Electromagnetic device

Abstract

Provided is an electromagnetic device capable of dispensing with the need for initial positioning and capable of sensorless vector control of a synchronous motor. An electromagnetic device (40) comprises: a γ-, δ-axis induced voltage observer (60) for estimating a γ-axis induced electromotive force (eγ) and a δ-axis induced electromotive force (eδ) which are generated by rotation of a prescribed field relative to an armature coil, the field being in a γ-δ coordinate system that synchronously rotates with a prescribed electrical angle phase difference with respect to a d-q coordinate system; a motion system angular velocity observer (62) for estimating the electrical angular velocity (ω) of the field from a δ-axis current and a δ-axis voltage in the γ-δ coordinate system; a path that leads to a d-q converter (48) or an inverse d-q converter (50) in vector control and that is obtained by time-integrating the phase difference (Δθ) between the d-q coordinate system and the γ-δ coordinate system, the phase difference being calculated from the γ-axis induced electromotive force (eγ) and the δ-axis induced electromotive force (eδ); and a path that leads to the d-q converter (48) or the inverse d-q converter (50) and that is obtained by time-integrating an estimated electrical angular velocity estimation value (ωes) of the field.

Description

electromagnetic device

[0001] The present invention relates to an electromagnetic device equipped with a sensorless vector controller.

[0002] When driving a synchronous motor with vector control (sensorless vector control) without using a rotation angle detector, there are two types: a first type that superimposes a high-frequency signal on the coil excitation current and detects the rotation angle from the change in the magnitude of the high-frequency component of the back electromotive force, and a second type that estimates the rotation angle from the coil excitation voltage and coil excitation current at the drive frequency. The first type is generally applied to salient-pole synchronous motors, while the latter is generally applied to non-salient-pole synchronous motors. In particular, the second type uses the induced electromotive force caused by the rotational motion of the field to estimate the rotation angle, so the rotation angle could not be estimated unless the rotor was rotating at a rotational speed that could generate a sufficient induced electromotive force. For this reason, sensorless vector control could not be applied when motion in which the rotational speed repeatedly changes between positive and negative was required for a non-salient-pole synchronous motor. In addition, initial positioning to coincide the origin of the electrical angle and the rotation angle was essential for performing vector control from the start of the synchronous motor.

[0003] Similarly, with linear synchronous motors, sensorless vector control was unable to restart a stopped linear motor element.

[0004] International Publication No. 2019 / 045017, International Publication No. 2021 / 054472

[0005] In view of the above, the present invention aims to provide an electromagnetic device equipped with a sensorless vector controller that enables sensorless vector control of a synchronous motor, including a linear motor, regardless of rotational speed or moving speed, and eliminates the need for initial positioning.

[0006] An electromagnetic device according to one aspect of the present invention comprises a non-salliance pole three-phase synchronous motor, coil excitation means for exciting three-phase armature coils, a vector control controller for commanding the coil excitation means to a three-phase excitation voltage, and the vector control controller controlling a dq coordinate system consisting of a d-axis and a q-axis that rotates synchronously with the field with the center of the north pole of the field as the origin of the d-axis, and a γδ coordinate system consisting of a γ-axis and a δ-axis that rotates synchronously with respect to the dq coordinate system by a predetermined electrical angular phase difference. The field, composed of permanent magnets, is controlled by the γ-axis current and δ-axis current, as well as the γ-axis voltage and δ-axis voltage in this γδ coordinate system. The system includes means for estimating the γ-axis and δ-axis components of the induced electromotive force generated due to relative rotation; means for calculating the phase difference between the dq coordinate system and the γδ coordinate system from the γ-axis induced electromotive force and the δ-axis induced electromotive force; means for estimating the relative rotational electrical angular velocity of the field from the δ-axis current and the δ-axis voltage; and a path through which the calculated phase difference between the dq coordinate system and the γδ coordinate system is integrated over time to reach a dq converter or inverse dq converter in vector control, and a path through which the estimated relative rotational electrical angular velocity of the field is integrated over time to reach the dq converter or inverse dq converter.

[0007] According to one aspect of the present invention, sensorless vector control of a synchronous motor, including a linear motor, is possible regardless of rotational speed or moving speed, and initial positioning is not required.

[0008] This is a perspective view of a Halbach field synchronous motor provided in an electromagnetic device according to a first embodiment of the present invention, in which a part of the Halbach field synchronous motor is shown broken along the axial direction. This is a cross-sectional view of a Halbach field synchronous motor provided in an electromagnetic device according to a first embodiment of the present invention, showing the upper half of the Halbach field portion of the Halbach field synchronous motor. This is a block diagram showing an example of the schematic configuration of an electromagnetic device according to a first embodiment of the present invention. This is a diagram illustrating an electromagnetic device according to a first embodiment of the present invention, showing an example of a coordinate system generally defined in vector control. This is a block diagram showing an example of the schematic configuration of a zero-phase angle holder provided in an electromagnetic device according to a first embodiment of the present invention. This is a block diagram showing an example of the schematic configuration of a current controller provided in an electromagnetic device according to a first embodiment of the present invention. This is a block diagram showing an example of the schematic configuration of a γ,δ axis induced voltage observer provided in an electromagnetic device according to a first embodiment of the present invention. This is a block diagram showing an example of the schematic configuration of a moving system angular velocity observer provided in an electromagnetic device according to a first embodiment of the present invention. This is a block diagram showing an example of the schematic configuration of a speed controller provided in an electromagnetic device according to a first embodiment of the present invention. This is a block diagram showing an example of the schematic configuration of a zero-phase angle holder provided in an electromagnetic device according to a first embodiment of the present invention. This is a perspective view of a part of a magnetic movable linear motor transport device as an example of an electromagnetic device according to a second embodiment of the present invention. This is a plan view of a part of a magnetic movable linear motor transport device as an example of an electromagnetic device according to a second embodiment of the present invention. This is a side view of a part of a magnetic movable linear motor transport device as an example of an electromagnetic device according to a second embodiment of the present invention, showing a cross section cut along the line A-A' shown in Figure 12. This is a perspective view of a part of a magnetic movable linear motor transport device as an example of an electromagnetic device according to a third embodiment of the present invention. This is a front view of a part of a magnetic movable linear motor transport device as an example of an electromagnetic device according to a third embodiment of the present invention. This is a top view of a part of a magnetic movable linear motor transport device as an example of an electromagnetic device according to a third embodiment of the present invention, showing a cross section cut along the line B-B' shown in Figure 15.

[0009] The embodiments of the present invention will be described below with appropriate reference to the drawings. Note that the drawings are schematic. Therefore, it should be noted that the relationship and ratio of thickness and planar dimensions may differ from those of reality, and there may be differences in the dimensional relationships and ratios between drawings. Furthermore, the embodiments described below are illustrative examples of devices and methods for realizing the technical concept of the present invention, and the technical concept of the present invention is not limited to the following embodiments in terms of the material, shape, structure, arrangement, etc., of the components.

