Method, system and device for estimating rotating speed of permanent magnet synchronous motor without position sensor

Abstract

The invention discloses a rotating speed estimation method, system and device for a permanent magnet synchronous motor without a position sensor, and the method comprises the steps: obtaining the d-axis stator current and d-axis stator voltage of the motor in a current control period; reconstructing the d-axis stator current and the d-axis stator voltage of the current control period based on the rotor flux linkage and the d-axis inductance of the motor to obtain a d-axis expansion current and a d-axis expansion voltage; and inputting the d-axis expansion current and the d-axis expansion voltage of the current control period into an adaptive observer to obtain a rotating speed estimation value and a rotor position estimation value of the motor in the current control period. According to the rotating speed estimation method, the rotating speed and the rotor position of the salient pole permanent magnet synchronous motor can be estimated through the adaptive observer, the rotating speed and the rotor position of the non-salient pole permanent magnet synchronous motor can also be estimated, and meanwhile the rotating speed and rotor position estimation precision of the motor is guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of electrical equipment, and particularly relates to a method, a system and a device for estimating the speed of a sensorless permanent magnet synchronous motor. Background Art

[0002] During the driving process of a permanent magnet synchronous motor, in order to ensure the stable operation of the permanent magnet synchronous motor, it is necessary to detect the speed and rotor position of the motor in real time to meet the precise control of speed and current. In the related art, a tangent-type saturation function is usually used as the sliding mode surface control function of the flux linkage sliding mode observer, and then the speed and rotor position angle of the motor are estimated.

[0003] The acquisition of the speed and rotor position of the motor is crucial for the motor drive system. Although the above technical solution can estimate the speed and rotor position of the motor, this technical solution is based on a non-salient pole permanent magnet synchronous motor and cannot be applied to a salient pole permanent magnet synchronous motor. Summary of the Invention

[0004] In view of the above problems, the present application provides a method, a system and a device for estimating the speed of a sensorless permanent magnet synchronous motor, which can estimate the speed and rotor position of both the salient pole permanent magnet synchronous motor and the non-salient pole permanent magnet synchronous motor through an adaptive observer, expanding the applicable range of the control method and ensuring the estimation accuracy of the speed and rotor position of the motor.

[0005] In a first aspect, the present application provides a method for estimating the speed of a sensorless permanent magnet synchronous motor, which acquires the d-axis stator current and d-axis stator voltage of the motor in the current control period; reconstructs the d-axis stator current and d-axis stator voltage in the current control period based on the rotor flux linkage of the motor in the current control period and the d-axis inductance of the motor to obtain the d-axis extended current and d-axis extended voltage in the current control period; inputs the d-axis extended current and d-axis extended voltage in the current control period into an adaptive observer to obtain the speed estimation value and rotor position estimation value of the motor in the current control period; wherein, the adaptive observer is determined based on the voltage equation of the motor, and the voltage equation includes the d-axis inductance and q-axis inductance of the motor.

[0006] In the technical solution of the embodiment of the present application, during the operation of the motor, the d-axis stator current and d-axis stator voltage of the motor in the current control period are obtained, and the d-axis stator current and d-axis stator voltage in the current control period are reconstructed based on the rotor magnetic flux of the motor in the current control period and the d-axis inductance of the motor, so as to obtain the d-axis extended current and d-axis extended voltage in the current control period. The d-axis extended current and d-axis extended voltage in the current control period are input into the adaptive observer to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period; wherein, the adaptive observer is determined based on the voltage equation of the motor, and the voltage equation includes the d-axis inductance and q-axis inductance of the motor. Thus, the first adaptive observer is determined based on the voltage equation including the d-axis inductance and q-axis inductance of the motor, so that the method can not only estimate the speed and rotor position of the salient-pole permanent magnet synchronous motor, but also estimate the speed and rotor position of the non-salient-pole permanent magnet synchronous motor, expanding the applicable range of the control method and ensuring the estimation accuracy of the motor speed and rotor position.

[0007] In some embodiments, the reconstructing the d-axis stator current and d-axis stator voltage in the current control period based on the rotor magnetic flux of the motor in the current control period and the d-axis inductance of the motor to obtain the d-axis extended current and d-axis extended voltage in the current control period includes: obtaining the sum of the d-axis equivalent current generated by the rotor magnetic flux on the d-axis inductance and the d-axis stator current in the current control period to obtain the d-axis extended current in the current control period; obtaining the sum of the d-axis equivalent voltage generated by the d-axis equivalent current on the stator resistance of the motor and the d-axis stator voltage in the current control period to obtain the d-axis extended voltage in the current control period.

[0008] In some embodiments, the adaptive observer includes a first adaptive observer, and the method for estimating the speed of the sensorless permanent magnet synchronous motor further includes: obtaining the q-axis stator current and q-axis stator voltage of the motor in the current control period; inputting the d-axis extended current, d-axis extended voltage, q-axis stator current and q-axis stator voltage in the current control period into the first adaptive observer to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period.

[0009] In some embodiments, reconstructing the d-axis stator current and d-axis stator voltage of the current control period based on the rotor magnetic flux of the motor in the current control period and the d-axis inductance of the motor to obtain the d-axis extended current and d-axis extended voltage of the current control period includes: obtaining the sum of the d-axis equivalent current generated by the rotor magnetic flux on the d-axis inductance and the d-axis stator current of the current control period to obtain the d-axis extended current of the current control period; obtaining the d-axis equivalent voltage generated by the d-axis equivalent current on the stator resistance of the motor, and obtaining the ratio of the sum of the d-axis equivalent voltage and the d-axis stator voltage of the current control period to the d-axis inductance to obtain the d-axis extended voltage of the current control period.

[0010] In some embodiments, the adaptive observer includes a second adaptive observer, and the method for estimating the speed of the sensorless permanent magnet synchronous motor further includes: obtaining the q-axis stator current and q-axis stator voltage of the motor in the current control period; reconstructing the q-axis stator voltage of the current control period based on the q-axis inductance to obtain the q-axis extended voltage of the current control period; inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis extended voltage of the current control period into the second adaptive observer to obtain the speed estimation value and rotor position estimation value of the motor in the current control period.

[0011] In this embodiment, in addition to the rotor magnetic flux ψ of the motor in the current control period f reconstructing the d-axis stator current i of the current control period d0 and the d-axis stator voltage u d0 to obtain the d-axis extended current i' of the current control period d0 and the d-axis extended voltage u' d0 further reconstructing the q-axis stator voltage u of the current control period based on the q-axis inductance L q to obtain the q-axis extended voltage u' of the current control period q0 then the second adaptive observer obtains the speed estimation value q0 of the motor in the current control period according to the d-axis extended current i' d0 d-axis extended voltage u' d0 q-axis stator current i q0 and q-axis extended voltage u' q0 At the same time, the second adaptive observer is also determined according to the voltage equation including the d-axis inductance and q-axis inductance of the motor, and can be applied to estimate the speed and rotor position of salient-pole permanent magnet synchronous motors and non-salient-pole permanent magnet synchronous motors. and the rotor position estimation value

[0012] In some embodiments, reconstructing the q-axis stator voltage of the current control period based on the q-axis inductance to obtain the q-axis extended voltage of the current control period includes: obtaining a ratio of the q-axis stator voltage of the current control period to the q-axis inductance to obtain the q-axis extended voltage of the current control period.

[0013] In some embodiments, the first adaptive observer includes a first state observer and an estimator. Inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis stator voltage of the current control period into the first adaptive observer to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period includes: inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis stator voltage of the current control period into the first state observer to obtain a first difference between the d-axis extended current and the estimated value of the d-axis extended current, and a second difference between the q-axis stator current and the estimated value of the q-axis stator current in the current control period; inputting the first difference between the d-axis extended current and the estimated value of the d-axis extended current, the second difference between the q-axis stator current and the estimated value of the q-axis stator current, the d-axis extended current, and the q-axis stator current in the current control period into the estimator to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period.

