. Determine the fuzzy output value out2 corresponding to the control output value out.

[0098] S29. Determine a switching coefficient based on the second domain range, the membership relationship, and the fuzzy output value.

[0099] In this embodiment of the present invention, step S28 specifically includes:

[0100] The control output value is defuzzified based on the center of gravity method to determine the fuzzy output value corresponding to the control output value.

[0101] In the embodiment of the present invention, the fuzzy output value out2 is calculated by formula (4):

[0102]

[0103] Among them, x i Represents the vector of i elements output after fuzzy processing (decision making); μ N Indicates the domain range of the output fuzzy value. When n is preferably 4, μ N This represents -4, -3, -2, -1, 0, 1, 2, 3, 4, which is 2n+1 vectors.

[0104] The following combination Figure 7 The method for calculating the rotor flux of an induction motor according to the present invention is described, and step S29 specifically includes:

[0105] S291. Determine the maximum and minimum values of the second domain range.

[0106] S292. Determine the sum and difference between the maximum value and the minimum value.

[0107] S293. Determine a switching coefficient based on the sum value, the difference value, the membership relationship and the fuzzy output value.

[0108] Specifically, in the embodiment of the present invention, the switching coefficient k is calculated by formula (5):

[0109]

[0110] The following combination Figure 8 The method for calculating the rotor flux of an induction motor according to the present invention is described, and step S10 specifically includes:

[0111] S11. Determine the first coordinate axis component i of the stator current of the induction motor in the two-phase stationary coordinate system sα (α axis), stator current second coordinate axis component i sβ (β axis), the first coordinate axis component u of the stator voltage in the two-phase stationary coordinate system sα (α axis), stator voltage second coordinate axis component u sβ (β axis), angular velocity ω of the induction motor, rotor resistance R r , rotor inductance L r , rotor mutual inductance L m , rotor electromagnetic time constant T r , pole pair number p, stator resistance Rs , stator inductance L s And the leakage magnetic coefficient σ, in the embodiment of the present invention, the electronic current i of the induction motor s The first coordinate axis component of the stator current i sα and the second axis component of the stator current i sβ The electronic voltage u of the induction motor is obtained by synthesis. s The first coordinate axis component u of the stator voltage sα and the second axis component of the stator voltage u sβ Obtained by synthesis.

[0112] S12, based on the first coordinate axis component i of the stator current sα , stator current second axis component i sβ , angular velocity ω, rotor resistance R r , rotor inductance L r , rotor mutual inductance L m , rotor electromagnetic time constant T r And the number of pole pairs p, determine the first component of the first rotor flux of the induction motor in the two-phase stationary coordinate system output by the current model ψ rα1 and the second component of the first rotor flux ψ rβ1 In the embodiment of the present invention, the first rotor flux calculation result ψ IM The first component of the first rotor flux ψ rα1 and the second component of the first rotor flux ψ rβ1 Obtained by synthesis.

[0113] Specifically, in the embodiment of the present invention, the first component result of the first rotor flux ψ is calculated by formula (6): rα1 , calculate the second component of the first rotor flux using formula (7) rβ1 :

[0114]

[0115]

[0116] S13, based on the first coordinate axis component i of the stator current sα , stator current second axis component i sβ , the first coordinate axis component u of the stator voltage in the two-phase stationary coordinate system sα , stator voltage second axis component u sβ , rotor inductance L r , rotor mutual inductance L m , stator resistance R s , stator inductance L sAnd the leakage coefficient σ, determine the first component of the second rotor flux of the induction motor in the two-phase stationary coordinate system output by the voltage model ψ rα2 and the second component of the second rotor flux ψ rβ2 In the embodiment of the present invention, the second rotor flux calculation result ψ VM The first component of the second rotor flux ψ rα2 and the second component of the second rotor flux ψ rβ2 Obtained by synthesis.

[0117] Specifically, in the embodiment of the present invention, the first component result of the second rotor flux ψ is calculated by formula (8): rα2 , calculate the second component of the second rotor flux ψ by formula (9) rβ2 :

[0118]

[0119]

[0120] The following combination Figure 9 The method for calculating the rotor flux of an induction motor according to the present invention is described, and step S30 specifically includes:

[0121] S31, determine the first component result ψ of the first rotor flux rα1 The result of the first component of the second rotor flux ψ rα2 The difference in the first component of the rotor flux between .

[0122] S32, determine the second component result ψ of the first rotor flux rβ1 The second component of the second rotor flux results in ψ rβ2 The difference in the second component of the rotor flux between them.