[0010] [First Embodiment] Figure 1 shows a cutaway of a Halbach field synchronous motor 10. The Halbach field synchronous motor 10 consists of a stator 20, which is formed by arranging air-core coils 12 on the inner surface of a cylindrical yoke 11 and fixing them together with a coil bracket 14 and a casing 16 in a predetermined manner, and a rotor 30, which consists of a Halbach field section 24 in which permanent magnets 22 are arranged in a Halbach shape inside an armor ring 23, a field support section 28 that fixes the Halbach field section 24 to a rotating shaft 26, and the rotating shaft 26. The rotor 30 is rotatably supported by the stator 20 via an air gap in a predetermined manner, such as bearings, which are not shown. Six air-core coils 12 are provided, and those positioned symmetrically with respect to the center of rotation are connected in series to form a three-phase armature coil 32. The end of the winding of the three-phase armature coil 32 is star-connected, and it goes without saying that the U-phase excitation voltage, V-phase excitation voltage, and W-phase excitation voltage are applied to the beginning of each phase winding.

[0011] Figure 2 shows a cross-sectional view of the upper half of the Halbach field section 24 of the Halbach field synchronous motor 10 shown in Figure 1. The arrows in Figure 2 indicate the magnetization direction of the permanent magnets 22, and the magnets are magnetized so that the magnetic flux runs in the direction of the arrows. In this case, the permanent magnets 22, whose magnetization direction rotates by 45° each, are arranged in a cylindrical shape. In Figure 2, the rotor 30 has eight magnetic poles. As a result, the back electromotive force generated in the air-core coil 12 when the rotor 30 rotates becomes a sinusoidal wave with very few superimposed harmonic components, which improves the accuracy of estimating the electrical angle of the rotor 30.

[0012] The electromagnetic device 40 according to the present invention is shown in FIG. 3. The electromagnetic device 40 includes a Halbach field-form synchronous motor 10 shown in FIG. 1, a coil excitation unit 42 such as a three-phase inverter or a power amplifier connected to a power source, and a vector controller 44 that outputs a command value of each phase voltage to be applied to the three-phase armature coil 32 to the coil excitation unit 42. The solid arrow lines indicate signal lines, and the double lines indicate power lines.

[0013] In the vector controller 44, the rotor 30 of the Halbach field-form synchronous motor 10 can be rotated following the angular velocity target value ω of the speed target value setter 46. ｅｓ The vector controller 44 includes a dq converter 48 that calculates the d-axis current i and the q-axis current i from the currents i, i, i of the air-core coils 12 of each phase detected by the current sensor unit 45 based on the rotational electrical angle θ of the rotating Halbach field portion 24, an inverse dq converter 50 that calculates the d-axis voltage v and the q-axis voltage v based on the rotational electrical angle θ and outputs the voltage command values v, v, v of each phase that the coil excitation unit 42 should output, an electrical angle calculator 52 that outputs the electrical angle estimated value θ and the electrical angular velocity estimated value ω from the d-axis current i, q-axis current i, d-axis voltage v, and q-axis voltage v, a speed controller 54 that calculates the q-axis current target value i for generating the appropriate motor torque based on the angular velocity target value ω output by the speed target value setter 46, a d-axis current setter 56 that outputs a predetermined d-axis current target value i, and a d-axis voltage v and a q-axis voltage v that match the actual d-axis current i and q-axis current i with the d-axis current target value i and the q-axis current target value i. ｕ i ｖ [[ID= 9]]i ｗ from the d-axis current i ｄ and the q-axis current i ｑ are calculated, an inverse dq converter 50 that calculates the d-axis voltage v ｄ and the q-axis voltage v ｑ and outputs the voltage command values v[[ID=2   0]] ｕｒ v ｖｒ v ｗｒ of each phase that the coil excitation unit 42 should output, and an electrical angle calculator 52 that outputs the electrical angle estimated value θ ｄ and the electrical angular velocity estimated value ω ｑ from the d-axis current i[[ID=   30]] ｄ the q-axis current i ｑ the d-axis voltage v ｅｓ and the q-axis voltage v<000001   7>A speed controller 54 that calculates the q-axis current target value i ｒｅｆ for generating the appropriate motor torque based on the angular velocity target value ω output by the speed target value setter 46, a d-axis current setter 56 that outputs a predetermined d-axis current target value i ｑ＿ｒｅｆ and a d-axis voltage v ｄ＿ｒｅｆ and a q-axis voltage v ｄ＿ｒｅｆ that match the actual d-axis current i ｑ＿ｒｅｆ and the q-axis current i ｄ with the d-axis current target value i ｑ and the q-axis current target value i ｄ and the q-axis voltage v ｑIt is equipped with a current controller 58 that outputs a current.

[0014] The electrical angle calculator 52 includes a γ- and δ-axis induced voltage observer 60, a motion system angular velocity observer 62, and a zero-phase angle holder 64. The γ- and δ-axis induced voltage observer 60 is the γ voltage v γ δ-axis voltage v δ and γ-axis current i γ , δ-axis current i δ From there, the induced electromotive force of each coordinate axis generated in the γδ coordinate system, which rotates with a phase difference Δθ in the dq coordinate system which rotates synchronously with the Halbach field 24 with the center of a predetermined N pole of the Halbach field 24 as the origin, is calculated and their estimated values ​​e are obtained. γ , e δ The output is shown in Figure 4. The coordinate systems generally defined in vector control are shown in Figure 4. In Figure 4, u, v, and w represent the three-phase coordinate system, α and β represent the αβ coordinate system (orthogonal coordinate system), d and q represent the dq coordinate system (rotating coordinate system), and γ and δ represent the γδ coordinate system (rotating coordinate system). The motion system angular velocity observer 62 outputs the q-axis current i from the dq converter 48. ｑ The q-axis voltage v output by the current controller 58 ｑ The vector control controller 44 calculates the electrical angular velocity ω of the rotor 30 based on the equations of motion and voltage equations related to the Halbach field synchronous motor 10, which is the object of control of the vector control controller 44, and outputs a second estimated electrical angular velocity ω^. At this time, the d-axis voltage v output by the current controller 58 ｄ This can be input to the motion system angular velocity observer 62 via the zero-order holder 66, which outputs the input value from one sample prior in digital control, and there is no problem with this. Also, due to the function of the zero-phase angle holder 64 described later, when the phase difference Δθ is small, the γ-axis voltage v γ δ-axis voltage v δ The voltage v is the d-axis voltage. ｄ q-axis voltage v ｑ It can be considered as such, and the γ-axis current i γ , δ-axis current i δ d-axis current i ｄ , q-axis current i ｑ It can be considered as such.

[0015] Here, if a phase difference Δθ exists between the dq converter 48 and the inverse dq converter 50, the electrical angle θ used for the conversion becomes θ + Δθ, so the current and voltage of each phase of the three-phase armature coil 32 are converted to and from the γδ coordinate system. Needless to say, if the phase difference Δθ is small, it is acceptable to assume that the conversion to and from the dq coordinate system occurs.