[0014] In some embodiments, inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis stator voltage of the current control period into the first state observer to obtain a first difference between the d-axis extended current and the estimated value of the d-axis extended current, and a second difference between the q-axis stator current and the estimated value of the q-axis stator current in the current control period includes: estimating the estimated value of the d-axis extended current in the current control period based on the d-axis extended voltage of the current control period, the estimated value of the d-axis extended current, the estimated value of the speed, the estimated value of the q-axis stator current, the first difference between the d-axis extended current and the estimated value of the d-axis extended current, and the second difference between the q-axis stator current and the estimated value of the q-axis stator current in the previous control period, and obtaining the first difference between the d-axis extended current and the estimated value of the d-axis extended current in the current control period; estimating the estimated value of the q-axis stator current in the current control period based on the q-axis stator voltage of the current control period, the estimated value of the q-axis stator current, the estimated value of the speed, the estimated value of the d-axis extended current, the first difference between the d-axis extended current and the estimated value of the d-axis extended current, and the second difference between the q-axis stator current and the estimated value of the q-axis stator current in the previous control period, and obtaining the second difference between the q-axis stator current and the estimated value of the q-axis stator current in the current control period.

[0015] This embodiment combines the parameters of the previous control period to estimate the estimated value of the d-axis extended current in this period and the estimated value of the q-axis stator current Thereby, the deviation amount within the current control period is determined, and based on this deviation amount, the deviation compensation is further determined, and finally the closed-loop state equation is obtained, ensuring the tracking effect of the control system.

[0016] In some embodiments, the first state observer estimates the estimated value of the d-axis extended current and the estimated value of the q-axis stator current of the current control period in the following manner:

[0017]

[0018]

[0019] Wherein, is the estimated value of the d-axis extended current of the current control period, is the estimated value of the q-axis stator current of the current control period, L d is the d-axis inductance, L q is the q-axis inductance, u' d0 is the d-axis extended voltage of the current control period, u q0 is the q-axis stator voltage of the current control period, R s is the stator resistance of the motor, is the estimated value of the d-axis extended current of the previous control period, is the estimated value of the q-axis stator current of the previous control period, is the estimated value of the rotational speed of the previous control period, ρ = L q / L d , g1 is the first gain coefficient, g2 is the second gain coefficient, e id1 is the first difference between the d-axis extended current and the estimated value of the d-axis extended current of the previous control period, e iq1 is the second difference between the q-axis stator current and the estimated value of the q-axis stator current of the previous control period.

[0020] In some embodiments, the second adaptive observer includes a second state observer and an estimator. Inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis extended voltage of the current control period into the second adaptive observer to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period includes: Inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis extended voltage of the current control period into the second state observer to obtain a first difference between the d-axis extended current and the estimated value of the d-axis extended current in the current control period, and a second difference between the q-axis stator current and the estimated value of the q-axis stator current; Inputting the first difference between the d-axis extended current and the estimated value of the d-axis extended current in the current control period, the second difference between the q-axis stator current and the estimated value of the q-axis stator current, the d-axis extended current, and the q-axis stator current into the estimator to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period.

[0021] In some embodiments, inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis extended voltage of the current control period into the second state observer to obtain a first difference between the d-axis extended current and the estimated value of the d-axis extended current in the current control period, and a second difference between the q-axis stator current and the estimated value of the q-axis stator current includes: Based on the d-axis extended voltage of the current control period, and the estimated value of the d-axis extended current, the estimated value of the speed, the estimated value of the q-axis stator current, the first difference between the d-axis extended current and the estimated value of the d-axis extended current, and the second difference between the q-axis stator current and the estimated value of the q-axis stator current in the previous control period, estimating the estimated value of the d-axis extended current in the current control period, and obtaining the first difference between the d-axis extended current and the estimated value of the d-axis extended current in the current control period; Based on the q-axis extended voltage of the current control period, and the estimated value of the q-axis stator current, the estimated value of the speed, the estimated value of the d-axis extended current, the first difference between the d-axis extended current and the estimated value of the d-axis extended current, and the second difference between the q-axis stator current and the estimated value of the q-axis stator current in the previous control period, estimating the estimated value of the q-axis stator current in the current control period, and obtaining the second difference between the q-axis stator current and the estimated value of the q-axis stator current in the current control period.

[0022] This embodiment combines the parameters of the previous control period to estimate the estimated value of the d-axis extended current in this period and the estimated value of the q-axis stator current Thereby determining the deviation amount in the current control period, and based on this deviation amount, further determining the deviation compensation, and finally obtaining the closed-loop state equation, which ensures the tracking effect of the control system.

[0023] In some embodiments, the second state observer estimates the estimated value of the d-axis extended current and the estimated value of the q-axis stator current in the current control period in the following manner:

[0024]

[0025]

[0026] Wherein, is the estimated value of the d-axis extended current in the current control period, is the estimated value of the q-axis stator current in the current control period, L d is the d-axis inductance, L q is the q-axis inductance, u′ d0 is the d-axis extended voltage in the current control period, u′ q0 is the q-axis extended voltage in the current control period, R s is the stator resistance of the motor, is the estimated value of the d-axis extended current in the previous control period, is the estimated value of the q-axis stator current in the previous control period, is the estimated value of the rotational speed in the previous control period, ρ = L q / L d , g1 is the first gain coefficient, g2 is the second gain coefficient, e id1 is the first difference between the d-axis extended current and the estimated value of the d-axis extended current in the previous control period, e iq1 is the second difference between the q-axis stator current and the estimated value of the q-axis stator current in the previous control period.

[0027] In some embodiments, inputting the first difference between the d-axis extended current and the estimated value of the d-axis extended current in the current control period, the second difference between the q-axis stator current and the estimated value of the q-axis stator current, the d-axis extended current, and the q-axis stator current into the estimator to obtain the estimated value of the rotational speed and the estimated value of the rotor position of the motor in the current control period includes: integrating the difference between the product of the d-axis extended current in the current control period and the second difference between the q-axis stator current and the estimated value of the q-axis stator current and the product of the q-axis stator current in the current control period and the first difference between the d-axis extended current and the estimated value of the d-axis extended current to obtain the estimated value of the rotational speed in the current control period; integrating the estimated value of the rotational speed in the current control period to obtain the change amount of the rotor position in the current control period, and obtaining the estimated value of the rotor position in the current control period by acquiring the change amount of the rotor position in the current control period and the estimated value of the rotor position of the motor in the previous control period.

[0028] Further, this embodiment takes into account the factor that the d-axis inductance and q-axis inductance of the salient-pole permanent magnet synchronous motor are not equal, and selects variables for constructing the Lyapunov function, that is, based on the first difference e id0 and the second difference e iq0 to satisfy the situation where the d-axis and q-axis of the salient-pole permanent magnet synchronous motor are not equal, thus meeting the applications of the salient-pole permanent magnet synchronous motor and the non-salient-pole permanent magnet synchronous motor.

[0029] In a second aspect, the present application provides a computer-readable storage medium, on which a program is stored, and when the program is executed by a processor, the above-mentioned speed estimation method for a sensorless permanent magnet synchronous motor is implemented.

[0030] In a third aspect, the present application proposes a speed estimation system for a sensorless permanent magnet synchronous motor, including: a memory, a processor, and a program stored on the memory and executable on the processor, and when the processor executes the program, the above-mentioned speed estimation method for a sensorless permanent magnet synchronous motor is implemented.

[0031] In a fourth aspect, the present application proposes a speed estimation device for a sensorless permanent magnet synchronous motor, the device includes: an acquisition module, configured to acquire the d-axis stator current and d-axis stator voltage of the motor in the current control period; an expansion module, configured to reconstruct the d-axis stator current and d-axis stator voltage of the current control period based on the rotor magnetic flux of the motor in the current control period and the d-axis inductance of the motor, to obtain the d-axis extended current and d-axis extended voltage of the current control period; an adaptive observer, configured to estimate the speed estimation value and rotor position estimation value of the motor in the current control period based on the d-axis extended current and d-axis extended voltage of the current control period; wherein, the adaptive observer is determined based on the voltage equation of the motor, and the voltage equation includes the d-axis inductance and q-axis inductance of the motor.

[0032] In a fifth aspect, the present application proposes an electrical device, including the above-mentioned speed estimation system for a sensorless permanent magnet synchronous motor, or, the above-mentioned speed estimation device for a sensorless permanent magnet synchronous motor.

