A design method and system for a stator permanent magnet linear oscillation motor considering saturation effect

Abstract

The present invention discloses a design method and system for a stator permanent magnet linear oscillation motor considering saturation effect, determines the design index and parameter limit range of the stator permanent magnet linear oscillation motor, calculates the effective value of the motor rated current under specific size parameters according to the efficiency and copper loss limit, and calculates the saturation coefficient and electromagnetic thrust of the stator and the mover core alignment part on the motor's easy saturation side in combination with the no-load and load nonlinear equivalent magnetic circuit models; judges whether the performance parameters such as the core saturation degree and electromagnetic thrust meet the requirements through the specific application of the corresponding design index, and if not, updates the size parameters, recalculates the saturation coefficient and output thrust until the design requirements are met. The present invention can overcome the problem that the traditional subdomain analysis method cannot handle the saturation problem and the three-dimensional finite element method has low calculation efficiency, quantitatively describes the relationship between the asymmetric core saturation effect of the stator and the design size parameters, and completes the size design and output characteristic evaluation of the stator permanent magnet linear oscillation motor.

Description

Technical Field

[0001] The invention belongs to the field of linear oscillation motors, and relates to a design method and system for a stator permanent magnet linear oscillation motor taking saturation effect into consideration. Background Art

[0002] Linear reciprocating motion is mainly achieved by traditional rotary motor + motion conversion mechanism, which has been criticized for its low transmission efficiency, high noise, complex structure, large size and poor reliability. If a linear oscillation motor is used for direct drive, the intermediate motion conversion mechanism can be omitted and linear reciprocating motion can be directly achieved, which is small in size and high in efficiency. This type of motor has great potential in various vehicle applications, such as active suspension systems, linear compressors, free piston engines, vibration energy harvesters, etc. Among them, permanent magnet linear oscillation motors using permanent magnets as excitation can further obtain a more compact structure, greater force density and higher efficiency, which has attracted widespread attention from academia and industry.

[0003] The current mainstream moving magnet permanent magnet linear oscillation motor still faces some inevitable defects. First, its magnets vibrate and are difficult to protect, which is detrimental to reliability. Second, due to the circumferentially laminated stator core, it suffers from magnetic leakage, resulting in a significant reduction in output performance. Therefore, the stator permanent magnet linear oscillation motor has received widespread attention and is a better alternative to the traditional moving magnet linear oscillation motor. On the one hand, the use of a transverse flux scheme in the magnetic circuit design can simplify the lamination process of the stator core. On the other hand, when the permanent magnet is mounted on the stator teeth or inserted into the stator yoke, this type of linear oscillation motor can adopt a single air gap design and an iron core mover to further simplify the structure and improve the output thrust and reliability.

[0004] However, according to the working principle of the linear oscillation motor, part of the core is inevitably in a high magnetic flux density due to the positive superposition of the armature and permanent magnet magnetic fields, while the rest is in a low magnetic flux density due to their mutual weakening. This phenomenon is more significant in the stator permanent magnet linear oscillation motor, usually manifested as completely different magnetic flux density levels of the two stators, resulting in asymmetric saturation. The traditional subdomain method used in the literature "Electromagnetic analysis of single-phase linear oscillatory actuator based on subdomain analytical model with end and stacking effects" (published in 2021 IEEE Transactions on Magnetics, Vol. 57, No. 2, pp. 1-5) is difficult to deal with such problems, and the general three-dimensional finite element analysis used in the literature "Electromagnetic design and dynamic characteristics of permanent magnet linear oscillating machines considering instantaneous inductance according to mover position" (published in 2020 IEEE Transactions on Applied Superconductivity Vol. 30, No. 4, pp. 1-5) is very time-consuming. Therefore, how to quantitatively describe the asymmetric saturation effect of the stator permanent magnet linear oscillation motor and incorporate it into the entire design process quickly and effectively to avoid its negative impact on the electromagnetic performance still needs in-depth research. Summary of the invention

[0005] The purpose of the present invention is to solve the problems in the prior art and to provide a design method and system for a stator permanent magnet linear oscillation motor taking into account the saturation effect.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention proposes a design method for a stator permanent magnet linear oscillation motor considering saturation effect, comprising the following steps:

[0008] Determine the design index of the stator permanent magnet linear oscillation motor and the parameter limit range of the stator permanent magnet linear oscillation motor; select the stator core split ratio, stator slot opening coefficient, permanent magnet width and permanent magnet thickness according to the design index of the stator permanent magnet linear oscillation motor;

[0009] Obtain the saturation coefficient of the part where the stator and the mover core are aligned on the easy-to-saturate side of the motor when a current equal to the effective value of the rated current is passed;

[0010] Within the parameter limit range of the stator permanent magnet linear oscillation motor, the influence curves of different stator core split ratios, stator slot opening coefficients, permanent magnet widths and permanent magnet thicknesses on the saturation coefficient are obtained considering the saturation effect, so as to realize the design of the stator permanent magnet linear oscillation motor considering the saturation effect.