[0123] S33, calculate the product between the difference of the first component of the rotor flux and the switching coefficient k, and obtain the result of the first component of the third rotor flux ψ rα3 , and calculate the product between the difference of the second component of the rotor flux and the switching coefficient k to obtain the third rotor flux second component result ψ rβ3 In an embodiment of the present invention, the calculation result of the third rotor flux is obtained by synthesizing the result of the first component of the third rotor flux and the result of the first component of the third rotor flux.

[0124] Finally, the calculation result of the third rotor flux can be expressed as: k(ψ VM -ψ IM ).

[0125] The following combination Figure 10 The method for calculating the rotor flux of an induction motor according to the present invention is described. Step S40 specifically includes:

[0126] S41, accumulating the first component result of the first rotor flux ψ rα1 The result of the first component of the third rotor flux ψ rα3 , and obtain the first component of the induction motor rotor flux ψ1.

[0127] S42, accumulating the second component of the first rotor flux ψ rβ1 The result of the second component of the third rotor flux ψ rβ3 , obtaining the second component result ψ2 of the induction motor rotor flux. In the embodiment of the present invention, the induction motor rotor flux calculation result ψ is obtained by synthesizing the first component result ψ1 of the induction motor rotor flux and the second component result ψ2 of the induction motor rotor flux.

[0128] Finally, the calculation result of the induction motor rotor flux ψ can be expressed as: ψ IM +k(ψ VM -ψ IM ).

[0129] The following describes an induction motor rotor flux calculation device provided by the present invention. The induction motor rotor flux calculation device described below and the induction motor rotor flux calculation method described above can be referenced to each other.

[0130] The following combination Figure 11 The induction motor rotor flux calculation device of the present invention is described, and the device comprises the following steps:

[0131] The first calculation module 50 is configured to determine a first rotor flux calculation result based on a current model, and to determine a second rotor flux calculation result based on a voltage model.

[0132] The first calculation module 50 uses the current model to calculate the first rotor flux calculation result ψ IM , the voltage model can be used to calculate the second rotor flux calculation result ψ VM .

[0133] The second calculation module 60 is used to perform fuzzy processing on the angular velocity of the induction motor to obtain a switching coefficient.

[0134] In the calculation of ψ IM and ψ VM Finally, in the embodiment of the present invention, the angular velocity ω of the induction motor is utilized, and a continuous switching coefficient k is outputted by performing fuzzy processing on ω.

[0135] Since the switching coefficient k is obtained based on the angular velocity ω, different operating conditions of the induction motor have different switching coefficients k. The switching coefficient k can be used to achieve smooth adjustment of the flux mixing results between different operating conditions.

[0136] The third calculation module 70 is configured to determine a rotor flux difference between the second rotor flux calculation result and the first rotor flux calculation result, and obtain a third rotor flux calculation result based on the switching coefficient and the rotor flux difference.

[0137] The fourth calculation module 80 is configured to determine a rotor flux calculation result of the induction motor based on the first rotor flux calculation result and the third rotor flux calculation result.

[0138] The switching coefficient k determines the output value of the flux mixture calculated by the current model 10 and the voltage model 20, that is, in the embodiment of the present invention, the switching coefficient k is based on ψ IM , ψ VM and k, and obtain the calculation result of the third rotor flux ψ.

[0139] The induction motor rotor flux calculation method of the present invention comprehensively utilizes the current model and the voltage model to mix the calculation results of the two models for output, thereby improving the accuracy of the flux calculation results and avoiding the use of a single model, which causes the flux calculation results to be affected by changes in motor parameters and reduce their accuracy. In addition, fuzzy control is used in the mixed output, and parameter characteristic data can be formulated into corresponding fuzzy control strategies for different motors. The switching coefficient can be applied to different working conditions, and smooth adjustment of the flux mixing results between different working conditions can be achieved, further improving the accuracy of the flux calculation results.

[0140] Figure 12 An example of a physical structure diagram of an electronic device is shown below. Figure 12 As shown, the electronic device may include: a processor 410, a communication interface 420, a memory 430, and a communication bus 440, wherein the processor 410, the communication interface 420, and the memory 430 communicate with each other via the communication bus 440. The processor 410 may call the logic commands in the memory 430 to execute the induction motor rotor flux calculation method, which includes:

[0141] Determine a first rotor flux calculation result based on the current model, and determine a second rotor flux calculation result based on the voltage model;

[0142] Perform fuzzy processing on the angular velocity of the induction motor to obtain the switching coefficient;

[0143] determining a rotor flux difference between the second rotor flux calculation result and the first rotor flux calculation result, and obtaining a third rotor flux calculation result based on the switching coefficient and the rotor flux difference;

[0144] The induction motor rotor flux calculation result is determined based on the first rotor flux calculation result and the third rotor flux calculation result.

