Phase-locked loop design method and device, equipment, storage medium and program product

Abstract

The invention relates to the technical field of power electronics, in particular to a phase-locked loop design method, device and equipment, a storage medium and a program product, and the method comprises the steps: constructing an equivalent model of a synchronous motor under a dq coordinate system; based on the equivalent model, resistance voltage drop and inductance voltage drop of the synchronous motor under the dq coordinate system are obtained; obtaining an error speed of the synchronous motor based on the resistance voltage drop and the inductance voltage drop; calculating an estimated rotating speed of the synchronous motor based on the obtained d-axis magnetic flux and q-axis voltage equation of the dq coordinate system; calculating a difference value between the estimated rotating speed and the error speed, and deriving the difference value to determine a real observation angle; and performing phase tracking on the synchronous motor based on the real observation angle. By estimating the rotating speed and the error speed, the real observation angle is calculated, so that the phase-locked loop has the advantages of being good in dynamic performance, high in stability, wide in application range and the like, and can be suitable for a synchronous motor outputting variable frequency.

Description

Technical Field

[0001] The present disclosure relates to the field of power electronics technology, and in particular, to a phase-locked loop design method, device, equipment, storage medium, and program product. Background Art

[0002] Synchronous motors have the advantages of small electromagnetic torque ripple coefficient, high torque inertia ratio, high energy density, fast dynamic response, and strong overload capacity, and have been increasingly widely used in fields such as aerospace, electric vehicles, and industrial control in recent years. The most common control method for synchronous motors is space vector control, and the core of space vector control lies in phase tracking. Therefore, traditional technologies usually use a phase-locked loop to achieve phase tracking. A phase-locked loop is a feedback control circuit that can use an externally input reference signal to control the frequency and phase of the internal oscillation signal in the loop, so as to stabilize and control the frequency, phase, and timing of the signal to meet various communication, data transmission, and signal processing requirements, and ensure the normal operation of the synchronous motor system.

[0003] Since the voltage frequency output by the synchronous motor is related to the rotational speed, the voltage and frequency in the synchronous motor system often change. When the excitation and rotational speed of the synchronous motor change, the frequency and amplitude of the generated electric energy also change. However, traditional phase-locked loops often use the expected frequency as compensation for loop control, which has limitations such as narrow bandwidth and low frequency band, and has disadvantages such as poor compatibility and inability to frequency conversion. Each time it is used, the parameters of the phase-locked loop need to be redesigned according to the actual situation of the synchronous motor, which seriously affects the progress of production and research and development. Summary of the Invention

[0004] In view of the above problems, the present disclosure is proposed. The present disclosure provides a phase-locked loop design method, device, equipment, storage medium, and program product.

[0005] According to one aspect of the present disclosure, a phase-locked loop design method is provided, including:

[0006] Construct an equivalent model of a synchronous motor in the dq coordinate system;

[0007] Based on the equivalent model, obtain the resistance voltage drop and inductance voltage drop of the synchronous motor in the dq coordinate system;

[0008] Based on the resistance voltage drop and the inductance voltage drop, obtain the error speed of the synchronous motor;

[0009] Based on the obtained d-axis magnetic flux and q-axis voltage equation of the dq coordinate system, calculate the estimated rotational speed of the synchronous motor;

[0010] Calculate the difference between the estimated rotational speed and the error speed, take the derivative of the difference, and determine the true observation angle of the synchronous motor;

[0011] Based on the true observation angle, perform phase tracking on the synchronous motor.

[0012] In addition, a phase-locked loop design method according to an aspect of the present disclosure further includes: constructing an equivalent model of a synchronous motor in the dq coordinate system, including:

[0013] Determine the first electromagnetic torque equation of the synchronous motor in the three-phase stationary coordinate system;

[0014] Using the Clarke transformation, convert the three-phase stationary coordinate system into a two-phase stationary coordinate system, and based on the first electromagnetic torque equation, determine the second electromagnetic torque equation in the two-phase stationary coordinate system;

[0015] Using the Park transformation, convert the two-phase stationary coordinate system into the dq coordinate system, and based on the second electromagnetic torque equation, determine the third electromagnetic torque equation in the dq coordinate system;

[0016] Based on the third electromagnetic torque equation, construct an equivalent model of the synchronous motor in the dq coordinate system.

[0017] In addition, a phase-locked loop design method according to an aspect of the present disclosure further includes: the resistance voltage drop includes the d-axis resistance voltage drop and the q-axis resistance voltage drop, and the inductance voltage drop includes the d-axis inductance voltage drop and the q-axis inductance voltage drop;

[0018] Based on the resistance voltage drop and the inductance voltage drop, obtain the error speed of the synchronous motor, including:

[0019] Based on the resistance voltage drop and the inductance voltage drop, calculate the error voltage;

[0020] Based on the error voltage, use a proportional-integral controller to obtain the error speed of the synchronous motor.