[0011] Preferably, according to the stator core split ratio k s , stator slot opening coefficient k so and permanent magnet width W pm , get the slot area A of the stator core s , the slot area of ​​the stator core is A s The calculation of is shown in formula (1):

[0012]

[0013] Among them, N p is the number of stator teeth, D so is the stator outer diameter;

[0014] Get the rated current effective value I rms The calculation of is shown in formula (2):

[0015]

[0016] Among them, N c is the number of turns of a single coil, k f is the set slot fill rate, ρ cu is the resistivity of copper, P cl is the copper loss, and l is the length of one turn of stator coil.

[0017] Preferably, the calculation for estimating the length l of one turn of the stator coil is as shown in formula (3):

[0018]

[0019] Among them, l s is the stator lamination thickness, W g is the double stator spacing;

[0020] According to the efficiency requirement η cl Determine the copper loss P cl Range, efficiency requirement η cl and copper loss P cl The relationship is shown in formula (4):

[0021]

[0022]

[0023] Where, f is the input electrical frequency, z m is the design stroke of the motor, P o is the output mechanical power of the linear oscillation motor, F rms Electromagnetic thrust.

[0024] Preferably, the input effective value is equal to the rated current effective value I rms Under the condition of current, the saturation coefficient k of the part where the stator and the rotor core are aligned on the saturation side of the motor sat The steps are as follows:

[0025] The magnetic characteristic curve (BH curve) of the core material is fitted in sections to obtain the corresponding magnetic flux and magnetomotive force relationship curve (Φ-F curve). Let the number of iterations k = 0 and assume that the core is not saturated; the magnetic flux Φ generated by the stator and mover core alignment part on the easy saturation side of the motor under the action of the armature equivalent magnetic circuit is calculated. g1_a (k) and the corresponding magnetic pressure drop F iron1_c (k); query the value of Φ according to the fitted Φ-F curve g1_a (k) Magnetic voltage drop F at the part where the stator and the rotor core are aligned on the saturation side of the motor iron1 (k);

[0026] Comparison F iron1 (k) and F iron1_c (k) Whether the absolute error between them is less than the upper limit of the allowable error e:

[0027] If F iron1 (k) and F iron1_c If the absolute error between (k) and (k) is greater than or equal to the upper limit of the allowable error e, then set k = k + 1 and update Φ g1_a (k) value, until F iron1 (k) and F iron1_c The absolute error between (k) and (k) is less than the upper limit of the allowable error e, and we get Φ g1_a It is the magnetic flux generated by the armature magnetic field at the part where the stator and mover cores are aligned on the saturation-prone side of the motor;

[0028] If F iron1 (k) and F iron1_c The absolute error between (k) and (k) is less than the upper limit of the allowable error e, and we get Φ g1_a It is the magnetic flux generated by the armature magnetic field at the part where the stator and mover cores are aligned on the saturation-prone side of the motor;

[0029] According to the no-load equivalent magnetic circuit, the magnetic flux Φ generated by the permanent magnet alone at the saturation side of the motor where the stator and the mover core are aligned is calculated. g1_pm ;

[0030] According to the fitted Φ-F curve, query the Φ of the jth iteration g1_sat (j) The corresponding magnetic voltage drop F at the part where the stator and the rotor core are aligned on the saturation side of the motor iron2 (j); Φ g1_sat (j) Calculate the magnetic voltage drop F at the part where the stator and the rotor core are aligned on the saturation side of the motor under the combined action of the permanent magnet and the armature current by bringing in the nonlinear equivalent magnetic circuit of the load. iron2_c (j);

[0031] Comparison F iron2 (j) and F iron2_c (j) Whether the absolute error between them is less than the upper limit of the allowable error e:

[0032] If F iron2 (j) and F iron2_c If the absolute error between (j) is greater than or equal to the upper limit of the allowable error e, then set j = j + 1 and update Φ g1_sat (j) value, until F iron2 (k) and F iron2_c The absolute error between (k) meets the calculation accuracy requirement, and we get Φ g1_sat That is, it is the magnetic flux generated by the joint action of the armature current and the permanent magnetic field at the aligned part of the stator and the mover core on the saturation side of the motor;

[0033] If F iron2 (j) and F iron2_c (j) is less than the upper limit of the allowable error e, then Φ g1_sat That is, it is the magnetic flux generated by the joint action of the armature current and the permanent magnetic field at the aligned part of the stator and the mover core on the saturation side of the motor;

[0034] Saturation coefficient k sat The calculation of is shown in formula (6):