[0016] As shown in Figure 5, the zero phase angle holder 64 outputs the estimated induced electromotive force e in the γ,δ coordinate system, which is the output of the γ,δ axis induced voltage observer 60. γ , e δ The arctangent unit 68 calculates the phase difference Δθ, and this is converted via the integrator 70 to the estimated electrical angle θ. ｅｓ The output is generated as follows, and by inputting it into the dq converter 48 instead of the electrical angle θ used in general vector control, a Phase-Locked-Loop (PLL) is formed that keeps the phase difference Δθ at zero, and the estimated electrical angle θ ｅｓ It functions to match the actual electrical angle θ. Here, the integrator 70 is the estimated electrical angle θ ｅｓ Since it outputs, the signal input from the arctangent unit 68 to the integrator 70 can be considered as the first estimated electrical angular velocity. At this time, if the rotational speed of the rotor 30 is low, the induced electromotive force generated in the γδ coordinate system becomes small, and as a result the estimated induced electromotive force e γ , e δ The phase difference Δθ becomes buried in noise and cannot be calculated. As a result, the estimated electrical angle θ ｅｓ However, the actual value deviates, causing the vector control to fail. To solve this problem, in the electromagnetic device 40 of the present invention, a second electrical angular velocity estimate ω^, which is the output of the motion system angular velocity observer 62, is introduced into the zero-phase angle holder 64. The output ω of the speed target value setter 46 ｒｅｆ As becomes smaller, the electrical angular velocity ω of the rotor 30 decreases accordingly, and the second estimated electrical angular velocity ω^ also decreases. When the absolute value of the second estimated electrical angular velocity ω^ is greater than a predetermined angular velocity set value α, the phase difference Δθ, which is the output of the arctangent calculator 68, is selected at switch 72 and the gain K is applied by the gain multiplier 76. θThe PLL is formed by multiplication, and vector control continues. When the absolute value of the second electrical angular velocity estimate ω^ becomes smaller than a predetermined angular velocity set value α, the zero value of the zero value setter 74 is selected by switch 72, and the PLL stops midway. At this time, the second electrical angular velocity estimate ω^ is input to the integrator 70 via the subtractor 78, and since the actual angular velocity ω is also small, the electrical angle estimate θ ｅｓ The error between the actual electrical angle θ and the induced electromotive force is small, and the vector control continues without failure. Thus, in the electromagnetic device 40 of the present invention, sensorless vector control using induced electromotive force is possible even when the angular velocity of the rotor 30 is low, and sensorless vector control can be performed even when the angular velocity crosses zero, such as in reciprocating motion, thus enabling high efficiency of the electric motor.

[0017] As shown in Figure 6, the current controller 58 receives the q-axis current target value i, which is the output of the speed controller 54, as an input signal. ｑ＿ｒｅｆ And the output of the d-axis current setter 56 is the d-axis current target value i ｄ＿ｒｅｆ And the output of the zero-phase angle holder 64 is the estimated electrical angular velocity ω ｅｓ And the output of the dq converter 48 is the γ-axis current i γ and δ-axis current i δ And the output of the γ,δ axis induced voltage observer 60 is the estimated induced electromotive force e in the γ axis coordinate system. γ and the estimated induced electromotive force e in the δ-axis coordinate system δ The current controller 58 uses a γδ coordinate system non-interferometer 80 and a d-axis current target value i. ｄ＿ｒｅｆ From the γ axis current i γ A subtractor 82 subtracts from the output of the subtractor 82, and a predetermined gain f is set to the output of the subtractor 82. γ２ A gain multiplier 84 that multiplies by, an integrator 86 that integrates the output of the gain multiplier 84 over time, and the γ-axis current i γ A predetermined gain f γ１ A gain multiplier 88 multiplies by a gain multiplier, a subtractor 90 subtracts the output of the gain multiplier 88 from the output of the integrator 86, and the q-axis current target value i ｑ＿ｒｅｆ from δ-axis current i δ A subtractor 92 subtracts from the output of the subtractor 92, and a predetermined gain f is set to the output of the subtractor 92. δ２ A gain multiplier 94 that multiplies by, an integrator 96 that integrates the output of the gain multiplier 94 over time, and the δ-axis current iδ multiply by a predetermined gain f δ１ It includes a gain multiplier 98 that multiplies, and a subtractor 100 that subtracts the output of the gain multiplier 98 from the output of the integrator 96.

[0018] The γδ coordinate system non-interference device 80 uses the estimated angular velocity ω, which is the output of the zero phase angle maintainer 64, ｅｓ , the γ-axis current i γ , and the δ-axis current i δ as inputs, and multiplies the δ-axis current i δ by the value of the q-axis self-inductance L ｑ per phase of the three-phase armature coil 32 in the dq coordinate system and outputs it. A gain multiplier 104 that multiplies the γ-axis current i γ by the value of the d-axis self-inductance L ｄ per phase of the three-phase armature coil 32 in the dq coordinate system and outputs it. A multiplier 106 that multiplies the output of the gain multiplier 102 and the estimated angular velocity ω ｅｓ , a multiplier 108 that multiplies the output of the gain multiplier 104 and the estimated angular velocity ω ｅｓ , a subtractor 110 that subtracts the output of the multiplier 106 from the output of the subtractor 90, an adder 112 that adds the output of the multiplier 108 to the output of the subtractor 100, and a subtractor 114 that subtracts the γ-axis induced electromotive force e γ from the output of the subtractor 110, and a subtractor 116 that subtracts the δ-axis induced electromotive force e δ from the output of the adder 112. The output of the subtractor 110 is the γ-axis voltage v γ , and the output of the adder 112 is the δ-axis voltage v δ . Furthermore, the output of the subtractor 114 is the d-axis voltage v γ , e δ that has the effect of canceling the induced electromotive force e ｄ , q-axis voltage v ｑ and is input to the inverse dq converter 50. Here, the q-axis self-inductance L ｑ and the d-axis self-inductance L ｄ are such that, since the Halbach field permanent magnet synchronous motor 10 is a non-salient pole machine, if the self-inductance of each phase of the three-phase armature coil 32 is L ａ , then L ｄ = L ｑ = 3L ａ / 2.

[0019] The γ, δ-axis induced voltage observer 60 calculates the estimated values e γ , e δ of the induced electromotive forces of the respective coordinate axes generated in the γδ coordinate system as follows. First, as inputs, the γ-axis voltage v γ , the δ-axis voltage v δ and the γ-axis current i γ and the δ-axis current i δ which are the outputs of the dq converter 48 are introduced. The voltage equations in the γδ coordinate system related to the three-phase armature coil 32 can be expressed as the following equations (1) and (2) by the action of the γδ coordinate system decoupler 80.

[0020]

[0021]

[0022] From equation (1), in the γ-axis induced voltage observer 60, the estimated value state vector x^ γ of the primary one-dimensional state observer with the γ-axis induced electromotive force e γ as a disturbance and the γ-axis current i γ can be expressed as the following equation (3).

[0023]

[0024] Hereinafter, the system matrix A γ , the input matrix b γ , the output matrix C γ ^, the state vector x γ and the estimated value convergence gain H γ ^ can be expressed as the following equations (4-1), (4-2), (4-3), (4-4) and (4-5). <000​​​​​​​​​​​

[0029] In other words, the solution to the differential equation expressed by the following equation (7) is the estimated state vector x^ γ The response is as follows, and the estimated value of the γ-axis induced electromotive force is e^ γ The following is obtained: Estimated γ-axis induced electromotive force e^ γ The estimated convergence gain H γ By setting ^ to a predetermined value, the γ-axis induced electromotive force e can be generated at a predetermined speed. γ It goes without saying that it converges to e^ γ and e γ They don't particularly distinguish between them.