[0021] In addition, a phase-locked loop design method according to an aspect of the present disclosure further includes: based on the obtained d-axis magnetic flux and q-axis voltage equation of the dq coordinate system, calculate the estimated speed of the synchronous motor, including:

[0022] Based on the q-axis voltage component, q-axis resistance voltage drop, and q-axis inductance voltage drop of the dq coordinate system, determine the q-axis voltage equation, and obtain the d-axis magnetic flux of the dq coordinate system;

[0023] Based on the ratio of the q-axis voltage equation to the d-axis magnetic flux, calculate the estimated speed of the synchronous motor.

[0024] In addition, a phase-locked loop design method according to an aspect of the present disclosure further includes: determining the first electromagnetic torque equation of the synchronous motor in the three-phase stationary coordinate system, including:

[0025] Based on the circuit reciprocity in the three-phase stationary coordinate system, determine the three-phase flux equations;

[0026] Based on the three-phase stator current equations in the three-phase stationary coordinate system, the three-phase flux equations, and the self-inductance and mutual-inductance coefficients of the winding coils, determine the three-phase flux linkage equations of the synchronous motor;

[0027] Based on the three-phase stator current equations and the three-phase flux linkage equations, determine the stator voltage equations of the synchronous motor in the three-phase stationary coordinate system;

[0028] Based on the stator voltage equations, determine the first electromagnetic torque equations of the synchronous motor in the three-phase stationary coordinate system.

[0029] In addition, according to the phase-locked loop design method of one aspect of the present disclosure, it further includes: Based on the first electromagnetic torque equations, determine the second electromagnetic torque equations in the two-phase stationary coordinate system, including:

[0030] Determine the flux linkage equations and voltage equations in the two-phase stationary coordinate system;

[0031] Based on the first electromagnetic torque equations, the flux linkage equations, and the voltage equations, determine the second electromagnetic torque equations in the two-phase stationary coordinate system;

[0032] Based on the second electromagnetic torque equations, determine the third electromagnetic torque equations in the dq coordinate system, including:

[0033] Based on the d-axis flux linkage and q-axis flux linkage of the dq coordinate system, determine the voltage equations in the dq coordinate system;

[0034] Based on the second electromagnetic torque equations and the voltage equations in the dq coordinate system, determine the third electromagnetic torque equations in the dq coordinate system.

[0035] According to another aspect of the present disclosure, there is provided a phase-locked loop design device, including:

[0036] A model construction module for constructing an equivalent model of the synchronous motor in the dq coordinate system;

[0037] A first acquisition module for acquiring the resistance voltage drop and inductance voltage drop of the synchronous motor in the dq coordinate system based on the equivalent model;

[0038] A second acquisition module for obtaining the error speed of the synchronous motor based on the resistance voltage drop and the inductance voltage drop;

[0039] A first calculation module for calculating the estimated speed of the synchronous motor based on the acquired d-axis magnetic flux and q-axis voltage equations of the dq coordinate system;

[0040] A second calculation module, configured to calculate a difference between the estimated rotational speed and the error speed, take a derivative of the difference, and determine a true observation angle of the synchronous motor;

[0041] A phase tracking module, configured to perform phase tracking on the synchronous motor based on the true observation angle.

[0042] According to another aspect of the present disclosure, there is provided a computer device, including a memory, a processor, and a computer program stored on the memory, where the processor executes the computer program to implement the method according to the above aspect.

[0043] According to another aspect of the present disclosure, there is provided a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the method according to the above aspect is implemented.

[0044] According to another aspect of the present disclosure, there is provided a computer program product, including a computer program, and when the computer program is executed by a processor, the method according to the above aspect is implemented.

[0045] As will be described in detail below, a phase-locked loop design method, apparatus, device, storage medium, and program product according to an embodiment of the present disclosure, by constructing a dq coordinate system, the d-axis of the dq coordinate system is in the same direction as the fundamental magnetic field direction of the rotor flux linkage, the q-axis is in the direction 90° ahead of the d-axis, the excitation current is usually used to control the magnetic field strength of the motor, and the torque current is used to control the output torque of the motor. By independently controlling these two current components, precise control of the synchronous motor can be achieved, and decoupling is realized. By estimating the rotational speed and the error speed, the true observation angle is calculated, so that the phase-locked loop of the present disclosure has advantages such as good dynamic performance, high stability, and wide adaptability, and can be applied to synchronous motors with variable output frequencies.

[0046] It should be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the claimed technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] By describing the embodiments of the present disclosure in more detail in conjunction with the accompanying drawings, the above and other objects, features, and advantages of the present disclosure will become more apparent. The drawings are used to provide further understanding of the embodiments of the present disclosure, and constitute a part of the specification, and are used to explain the present disclosure together with the embodiments of the present disclosure, and do not constitute a limitation to the present disclosure. In the drawings, the same reference numerals generally represent the same components or steps.

[0048] Figure 1 is a flowchart illustrating the application of the phase-locked loop design method according to an embodiment of the present disclosure.

[0049] Figure 2It is another flowchart showing the phase-locked loop design method according to an embodiment of the present disclosure.

[0050] Figure 3 It is a schematic diagram showing the synchronous motor system model according to an embodiment of the present disclosure.

[0051] Figure 4 It is a schematic diagram showing the αβ-axis decomposition system of the synchronous motor system according to an embodiment of the present disclosure.