[0035]

[0036] Preferably, the magnetic flux Φ generated by the permanent magnet alone at the saturation-prone side of the motor where the stator and the mover core are aligned is g1_pm As shown in formula (7);

[0037]

[0038] When the core is saturated, the permanent magnet and the armature current work together to generate an actual magnetic flux Φ at the part where the stator and the mover core are aligned on the motor's saturation side. g1_sat The range can be narrowed to the range shown in formula (8), let j = 0, Φ g1_sat (j) = Φ g1_pm +Φ g1_a ;

[0039] Φ g1_pm ≤Φ g1_sat ≤Φ g1_a +Φ g1_pm (8)

[0040] Among them, F pm is the magnetomotive force of the permanent magnet, R g1 (z) is the air gap reluctance of the stator and mover core aligned on the saturation side of the motor, R' g1 (z) is the air gap magnetic resistance of the stator and the rotor core on the side that is not easy to saturate, R σ is the total leakage resistance, R pm is the self-demagnetization reluctance of the permanent magnet.

[0041] Preferably, according to different stator core crack ratios k s , stator slot opening coefficient k so , Permanent magnet width W pm and the permanent magnet thickness H pm , determine the different stator core crack ratios k s , stator slot opening coefficient k so , Permanent magnet width W pm and the permanent magnet thickness H pm Saturation coefficient k sat impact.

[0042] Preferably, according to the stator core split ratio k s , stator slot opening coefficient k so and permanent magnet width W pm Slot area A s The influence of copper loss P is determined cl , stator core crack ratio k s , stator slot opening coefficient k so and permanent magnet width W pm Rated current effective value I rms impact.

[0043] Preferably, according to different rated current effective values ​​I rms , Permanent magnet width W pm and the permanent magnet thickness H pm , determine the rated current effective value I rms , Permanent magnet width W pm and the permanent magnet thickness H pm Saturation coefficient k sat impact.

[0044] The present invention proposes a stator permanent magnet linear oscillation motor design system considering saturation effect, comprising:

[0045] A parameter selection module, wherein the parameter selection module is used to determine the design index of the stator permanent magnet linear oscillation motor and the parameter limit range of the stator permanent magnet linear oscillation motor; according to the design index of the stator permanent magnet linear oscillation motor, the stator core split ratio, the stator slot opening coefficient, the permanent magnet width and the permanent magnet thickness are selected;

[0046] A saturation coefficient acquisition module, wherein the saturation coefficient acquisition module is used to obtain the saturation coefficient of the portion where the stator and the mover core are aligned on the motor's easy saturation side when a current equal to the effective value of the rated current is passed;

[0047] An influence curve acquisition module is used to obtain the influence curve of different stator core split ratios, stator slot opening coefficients, permanent magnet widths and permanent magnet thicknesses on the saturation coefficient under the saturation effect within the parameter limit range of the stator permanent magnet linear oscillation motor, so as to realize the design of the stator permanent magnet linear oscillation motor under the saturation effect.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] A design method for a stator permanent magnet linear oscillation motor considering saturation effect can describe the saturation degree of the core, quickly and quantitatively evaluate the influence of asymmetric saturation effect on electromagnetic output characteristics, and incorporate it into the motor structure design process, thereby effectively avoiding the negative impact of saturation effect. The present invention can quantitatively describe the relationship between the asymmetric core saturation effect and the design size parameters of the stator of the stator permanent magnet linear oscillation motor through the introduced saturation coefficient; when the design size parameters change and cause the core to enter the deep saturation area, the output characteristics are calculated more accurately, and the feasibility of the motor design scheme is improved; the present invention does not rely on the time-consuming three-dimensional finite element simulation, which is conducive to engineering designers to quickly and accurately complete the size design and output characteristic evaluation of the stator permanent magnet linear oscillation motor. The design scheme with the best comprehensive performance is selected from the design schemes that meet the output thrust requirements, and the design of the stator permanent magnet linear oscillation motor considering the saturation effect is realized.

[0050] Furthermore, based on the space and efficiency constraints of the stator permanent magnet linear oscillation motor, the design requirements of the motor's volume power density and efficiency maximization can be effectively met; in the calculation process of the saturation coefficient proposed in the present invention, the initial value selection and iterative update range of the magnetic flux are reduced by the physical properties of nonlinear ferromagnetic materials, which can effectively ensure the convergence of the calculation.

[0051] The present invention proposes a system for a stator permanent magnet linear oscillation motor design method that takes into account the saturation effect. The system is divided into a parameter selection module, a saturation coefficient acquisition module, an influence curve acquisition module and a motor design module. A modular concept is adopted to make each module independent of each other, thereby facilitating unified management of each module. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0053] Figure 1 This is a flow chart of the design method of a stator permanent magnet linear oscillation motor taking into account the saturation effect of the present invention.