[0033] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification, and in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the specific embodiments of the present application are hereinafter specifically exemplified. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Upon reading the following detailed description of the preferred embodiments, various other advantages and benefits will become apparent to those of ordinary skill in the art. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not considered to be a limitation of the present application. Moreover, in all the drawings, the same reference numerals are used to denote the same components. In the drawings:

[0035] Figure 1 is a flowchart of a speed estimation method for a sensorless permanent magnet synchronous motor according to some embodiments of the present application;

[0036] Figure 2 is a schematic diagram of a control system for a sensorless permanent magnet synchronous motor according to some embodiments of the present application;

[0037] Figure 3 is a schematic diagram of an adaptive observer according to some embodiments of the present application;

[0038] Figure 4 is a block schematic diagram of a speed estimation system for a sensorless permanent magnet synchronous motor according to some embodiments of the present application;

[0039] Figure 5 is a block schematic diagram of a speed estimation device for a sensorless permanent magnet synchronous motor according to some embodiments of the present application;

[0040] Figure 6 is a block schematic diagram of an electrical device according to some embodiments of the present application;

[0041] Figure 7 is a block schematic diagram of an electrical device according to other embodiments of the present application.

[0042] Reference numerals:

[0043] speed estimation system 100 for a sensorless permanent magnet synchronous motor, memory 110, processor 120, detection probe 130, speed estimation device 200 for a sensorless permanent magnet synchronous motor, acquisition module 210, extension module 220, adaptive observer 230, electrical device 1000. Detailed embodiments

[0044] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solutions of the present application more clearly and thus are only examples and cannot be used to limit the protection scope of the present application.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs; the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "comprising" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion.

[0046] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity, specific order, or primary-secondary relationship of the indicated technical features. In the description of the embodiments of this application, "a plurality of" means more than two, unless otherwise specifically defined.

[0047] Referring to "embodiments" herein means that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0048] In the description of the embodiments of this application, the term "and / or" is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0049] In the description of the embodiments of this application, the term "a plurality of" refers to more than two (including two). Similarly, "a plurality of groups" refers to more than two groups (including two groups), and "a plurality of pieces" refers to more than two pieces (including two pieces).

[0050] In the description of the embodiments of this application, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of this application and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of this application.

[0051] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0052] To ensure the operation stability of the permanent magnet synchronous motor, it is necessary to observe the speed and rotor position of the motor in real time during the operation of the permanent magnet synchronous motor.

[0053] In the related art, a tangent-type saturation function is used as the sliding mode surface control function of the flux linkage sliding mode observer, and a speed adaptive observation module based on the Lyapunov function is used to obtain the speed and rotor position angle. In another related art, a signal processing method is used to digitally process the change process of the back electromotive force of the three-phase winding, extract the position feature points of the back electromotive force during the rotation of the motor, and estimate the rotor position information at the feature points by using the extended Kalman filter method, so as to obtain the accurate position of the rotor.

[0054] Although the above technical solutions can estimate the speed and rotor position of the permanent magnet synchronous motor, the above technical solutions are based on the surface-mounted permanent magnet synchronous motor and cannot be applied to the salient-pole permanent magnet synchronous motor. At the same time, the above technical solutions perform data calculations based on the fourth-order state equation in the actual calculation process, with a large amount of calculation and complex implementation.

[0055] To solve the above technical problems, the present application proposes a method for estimating the speed of a sensorless permanent magnet synchronous motor. During the operation of the motor, the d-axis stator current and d-axis stator voltage of the motor in the current control period are obtained, and based on the rotor flux linkage of the motor in the current control period and the d-axis inductance of the motor, the d-axis stator current and d-axis stator voltage in the current control period are reconstructed to obtain the d-axis extended current and d-axis extended voltage in the current control period. The d-axis extended current and d-axis extended voltage in the current control period are input into the adaptive observer to obtain the speed estimation value and rotor position estimation value of the motor in the current control period, where the adaptive observer is determined based on the voltage equation of the motor, and the voltage equation includes the d-axis inductance and q-axis inductance of the motor.

[0056] In the technical solution of the embodiment of the present application, during the operation of the motor, the d-axis stator current and d-axis stator voltage of the motor in the current control period are acquired, and based on the rotor magnetic flux of the motor in the current control period and the d-axis inductance of the motor, the d-axis stator current and d-axis stator voltage in the current control period are reconstructed to obtain the d-axis extended current and d-axis extended voltage in the current control period. The d-axis extended current and d-axis extended voltage in the current control period are input into the adaptive observer to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period; wherein, the adaptive observer is determined based on the voltage equation of the motor, and the voltage equation includes the d-axis inductance and q-axis inductance of the motor. Thus, the adaptive observer is determined based on the voltage equation including the d-axis inductance and q-axis inductance of the motor, so that this method can not only estimate the speed and rotor position of the salient-pole permanent magnet synchronous motor, but also estimate the speed and rotor position of the non-salient-pole permanent magnet synchronous motor, expanding the applicable range of the control method and ensuring the estimation accuracy of the motor speed and rotor position.

[0057] For the convenience of description, the following embodiments will be combined with Figure 1 to illustrate the speed estimation method of the sensorless permanent magnet synchronous motor of the present application.

[0058] Refer to Figure 1 , the speed estimation method of the sensorless permanent magnet synchronous motor in the present application may include the following steps:

[0059] S1, acquire the d-axis stator current i d0 and the d-axis stator voltage u d0 of the motor in the current control period;

[0060] S2, based on the rotor magnetic flux ψ f of the motor in the current control period and the d-axis inductance L d of the motor, reconstruct the d-axis stator current i d0 and the d-axis stator voltage u d0 in the current control period to obtain the d-axis extended current i' d0 and the d-axis extended voltage u' d0 in the current control period;

[0061] S3, input the d-axis extended current i' d0 and the d-axis extended voltage u' d0 in the current control period into the adaptive observer to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period. Wherein, the adaptive observer is determined based on the voltage equation of the motor, and the voltage equation includes the d-axis inductance L d and the q-axis inductance L q of the motor.

[0062] Referring to Figure 2 as shown, in the control process of a permanent magnet synchronous motor, the three-phase current i a of the permanent magnet synchronous motor is sampled, and after Park transformation, the d-axis stator current i b and the q-axis stator current i c are obtained. Then, the difference between the given speed d and the estimated speed q is passed through a speed regulator to obtain the reference torque T . Based on the reference torque T ref , the bus voltage U ref , and the estimated speed dc , the maximum torque current ratio control and field weakening control are combined to obtain the d-axis reference current and the q-axis reference current . The difference between the d-axis reference current and the d-axis stator current i d is input into the d-axis current regulator to obtain the d-axis stator voltage u d . The difference between the q-axis reference current and the q-axis stator current i q is input into the q-axis current regulator to obtain the q-axis stator voltage u q . The d-axis stator voltage u d and the q-axis stator voltage u q are input into the modulation module after rotation transformation. The modulation module generates a PWM (Pulse Width Modulation) signal, and the inverter converts the received PWM signal into three-phase current to control the operation of the permanent magnet synchronous motor. In the embodiment of the present application, the d-axis stator current i d0 of the current control cycle obtained by the above Park transformation is reconstructed to obtain the d-axis extended current i' d0 of the current control cycle. The d-axis stator voltage u d0 is reconstructed to obtain the d-axis extended voltage u' d0 of the current control cycle. Then, the d-axis extended current i' d0 and the d-axis extended voltage u' d0 of the current control cycle are input into the adaptive observer. The adaptive observer obtains the adaptive law of the estimated speed based on the Lyapunov stability theorem. According to the received d-axis extended current i' d0 and the d-axis extended voltage u' d0 of the current control cycle, the estimated speed and the estimated rotor position

[0063] of the motor in the current control cycle are calculated. and the estimated rotor position Estimated speed value of the current control cycle and estimated rotor position for use in motor control, e.g., a given speed The difference from the estimated speed is used to obtain the reference torque T through a speed regulator ref , the estimated rotor position is used for the rotational transformation of the d-axis stator voltage u d and the q-axis stator voltage u q . The estimated rotor position is used for the Park transformation of the three-phase currents i a , i b , i c . In the synchronous rotating coordinate system, the voltage equation of an ideal permanent magnet synchronous motor is: resistance voltage drop + magnetic field voltage drop + back electromotive force, as shown in formulas (1) and (2) specifically.

[0064]

[0065]

[0066] where u d is the d-axis stator voltage, R s is the stator resistance, i d is the d-axis stator current, L d is the d-axis inductance, ω r is the rotor electrical angular velocity, L q is the q-axis inductance, i q is the q-axis stator current, u q is the q-axis stator voltage, ψ f is the rotor magnetic flux.