[0145] In addition, the logical commands in the above-mentioned memory 430 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software medium. The computer software medium is stored in a storage medium and includes several commands for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0146] On the other hand, the present invention further provides a computer program medium, wherein the computer program medium includes a computer program, and the computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can perform the induction motor rotor flux calculation method provided by the above methods, which includes:

[0147] Determine a first rotor flux calculation result based on the current model, and determine a second rotor flux calculation result based on the voltage model;

[0148] Perform fuzzy processing on the angular velocity of the induction motor to obtain the switching coefficient;

[0149] determining a rotor flux difference between the second rotor flux calculation result and the first rotor flux calculation result, and obtaining a third rotor flux calculation result based on the switching coefficient and the rotor flux difference;

[0150] The induction motor rotor flux calculation result is determined based on the first rotor flux calculation result and the third rotor flux calculation result.

[0151] In another aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for calculating the rotor flux of an induction motor provided by the above methods is implemented. The method includes:

[0152] Determine a first rotor flux calculation result based on the current model, and determine a second rotor flux calculation result based on the voltage model;

[0153] Perform fuzzy processing on the angular velocity of the induction motor to obtain the switching coefficient;

[0154] determining a rotor flux difference between the second rotor flux calculation result and the first rotor flux calculation result, and obtaining a third rotor flux calculation result based on the switching coefficient and the rotor flux difference;

[0155] The induction motor rotor flux calculation result is determined based on the first rotor flux calculation result and the third rotor flux calculation result.

[0156] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0157] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the above technical solution, in essence, or the part that contributes to the prior art, can be embodied in the form of a software medium, which can be stored in a computer-readable storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of commands for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiment.

[0158] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for calculating the rotor flux of an induction motor, characterized in that: The method comprises: Determine a first rotor flux calculation result based on the current model, and determine a second rotor flux calculation result based on the voltage model; A switching coefficient is determined based on the angular velocity of the induction motor; the switching coefficient corresponds to the angular velocity one-to-one, each angular velocity corresponds to one switching coefficient, the switching coefficient is determined by a second domain range, a membership relationship, and a fuzzified output value, the second domain range is determined based on an initial switching coefficient, the membership relationship is determined based on the angular velocity of the induction motor and the initial switching coefficient, the fuzzified output value is determined by a control output value calculated based on the fuzzified relationship, a fuzzy rule of the induction motor, and an error component of the initial switching coefficient, and the fuzzified relationship is obtained by fuzzifying the first domain range and the second domain range and the membership relationship, respectively; determining a rotor flux difference between the second rotor flux calculation result and the first rotor flux calculation result, and obtaining a third rotor flux calculation result based on the switching coefficient and the rotor flux difference; The induction motor rotor flux calculation result is determined based on the first rotor flux calculation result and the third rotor flux calculation result.

2. The method for calculating the rotor flux of an induction motor according to claim 1, wherein: The determining of the switching coefficient based on the angular velocity of the induction motor specifically includes: determining an angular velocity of the induction motor and a first domain range of the angular velocity; Determine the second domain range of the initial switching coefficient; Taking the angular velocity and the initial switching parameter as input parameters, establishing a membership relationship between the input parameters and the fuzzy value; Based on the first domain range and the membership relationship, fuzzy processing is performed on the angular velocity to establish a first fuzzy relationship between the angular velocity and the corresponding fuzzy value of the angular velocity; Based on the second domain range and the membership relationship, the initial switching coefficient is fuzzified to establish a second fuzzy relationship between the initial switching coefficient and the corresponding fuzzy value of the switching coefficient; Establish fuzzy rules based on the motor temperature rise characteristics and electromagnetic characteristics of induction motors; determining an error component of the initial switching coefficient, and determining a control output value based on the fuzzified relationship, the fuzzy rule, and the error component; Determining a fuzzy output value corresponding to the control output value; The switching coefficient is determined based on the second domain range, the membership relationship and the fuzzified output value.

3. The method for calculating the rotor flux of an induction motor according to claim 2, wherein: The determining of the fuzzy output value corresponding to the control output value specifically includes: Defuzzification is performed on the control output value based on a center of gravity method to determine a fuzzy output value corresponding to the control output value.

4. The method for calculating the rotor flux of an induction motor according to claim 2, wherein: The determining the switching coefficient based on the second domain range, the membership relationship and the fuzzified output value specifically includes: Determine the maximum and minimum values of the second domain; Determine the sum and difference between the maximum value and the minimum value; The switching coefficient is determined based on the sum value, the difference value, the membership relationship and the fuzzified output value.