[0054] Figure 2 It is a three-dimensional half-section schematic diagram of the stator permanent magnet linear oscillation motor of the present invention and a radial cross-section schematic diagram ((a) three-dimensional half-section diagram; (b) radial cross-section diagram).

[0055] Figure 3 The axial cross-sectional view and area division diagram of the permanent magnet linear oscillation motor stator of the present invention ((a) the easy saturation area under the positive superposition of the magnetic field of the left core; (b) the easy saturation area under the positive superposition of the magnetic field of the right core).

[0056] Figure 4 It is the equivalent magnetic circuit of the motor of the present invention under the action of the permanent magnet alone.

[0057] Figure 5 It is the equivalent magnetic circuit of the easily saturated side region I of the motor of the present invention under the action of the armature current alone.

[0058] Figure 6 It is the equivalent magnetic circuit of the easily saturated side region I of the motor of the present invention under the combined action of the armature current and the permanent magnet.

[0059] Figure 7 This is a flow chart of iterative calculation of the saturation coefficient of the present invention.

[0060] Figure 8 The diagram of the change of the effective value of the current according to the design size parameters (a)k s and k so For electricity rms The influence of (b) W pm to I rms impact of the pandemic).

[0061] Fig. 9 The diagram of the main indicators of the motor of the present invention changing with the design size parameters (a)k s and k so Impact on the mass of the mover; (b) k s and k so For current F rms The influence of (c)Wpm and H pm F rms The influence of (d)W pm and H pm Impact on permanent magnet utilization).

[0062] Fig.10 The motor designed for the present invention outputs power and thrust waveforms in one cycle.

[0063] Fig.11 This is a design system diagram of the stator permanent magnet linear oscillation motor taking the saturation effect into consideration for the present invention. DETAILED DESCRIPTION

[0064] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0065] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0066] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0067] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0068] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0069] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0070] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0071] The present invention proposes a design method for a stator permanent magnet linear oscillation motor taking into account the saturation effect, such as Figure 1 As shown, the following steps are included:

[0072] Determine the design index of the stator permanent magnet linear oscillation motor and the parameter limit range of the stator permanent magnet linear oscillation motor; select the stator core split ratio, stator slot opening coefficient, permanent magnet width and permanent magnet thickness according to the design index of the stator permanent magnet linear oscillation motor;

[0073] Obtain the saturation coefficient of the part where the stator and the mover core are aligned on the easy-to-saturate side of the motor when a current equal to the effective value of the rated current is passed;

[0074] Within the parameter limit range of the stator permanent magnet linear oscillation motor, the influence curves of different stator core split ratios, stator slot opening coefficients, permanent magnet widths and permanent magnet thicknesses on the saturation coefficient are obtained considering the saturation effect, so as to realize the design of the stator permanent magnet linear oscillation motor considering the saturation effect.

[0075] like Figure 2 The figure shows the three-dimensional topological structure of the stator permanent magnet transverse flux moving iron core type linear oscillation motor and its radial cross-section schematic diagram, and also includes the annotations of its main dimensional parameters. Among them: the stator core 1 is made of silicon steel sheets stacked along the z direction in the figure; the moving core 2 is made of silicon steel sheets stacked along the z direction in the figure; the coil 3 is wound across the teeth aligned in the z direction of the double stator; the permanent magnet 4 is embedded in the yoke at the bottom of the stator core slot.

[0076] like Figure 3 The figure shows an axial cross-section of a stator permanent magnet transverse flux moving iron core type linear oscillating motor. 1 is the magnetic flux generated by the armature current and its direction; 2 is the magnetic flux generated by the permanent magnet and its direction; 3 is the moving iron core; 4 is the stator iron core; 5 is the coil and the direction of the current therein. Figure 3 It can be seen that under the action of current and permanent magnet magnetic field, there must be a positive superposition of two magnetic fields in one side of the core, which makes it easy for the core where the stator and the mover are aligned (i.e., the core in area I) to enter a saturation state.

[0077] The specific implementation steps of a stator permanent magnet linear oscillation motor design method considering saturation effect proposed by the present invention are as follows:

[0078] Step 1: Determine the parameter constraints of the motor according to the design index. In this implementation example, the design index is shown in Table 1.

[0079] Table 1 Design requirements and constraints

[0080]

[0081] According to the output mechanical power P of the linear oscillation motor o Determine the electromagnetic thrust F rms , the output mechanical power P of the linear oscillation motor o and electromagnetic thrust F rms The relationship is shown in formula (1):

[0082]

[0083] According to the efficiency requirement η cl Determine the copper loss P cl Range, efficiency requirement η cl and copper loss P cl The relationship is shown in formula (2):

[0084]

[0085] Step 2: Calculate the stator core crack ratio k s , stator slot opening coefficient k so , Permanent magnet width W pm and the permanent magnet thickness H pm In this embodiment, the initial values ​​of these main size parameters are selected as 0.5, 0.6, 10 mm and 2 mm.