[0067] In the above formulas (1) and (2), L d is used to represent the d-axis inductance and L q is used to represent the q-axis inductance. Therefore, the voltage equation already reflects the surface-mounted permanent magnet synchronous motor and the salient-pole permanent magnet synchronous motor when selected. Specifically, when L s is equal to L q , it represents the voltage equation of the surface-mounted permanent magnet synchronous motor; when L s is not equal to L q , it represents the voltage equation of the salient-pole permanent magnet synchronous motor.

[0068] The adaptive observer is determined based on formulas (1) and (2) so that it can be applicable to the determination of the estimated speed value and the estimated rotor position and can be used to estimate the speed and rotor position of the salient-pole permanent magnet synchronous motor and the surface-mounted permanent magnet synchronous motor.

[0069] According to some embodiments of the present application, based on the rotor magnetic flux ψ of the motor in the current control period f and the d-axis inductance L of the motor d , the d-axis stator current i of the current control period d0 and the d-axis stator voltage u d0 are reconstructed to obtain the d-axis extended current i' d0 and the d-axis extended voltage u' d0 of the current control period, including: obtaining the d-axis equivalent current generated by the rotor magnetic flux ψ f on the d-axis inductance L d and the sum of the d-axis stator current i of the current control period to obtain the d-axis extended current i' d0 of the current control period; obtaining the sum of the d-axis equivalent voltage d0 generated by the d-axis equivalent current on the stator resistance R s of the motor and the d-axis stator voltage u of the current control period to obtain the d-axis extended voltage u' d0 of the current control period. d0 .

[0070] Specifically, the calculation formula of the d-axis extended current i' d0 of the current control period is as follows:

[0071]

[0072] where i' d0 is the d-axis extended current of the current control period, is the d-axis equivalent current generated by the rotor magnetic flux on the d-axis inductance, and i d0 is the d-axis stator current of the current control period.

[0073] The calculation formula of the d-axis extended voltage u' d0 of the current control period is as follows:

[0074]

[0075] where u' d0 is the d-axis extended voltage of the current control period, u d0 is the d-axis stator voltage of the current control period, is the d-axis equivalent voltage generated by the d-axis equivalent current on the stator resistance of the motor.

[0076] According to some embodiments of the present application, the adaptive observer includes a first adaptive observer. The method for estimating the rotational speed of a permanent magnet synchronous motor without a position sensor further includes: obtaining the q-axis stator current \(i\) of the motor in the current control period q0 and the q-axis stator voltage \(u\) q0 ; inputting the d-axis extended current \(i'\) d0 , the d-axis extended voltage \(u'\) d0 , the q-axis stator current \(i\) q0 and the q-axis stator voltage \(u\) q0 of the current control period into the first adaptive observer to obtain the estimated rotational speed value and the estimated rotor position value

[0077] Specifically, the inputs of the first adaptive observer are the d-axis extended current \(i'\) d0 , the d-axis extended voltage \(u'\) d0 , the q-axis stator current \(i\) q0 and the q-axis stator voltage \(u\) q0 of the current control period. The first adaptive observer observes and estimates the motor system based on the d-axis extended current \(i'\) d0 , the d-axis extended voltage \(u'\) d0 , the q-axis stator current \(i\) q0 and the q-axis stator voltage \(u\) q0 of the current control period, so as to obtain the estimated rotational speed value and the estimated rotor position value The estimated rotational speed value and the estimated rotor position value are used for motor control.

[0078] According to some embodiments of the present application, based on the rotor magnetic flux \(\psi\) f of the motor in the current control period and the d-axis inductance \(L\) d of the motor, the d-axis stator current \(i\) d0 and the d-axis stator voltage \(u\) d0 of the current control period are reconstructed to obtain the d-axis extended current \(i'\) d0 and the d-axis extended voltage \(u'\) d0 , including: obtaining the d-axis equivalent current f generated by the rotor magnetic flux \(\psi\) d on the d-axis inductance \(L\) and the sum of the d-axis stator current \(i\) d0 of the current control period to obtain the d-axis extended current \(i'\) d0 ; obtaining the d-axis equivalent voltage generated by the d-axis equivalent current s on the stator resistance \(R\) of the motor and obtain the d-axis equivalent voltage and the sum of the d-axis stator voltage u of the current control period d0 and the ratio of the d-axis inductance L d to obtain the d-axis extended voltage u' of the current control period d0 .

[0079] Specifically, the calculation formula for the d-axis extended current i' of the current control period d0 is formula (3), and the calculation formula for the d-axis extended voltage u' of the current control period d0 is:

[0080]

[0081] where u' d0 is the d-axis extended voltage of the current control period, u d0 is the d-axis stator voltage, L d is the d-axis inductance, R s is the stator resistance, ψ f is the rotor magnetic flux.

[0082] This embodiment uses as the calculation coefficient, and the d-axis extended voltage u' of the current control period obtained through formula (5) d0 , compared with the d-axis extended voltage u' of the current control period obtained by using the above formula (4) d0 , can reduce the calculation amount in the adaptive observer.

[0083] According to some embodiments of the present application, the adaptive observer includes a second adaptive observer, and the speed estimation method for the sensorless permanent magnet synchronous motor further includes: obtaining the q-axis stator current i of the motor in the current control period q0 and the q-axis stator voltage u q0 ; reconstructing the q-axis stator voltage u of the current control period based on the q-axis inductance L q to obtain the q-axis extended voltage u' of the current control period q0 ; inputting the d-axis extended current i', the d-axis extended voltage u', the q-axis stator current i q0 , the d-axis extended current i' of the current control period d0 , the d-axis extended voltage u', d0 , the q-axis stator current i q0 and the q-axis extended voltage u' q0 into the second adaptive observer to obtain the speed estimation value of the motor in the current control period and the rotor position estimation value

[0084] In this embodiment, in addition to based on the rotor magnetic flux ψ of the motor in the current control period f and the d-axis inductance Ld The d-axis stator current \(i\) of the current control period d0 and the d-axis stator voltage \(u\) d0 are reconstructed to obtain the d-axis extended current \(i'\) of the current control period d0 and the d-axis extended voltage \(u'\) d0 In addition, based on the q-axis inductance \(L\) q the q-axis stator voltage \(u\) of the current control period q0 is reconstructed to obtain the q-axis extended voltage \(u'\) of the current control period q0 , and then the second adaptive observer observes the motor system according to the d-axis extended current \(i'\) of the current control period d0 , the d-axis extended voltage \(u'\) d0 , the q-axis stator current \(i\) q0 and the q-axis extended voltage \(u'\) q0 and estimates the estimated value of the motor speed and the estimated value of the rotor position in the current control period of the motor

[0085] Among them, the second adaptive observer is also determined according to the voltage equation of the motor in the above formulas (1) and (2), so as to be applicable to estimating the speed and rotor position of the salient-pole permanent magnet synchronous motor and the non-salient-pole permanent magnet synchronous motor.

[0086] According to some embodiments of the present application, based on the q-axis inductance \(L\) q the q-axis stator voltage \(u\) of the current control period d0 is reconstructed to obtain the q-axis extended voltage \(u'\) of the current control period q0 , including: obtaining the q-axis stator voltage \(u\) of the current control period q0 and the ratio of the q-axis inductance \(L\) q to obtain the q-axis extended voltage \(u'\) of the current control period q0 .

[0087] That is to say, the calculation formula of the q-axis extended voltage \(u'\) of the current control period q0 is:

[0088]

[0089] Among them, \(u'\) q0 is the q-axis extended voltage of the current control period, \(u\) q0 is the q-axis stator voltage of the current control period, and \(L\) q is the q-axis inductance.