[0030]

[0031] Similarly, the d-axis voltage equation in equation (2) has the same structure as equation (1), so the estimated δ-axis induced electromotive force e^(2) is obtained in equation (8). δ You can obtain this.

[0032]

[0033] Figure 7 shows the γ,δ axis induced voltage observer 60. As expressed in equations (7) and (8), the estimated γ,δ axis current i^ γ ,i^ δ These are input to gain multipliers 120 and 122, and introduced to subtractors 124 and 126, respectively, and the γ and δ axis currents i γ , i δ These are subtracted from each other, and the subtraction results are input to gain multipliers 128 and 130. The outputs of gain multipliers 128 and 130 are input to integrators 132 and 134, which become the solution to the differential equation in the second row of the matrix shown in equations (7) and (8), and are the estimated values ​​of the induced electromotive force e^ of each coordinate axis occurring in the γδ coordinate system. γ , e^ δ (or e γ , e δ The output is ). The outputs of integrators 132 and 134 are multiplied by the gains of gain multipliers 136 and 138 and input to adders 140 and 142. The outputs of subtractors 144 and 146 are also input to adders 140 and 142. Subtractors 144 and 146 receive the γ-axis voltage v, which is the output of current controller 58. γδ-axis voltage v δ The γ-axis current i introduced from the dq converter 48 is obtained by multiplying the gain of the gain multipliers 148 and 150 by the value obtained from the gain multipliers 148 and 150. γ , δ-axis current i δ The values ​​obtained by multiplying the output by the gains of gain multipliers 152 and 154 are subtracted and output. Finally, in adders 156 and 158, the outputs of adders 140 and 142 are added to the outputs of gain multipliers 120 and 122, and the result of the calculation is input to integrators 160 and 162, which becomes the solution to the differential equation in the first row of the matrix in equations (7) and (8), and the estimated current values ​​i^ for each coordinate axis of the γδ coordinate system γ ,i^ δ The following is output from integrators 160 and 162.

[0034] The motion system angular velocity observer 62 is derived from the equation of motion (equation (9) below) and the voltage equation (equation (10) below) related to the Halbach field synchronous motor 10.

[0035]

[0036]

[0037] Here, P ｎ is a polar logarithm, I θ ρ represents the moment of inertia of the rotor 30 about its axis of rotation, ρ represents the angular velocity resistance coefficient, and ψ ａ This indicates the number of magnetic flux links per phase of the three-phase armature coil 32 due to the permanent magnet 22 in the dq coordinate system, and T ｄ ω represents the disturbance torque acting on the rotor 30. ｍ P is the mechanical rotational angular velocity, and P is the electrical angular velocity ω. ｎ It is 1 / 1. Equations (9) and (10) hold because the phase difference Δθ is small due to the action of the zero-phase angle holder 64. Furthermore, it goes without saying that equation (10), like equations (1) and (2), is simplified by the action of the γδ coordinate system non-interferometer 80.

[0038] From equations (9) and (10), the disturbance torque T in the moving system angular velocity observer 62 ｄ The angular velocity ω and q-axis current i are disturbances. ｑ Along with the estimated value, the estimated state vector x^ of the same-dimensional state observer is used as an estimate.ｋ This can be expressed as shown in equation (11) below.

[0039]

[0040] Below, System Matrix A ｋ , input matrix b ｋ , output matrix C ｋ ^, state vector x ｋ and estimated convergence gain H ｋ ^ can be expressed as shown in the following equations (12-1), (12-2), (12-3), (12-4), and (12-5).

[0041]

[0042] Here, the system matrix A of the same-dimensional state observer. ｋ If we express ^ as shown in equation (13) below, then a state observer of the same dimension can be expressed as shown in equation (14) below.

[0043]

[0044]

[0045] In other words, the solution to the differential equation (15) below is the estimated state vector x^ ｋ This is the response, and the second estimated electrical angular velocity ω^ is obtained.

[0046]

[0047] Figure 8 shows the motion system angular velocity observer 62. As shown in equation (15), the mechanical rotational angular velocity ω ｍ We estimate the value ω ｍ ^ to P ｎ By multiplying, a second estimated electrical angular velocity ω^ is obtained. The estimated rotational angular velocity of the machine ω^ ｍ ^, estimated value of q-axis current i ｑ ^, Estimated disturbance torque T ｄ The ^ is output from integrators 180, 182, and 184 respectively, and the disturbance torque estimate T ｄ The ^ is multiplied by a predetermined gain in the gain multiplier 186 and then introduced into the subtractor 188. Also, the q-axis current i introduced from the dq converter 48 ｑThe output value of the gain multiplier 190 is multiplied by a predetermined gain and then introduced into the subtractor 188. In the subtractor 188, the output value of the gain multiplier 190 is subtracted from the output value of the gain multiplier 186, and the subtraction result is introduced into the adder / subtractor 192. Meanwhile, the output of the integrator 182, i, is the estimated q-axis current. ｑ The value ^ is multiplied by a predetermined gain by the gain multiplier 194 and then introduced into the adder / subtractor 192. Also, the output of the integrator 180 is the estimated mechanical rotational angular velocity ω ｍ The ^ is multiplied by a predetermined gain in the gain multiplier 196 and introduced into the adder / subtractor 192. In the adder / subtractor 192, the output of the subtractor 188 and the output of the gain multiplier 194 are added together, and the output of the gain multiplier 196 is subtracted, and the result of the calculation is introduced into the integrator 180, where time integration is performed. This yields the solution to the first line of the differential equation shown in equation (15), and the estimated mechanical rotational angular velocity ω is output from the integrator 180. ｍ ^ represents the actual machine rotational angular velocity ω ｍ It converges to the value of . The output of this integrator 180 is multiplied by the gain multiplier 197 to P ｎ By multiplying, the second estimated electrical angular velocity ω^ is calculated. Next, the output of the adder 198 is introduced into the integrator 182. In the adder 198, the output of the integrator 182, i, is used to calculate the q-axis current estimate i. ｑ The result of multiplying the value by a predetermined gain by the gain multiplier 200 and the result of the subtractor 203 are added together. In the subtractor 202, the δ-axis voltage v is received from the current controller 58. δ The q-axis voltage v ｑ It is introduced as such, and the q-axis voltage v ｑ The output of the gain multiplier 204 multiplies the q-axis current i by a predetermined value. ｑ The result of multiplying the output by a predetermined value by the gain multiplier 206 is subtracted and output. The output of the subtractor 202 is introduced into the subtractor 203, where the value obtained by multiplying the output of the integrator 180 by the gain of the gain multiplier 205 is subtracted and introduced into the adder 198. As a result, the solution to the second line of the differential equation shown in equation (15) is obtained, and the estimated q-axis current i is output from the integrator 182. ｑ ^ represents the actual q-axis current i ｑ It converges to the value of .