5. The method for calculating the rotor flux of an induction motor according to claim 1, wherein: The determining of the first rotor flux calculation result based on the current model and the determining of the second rotor flux calculation result based on the voltage model specifically include: Determine the first coordinate axis component of the stator current and the second coordinate axis component of the stator current in the two-phase stationary coordinate system, the first coordinate axis component of the stator voltage and the second coordinate axis component of the stator voltage in the two-phase stationary coordinate system, the angular velocity, rotor resistance, rotor inductance, rotor mutual inductance, rotor electromagnetic time constant, pole pair number, stator resistance, stator inductance, and leakage flux coefficient of the induction motor; the electronic current of the induction motor is synthesized by the first coordinate axis component of the stator current and the second coordinate axis component of the stator current, and the electronic voltage of the induction motor is synthesized by the first coordinate axis component of the stator voltage and the second coordinate axis component of the stator voltage; Determine, based on the first coordinate axis component of the stator current, the second coordinate axis component of the stator current, the angular velocity, the rotor resistance, the rotor inductance, the rotor mutual inductance, the rotor electromagnetic time constant, and the number of pole pairs, a first rotor flux first component result and a first rotor flux second component result of the induction motor in a two-phase stationary coordinate system output by a current model; the first rotor flux calculation result is obtained by synthesizing the first rotor flux first component result and the first rotor flux second component result; Based on the first coordinate axis component of the stator current, the second coordinate axis component of the stator current, the first coordinate axis component of the stator voltage, the second coordinate axis component of the stator voltage, the rotor inductance, the rotor mutual inductance, the stator resistance, the rotor resistance and the leakage magnetic coefficient, the second rotor flux first component result and the second rotor flux second component result of the induction motor output by the voltage model in the two-phase stationary coordinate system are determined; the second rotor flux calculation result is obtained by synthesizing the second rotor flux first component result and the second rotor flux second component result.

6. The method for calculating the rotor flux of an induction motor according to claim 5, characterized in that: Determining a rotor flux difference between the second rotor flux calculation result and the first rotor flux calculation result, and obtaining a third rotor flux calculation result based on the switching coefficient and the rotor flux difference, specifically includes: determining a rotor flux first component difference between the first rotor flux first component result and the second rotor flux first component result; determining a rotor flux second component difference between the first rotor flux second component result and the second rotor flux second component result; The product between the difference between the first component of the rotor flux and the switching coefficient is calculated to obtain the first component result of the third rotor flux, and the product between the difference between the second component of the rotor flux and the switching coefficient is calculated to obtain the second component result of the third rotor flux; the third rotor flux calculation result is obtained by synthesizing the third rotor flux first component result and the third rotor flux first component result.

7. The method for calculating the rotor flux of an induction motor according to claim 6, characterized in that: The determining the induction motor rotor flux calculation result based on the first rotor flux calculation result and the third rotor flux calculation result specifically includes: Accumulating the first rotor flux first component result and the third rotor flux first component result to obtain the induction motor rotor flux first component result; The first rotor flux second component result and the third rotor flux second component result are accumulated to obtain the induction motor rotor flux second component result; the induction motor rotor flux calculation result is obtained by synthesizing the induction motor rotor flux first component result and the induction motor rotor flux second component result.

8. An induction motor rotor flux calculation device, characterized in that: The device comprises: a first calculation module, configured to determine a first rotor flux calculation result based on a current model, and to determine a second rotor flux calculation result based on a voltage model; a second calculation module for determining a switching coefficient based on the angular velocity of the induction motor; the switching coefficients having a one-to-one correspondence with the angular velocities, with each angular velocity corresponding to one switching coefficient; the switching coefficients being determined by a second domain range, a membership relationship, and a fuzzified output value; the second domain range being determined based on an initial switching coefficient; the membership relationship being determined based on the angular velocity of the induction motor and the initial switching coefficient; the fuzzified output value being determined by a control output value calculated based on the fuzzified relationship, a fuzzy rule of the induction motor, and an error component of the initial switching coefficient; the fuzzified relationship being obtained by fuzzifying the first domain range and the second domain range with the membership relationship, respectively; a third calculation module, configured to determine a rotor flux difference between the second rotor flux calculation result and the first rotor flux calculation result, and obtain a third rotor flux calculation result based on the switching coefficient and the rotor flux difference; The fourth calculation module is used to determine the induction motor rotor flux calculation result based on the first rotor flux calculation result and the third rotor flux calculation result.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the method for calculating the rotor flux of an induction motor according to any one of claims 1 to 7 are implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for calculating the rotor flux of an induction motor according to any one of claims 1 to 7 are implemented.

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