[0090] Due to vector control, the component of the rotor flux linkage \(\psi\) f on the q-axis is 0, and the component of the rotor flux linkage on the d-axis will cause the rotor flux linkage \(\psi\) fInduced electromotive force is generated on the d-axis. Therefore, this embodiment is based on the rotor magnetic flux ψ f Construct current state variables, which can take into account the influence of the change of rotor magnetic flux. At the same time, since the component of the rotor magnetic flux on the q-axis is 0, the q-axis current does not change, and the q-axis voltage is also multiplied by the coefficient

[0091] In this embodiment, the d-axis extended current i′ of the current control period is calculated through formula (3) d0 , the d-axis extended voltage u′ of the current control period is calculated through formula (5) d0 , the q-axis extended voltage u′ of the current control period is calculated through formula (6) q0 , the second adaptive observer is based on the q-axis stator current i q0 , and the reconstructed d-axis extended current i′ d0 , d-axis extended voltage u′ d0 , q-axis extended voltage u′ q0 , to obtain the estimated value of the motor speed in the current control period and the estimated value of the rotor position

[0092] According to some embodiments of the present application, the first adaptive observer includes a first state observer and an estimator. The d-axis extended current i′ of the current control period d0 , d-axis extended voltage u′ d0 , q-axis stator current i q0 and q-axis stator voltage u q0 are input to the first adaptive observer to obtain the estimated value of the motor speed in the current control period and the estimated value of the rotor position including: inputting the d-axis extended current i′ of the current control period d0 , d-axis extended voltage u′ d0 , q-axis stator current i q0 and q-axis stator voltage u q0 to the first state observer to obtain the first difference e d0 between the d-axis extended current i′ of the current control period and the estimated value of the d-axis extended current , and the second difference e id0 between the q-axis stator current i q0 and the estimated value of the q-axis stator current . The first difference e iq0 between the d-axis extended current i′ of the current control period and the estimated value of the d-axis extended current d0 , the q-axis stator current i and the estimated value of the q-axis stator current id0 , q-axis stator current i q0 and the estimated value of the q-axis stator current The second difference e between iq0 and the d-axis extended current i′ d0 and the q-axis stator current i q0 are input into the estimator to obtain the estimated value of the motor speed in the current control period and the estimated value of the rotor position

[0093] Specifically, the first state observer is based on the d-axis extended current i′ in the current control period d0 and the d-axis extended voltage u′ d0 and the q-axis stator current i q0 and the q-axis stator voltage u q0 First, estimate the d-axis stator current in the current control period to determine the estimated value of the d-axis extended current in the current control period and estimate the q-axis stator current in the current control period to determine the estimated value of the q-axis stator current Then, subtract the estimated value of the d-axis extended current d0 from the d-axis extended current i′ in the current control period to obtain the first difference e id0 , subtract the estimated value of the q-axis stator current q0 from the q-axis stator current i to obtain the second difference e iq0 , and the first difference e id0 and the second difference e iq0 are the deviation amounts in the current control period. The estimator determines the speed and rotor position of the motor in the current control period according to the first difference e d0 between the d-axis extended current i′ in the current control period and the estimated value of the d-axis extended current id0 , the second difference e q0 between the q-axis stator current i and the estimated value of the q-axis stator current iq0 , the d-axis extended current i′ d0 and the q-axis stator current i q0 .

[0094] In this embodiment, the estimator estimates the speed and rotor position in the current control period according to the deviation amount in the current control period, as well as the d-axis extended current i′ d0 and the q-axis stator current i q0 , that is, obtain the estimated value of the motor speed in the current control period and the estimated value of the rotor position

[0095] In this application, the estimated value of the d-axis extended current in the current control period and the estimated value of the q-axis stator current The determination method is based on the voltage equation of the permanent magnet synchronous motor. The estimated value of the d-axis extended current in the current control period is as follows And the estimated value of the q-axis stator current The determination method will be described in detail.

[0096] For formula (1), through formula transformation, we can get:

[0097]

[0098] According to formula (3), it can be transformed to get:

[0099]

[0100] According to formula (4), it can be transformed to get:

[0101]

[0102] Substituting formula (8) and formula (9) into formula (7), we can get:

[0103]

[0104] The formula transformation of formula (10) is as follows:

[0105]

[0106] Simplifying formula (11) gives:

[0107]

[0108] According to the derivative rule that the derivative of a constant is zero, that is, formula Then, formula (12) can be transformed to:

[0109]

[0110] For formula (2), through formula transformation, we can get:

[0111]

[0112] Substituting formula (8) into formula (14), we can get:

[0113]

[0114] The formula transformation of formula (15) gives:

[0115]

[0116]

[0117]

[0118] Thus, through the above formula transformation, the two-order state equation formulas (13) and (18) in the synchronous rotating coordinate system are obtained from the voltage equation of the permanent magnet synchronous motor.

[0119] During the application process, the d-axis extended current i′ in the current control period can be d0 and the d-axis extended voltage u′ d0 , the q-axis stator current i q0 are input into formula (13), and the calculation result is integrated to obtain the estimated value of the d-axis extended current in the current control period Then, the d-axis extended current i′ d0 is subtracted from the estimated value of the d-axis extended current to obtain the first difference e in the current control period id0 .

[0120] Meanwhile, the d-axis extended current i′ in the current control period d0 , the q-axis stator current i q0 and the q-axis stator voltage u q0 are substituted into formula (18), and the calculation result is integrated to obtain the estimated value of the q-axis stator current Then, the q-axis stator current i q0 is subtracted from the estimated value of the q-axis stator current to obtain the second difference e iq0 .

[0121] The estimator estimates the rotational speed and rotor position in the current control period based on the first difference e id0 , the second difference e iq0 , as well as the d-axis extended current i′ d0 and the q-axis stator current i q0 , that is, the estimated value of the rotational speed of the motor in the current control period and the estimated value of the rotor position

[0122] Combined Figure 3 , according to some embodiments of the present application, the d-axis extended current i′ in the current control period d0 , the d-axis extended voltage u′ d0 , the q-axis stator current i q0 and the q-axis stator voltage u q0 are input into the first state observer to obtain the first difference e d0 between the d-axis extended current i′ and the estimated value of the d-axis extended current id0 , and the q-axis stator current i q0The second difference e between the estimated value of the q-axis stator current includes: based on the d-axis extended voltage u' of the current control period iq0 , and the estimated value of the d-axis extended current of the previous control period d0 The estimated rotational speed The estimated value of the q-axis stator current The first difference e between the estimated value of the d-axis extended current i' and the estimated value of the d-axis extended current d1 id1 and the q-axis stator current i q1 iq1 The second difference e between the estimated value of the q-axis stator current iq1 to estimate the estimated value of the d-axis extended current of the current control period and obtain the d-axis extended current i' of the current control period d0 The first difference e between the estimated value of the d-axis extended current i' and the estimated value of the d-axis extended current id0 q0 Based on the q-axis stator voltage u of the current control period, and the estimated value of the q-axis stator current of the previous control period The estimated rotational speed The estimated value of the d-axis extended current The first difference e between the estimated value of the d-axis extended current i' d1 and the estimated value of the d-axis extended current id1 and the q-axis stator current i q1 iq1 The second difference e between the estimated value of the q-axis stator current iq1 q0 to estimate the estimated value of the q-axis stator current of the current control period and obtain the q-axis stator current i of the current control period q0 The second difference e between the estimated value of the q-axis stator current iq0 iq0 .

[0123] To ensure the tracking effect of the control system, this embodiment combines the parameters of the previous control period to estimate the estimated value of the d-axis extended current of this period and the estimated value of the q-axis stator current so as to determine the deviation amount within the current control period. And based on this deviation amount, the deviation compensation is determined, and finally the closed-loop state equation is obtained.

[0124] According to some embodiments of the present application, the first state observer estimates the estimated value of the d-axis extended current of the current control period in the following manner and the estimated value of the q-axis stator current

[0125]

[0126]

[0127] Among them, is the estimated value of the d-axis extended current in the current control period, is the estimated value of the q-axis stator current in the current control period, L d is the d-axis inductance, L q is the q-axis inductance, u′ d0 is the d-axis extended voltage in the current control period, u q0 is the q-axis stator voltage in the current control period, R s is the stator resistance of the motor, is the estimated value of the d-axis extended current in the previous control period, is the estimated value of the q-axis stator current in the previous control period, is the estimated value of the rotational speed in the previous control period, ρ = L q / L d , g1 is the first gain coefficient, g2 is the second gain coefficient, e id1 is the d-axis extended current i′ in the previous control period d1 and the first difference between the estimated value of the d-axis extended current , e iq1 is the q-axis stator current i in the previous control period q1 and the second difference between the estimated value of the q-axis stator current .