[0048] Finally, a gain multiplier 208 is connected to the integrator 184, and a predetermined gain is multiplied by the output value of the subtractor 210. The subtractor 210 subtracts the q-axis current estimate i, which is the output of the integrator 182. ｑ ^ to q axis current i ｑ This is subtracted. As a result, the solution to the third line of the differential equation shown in equation (15) is obtained, and the disturbance torque estimate T is output from the integrator 184. ｄ ^ represents the actual disturbance torque T ｄ It converges to the value of . The calculation of the motion system angular velocity observer 62 described so far is used to determine the q-axis current i ｑ and q-axis voltage v ｑ It goes without saying that this allows for the estimation of the electrical angular velocity ω.

[0049] The configuration of the speed controller 54 is shown in Figure 9. The speed controller 54 receives the angular velocity target value ω output by the speed target value setter 46. ｒｅｆ and the estimated electrical angular velocity ω output by the zero-phase angle holder 64 ｅｓ The input is the estimated electrical angular velocity ω ｅｓ A gain multiplier 220 multiplies the value by a predetermined gain, a subtractor 224 subtracts the output of the gain multiplier 220 from the output of the integrator 222, and the angular velocity target value ω ｒｅｆ From the estimated electrical angular velocity ω ｅｓ The system consists of a subtractor 226 that subtracts ω and a gain multiplier 228 that multiplies the result of the subtractor 226 by a predetermined gain, with the output of the gain multiplier 228 being input to the integrator 222. As a result, if the speed control system is stable, the input to the integrator 222 must be zero, and as a result the angular velocity target value ω ｒｅｆ and the estimated electrical angular velocity ω ｅｓ They match.

[0050] The operation of the electromagnetic device 40 of the present invention with the above configuration will now be described. The coil excitation unit 42 and the vector control controller 44 are powered by means not shown, and if the speed target value setter 46 outputs zero, the Halbach field synchronous motor 10 is stopped. From this point onward, since the Halbach field synchronous motor 10 is a non-salliant pole machine, the d-axis current target value i output from the d-axis current setter 56 will be stopped. ｄ＿ｒｅｆ ω is set to zero. On the other hand, the speed target value setter 46 sets the angular velocity target value ω ｒｅｆAs the value is gradually increased, the estimated electrical angular velocity ω is measured in the speed controller 54. ｅｓ Since it is zero, the target value of the q-axis current i ｑ＿ｒｅｆ As the current controller 58 increases, the d-axis current i ｄ The q-axis voltage v increases ｑ The following is output, and via the inverse dq converter 50, the voltage command value v for each phase to be used to excite each phase of the three-phase armature coil 32 is output. ｕｒ ,v ｖｒ ,v ｗｒ The voltage is input to the coil excitation unit 42, which applies the three-phase excitation voltages Vu, Vv, and Vw to the three-phase armature coil 32 of the Halbach field synchronous motor 10.

[0051] Then, although there is some phase difference Δθ, a moving magnetic field is generated in the three-phase armature coil 32, and the strength of the moving magnetic field gradually increases due to the action of the speed controller 54, so torque acts on the Halbach field section 24 and the rotor 30 starts to rotate. At the time when rotation starts, the induced electromotive force generated in the three-phase armature coil 32 due to the rotation of the Halbach field section 24 is small, so the estimated value of the γ-axis induced electromotive force e is the output of the γ,δ axis induced voltage observer 60. γ , δ-axis induced electromotive force estimated value e δ It is buried in noise. At this time, the motion system angular velocity observer outputs a second electrical angular velocity estimate ω^, so the zero phase angle holder 64 adjusts the electrical angle estimate θ in accordance with the rotation of the rotor 30. ｅｓ The moving magnetic field increases. Eventually, as the moving magnetic field increases due to the action of the speed controller 54, the rotor 30 rapidly increases its electrical angular velocity ω to the rotational speed of the moving magnetic field due to the synchronous pull-in phenomenon. Then, the estimated value of the γ-axis induced electromotive force e, which is the output of the γ,δ axis induced voltage observer 60, increases. γ , δ-axis induced electromotive force estimated value e δ As the signal-to-noise ratio is improved, the phase difference Δθ can be calculated in the zero-phase-angle holder 64, and the second estimated electrical angular velocity ω^ becomes larger. Therefore, a PLL is formed in the switch 72 within the zero-phase-angle holder 64 that holds the phase difference Δθ to zero when the second estimated electrical angular velocity ω^ exceeds the angular velocity set value a, and sensorless vector control is initiated. Needless to say, once sensorless vector control is initiated, highly efficient motor driving can be achieved.

[0052] Eventually, the angular velocity target value ω will cause the speed target value setter to rotate in the reverse direction after deceleration. ｒｅｆ When this is output, the electrical angular velocity ω of the rotor 30 decreases, and the second estimated electrical angular velocity ω^ falls below the set angular velocity a. Then the PLL is released at switch 72. However, even if the PLL is released, the second estimated electrical angular velocity ω^ is integrated by the integrator 70 in the zero-phase angle holder 64, so the estimated electrical angle θ ｅｓ This does not deviate from the actual value, and sensorless vector control continues with a small phase difference Δθ.

[0053] And the target angular velocity value ω ｒｅｆ As the absolute value of the voltage crosses zero and increases, the second estimated electrical angular velocity ω^ will again exceed the angular velocity setpoint a at switch 72, forming a PLL, and sensorless vector control continues with zero phase difference. In this way, the electromagnetic device 40 of the present invention enables sensorless vector control regardless of the rotational speed of the rotor 30. Therefore, the rotor rotation angle detection means such as encoders and resolvers that were required in conventional vector control become unnecessary, improving the convenience and reliability of the system and reducing costs. Furthermore, by setting the origin by flowing a predetermined current through each phase of the three-phase armature coil at the start of operation, it becomes possible to drive the motor with sensorless vector control from the start of operation, further improving efficiency.

[0054] Furthermore, the present invention may be modified in various ways within the scope of the claims. For example, in the first embodiment, the zero-phase-angle holder 64 outputs an estimated electrical angular velocity ω as an estimated electrical angular velocity value in the speed controller 54 and the current controller 58. ｅｓ Although it was introduced in both, there is no problem in introducing the second electrical angular velocity estimate ω^ output by the motion system angular velocity observer 62 into either one or both.

[0055] Furthermore, in the zero-phase-angle holder 64, the second estimated electrical angular velocity ω^ and the phase difference Δθ are connected via the integrator 70 to the dq converter 48 and the inverse dq converter 50. However, as shown in Figure 10, there is no problem if the estimated electrical angular velocity ω^ and the phase difference Δθ are connected via separate integrators to the dq converter 48 and the inverse dq converter 50. In the zero-phase-angle holder 230, in addition to the integrator 70 that integrates the estimated electrical angular velocity ω^ over time, an integrator 232 is provided for the phase difference Δθ. As a result, the paths of the second estimated electrical angular velocity ω^ and the phase difference Δθ to the dq converter 48 and the inverse dq converter 50 via the integrator 70 are separated, and when the switch 72 is switched, the estimated electrical angular velocity ω ｅｓ This can suppress fluctuations. Note that the same symbol is used for identical sections, and the explanation is omitted.