[0086] According to the stator core crack ratio k s , stator slot opening coefficient k so and permanent magnet width W pm Calculate the slot area A of the stator core s , the slot area of ​​the stator core is A s The calculation of is shown in formula (3):

[0087]

[0088] Among them, N p is the number of stator teeth, D so is the stator outer diameter;

[0089] The estimated calculation of the length l of one turn of stator coil is shown in formula (4):

[0090]

[0091] Among them, l s is the stator lamination thickness, W g is the double stator spacing;

[0092] According to the copper loss P cl , the slot area of ​​the stator core A s and the length l of one turn of stator coil to calculate the rated current effective value I rms , calculated as shown in formula (5):

[0093]

[0094] Step 3: Calculate the effective value of the input current equal to the rated current effective value I rms The saturation coefficient k of the part where the stator and the rotor core are aligned on the motor's saturation side under the current sat The process of this step is as follows Figure 7 As shown;

[0095] The magnetic characteristic curve (BH curve) of the core material is fitted piecewise to obtain the corresponding magnetic flux and magnetomotive force relationship curve (Φ-F curve), and the number of iterations k=0 and it is assumed that the core is not saturated;

[0096] According to the armature equivalent magnetic circuit, Figure 4 As shown in the figure, the magnetic flux Φ generated by the armature magnetic field alone at the saturation side of the motor where the stator and the mover core are aligned is calculated. g1_a (k) and the corresponding magnetic pressure drop F iron1_c (k);

[0097] According to the fitted Φ-F curve, query the g1_a (k) Magnetic voltage drop F at the part where the stator and the rotor core are aligned on the saturation side of the motor iron1 (k);

[0098] Comparison F iron1 (k) and F iron1_c (k) Whether the absolute error between them is less than the upper limit of the allowable error e:

[0099] If F iron1 (k) and F iron1_c If the absolute error between (k) and (k) is greater than or equal to the upper limit of the allowable error e, then set k = k + 1 and update Φ g1_a (k), repeat the above steps until F iron1 (k) and F iron1_c The absolute error between (k) meets the calculation accuracy requirement. At this time, the Φ obtained by the last update g1_aIt is the magnetic flux generated by the armature magnetic field at the part where the stator and mover cores are aligned on the saturation-prone side of the motor;

[0100] If F iron1 (k) and F iron1_c The absolute error between (k) and (k) is less than the upper limit of the allowable error e, and we get Φ g1_a It is the magnetic flux generated by the armature magnetic field at the aligned part of the stator and mover cores on the saturation side of the motor.

[0101] According to the no-load equivalent magnetic circuit, Figure 5 As shown in the figure, the magnetic flux Φ generated by the permanent magnet alone at the aligned part of the stator and the mover core on the motor's saturation side is calculated. g1_pm , as shown in formula (6); it is easy to know that, considering the core saturation, the actual magnetic flux Φ is generated at the part where the stator and the mover core are aligned on the easy saturation side of the motor under the combined action of the permanent magnet and the armature current. g1_sat The range can be narrowed to the range expressed by formula (7), let j = 0, Φ g1_sat (j) = Φ g1_pm +Φ g1_a ;

[0102]

[0103] Φ g1_pm ≤Φ g1_sat ≤Φ g1_a +Φ g1_pm (7)

[0104] Among them, F pm is the magnetomotive force of the permanent magnet, R g1 (z) is the air gap reluctance of the stator and mover core aligned on the saturation side of the motor, R' g1 (z) is the air gap magnetic resistance of the stator and the rotor core on the side that is not easy to saturate, R σ is the total leakage resistance, R pm is the self-demagnetization reluctance of the permanent magnet.

[0105] According to the fitted Φ-F curve, query the Φ of the jth iteration g1_sat (j) The corresponding magnetic voltage drop F at the part where the stator and the rotor core are aligned on the saturation side of the motor iron2 (j);

[0106] Φ g1_sat (j) Substitute the load nonlinear equivalent magnetic circuit, such as Figure 6 , calculate the magnetic voltage drop F at the part where the stator and the mover core are aligned on the motor's saturation side under the combined action of the permanent magnet and the armature current iron2_c (j);

[0107] Comparison F iron2 (j) and F iron2_c(j) Whether the absolute error between them is less than the upper limit of the allowable error e:

[0108] If F iron2 (j) and F iron2_c If the absolute error between (j) and (j) is greater than or equal to the upper limit of the allowable error e, then set j = j + 1 and update Φ within the range constrained by equation (7). g1_sat (j), repeat the above steps until F iron2 (k) and F iron2_c The absolute error between (k) meets the calculation accuracy requirement. At this time, the Φ obtained by the last update g1_sat That is, it is the magnetic flux generated by the joint action of the armature current and the permanent magnetic field at the aligned part of the stator and the mover core on the saturation side of the motor;

[0109] If F iron2 (j) and F iron2_c (j) is less than the upper limit of the allowable error e, then Φ g1_sat That is, it is the magnetic flux generated by the aligned part of the stator and mover cores on the saturation side of the motor under the joint action of the armature current and the permanent magnetic field.