[0128] Specifically, in the process of estimating the rotational speed of the permanent magnet synchronous motor, first determine the d-axis stator current i d0 , d-axis stator voltage u d0 , q-axis stator current i q0 and q-axis stator voltage u q0 in the current control period, and then reconstruct the d-axis stator current i d0 and d-axis stator voltage u d0 in the current control period to obtain the d-axis extended current i′ d0 and d-axis extended voltage u′ d0 in the current control period. Input the d-axis extended current i′ d0 , d-axis extended voltage u′ d0 , q-axis stator current i q0 and q-axis stator voltage u q0 in the current control period into the first adaptive observer, and then combine the parameters of the previous control period and substitute them into formula (19) and formula (20) to calculate and obtain the estimated value of the d-axis extended current Estimated value of q-axis stator current in the current control period And further calculate the first difference e in this control period id0 and the second difference e iq0 Furthermore, based on the first difference e id0 and the second difference e iq0 in the current control period, the d-axis extended current i′ d0 and the q-axis stator current i q0 calculate the estimated value of the motor speed in the current control period and the estimated value of the rotor position

[0129] According to some embodiments of the present application, the second adaptive observer includes a second state observer and an estimator. Input the d-axis extended current i′ d0 , the d-axis extended voltage u′ d0 , the q-axis stator current i q0 and the q-axis extended voltage u′ q0 in the current control period into the second adaptive observer to obtain the estimated value of the motor speed and the estimated value of the rotor position including: Input the d-axis extended current i′ d0 , the d-axis extended voltage u′ d0 , the q-axis stator current i q0 and the q-axis extended voltage u′ q0 in the current control period into the second state observer to obtain the first difference e d0 between the d-axis extended current i′ in the current control period and the estimated value of the d-axis extended current id0 , and the second difference e q0 between the q-axis stator current i in the current control period and the estimated value of the q-axis stator current iq0 ; Input the first difference e d0 between the d-axis extended current i′ in the current control period and the estimated value of the d-axis extended current id0 , the second difference e q0 between the q-axis stator current i in the current control period and the estimated value of the q-axis stator current iq0 , the d-axis extended current i′ d0 and the q-axis stator current i q0 in the current control period into the estimator to obtain the estimated value of the motor speed and the estimated value of the rotor position

[0130] That is to say, the second state observer is based on the d-axis extended current i′ d0, d-axis extended voltage u′ d0 , q-axis stator current i q0 and q-axis extended voltage u′ q0 , first estimate the d-axis stator current of the current control period to determine the estimated value of the d-axis extended current of the current control period and estimate the q-axis stator current of the current control period to determine the estimated value of the q-axis stator current Then, the d-axis extended current i′ of the current control period d0 is subtracted from the estimated value of the d-axis extended current to obtain the first difference e id0 , subtract the q-axis stator current i q0 from the estimated value of the q-axis stator current to obtain the second difference e iq0 , the first difference e between the d-axis extended current i′ d0 and the estimated value of the d-axis extended current , the second difference e between the q-axis stator current i id0 and the estimated value of the q-axis stator current q0 is the deviation of the current control period. The estimator estimates the rotational speed and rotor position of the current control period based on the deviation of the current control period, as well as the d-axis extended current i′ and the q-axis stator current i iq0 , that is, the estimated value of the rotational speed of the motor in the current control period d0 and the estimated value of the rotor position q0 are obtained and the estimated value of the rotor position

[0131] Furthermore, according to formula (6), it can be transformed to obtain:

[0132] u q = L q u′ q (21)

[0133] Substitute formula (21) and formula (8) into formula (14) to obtain:

[0134]

[0135] Perform formula transformation on formula (22):

[0136]

[0137]

[0138]

[0139] Thus, the two-order state equation formulas (13) and (25) in the synchronous rotating coordinate system are obtained from the voltage equation of the permanent magnet synchronous motor in this embodiment.

[0140] In the application process, the d-axis extended current i′ of the current control period d0 , the d-axis extended voltage u′ d0 , and the q-axis stator current i q0 are input into formula (13), and the calculation result is integrated to obtain the estimated value of the d-axis extended current of the current control period Then, the d-axis extended current i′ d0 and the estimated value of the d-axis extended current are subtracted to obtain the first difference e of the current control period id0 .

[0141] At the same time, the d-axis extended current i′ of the current control period d0 , the q-axis stator current i q0 and the q-axis extended voltage u′ q0 are substituted into formula (25), and the calculation result is integrated to obtain the estimated value of the q-axis stator current Then, the q-axis stator current i q0 and the estimated value of the q-axis stator current are subtracted to obtain the second difference e iq0 .

[0142] The estimator estimates the rotational speed and rotor position of the current control period according to the first difference e id0 , the second difference e iq0 , as well as the d-axis extended current i′ d0 and the q-axis stator current i q0 , that is, the estimated value of the rotational speed of the motor in the current control period and the estimated value of the rotor position

[0143] According to some embodiments of the present application, the d-axis extended current i′ of the current control period d0 , the d-axis extended voltage u′ d0 , the q-axis stator current i q0 and the q-axis extended voltage u′ q0 are input into the second state observer to obtain the first difference e d0 between the d-axis extended current i′ of the current control period and the estimated value of the d-axis extended current , and the second difference e id0 between the q-axis stator current i q0 and the estimated value of the q-axis stator current , including: based on the d-axis extended voltage u′ of the current control period iq0 d0 ​, and the estimated value of the d-axis extended current in the previous control period Estimated rotational speed Estimated value of the q-axis stator current d-axis extended current i′ d1 And the estimated value of the d-axis extended current The first difference e between them id1 And the q-axis stator current i q1 And the estimated value of the q-axis stator current The second difference e between them iq1 , estimate the estimated value of the d-axis extended current in the current control period And obtain the d-axis extended current i′ in the current control period d0 And the estimated value of the d-axis extended current The first difference e between them id0 . Based on the q-axis extended voltage u′ in the current control period q0 , and the estimated value of the q-axis stator current in the previous control period Estimated rotational speed Estimated value of the d-axis extended current d-axis extended current i′ d1 And the estimated value of the d-axis extended current The first difference e between them id1 And the q-axis stator current i q1 And the estimated value of the q-axis stator current The second difference e between them iq1 , estimate the estimated value of the q-axis stator current in the current control period And obtain the q-axis stator current i in the current control period q0 And the estimated value of the q-axis stator current The second difference e between them iq0 .

[0144] To ensure the tracking effect of the control system, this embodiment combines the parameters of the previous control period to estimate the estimated value of the d-axis extended current in this period And the estimated value of the q-axis stator current Thereby determining the deviation amount in this control period, and based on this deviation amount, determining the deviation compensation, and finally obtaining the closed-loop state equation.

[0145] According to some embodiments of the present application, the second state observer estimates the estimated value of the d-axis extended current in the current control period in the following manner And the estimated value of the q-axis stator current

[0146]

[0147] Wherein, is the estimated d-axis extended current for the current control period, is the estimated q-axis stator current for the current control period, L d is the d-axis inductance, L q is the q-axis inductance, u′ d0 is the d-axis extended voltage for the current control period, u′ q0 is the q-axis extended voltage for the current control period, R s is the stator resistance of the motor, is the estimated d-axis extended current for the previous control period, is the estimated q-axis stator current for the previous control period, is the estimated rotational speed for the previous control period, ρ = L q / L d , g1 is the first gain coefficient, g2 is the second gain coefficient, e id1 is the d-axis extended current i′ for the previous control period d1 and the estimated d-axis extended current The first difference between them, e iq1 is the q-axis stator current i for the previous control period q1 and the estimated q-axis stator current The second difference between them.

