Permanent magnet synchronous motor phase sequence learning method of rotary transformer

Abstract

The invention discloses a phase sequence learning method for a permanent magnet synchronous motor of a rotary transformer, which comprises a motor positive and negative phase sequence learning process: step A1, a preset direct-axis current and an electrical angle of the permanent magnet synchronous motor are given, and the electrical angle of the permanent magnet synchronous motor is positively increased; a2, sine and cosine signals of the rotary transformer in the rotating process are obtained, and the positive and negative phase sequences are judged according to the sine and cosine signals; the absolute position difference learning process of the rotary transformer and the permanent magnet synchronous motor comprises the steps that B1, preset direct-axis current of the permanent magnet synchronous motor is given, and the electrical angle of the permanent magnet synchronous motor is set to be zero degree; b2, the electrical angle of the permanent magnet synchronous motor is increased until the rotary transformer outputs zero position information; and step B3, acquiring a current rotated angle of the permanent magnet synchronous motor, and calculating an absolute position difference and a rotor position of the rotary transformer and the permanent magnet synchronous motor. According to the method, the problems of phase sequence learning and angle analysis under different pole pair number combinations of different rotary transformers and permanent magnet synchronous motors are solved.

Description

Technical Field

[0001] The invention relates to the technical field of phase sequence learning, and in particular to a phase sequence learning method for a permanent magnet synchronous motor of a rotary transformer. Background Art

[0002] The resolver is an electromagnetic sensor consisting of a stator and a rotor. It is used to measure the angular displacement and angular velocity of the rotating shaft of a rotating object. It has the advantages of high temperature resistance, humidity resistance, shock resistance, and anti-interference. It is mainly used in automotive-grade permanent magnet synchronous motor systems.

[0003] When installing a rotary encoder with a permanent magnet synchronous motor, the same number of pole pairs is usually used, that is, the number of pole pairs of the rotary encoder is equal to the number of pole pairs of the permanent magnet synchronous motor, and a mechanical limit method is used mechanically to make the zero positions of the two correspond one-to-one, that is, the mechanical zero positions correspond one-to-one. In this way, the angle derived by the rotary encoder corresponds one-to-one to the electrical angle of the motor, and no additional compensation is required. However, usually, if a motor needs to be equipped with an external rotary encoder, there is a situation where the number of pole pairs of the rotary encoder is not equal to the number of pole pairs of the permanent magnet synchronous motor, and there is a lack of zero point limit during the mechanical installation process, then an additional algorithm is required for compensation calculation. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a phase sequence learning method for a permanent magnet synchronous motor of a rotary transformer to solve the technical problem of how to accurately perform phase sequence learning and angle analysis under different pole pair combinations of different rotary transformers and permanent magnet synchronous motors.

[0005] The present invention provides a permanent magnet synchronous motor phase sequence learning method for a rotary transformer, comprising: a motor positive and negative phase sequence learning process and an absolute position difference learning process between the rotary transformer and the permanent magnet synchronous motor,

[0006] The motor positive and negative phase sequence learning process specifically includes the following steps:

[0007] Step A1: giving a preset direct-axis current and electrical angle of the permanent magnet synchronous motor, and increasing the electrical angle of the permanent magnet synchronous motor in a positive direction;

[0008] Step A2: Obtain the sine signal and cosine signal of the rotary transformer during the rotation of the permanent magnet synchronous motor.

[0009] When the sine signal leads the cosine signal, the phase sequence of the permanent magnet synchronous motor relative to the rotary transformer is a positive phase sequence; when the cosine signal leads the sine signal, the phase sequence of the permanent magnet synchronous motor relative to the rotary transformer is a negative phase sequence;

[0010] The absolute position difference learning process of the resolver and permanent magnet synchronous motor includes the following steps:

[0011] Step B1: Given a preset direct-axis current of the permanent magnet synchronous motor, the electrical angle of the permanent magnet synchronous motor is set to zero degree;

[0012] Step B2: increasing the electrical angle of the permanent magnet synchronous motor from zero degrees until the resolver outputs zero position information;

[0013] Step B3: Obtain the current rotation angle of the permanent magnet synchronous motor, calculate the absolute position difference between the resolver and the permanent magnet synchronous motor according to the positive and negative relationship of the phase sequence and the number of pole pairs of the permanent magnet synchronous motor, and obtain the rotor position of the permanent magnet synchronous motor according to the number of pole pairs of the resolver.