[0110] Among them, the saturation coefficient k sat The calculation is shown in formula (8):

[0111]

[0112] Step 4: Calculate different stator core crack ratios k within the size parameter limit s , stator slot opening coefficient k so , Permanent magnet width W pm , Permanent magnet thickness H pm The main dimensions of the saturation coefficient k sat The impact of

[0113] Calculate the stator core crack ratio k s , stator slot opening coefficient k so , Permanent magnet width W pm The main parameters of A s The influence of P given by formula (2) cl Constraint calculation of their rated current effective value I rms In this specific implementation example, the design parameters affect the current as follows: Figure 8 As shown, it mainly includes the stator core crack ratio k s and stator slot opening factor k so Rated current effective value I rms The influence of the permanent magnet width W pm Rated current effective value I rms The impact of Figure 8As shown in (a) and (b);

[0114] According to different stator core crack ratio k s , stator slot opening coefficient k so , Permanent magnet width W pm and the permanent magnet thickness H pm The rated current effective value I calculated by combining the above steps rms , calculate the main size parameters for the saturation coefficient k sat The calculation results in this embodiment are shown in Table 2 and Table 3, where k sat =1 means that the core operating point is in the linear region of the BH curve, and the saturation effect can be ignored. The saturation coefficient k sat A larger value means a deeper saturation;

[0115] Table 2 Different k s and k so Combination pair k sat Impact

[0116]

[0117] Table 3 Different H pm and W pm Combination pair k sat Impact

[0118]

[0119] Table 4 Main size parameters of motor

[0120]

[0121] According to the saturation coefficient k sat The change of the value quantitatively evaluates the influence of the saturation effect caused by the change of the size parameter on the main output performance. The calculation results in this implementation example are as follows Fig. 9 As shown, including the stator core split ratio k s and stator slot opening factor k so Impact on the quality of the mover, stator core crack ratio k s and stator slot opening factor k so Electromagnetic thrust F rms The influence of permanent magnet width W pm and the permanent magnet thickness H pm Electromagnetic thrust F rms The influence of permanent magnet width W pm and the permanent magnet thickness H pm Impact on permanent magnet utilization;

[0122] Step 5: Under the premise of meeting the output thrust requirements, it is preferred to have a lighter mover mass, a higher unit permanent magnet utilization rate, and a saturation coefficient k. sat The size parameter design scheme slightly greater than 1, the motor design scheme selected in this implementation example is listed in Table 4;

[0123] like Fig.10 As shown in the figure, the output characteristic verification result of the finite element simulation model built according to the motor parameters listed in Table 4 is obtained. It can be seen from the figure that within one cycle, the output average power of the designed stator permanent magnet transverse flux linear oscillation motor is 120W, the thrust effective value is 53N, and the efficiency when only copper loss is considered is 86.3%, which has met the efficiency design requirements and fully verified the effectiveness of the proposed method. In addition, it only takes 10s to obtain the above design scheme using the design method of the present invention, while it takes more than 32h to use the finite element method, which verifies the rapidity of the method.

[0124] The present invention proposes a stator permanent magnet linear oscillation motor design system considering saturation effect, such as Fig.11 As shown, including:

[0125] A parameter selection module, wherein the parameter selection module is used to determine the design index of the stator permanent magnet linear oscillation motor and the parameter limit range of the stator permanent magnet linear oscillation motor; according to the design index of the stator permanent magnet linear oscillation motor, the stator core split ratio, the stator slot opening coefficient, the permanent magnet width and the permanent magnet thickness are selected;

[0126] A saturation coefficient acquisition module, wherein the saturation coefficient acquisition module is used to obtain the saturation coefficient of the portion where the stator and the mover core are aligned on the motor's easy saturation side when a current equal to the effective value of the rated current is passed;

[0127] An influence curve acquisition module is used to obtain the influence curve of different stator core split ratios, stator slot opening coefficients, permanent magnet widths and permanent magnet thicknesses on the saturation coefficient under the saturation effect within the parameter limit range of the stator permanent magnet linear oscillation motor, so as to realize the design of the stator permanent magnet linear oscillation motor under the saturation effect.