[0148] In this embodiment, during the process of estimating the rotational speed of the permanent magnet synchronous motor, first obtain the d-axis stator current i of the current control period d0 , d-axis stator voltage u d0 , q-axis stator current i q0 and q-axis stator voltage u q0 , then reconstruct the d-axis stator current i of the current control period d0 and d-axis stator voltage u d0 to obtain the d-axis extended current i′ of the current control period d0 and d-axis extended voltage u′ d0 , and reconstruct the q-axis stator voltage u of the current control period q0 to obtain the q-axis extended voltage u′ of the current control period q0 , input the d-axis extended current i′ of the current control period d0 , d-axis extended voltage u′ d0 , q-axis stator current i q0 and q-axis stator voltage u q0 into the second adaptive observer, and then combine the parameters of the previous control period, substitute them into formula (26) and formula (27) to calculate the estimated d-axis extended current for the current control period The estimated q-axis stator current for the current control period And further calculate the d-axis extended current i' of the current control period d0 and the estimated value of the d-axis extended current to obtain the first difference e id0 between the q-axis stator current i q0 and the estimated value of the q-axis stator current to obtain the second difference e iq0 Furthermore, according to the d-axis extended current i' of the current control period d0 and the estimated value of the d-axis extended current to obtain the first difference e id0 between the q-axis stator current i q0 and the estimated value of the q-axis stator current to obtain the second difference e iq0 Based on the d-axis extended current i' d0 and the q-axis stator current i q0 calculate the estimated value of the motor speed and the estimated value of the rotor position in the current control period and the estimated value of the rotor position

[0149] According to some embodiments of the present application, the d-axis extended current i' of the current control period d0 and the estimated value of the d-axis extended current to obtain the first difference e id0 between the q-axis stator current i q0 and the estimated value of the q-axis stator current to obtain the second difference e iq0 Based on the d-axis extended current i' d0 and the q-axis stator current i q0 input to the estimator to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period and the estimated value of the rotor position Including: the product of the second difference e d0 between the d-axis extended current i' of the current control period and the q-axis stator current i q0 and the estimated value of the q-axis stator current and the product of the q-axis stator current i of the current control period iq0 and the first difference e q0 between the d-axis extended current i' and the estimated value of the d-axis extended current d0 to obtain the estimated value of the speed in the current control period id0 Integrate the difference between the products to obtain the estimated value of the speed in the current control period Integrate the estimated value of the speed in the current control period to obtain the change in the rotor position in the current control period, and obtain the change in the rotor position in the current control period and the estimated value θ0 of the rotor position of the motor in the previous control period to obtain the estimated value of the rotor position in the current control period​

[0150] Specifically, a function formula is determined based on the Lyapunov stability theorem:

[0151]

[0152] Among them, ρ = L q / L d .

[0153] According to the Lyapunov stability theorem, when , the system is globally asymptotically stable, and the adaptive law for estimating the rotational speed is obtained:

[0154]

[0155] Or

[0156]

[0157] For example, can be expanded. When , if is satisfied, then the adaptive law for estimating the rotational speed is determined as formula (29).

[0158] When the adaptive law for estimating the rotational speed adopts formula (29), the calculated formula for the rotational speed estimate value of the current control period is:

[0159]

[0160] Among them, is the rotational speed estimate value of the current control period, i′ d0 is the d-axis extended current of the current control period, e iq0 is the q-axis stator current i q0 of the current control period and the second difference between the q-axis stator current estimated value , i q0 is the q-axis stator current of the current control period, e id0 is the first difference between the d-axis extended current i′ d0 of the current control period and the d-axis extended current estimated value .

[0161] The calculated formula for the rotor position estimated value is:

[0162]

[0163] Among them, is the rotor position estimated value of the current period, is the estimated rotational speed value for the current control period, and θ0 is the estimated rotor position value for the previous control period.

[0164] In this embodiment, a second-order state equation is applied to estimate the rotational speed value of the permanent magnet synchronous motor for the current control period. And further from the estimated rotational speed value the estimated rotor position value is calculated.

[0165] Further, this embodiment takes into account the factor that the d-axis inductance and q-axis inductance of the salient pole permanent magnet synchronous motor are not equal, and selects variables for constructing the Lyapunov function, that is, based on the first difference e id0 and the second difference e iq0 to consider the unequal situation of the d-axis and q-axis of the salient pole permanent magnet synchronous motor, thus meeting the applications of the salient pole permanent magnet synchronous motor and the non-salient pole permanent magnet synchronous motor. At the same time, the rotational speed estimation method disclosed in this application reduces the order of the state equation, making its programming implementation simple and greatly reducing the amount of computation.

[0166] Corresponding to the above embodiment, the present application also proposes a computer-readable storage medium.

[0167] The computer-readable storage medium of the embodiment of the present application stores a program thereon, and when the program is executed by a processor, it implements the above-mentioned rotational speed estimation method for a sensorless permanent magnet synchronous motor.

[0168] Corresponding to the above embodiment, the present application also proposes a rotational speed estimation system for a sensorless permanent magnet synchronous motor.

[0169] Referring to Figure 4 , the rotational speed estimation system 100 of the sensorless permanent magnet synchronous motor of the present application includes: a memory 110, a processor 120, and a program stored on the memory 110 and executable on the processor 120. When the processor 120 executes the program, it implements the above-mentioned rotational speed estimation method for a sensorless permanent magnet synchronous motor.

[0170] Corresponding to the above embodiment, the present application also proposes a rotational speed estimation device for a sensorless permanent magnet synchronous motor.

[0171] Referring to Figure 5, the speed estimation device 200 of the sensorless permanent magnet synchronous motor of the present application includes: an acquisition module 210, an expansion module 220, and an adaptive observer 230. Among them, the acquisition module 210 is used to acquire the d-axis stator current and d-axis stator voltage of the motor in the current control cycle. The expansion module 220 is used to reconstruct the d-axis stator current and d-axis stator voltage in the current control cycle based on the rotor magnetic flux of the motor in the current control cycle and the d-axis inductance of the motor, so as to obtain the d-axis extended current and d-axis extended voltage in the current control cycle. The adaptive observer 230 is used to estimate the speed estimation value and rotor position estimation value of the motor in the current control cycle based on the d-axis extended current and d-axis extended voltage in the current control cycle; among them, the adaptive observer 230 is determined based on the voltage equation of the motor, and the voltage equation includes the d-axis inductance and q-axis inductance of the motor.

[0172] Corresponding to the above embodiments, the present application also proposes an electrical device.

[0173] Referring to Figure 6 , the electrical device 1000 of the present application includes the above-mentioned speed estimation system 100 of the sensorless permanent magnet synchronous motor, or, as Figure 7 shown, the electrical device 1000 of the present application includes the speed estimation device 200 of the sensorless permanent magnet synchronous motor.

[0174] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered by the scope of the claims and the description of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for estimating the speed of a sensorless permanent magnet synchronous motor, characterized in that, The method includes: Obtaining the d-axis stator current and d-axis stator voltage of the motor in the current control period; Reconstructing the d-axis stator current and d-axis stator voltage of the current control period based on the rotor magnetic flux of the motor in the current control period and the d-axis inductance of the motor to obtain the d-axis extended current and d-axis extended voltage of the current control period; Inputting the d-axis extended current and d-axis extended voltage of the current control period into an adaptive observer to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period; wherein, the adaptive observer is determined based on the voltage equation of the motor, and the voltage equation includes the d-axis inductance and q-axis inductance of the motor.

2. The method according to claim 1, characterized in that, The reconstructing the d-axis stator current and d-axis stator voltage of the current control period based on the rotor magnetic flux of the motor in the current control period and the d-axis inductance of the motor to obtain the d-axis extended current and d-axis extended voltage of the current control period includes: Obtaining the sum of the d-axis equivalent current generated by the rotor magnetic flux on the d-axis inductance and the d-axis stator current of the current control period to obtain the d-axis extended current of the current control period; Obtaining the sum of the d-axis equivalent voltage generated by the d-axis equivalent current on the stator resistance of the motor and the d-axis stator voltage of the current control period to obtain the d-axis extended voltage of the current control period.

3. The method according to claim 2, wherein The adaptive observer includes a first adaptive observer, and the method further includes: Obtaining the q-axis stator current and q-axis stator voltage of the motor in the current control period; Inputting the d-axis extended current, d-axis extended voltage, q-axis stator current and q-axis stator voltage of the current control period into the first adaptive observer to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period.

4. The method according to claim 1, wherein The reconstructing the d-axis stator current and d-axis stator voltage of the current control period based on the rotor magnetic flux of the motor in the current control period and the d-axis inductance of the motor to obtain the d-axis extended current and d-axis extended voltage of the current control period includes: Obtaining the sum of the d-axis equivalent current generated by the rotor magnetic flux on the d-axis inductance and the d-axis stator current of the current control period to obtain the d-axis extended current of the current control period; Obtaining the d-axis equivalent voltage generated by the d-axis equivalent current on the stator resistance of the motor, and obtaining the ratio of the sum of the d-axis equivalent voltage and the d-axis stator voltage of the current control period to the d-axis inductance to obtain the d-axis extended voltage of the current control period.