[0014] Furthermore, in step A1, the preset direct-axis current satisfies:

[0015]

[0016] Where T is the load torque, p is the number of pole pairs of the permanent magnet synchronous motor, and ψ is the flux linkage of the permanent magnet synchronous motor.

[0017] Furthermore, in step A2, the sine signal and the cosine signal are discretely processed, and the leading state between the sine signal and the cosine signal is determined according to the discrete result.

[0018] Furthermore, the specific method of the discrete processing is:

[0019] Discretize the sine signal and cosine signal to get the discrete values ​​of the sine signal and cosine signal [S(θ), C(θ)]:

[0020]

[0021] Wherein, sinθ is the sine signal; cosθ is the cosine signal; S(θ) is the discrete value of the sine signal, and C(θ) is the discrete value of the cosine signal;

[0022] The specific method for judging based on discrete results is:

[0023] When [S(θ), C(θ)] is [1, 0], [1, 1], [0, 1], [0, 0], the sine signal leads the cosine signal;

[0024] When [S(θ), C(θ)] is [0, 1], [1, 1], [1, 0], [0, 0], the cosine signal leads the sine signal.

[0025] Furthermore, in step B3, the specific method of logarithmically calculating the absolute position difference between the resolver and the permanent magnet synchronous motor is:

[0026] When the phase sequence of the permanent magnet synchronous motor relative to the resolver is a positive phase sequence, the calculation formula for the absolute position difference is:

[0027]

[0028] When the phase sequence of the permanent magnet synchronous motor relative to the resolver is in reverse phase sequence, the calculation formula for the absolute position difference is:

[0029]

[0030] Wherein, Δθ is the current rotation angle of the permanent magnet synchronous motor; p is the number of pole pairs of the permanent magnet synchronous motor.

[0031] Furthermore, in step B3, the specific formula for obtaining the rotor position of the permanent magnet synchronous motor according to the pole pair number of the rotary transformer is:

[0032]

[0033] Where, Q is the number of pole pairs of the resolver, that is, the number of zero points; Δθ a is the absolute position difference; θ z (n) is the rotor position of the permanent magnet synchronous motor corresponding to the nth zero point.

[0034] Beneficial effects of the present invention:

[0035] The present invention discretizes the sine and cosine signals of the rotary transformer, and can know whether the phase sequence of the permanent magnet synchronous motor is a positive phase sequence or a negative phase sequence only by judging the timing of the switching quantity of the sine and cosine signals, without the need to fully analyze the angle.

[0036] The present invention solves the phase sequence learning and angle analysis problems under different combinations of different pole pairs of resolvers and permanent magnet synchronous motors by learning the positive and negative phase sequences of the motor and the absolute position difference between the resolver and the permanent magnet synchronous motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0038] Figure 1 It is a schematic diagram of a flow chart in a specific embodiment of the present invention;

[0039] Figure 2 It is a system schematic diagram in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0041] The present invention is further illustrated below in conjunction with specific embodiments. Those skilled in the art should understand that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention, and modifications to various equivalent forms of the present invention fall within the scope defined by the appended claims of this application.

[0042] like Figure 1 As shown, the present invention provides a phase sequence learning method for a permanent magnet synchronous motor of a rotary transformer, including: a motor positive and negative phase sequence learning process and an absolute position difference learning process between the rotary transformer and the permanent magnet synchronous motor,

[0043] The motor positive and negative phase sequence learning process specifically includes the following steps:

[0044] Step A1: giving a preset direct-axis current and electrical angle of the permanent magnet synchronous motor, and increasing the electrical angle of the permanent magnet synchronous motor in a positive direction;

[0045] Assume that the direct axis current satisfies:

[0046]

[0047] In the formula, T is the load torque, p is the number of pole pairs of the permanent magnet synchronous motor, and ψ is the flux linkage of the permanent magnet synchronous motor;

[0048] Step A2: Obtain the sine signal and cosine signal of the rotary transformer during the rotation of the permanent magnet synchronous motor.