[0128] In summary, the present invention discloses a stator permanent magnet linear oscillation motor design method and system considering the saturation effect. In the past, the conventional sub-domain method was difficult to handle the asymmetric saturation problem in the design process of the permanent magnet linear oscillation motor, and the general three-dimensional finite element analysis was very time-consuming. The present invention proposes a stator permanent magnet linear oscillation motor design method considering the saturation effect. By introducing the saturation coefficient k of the part where the stator and the rotor core are aligned on the saturated side of the motor, the saturation coefficient k of the stator and the rotor core aligned on the saturated side of the motor is sat, quantitatively describes the relationship between the asymmetric core saturation effect and the design size parameters of the stator permanent magnet linear oscillation motor, does not rely on the time-consuming three-dimensional finite element simulation, and is conducive to engineering designers to quickly and accurately complete the size design and output characteristic evaluation of the stator permanent magnet linear oscillation motor.

[0129] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A design method for a stator permanent magnet linear oscillation motor considering saturation effect, characterized in that: The following steps are involved: Determine the design index of the stator permanent magnet linear oscillation motor and the parameter limit range of the stator permanent magnet linear oscillation motor; select the stator core split ratio, stator slot opening coefficient, permanent magnet width and permanent magnet thickness according to the design index of the stator permanent magnet linear oscillation motor; Obtain the saturation coefficient of the part where the stator and the mover core are aligned on the easy-to-saturate side of the motor when a current equal to the effective value of the rated current is passed; Within the parameter limit range of the stator permanent magnet linear oscillation motor, the influence curves of different stator core split ratios, stator slot opening coefficients, permanent magnet widths and permanent magnet thicknesses on the saturation coefficient are obtained considering the saturation effect, so as to realize the design of the stator permanent magnet linear oscillation motor considering the saturation effect.

2. The method for designing a stator permanent magnet linear oscillation motor considering saturation effect according to claim 1, characterized in that: According to the stator core crack ratio k s , stator slot opening coefficient k so and permanent magnet width W pm , get the slot area A of the stator core s , the slot area of ​​the stator core is A s The calculation of is shown in formula (1): Among them, N p is the number of stator teeth, D so is the stator outer diameter; Get the rated current effective value I rms The calculation of is shown in formula (2): Among them, N c is the number of turns of a single coil, k f is the set slot fill rate, ρ cu is the resistivity of copper, P cl is the copper loss, and l is the length of one turn of stator coil.

3. The design method of a stator permanent magnet linear oscillation motor considering saturation effect according to claim 2, characterized in that: The estimated calculation of the length l of one turn of stator coil is shown in formula (3): Among them, l s is the stator lamination thickness, W g is the double stator spacing; According to the efficiency requirement η cl Determine the copper loss P cl Range, efficiency requirement η cl and copper loss P cl The relationship is shown in formula (4): Where, f is the input electrical frequency, z m is the design stroke of the motor, P o is the output mechanical power of the linear oscillation motor, F rms Electromagnetic thrust.

4. The method for designing a stator permanent magnet linear oscillation motor considering saturation effect according to claim 3, characterized in that: Get the input effective value equal to the rated current effective value I rms Under the condition of current, the saturation coefficient k of the part where the stator and the rotor core are aligned on the saturation side of the motor sat The steps are as follows: The magnetic characteristic curve (BH curve) of the core material is fitted in sections to obtain the corresponding magnetic flux and magnetomotive force relationship curve (Φ-F curve). Let the number of iterations k = 0 and assume that the core is not saturated; the magnetic flux Φ generated by the stator and mover core alignment part on the easy saturation side of the motor under the action of the armature equivalent magnetic circuit is calculated. g1_a (k) and the corresponding magnetic pressure drop F iron1_c (k); query the value of Φ according to the fitted Φ-F curve g1_a (k) Magnetic voltage drop F at the part where the stator and the rotor core are aligned on the saturation side of the motor iron1 (k); Compare F iron1 (k) and F iron1_c (k) Whether the absolute error between them is less than the upper limit of the allowable error e: If F iron1 (k) and F iron1_c If the absolute error between (k) and (k) is greater than or equal to the upper limit of the allowable error e, then set k = k + 1 and update Φ g1_a (k) value, until F iron1 (k) and F iron1_c The absolute error between (k) and (k) is less than the upper limit of the allowable error e, and we get Φ g1_a It is the magnetic flux generated by the armature magnetic field at the part where the stator and mover cores are aligned on the saturation-prone side of the motor; If F iron1 (k) and F iron1_c The absolute error between (k) and (k) is less than the upper limit of the allowable error e, and we get Φ g1_a It is the magnetic flux generated by the armature magnetic field at the part where the stator and mover cores are aligned on the saturation-prone side of the motor; According to the no-load equivalent magnetic circuit, the magnetic flux Φ generated by the permanent magnet alone at the saturation side of the motor where the stator and the mover core are aligned is calculated. g1_pm ; According to the fitted Φ-F curve, query the Φ of the jth iteration g1_sat (j) The corresponding magnetic voltage drop F at the part where the stator and the rotor core are aligned on the saturation side of the motor iron2 (j); Φ g1_sat (j) Calculate the magnetic voltage drop F at the part where the stator and the rotor core are aligned on the saturation side of the motor under the combined action of the permanent magnet and the armature current by bringing in the nonlinear equivalent magnetic circuit of the load. iron2_c (j); Compare F iron2 (j) and F iron2_c (j) Whether the absolute error between them is less than the upper limit of the allowable error e: If F iron2 (j) and F iron2_c If the absolute error between (j) is greater than or equal to the upper limit of the allowable error e, then set j = j + 1 and update Φ g1_sat (j) value, until F iron2 (k) and F iron2_c The absolute error between (k) meets the calculation accuracy requirement, and we get Φ g1_sat That is, it is the magnetic flux generated by the joint action of the armature current and the permanent magnetic field at the aligned part of the stator and the mover core on the saturation side of the motor; If F iron2 (j) and F iron2_c (j) is less than the upper limit of the allowable error e, then Φ g1_sat That is, it is the magnetic flux generated by the joint action of the armature current and the permanent magnetic field at the aligned part of the stator and the mover core on the saturation side of the motor; Saturation coefficient k sat The calculation of is shown in formula (6):