5. The method according to claim 4, wherein The adaptive observer includes a second adaptive observer, and the method further includes: Obtaining the q-axis stator current and q-axis stator voltage of the motor in the current control period; Reconstructing the q-axis stator voltage of the current control period based on the q-axis inductance to obtain the q-axis extended voltage of the current control period; Inputting the d-axis extended current, d-axis extended voltage, q-axis stator current and q-axis extended voltage of the current control period into the second adaptive observer to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period.

6. The method according to claim 5, wherein Reconstructing the q-axis stator voltage of the current control period based on the q-axis inductance to obtain the q-axis extended voltage of the current control period includes: Obtaining the ratio of the q-axis stator voltage of the current control period to the q-axis inductance to obtain the q-axis extended voltage of the current control period.

7. The method according to claim 3, wherein The first adaptive observer includes a first state observer and an estimator. Inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis stator voltage of the current control period into the first adaptive observer to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period includes: Inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis stator voltage of the current control period into the first state observer to obtain a first difference between the d-axis extended current and the estimated value of the d-axis extended current, and a second difference between the q-axis stator current and the estimated value of the q-axis stator current in the current control period; Inputting the first difference between the d-axis extended current and the estimated value of the d-axis extended current, the second difference between the q-axis stator current and the estimated value of the q-axis stator current, the d-axis extended current, and the q-axis stator current in the current control period into the estimator to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period.

8. The method according to claim 7, wherein Inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis stator voltage of the current control period into the first state observer to obtain a first difference between the d-axis extended current and the estimated value of the d-axis extended current, and a second difference between the q-axis stator current and the estimated value of the q-axis stator current in the current control period includes: Based on the d-axis extended voltage of the current control period, and the estimated value of the d-axis extended current, the estimated value of the speed, the estimated value of the q-axis stator current, the first difference between the d-axis extended current and the estimated value of the d-axis extended current, and the second difference between the q-axis stator current and the estimated value of the q-axis stator current in the previous control period, estimating the estimated value of the d-axis extended current in the current control period, and obtaining the first difference between the d-axis extended current and the estimated value of the d-axis extended current in the current control period; Based on the q-axis stator voltage of the current control period, and the estimated value of the q-axis stator current, the estimated value of the speed, the estimated value of the d-axis extended current, the first difference between the d-axis extended current and the estimated value of the d-axis extended current, and the second difference between the q-axis stator current and the estimated value of the q-axis stator current in the previous control period, estimating the estimated value of the q-axis stator current in the current control period, and obtaining the second difference between the q-axis stator current and the estimated value of the q-axis stator current in the current control period.

9. The method according to claim 8, wherein The first state observer estimates the estimated value of the d-axis extended current and the estimated value of the q-axis stator current in the current control period by the following method: Among them, is the estimated d-axis extended current value of the current control period, is the estimated q-axis stator current value of the current control period, L d is the d-axis inductance, L q is the q-axis inductance, u′ d0 is the d-axis extended voltage of the current control period, u q0 is the q-axis stator voltage of the current control period, R s is the stator resistance of the motor, is the estimated d-axis extended current value of the previous control period, is the estimated q-axis stator current value of the previous control period, is the estimated rotational speed value of the previous control period, ρ = L q / L d , g1 is the first gain coefficient, g2 is the second gain coefficient, e id1 is the first difference between the d-axis extended current and the estimated d-axis extended current value of the previous control period, e iq1 is the second difference between the q-axis stator current and the estimated q-axis stator current value of the previous control period.

10. The method according to claim 5, wherein The second adaptive observer includes a second state observer and an estimator. Inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis extended voltage of the current control period into the second adaptive observer to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period includes: Inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis extended voltage of the current control period into the second state observer to obtain a first difference between the d-axis extended current and the estimated value of the d-axis extended current, and a second difference between the q-axis stator current and the estimated value of the q-axis stator current in the current control period; Inputting the first difference between the d-axis extended current and the estimated value of the d-axis extended current, the second difference between the q-axis stator current and the estimated value of the q-axis stator current, the d-axis extended current, and the q-axis stator current of the current control period into the estimator to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period.

11. The method according to claim 10, characterized in that, The inputting the d-axis extended current, d-axis extended voltage, q-axis stator current, and q-axis extended voltage of the current control period into the second state observer to obtain a first difference between the d-axis extended current and the estimated value of the d-axis extended current, and a second difference between the q-axis stator current and the estimated value of the q-axis stator current in the current control period includes: Based on the d-axis extended voltage of the current control period, and the estimated value of the d-axis extended current, the estimated value of the speed, the estimated value of the q-axis stator current, the first difference between the d-axis extended current and the estimated value of the d-axis extended current, and the second difference between the q-axis stator current and the estimated value of the q-axis stator current of the previous control period, estimating the estimated value of the d-axis extended current of the current control period, and obtaining the first difference between the d-axis extended current and the estimated value of the d-axis extended current of the current control period; Based on the q-axis extended voltage of the current control period, and the estimated value of the q-axis stator current, the estimated value of the speed, the estimated value of the d-axis extended current, the first difference between the d-axis extended current and the estimated value of the d-axis extended current, and the second difference between the q-axis stator current and the estimated value of the q-axis stator current of the previous control period, estimating the estimated value of the q-axis stator current of the current control period, and obtaining the second difference between the q-axis stator current and the estimated value of the q-axis stator current of the current control period.

12. The method according to claim 11, wherein The second state observer estimates the estimated value of the d-axis extended current and the estimated value of the q-axis stator current of the current control period in the following manner: Wherein, is the estimated value of the d-axis extended current in the current control period, is the estimated value of the q-axis stator current in the current control period, L d is the d-axis inductance, L q is the q-axis inductance, u′ d0 is the d-axis extended voltage in the current control period, u′ q0 is the q-axis extended voltage in the current control period, R s is the stator resistance of the motor, is the estimated value of the d-axis extended current in the previous control period, is the estimated value of the q-axis stator current in the previous control period, is the estimated value of the rotational speed in the previous control period, ρ = L q / L d , g1 is the first gain coefficient, g2 is the second gain coefficient, e id1 is the first difference between the d-axis extended current and the estimated value of the d-axis extended current in the previous control period, e iq1 is the second difference between the q-axis stator current and the estimated value of the q-axis stator current in the previous control period.

13. The method according to claim 7 or 10, characterized in that, The inputting the first difference between the d-axis extended current and the estimated value of the d-axis extended current, the second difference between the q-axis stator current and the estimated value of the q-axis stator current, the d-axis extended current, and the q-axis stator current of the current control period into the estimator to obtain the estimated value of the motor speed and the estimated value of the rotor position in the current control period includes: Integrate the difference between the product of the d-axis extended current and the second difference between the q-axis stator current and the estimated value of the q-axis stator current in the current control period and the product of the q-axis stator current and the first difference between the d-axis extended current and the estimated value of the d-axis extended current in the current control period to obtain the estimated value of the rotational speed in the current control period; Integrate the estimated value of the rotational speed in the current control period to obtain the change in rotor position in the current control period, and obtain the estimated value of the rotor position in the current control period by acquiring the change in rotor position in the current control period and the estimated value of the rotor position of the motor in the previous control period.

14. A computer-readable storage medium, characterized in that, A program is stored thereon, and when the program is executed by a processor, the method according to any one of claims 1-13 is implemented.

15. A speed estimation system for a sensorless permanent magnet synchronous motor, characterized in that, Comprising: A memory, a processor, and a program stored on the memory and executable on the processor, and when the processor executes the program, the method according to any one of claims 1-13 is implemented.

16. A speed estimation device for a sensorless permanent magnet synchronous motor, characterized in that, The device comprises: An acquisition module, configured to acquire the d-axis stator current and the d-axis stator voltage of the motor in the current control period; An extension module, configured to reconstruct the d-axis stator current and the d-axis stator voltage in the current control period based on the rotor flux linkage of the motor in the current control period and the d-axis inductance of the motor to obtain the d-axis extended current and the d-axis extended voltage in the current control period; An adaptive observer, configured to estimate the estimated value of the rotational speed and the estimated value of the rotor position of the motor in the current control period based on the d-axis extended current and the d-axis extended voltage in the current control period; wherein, the adaptive observer is determined based on the voltage equation of the motor, and the voltage equation includes the d-axis inductance and the q-axis inductance of the motor.

17. An electrical device, characterized in that, Comprising the rotational speed estimation system of the sensorless permanent magnet synchronous motor according to claim 15, or the rotational speed estimation device of the sensorless permanent magnet synchronous motor according to claim 16.

Images