[0049] Discretize the sine signal and cosine signal to get the discrete values ​​of the sine signal and cosine signal [S(θ), C(θ)]:

[0050]

[0051] Wherein, sinθ is the sine signal; cosθ is the cosine signal; S(θ) is the discrete value of the sine signal, and C(θ) is the discrete value of the cosine signal;

[0052] When [S(θ), C(θ)] is [1, 0], [1, 1], [0, 1], [0, 0], the sine signal leads the cosine signal;

[0053] When [S(θ), C(θ)] is [0, 1], [1, 1], [1, 0], [0, 0], the cosine signal leads the sine signal;

[0054] When the sine signal leads the cosine signal, the phase sequence of the permanent magnet synchronous motor relative to the rotary transformer is a positive phase sequence; when the cosine signal leads the sine signal, the phase sequence of the permanent magnet synchronous motor relative to the rotary transformer is a negative phase sequence;

[0055] The absolute position difference learning process of the resolver and permanent magnet synchronous motor includes the following steps:

[0056] Step B1: Given a preset direct-axis current of the permanent magnet synchronous motor, the electrical angle of the permanent magnet synchronous motor is set to zero degrees, so that the motor is positioned at zero degrees;

[0057] Step B2: increasing the electrical angle of the permanent magnet synchronous motor from zero degrees until the resolver outputs zero position information;

[0058] Step B3: Obtain the current rotation angle of the permanent magnet synchronous motor, and calculate the absolute position difference between the resolver and the permanent magnet synchronous motor according to the positive and negative relationship of the phase sequence and the number of pole pairs of the permanent magnet synchronous motor.

[0059] Among them, the specific method of logarithmically calculating the absolute position difference between the resolver and the permanent magnet synchronous motor is:

[0060] When the phase sequence of the permanent magnet synchronous motor relative to the resolver is a positive phase sequence, the calculation formula for the absolute position difference is:

[0061]

[0062] When the phase sequence of the permanent magnet synchronous motor relative to the resolver is in reverse phase sequence, the calculation formula for the absolute position difference is:

[0063]

[0064] Wherein, Δθ is the current rotation angle of the permanent magnet synchronous motor; p is the number of pole pairs of the permanent magnet synchronous motor.

[0065] Under different combinations of the number of pole pairs of the resolver, the relationship between the zero point of the resolver and the rotor position of the permanent magnet synchronous motor is:

[0066] When the number of pole pairs of the resolver is Q, there are Q zero points; the nth zero point corresponds to the rotor position θ of the permanent magnet synchronous motor. z for:

[0067]

[0068] Where, Q is the number of pole pairs of the resolver, that is, the number of zero points; Δθa is the absolute position difference; θ z (n) is the rotor position of the permanent magnet synchronous motor corresponding to the nth zero point.

[0069] The rotor position of the permanent magnet synchronous motor under different rotating transformer pole pairs can be calculated according to the above formula.

[0070] For example, for an 8-pole rotary transformer and a 4-pole permanent magnet synchronous motor, when Δθ a =10°, the first to eighth zero positions are calculated according to the above process: θ z (1) = 10°, θ z (2) = 55°, θ z (3) = 100°, θ z (4) = 145°, θ z (5) = 190°, θ z (6) = 235°, θ z (7) = 280°, θ z (7) = 325°.

[0071] like Figure 2 As shown, the present invention also provides a permanent magnet synchronous motor phase sequence learning system for a rotary transformer that can run a permanent magnet synchronous motor phase sequence learning method for a rotary transformer, comprising: a permanent magnet synchronous motor 51, a permanent magnet synchronous motor drive module 52, a rotary transformer 53, a rotary transformer excitation module 54, a sine and cosine signal acquisition module 55, a sine and cosine signal discrete and angle analysis module 56, a phase judgment module 57 and an angle judgment module 58;

[0072] The permanent magnet synchronous motor driving module 52 is connected to the permanent magnet synchronous motor 51 and is used to drive the permanent magnet synchronous motor to rotate;

[0073] The rotary transformer 53 is connected to the permanent magnet synchronous motor 51 and is used to obtain the rotation angle of the permanent magnet synchronous motor;

[0074] The rotary transformer excitation module 54 is connected to the rotary transformer 53 and is used to excite the rotary transformer;

[0075] The sine and cosine signal acquisition module 55 is connected to the rotary transformer 53 and is used to collect the sine and cosine signals output by the rotary transformer;

[0076] The sine and cosine signal discrete and angle analysis module 56 is connected to the sine and cosine signal acquisition module 55, and is used to process the sine and cosine signals to obtain the angle information and discrete information of the rotary transformer;

[0077] The phase judgment module 57 is connected to the sine and cosine signal discrete and angle analysis module 56 and the permanent magnet synchronous motor driving module 52 respectively, and is used to judge the phase sequence of the permanent magnet synchronous motor according to the driving angle of the permanent magnet synchronous motor and the sine and cosine discrete information of the rotary transformer;

[0078] The angle judgment module 58 is connected to the sine and cosine signal discreteness and angle analysis module 56 and the permanent magnet synchronous motor drive module 52 respectively, and is used to obtain the absolute position difference between the resolver and the permanent magnet synchronous motor according to the drive angle of the permanent magnet synchronous motor and the analysis angle of the sine and cosine information of the resolver.