[0056] The integrators 70, 86, 96, 132, 134, 160, 162, 180, 182, 184, 222, and 232 mentioned above may also be time integrators. Furthermore, although the vector control controller 44 drove the Halbach field synchronous motor 10 via a coil excitation unit 42 connected to a power supply, this does not limit the controlled object in any way; it may be a synchronous generator, and it may be a linear motor instead of a rotating electric machine.

[0057] [Second Embodiment] A second embodiment of the present invention will be described below. The electromagnetic device of this embodiment can be configured as a magnet-movable linear motor transport device 300 as shown in Figures 11 to 13. Figure 11 is a perspective view of the linear motor transport device 300, Figure 12 is a front view of Figure 11, and Figure 13 is a side view of a cross-section cut along the line A-A' shown in Figure 12. The linear motor transport device 300 is equipped with a track 302 and transport vehicles 304.

[0058] The track 302 comprises a base 306 with a U-shaped cross-section, a pair of left and right air levitation guides 308, and an armature 310. The air levitation guides 308 have an L-shaped cross-section, and countless tiny holes are made on surfaces 308A and 308B by micro-machining. Compressed air is sent into the inside of the air levitation guides 308 from a compressor (not shown), causing air to be ejected. The armature 310 consists of a plurality of air-core coils 312 excited by a three-phase alternating current, and an armature base 318 which has three-phase power lines inside for transmitting the three-phase current to the air-core coils 312. Each component of the armature 310 is fixed to the armature base 318 by a predetermined fixing method, such as adhesive. Furthermore, the air-core coils 312 are distinguished as follows: air-core coils excited in the U phase are designated as air-core coil 312U, air-core coils excited in the V phase are designated as air-core coil 312V, and air-core coils excited in the W phase are designated as air-core coil 312W.

[0059] The transport vehicle 304 is equipped with a frame 320, a Halbach array field 322 on the underside of the frame 320, and air sliders 324 at the four corners of the frame 320 to receive air blown out from surfaces 308A and 308B of the air levitation guide 308 and to provide non-contact support and non-contact guidance for the transport vehicle 304.

[0060] The Halbach field array 322 consists of five permanent magnets 322A, 322B, 322C, 322D, and 322E, whose magnetized surfaces are parallel to the direction of travel (y-direction) of the transport vehicle 304 and whose magnetization angles rotate 72° clockwise along the direction of travel (y-direction). In this embodiment, the permanent magnet 322C in the center of the vehicle is magnetized downwards. This has the advantage of facilitating origin adjustment, which aligns the origin of the moving magnetic field created by the air-core coil 312 with the origin of the vehicle position by aligning the center of the permanent magnet 322C with the center of the U-phase coil of the air-core coil 312. The Halbach field array 322 has a length equivalent to one electrical angle period, and the air-core coils 312 are connected in series for each phase, in a star configuration, so that they are excited with the same excitation current value in each of the U, V, and W phases, based on the precise position of the Halbach field array 322 estimated by the electrical angle calculator 52. The coil end opposite the neutral point of each phase star connection is connected to the coil excitation unit 42 shown in Figure 3, and sensorless vector control is performed. Furthermore, even if the Halbach array field 322 is longer than two electrical angle periods, as long as the length of the orbit 302 is an integer multiple of three electrical angle periods or more, the number of air-core coils in each phase will be the same, and there will be no problem in being excited with a three-phase balanced excitation current value.

[0061] Here, we will explain the modifications required to drive a field-movable linear motor using sensorless vector control. If the pole pitch of the linear motor field is τ and the distance traveled from the reference point is y, the relationship between the rotational electrical angle θ of the rotating machine and the travel distance y can be expressed as shown in equation (16) below.

[0062]

[0063] Therefore, the velocity in the y direction is v ｙ Let ρ be the velocity resistance, m be the mass of the movable element, and P be the number of pole pairs. ｎ Let ψ be the number of magnetic flux links formed by a permanent magnet linked to one armature coil. ａ Therefore, the equation of motion can be expressed as shown in equation (17) below.

[0064]

[0065] The voltage equation is given by L, where L is the q-axis inductance per coil.ｑ Let R be the coil resistance per coil. ａ Let the q-axis applied voltage as seen from the power supply be e ｑ The number of coils connected in series to each phase of the power supply is C. ｎ Therefore, it can be expressed as shown in equation (18) below.

[0066]

[0067] Comparing equations (16), (17), and (18) with equations (9) and (10), it goes without saying that the vector control controller 44 can be modified for linear motor drive with the same structure.

[0068] The operation of the linear motor transport device 300 configured in this way will now be explained. When the power supply (not shown) is turned on, the vector control drive control unit (not shown) starts vector control to a preset speed control, for example, and the air-core coil 312 is excited. When the air-core coil 312 is excited, the magnetic poles of the moving magnetic field are controlled to a strength corresponding to the speed of the Halbach array field 322, so that an electromagnetic force acts on the N and S poles of the Halbach array field 322 and the transport vehicle 304 starts to levitate and move. At this time, as the transport vehicle 304 moves, a back electromotive force is generated in the air-core coil 312 by the magnetic field generated by the Halbach array field 322.

[0069] According to this embodiment, the flux linkage of the magnetic flux linked to the two air-core coils 312 of each phase is a sinusoidal component with the same amplitude but a phase difference of 120°. Therefore, as seen from the three-phase power supply, the back electromotive force generated in the air-core coils 312 is a similar sinusoidal component, and the excitation current flowing due to the difference between the power supply voltage and the back electromotive force is also a sinusoidal component. Accordingly, according to this embodiment, the electromagnetic force acting between a finite-length Halbach array field, whose length is an integer multiple of the magnetic pole period, and the opposing three-phase air-core coil can be made equal to the electromagnetic force extracted from an integer multiple of the magnetic pole period of the electromagnetic force acting between three-phase air-core coils arranged opposite each other in a magnetic flux density distribution formed by arranging an infinite number of Halbach array fields.

[0070] Therefore, the Halbach array field 322 is composed of permanent magnets 322A to 322E that are magnetized by a rotation of 72°, which is obtained by dividing 360° by the integer 5. However, if the Halbach array field 322 is arranged infinitely, as shown in Patent Document 1, the magnetic flux density distribution near the lower surface of the Halbach array field 322 will contain a fundamental wave and a sixth spatial harmonic of an engineeringly significant magnitude. However, since the sixth spatial harmonic component is a multiple of 3 of the fundamental wave, no thrust ripple occurs in the thrust (electromagnetic force) acting on the Halbach array field 322 and the air-core coil 312. For this reason, in the vector control controller 44, the estimated electrical angle θ ｅｓ Since the thrust precisely matches the actual electrical angle θ, a smooth thrust acts on the transport vehicle 304, resulting in no vibration or noise. Consequently, the cargo is not damaged by vibration, and even fragile items such as semiconductor wafers can be transported to the target location without damage. Furthermore, because thrust ripple is not generated, acceleration and deceleration can be performed according to the target value, and the linear motor transport device 300 can also be used as a vibration testing machine.