5. The method for designing a stator permanent magnet linear oscillation motor considering saturation effect according to claim 4, characterized in that: The magnetic flux Φ generated by the permanent magnet alone at the saturation side of the motor where the stator and the mover core are aligned g1_pm As shown in formula (7); When the core is saturated, the permanent magnet and the armature current work together to generate an actual magnetic flux Φ at the part where the stator and the mover core are aligned on the motor's saturation side. g1_sat The range can be narrowed to the range shown in formula (8), let j = 0, Φ g1_sat (j) = Φ g1_pm +Φ g1_a ; F g1_pm ≤Φ g1_sat ≤Φ g1_a +F g1_pm (8) Among them, F pm is the magnetomotive force of the permanent magnet, R g1 (z) is the air gap reluctance of the stator and mover core aligned on the saturation side of the motor, R' g1 (z) is the air gap magnetic resistance of the stator and the rotor core on the side that is not easy to saturate, R σ is the total leakage resistance, R pm is the self-demagnetization reluctance of the permanent magnet.

6. The method for designing a stator permanent magnet linear oscillation motor considering saturation effect according to claim 5, characterized in that: According to different stator core crack ratio k s , stator slot opening coefficient k so , Permanent magnet width W pm and the permanent magnet thickness H pm , determine the different stator core crack ratios k s , stator slot opening coefficient k so , Permanent magnet width W pm and the permanent magnet thickness H pm Saturation coefficient k sat impact.

7. The method for designing a stator permanent magnet linear oscillation motor considering saturation effect according to claim 5, characterized in that: According to the stator core crack ratio k s , stator slot opening coefficient k so and permanent magnet width W pm Slot area A s The influence of copper loss P is determined cl , stator core crack ratio k s , stator slot opening coefficient k so and permanent magnet width W pm Rated current effective value I rms impact.

8. The method for designing a stator permanent magnet linear oscillation motor considering saturation effect according to claim 5, characterized in that: According to different rated current effective value I rms , Permanent magnet width W pm and the permanent magnet thickness H pm , determine the rated current effective value I rms , Permanent magnet width W pm and the permanent magnet thickness H pm Saturation coefficient k sat impact.

9. A stator permanent magnet linear oscillation motor design system considering saturation effect, characterized in that: include: A parameter selection module, wherein the parameter selection module is used to determine the design index of the stator permanent magnet linear oscillation motor and the parameter limit range of the stator permanent magnet linear oscillation motor; according to the design index of the stator permanent magnet linear oscillation motor, the stator core split ratio, the stator slot opening coefficient, the permanent magnet width and the permanent magnet thickness are selected; A saturation coefficient acquisition module, wherein the saturation coefficient acquisition module is used to obtain the saturation coefficient of the portion where the stator and the mover core are aligned on the motor's easy saturation side when a current equal to the effective value of the rated current is passed; An influence curve acquisition module is used to obtain the influence curve of different stator core split ratios, stator slot opening coefficients, permanent magnet widths and permanent magnet thicknesses on the saturation coefficient under the saturation effect within the parameter limit range of the stator permanent magnet linear oscillation motor, so as to realize the design of the stator permanent magnet linear oscillation motor under the saturation effect.

Images