[0079] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A phase sequence learning method for a permanent magnet synchronous motor of a rotary transformer, characterized in that: include: The learning process of the motor's positive and negative phase sequence and the absolute position difference learning process of the resolver and permanent magnet synchronous motor, The motor positive and negative phase sequence learning process specifically includes the following steps: Step A1: giving a preset direct-axis current and electrical angle of the permanent magnet synchronous motor, and increasing the electrical angle of the permanent magnet synchronous motor in a positive direction; Step A2: Obtain the sine signal and cosine signal of the rotary transformer during the rotation of the permanent magnet synchronous motor. When the sine signal leads the cosine signal, the phase sequence of the permanent magnet synchronous motor relative to the rotary transformer is a positive phase sequence; when the cosine signal leads the sine signal, the phase sequence of the permanent magnet synchronous motor relative to the rotary transformer is a negative phase sequence; The absolute position difference learning process of the resolver and permanent magnet synchronous motor includes the following steps: Step B1: Given a preset direct-axis current of the permanent magnet synchronous motor, the electrical angle of the permanent magnet synchronous motor is set to zero degree; Step B2: increasing the electrical angle of the permanent magnet synchronous motor from zero degrees until the resolver outputs zero position information; Step B3: Obtain the current rotation angle of the permanent magnet synchronous motor, calculate the absolute position difference between the resolver and the permanent magnet synchronous motor according to the positive and negative relationship of the phase sequence and the number of pole pairs of the permanent magnet synchronous motor, and obtain the rotor position of the permanent magnet synchronous motor according to the number of pole pairs of the resolver.

2. The method for learning the phase sequence of a permanent magnet synchronous motor of a rotary transformer according to claim 1, characterized in that: In step A1, the preset direct-axis current satisfies: Where T is the load torque, p is the number of pole pairs of the permanent magnet synchronous motor, and ψ is the flux linkage of the permanent magnet synchronous motor.

3. The phase sequence learning method of the permanent magnet synchronous motor of the rotary transformer according to claim 1, characterized in that: In the step A2, the sine signal and the cosine signal are discretely processed, and the leading state between the sine signal and the cosine signal is determined according to the discrete result.

4. The method for learning the phase sequence of a permanent magnet synchronous motor of a rotary transformer according to claim 3, characterized in that: The specific method of the discrete processing is: Discretize the sine signal and cosine signal to get the discrete values ​​of the sine signal and cosine signal [S(θ), C(θ)]: Wherein, sinθ is the sine signal; cosθ is the cosine signal; S(θ) is the discrete value of the sine signal, and C(θ) is the discrete value of the cosine signal; The specific method for judging based on discrete results is: When [S(θ), C(θ)] is [1, 0], [1, 1], [0, 1], [0, 0], the sine signal leads the cosine signal; When [S(θ), C(θ)] is [0, 1], [1, 1], [1, 0], [0, 0], the cosine signal leads the sine signal.

5. The method for learning the phase sequence of a permanent magnet synchronous motor of a rotary transformer according to claim 1, characterized in that: In step B3, the specific method for logarithmically calculating the absolute position difference between the resolver and the permanent magnet synchronous motor is: When the phase sequence of the permanent magnet synchronous motor relative to the resolver is a positive phase sequence, the calculation formula for the absolute position difference is: When the phase sequence of the permanent magnet synchronous motor relative to the resolver is in reverse phase sequence, the calculation formula for the absolute position difference is: Wherein, Δθ is the current rotation angle of the permanent magnet synchronous motor; p is the number of pole pairs of the permanent magnet synchronous motor.

6. The method for learning the phase sequence of a permanent magnet synchronous motor of a rotary transformer according to claim 1 or 5, characterized in that: In step B3, the specific formula for obtaining the rotor position of the permanent magnet synchronous motor according to the pole pair number of the rotary transformer is: Where, Q is the number of pole pairs of the resolver, that is, the number of zero points; Δθ a is the absolute position difference; θ z (n) is the rotor position of the permanent magnet synchronous motor corresponding to the nth zero point.

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