[0071] [Third Embodiment] Next, a third embodiment will be described. The same symbols will be used for the same parts and their descriptions will be omitted. The electromagnetic device of this embodiment can be configured as a magnet-movable type linear motor vibration device 400 as shown in Figures 14 to 16. Figure 14 is a perspective view of the magnet-movable type linear motor vibration device 400, Figure 15 is a front view of Figure 14, and Figure 16 is a top view of the cross section B-B' shown in Figure 15. The linear motor vibration device 400 is equipped with a track 402 and a vibration trolley 404.

[0072] The track 402 comprises a base 406, a pair of left and right air levitation guides 308, and an armature 408. The armature 408 consists of a molded coil 410 formed by molding multiple air-core coils 312 that are excited by a three-phase alternating current, and an armature base 412 that has three-phase power lines inside for supplying three-phase current to the air-core coils 312. The air-core coils 312 are distinguished as follows: air-core coils excited in the U phase are called air-core coil 312U, air-core coils excited in the V phase are called air-core coil 312V, and air-core coils excited in the W phase are called air-core coil 312W. There are the same number of these for each phase.

[0073] The vibration-generating trolley 404 is equipped with a non-magnetic frame 414 with an inverted U-shaped cross-section, a dual Halbach array field 416 on the inner side surface of the frame 414, and air sliders 418 on the left and right lower surfaces of the frame 414 to receive air blown out from surfaces 308A and 308B of the air levitation guide 308 and to provide non-contact support and non-contact guidance for the vibration-generating trolley 404. A non-magnetic material is used for the frame 414 because the length of the frame 414 is not sufficiently longer than the length of the Halbach array field compared to the frame 320 of the first embodiment. If a member placed on the weaker side of the Halbach array field has magnetism, the sum of the magnetic flux linkages linked to the armature coil near both ends of the Halbach array field will not be equal to the sum of the magnetic flux linkages linked to the armature coil near the center of the Halbach array field, resulting in torque ripple.

[0074] The dual Halbach array field 416 consists of a Halbach array field 420 and a Halbach array field 420' positioned opposite it. The Halbach array field 420 consists of eight permanent magnets 420A, 420B, 420C, 420D, 420E, 420F, 420G, and 420H, whose magnetized surfaces are parallel to the direction of travel (y-direction) of the vibration trolley 404 and whose magnetization angles rotate 90° clockwise along the direction of travel (y-direction). Seven non-magnetic, non-conductive partition walls 422 are inserted between the permanent magnets 420A to 420H, and the sum of the width of one permanent magnet parallel to the direction of travel (y-direction) and the width of the partition wall 422 is one-eighth of the length of one period of the electrical angle of the armature 408 (the distance between the centers of the in-phase air-core coils 312), and the width of the partition wall 422 is one-quarter of the width of one permanent magnet.

[0075] Furthermore, the Halbach field array 420' consists of eight permanent magnets 420A', 420B', 420C', 420D', 420E', 420F', 420G', and 420H' whose magnetized surfaces are parallel to the direction of travel (y-direction) of the excitation trolley 404 and whose magnetization angles rotate 90° counterclockwise along the direction of travel (y-direction). Seven non-magnetic, non-conductive partition walls 422, the same as those in the Halbach field array 420, are inserted between the permanent magnets 420A' to 420H'. The sum of the width of one permanent magnet parallel to the direction of travel (y-direction) and the width of the partition wall 422 is one-eighth of the length of one period of the electrical angle of the armature 408 (the distance between the centers of the in-phase air-core coils 312), and the width of the partition wall 422 is one-quarter of the width of one permanent magnet.

[0076] In this embodiment, the magnetization is such that the magnetic flux in the gap between the centerlines of the dual Halbach array field 416 is in the x-direction, and the centerline of the vibration trolley 404 coincides with the centerline of the dual Halbach array field 416, the N-pole centerline of the Halbach array field 420, and the S-pole centerline of the Halbach array field 420'. These centerlines are shown as straight dashed lines in Figure 16. Therefore, when performing the origin adjustment necessary to control the position, speed, and thrust of the vibration trolley 404, the origin adjustment is completed by aligning the centerline of the vibration trolley 404 with the center position of the U-phase coil of the air-core coil 312. Thus, this embodiment has the advantage of making origin adjustment easy.

[0077] The operation of the linear motor vibration device 400 configured in this way will now be explained. When the power supply (not shown) is turned on, the vibration trolley 404 starts to levitate and move due to the operation of the drive unit (not shown). At this time, as the vibration trolley 404 moves, a back electromotive force is generated in the air-core coil 312 by the magnetic field generated by the dual Halbach array field 416. According to this embodiment, the number of magnetic flux links between the two air-core coils 312 of each phase is a sinusoidal component with the same amplitude and a phase difference of 240°. For this reason, the back electromotive force generated in the air-core coil 312 as seen from the three-phase power supply is a similar sinusoidal component, and the excitation current flowing due to the difference between the power supply voltage and the back electromotive force is also a sinusoidal component. However, in this embodiment, the ratio of the number of magnetic poles to the number of coils per electrical angle period is 4:3. Therefore, in the connection between the coil excitation unit 42 and the linear motor vibration device 400, the V-phase voltage of the coil excitation unit 42 is applied to the air-core coil 312W, and the W-phase voltage of the coil excitation unit 42 is applied to the air-core coil 312V. Since the ratio of the number of magnetic poles to the number of coils per electrical angle period is 4:3, the number of magnetic flux links with the coils becomes larger than when the ratio of the number of magnetic poles to the number of coils is 2:3. For this reason, it goes without saying that a stronger thrust will be applied to the vibration trolley 404 if the size of the dual Halbach array field 416 is the same.

[0078] Here, the effect of the partition wall 422 provided in this embodiment will be explained. According to this embodiment, the electromagnetic force acting between a finite-length Halbach array field, whose length is an integer multiple of the magnetic pole period, and a three-phase air-core coil facing it can be made equal to the electromagnetic force obtained by extracting an integer multiple of the magnetic pole period from the electromagnetic force acting between three-phase air-core coils arranged opposite each other in the magnetic flux density distribution formed by arranging an infinite number of Halbach array fields. If dual Halbach array fields 416 without partition wall 422 are arranged infinitely, as described in Patent Document 1, the magnetic flux density distribution on the side where the magnetic field of the Halbach array field, which is composed of permanent magnets rotated and magnetized by 90° (360° divided by an integer 4), becomes stronger includes a fundamental wave and a fifth spatial harmonic of engineering significance. However, when the partition wall 422 is provided, as described in Patent Document 2, the fifth spatial harmonic of the magnetic flux density distribution formed in the space on the armature side by the infinite-length Halbach array field can be canceled, and the magnetic flux density distribution created by the Halbach array field does not contain spatial harmonics of an engineeringly significant size.

[0079] Therefore, the flux linkage of the magnetic flux linked to the two air-core coils 312 of each selectively excited phase is a sinusoidal (fundamental wave) component with the same amplitude but a phase difference of 240°, and no thrust ripple occurs in the thrust (electromagnetic force) acting between the dual Halbach array field 416 and the air-core coils 312. For this reason, in the vector control controller 44, the estimated electrical angle θ ｅｓ Since the vibration force precisely matches the actual electrical angle θ, acceleration and deceleration can be performed according to the target value, and the vibration trolley 404 can apply the desired vibration force to the vibration test specimen with a simple configuration. Furthermore, a smooth thrust acts on the vibration trolley 404, so no vibration or noise is generated. Therefore, the load will not be damaged by vibration, and it can also be used as a conveying device to transport fragile items to a target location.

[0080] As described above, the electromagnetic device according to the present invention can be used in various modified forms. In the above-described embodiment, the rotational magnetization angles of the Halbach array were set to 72° and 90°, but the rotational magnetization angle can be any angle obtained by dividing 360° by an integer. Furthermore, the predetermined period length of the magnetic poles of the Halbach array field only needs to be an integer multiple of one rotation of the magnetic pole, and there is no problem if it is 3 periods or longer.

[0081] Furthermore, in the above-described embodiment, the permanent magnets constituting the Halbach array field were magnetized such that the position of the north pole on the side where the magnetic field of the Halbach array field is strengthened is at the center of the field. However, there is no problem in magnetizing the permanent magnets so that the position of the north or south pole is at any position in the field.

[0082] Furthermore, the armature base 318, on which the armature air-core coil is positioned on its upper surface, may be made of a ferromagnetic material. In this case, the Halbach array field 322 will be attracted to the armature base 318. However, if the transport vehicle 304 is supported by wheels rather than air levitation, a stronger thrust can be obtained.

[0083] In addition, although the Halbach field array is arranged in a straight line in this invention, it may be formed in an arc shape or other curved shape. Furthermore, although the permanent magnet shape in the cross-section parallel to the magnetization direction is rectangular, this does not limit the cross-sectional shape of the permanent magnet in any way, and it may be modified in various ways, such as an isosceles triangle, trapezoid, sector, or circle, within the scope of the claims.

[0084] Furthermore, the Halbach array field may be formed by cutting it out at any position as long as there is an interval of an integer multiple of one period of the electric angle from an infinitely long Halbach array field. In addition, although air levitation was applied to support the transport vehicle and frame in the second and third embodiments, this does not limit the method of supporting the movable element in any way, and magnetic levitation support, wheel support, or sliding support may also be used. Moreover, various modifications can be made within the scope of the claims.

[0085] 10 Halbach field synchronous motor 11 Yoke 12 Air-core coil 14 Coil bracket 16 Casing 20 Stator 22 Permanent magnet 23 Armor ring 24 Halbach field section 26 Rotating shaft 28 Field support section 30 Rotor 32 Three-phase armature coil 40 Electromagnetic device 42 Coil excitation section 44 Vector control controller 45 Current sensor section 46 Speed ​​target value setter 48 DQ converter 50 Inverse DQ converter 52 Electrical angle calculator 54 Speed ​​controller 56 D-axis current setter 58 Current controller 60 Axis induced voltage observer 62 Motion system angular velocity observer 64 Zero phase angle holder 66 0th order holder 68 Inverse tangent calculator Gain multipliers: 70, 86, 96, 132, 134, 160, 162, 180, 182, 184, 222, 232 Integrators: 72 Switches: 74 Zero setters: 76, 84, 88, 94, 98, 102, 104, 120, 122, 128, 130, 136, 138, 148, 150, 152, 154, 186, 190, 194, 196, 197, 200, 204, 205, 206, 208, 220, 228 Gain multipliers: 78, 82, 90, 92, 100, 110, 114, 116, 124, 126, 144, 146, 188, 202, 203, 210, 224, 226 Subtractor 80 Coordinate system non-interferometer 106, 108 Multiplier 112, 140, 142, 156, 158, 198 Adder 192 Addition / subtractor 230 Zero phase angle holder 300 Linear motor transport device 302, 402 Track 304 Transport vehicle 306, 406 Base 308 Air levitation guide 308A, 308B Surface 310, 408 Armature 312, 312U, 312V, 312W Air core coil 318, 412 Armature base 320, 414 Base frame 322, 420, 420' Halbach array field 322A, 322B, 322C, 322D, 322E, 420A, 420A', 420B, 420B', 420C, 420C', 420D, 420D', 420E, 420E', 420F, 420F', 420G, 420G', 420H, 420H' Permanent magnets 324, 418 Air sliders 400 Linear motor vibration device 404 Vibration trolley 410 Molded coil 416 Dual Halbach array field 422 Bulkhead

Claims

1. A non-salliance pole three-phase synchronous motor; coil excitation means for exciting three-phase armature coils; a vector control controller for commanding a three-phase excitation voltage to the coil excitation means; means for estimating the γ-axis and δ-axis components of the induced electromotive force generated by the rotation of the field, composed of permanent magnets, relative to the armature coils, from the γ-axis current and δ-axis current and γ-axis voltage and δ-axis voltage in a γδ coordinate system consisting of γ-axis and δ-axis that rotate synchronously with respect to the dq coordinate system with a predetermined electrical angular phase difference relative to the dq coordinate system; means for calculating the phase difference between the dq coordinate system and the γδ coordinate system from the γ-axis induced electromotive force and δ-axis induced electromotive force; means for estimating the relative rotational electrical angular velocity of the field from the δ-axis current and δ-axis voltage. An electromagnetic device comprising a path through which the calculated phase difference between the dq coordinate system and the γδ coordinate system is integrated over time to reach a dq converter or inverse dq converter in vector control, and a path through which the estimated relative rotational electric angular velocity of the field is integrated over time to reach the dq converter or inverse dq converter.

2. The electromagnetic device according to claim 1, wherein the non-salliance pole three-phase synchronous motor is equipped with a Halbach field array and the opposing armature coils are air-core.

3. The electromagnetic device according to claim 1, wherein the non-salliant three-phase synchronous motor is a non-salliant linear motor.

4. The electromagnetic device according to claim 3, wherein the non-salliant pole linear motor has a finite-length Halbach array field.

5. The electromagnetic device according to claim 4, wherein the finite-length Halbach array field is a dual Halbach field.

6. The electromagnetic device according to claim 1, wherein the time-integrating integrator is common to both the path through which the calculated phase difference between the dq coordinate system and the γδ coordinate system is integrated over time and the path through which the estimated relative rotational electric angular velocity of the field is integrated over time.

7. The electromagnetic device according to claim 1, further comprising means for interrupting the path over which the calculated phase difference between the dq coordinate system and the γδ coordinate system is integrated over time, in accordance with the estimated value of the relative rotational electric angular velocity of the field.

8. The electromagnetic device according to claim 1, which has means for delaying the information of the γ-axis voltage and δ-axis voltage by one sample compared to the information of the γ-axis current and δ-axis current in the digital control of the vector control controller.

9. The electromagnetic device according to claim 1, which has non-interference means for canceling out the influence of a voltage term caused by a q-axis current or a δ-axis current in the d-axis voltage equation or γ-axis voltage equation relating to the armature coil in the γδ coordinate system, or non-interference means for canceling out the influence of a voltage term caused by a d-axis current or a γ-axis current in the q-axis voltage equation or δ-axis voltage equation relating to the armature coil in the γδ coordinate system.

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