[0052] Figure 5 It is a schematic diagram showing the dq-axis decomposition system of the synchronous motor system according to an embodiment of the present disclosure.

[0053] Figure 6 It is a schematic diagram showing the system of the equivalent model in the dq coordinate system according to an embodiment of the present disclosure.

[0054] Figure 7 It is a schematic diagram showing the phase waveform under the 50Hz working condition according to an embodiment of the present disclosure.

[0055] Figure 8 It is a schematic diagram showing the phase waveform under the 100Hz working condition according to an embodiment of the present disclosure.

[0056] Figure 9 It is a schematic diagram showing the phase waveform under the 200Hz working condition according to an embodiment of the present disclosure.

[0057] Figure 10 It is a schematic diagram showing the structure of the phase-locked loop design device according to an embodiment of the present disclosure.

[0058] Figure 11 It is a schematic diagram showing the structure of the computer device according to an embodiment of the present disclosure.

[0059] Figure 12 It is a schematic diagram showing the computer program product according to an embodiment of the present disclosure. Detailed implementation manners

[0060] In order to make the objectives, technical solutions, and advantages of the present disclosure more apparent, exemplary embodiments according to the present disclosure will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments of the present disclosure. It should be understood that the present disclosure is not limited by the exemplary embodiments described herein.

[0061] Synchronous motors have the advantages of small electromagnetic torque ripple coefficient, high torque inertia ratio, high energy density, fast dynamic response, and strong overload capacity. In recent years, they have been increasingly widely used in fields such as aerospace, electric vehicles, and industrial control. The most common control method for synchronous motors is space vector control, and the core of space vector control lies in phase tracking. Therefore, traditional technologies usually use a phase-locked loop to achieve phase tracking. A phase-locked loop is a feedback control circuit that can use an externally input reference signal to control the frequency and phase of the internal oscillation signal of the loop, to stabilize and control the frequency, phase, and timing of the signal, to meet various communication, data transmission, and signal processing requirements, and to ensure the normal operation of the synchronous motor system.

[0062] Since the voltage frequency output by a synchronous motor is related to the rotational speed, the voltage and frequency in the synchronous motor system often change. When the excitation and rotational speed of the synchronous motor change, the frequency and amplitude of the generated electrical energy also change. However, traditional phase-locked loops often use the expected frequency as compensation for loop control, which has limitations such as narrow bandwidth and low frequency band, and has the disadvantages of poor compatibility and inability to vary the frequency. Each time it is used, the parameters of the phase-locked loop need to be redesigned according to the actual situation of the synchronous motor, which seriously affects the progress of production and research and development.

[0063] As described above, a phase-locked loop design method, device, equipment, storage medium, and program product according to an embodiment of the present disclosure are described with reference to the accompanying drawings. By constructing a dq coordinate system, the d-axis of the dq coordinate system is in the same direction as the fundamental magnetic field direction of the rotor magnetic flux, and the q-axis is in the direction 90° ahead of the d-axis. The excitation current is usually used to control the magnetic field strength of the motor, and the torque current is used to control the output torque of the motor. By independently controlling these two current components, precise control of the synchronous motor can be achieved, and decoupling is realized. By estimating the rotational speed and the error speed, the true observed angle is calculated, so that the phase-locked loop of the present disclosure has the advantages of good dynamic performance, high stability, and wide adaptability, and can be applied to synchronous motors with variable output frequencies.

[0064] For ease of understanding of this embodiment, first, a phase-locked loop design method disclosed in an embodiment of the present disclosure is introduced in detail. The execution subject of the phase-locked loop design method provided in the embodiment of the present disclosure is generally a computer device with certain computing capabilities. Such a computer device includes, for example: a terminal device, a server, or other processing devices. The terminal device can be a user equipment (UE), a mobile device, a user terminal, a terminal, a cellular phone, a cordless phone, a personal digital assistant (PDA), a handheld device, a computing device, a vehicle-mounted device, a wearable device, etc. In some possible implementation manners, the phase-locked loop design method can be implemented by a processor invoking computer-readable instructions stored in a memory.

[0065] As shown in Figure 1 the flowchart of the phase-locked loop design method provided by the present disclosure embodiment, the method includes S101-S106:

[0066] S101: Construct an equivalent model of a synchronous motor in the dq coordinate system.

[0067] Among them, the rotation angular velocity of the dq coordinate system is the same as the rotor angular velocity. Therefore, the d-axis is in the same direction as the fundamental magnetic field direction of the rotor magnetic flux, and the q-axis is in the direction 90° ahead of the d-axis. In the dq coordinate system, the excitation current and torque current can be independently controlled to achieve decoupling. S101 specifically includes the following steps 1-4:

[0068] Step 1: Determine the first electromagnetic torque equation of the synchronous motor in the three-phase stationary coordinate system.

[0069] The three-phase stationary coordinate system includes the abc axes (i.e., the ABC three-phase winding coils), specifically including:

[0070] 1) Based on the circuit reciprocity of the three-phase stationary coordinate system, determine the three-phase flux equations. The three-phase flux equations are specifically as follows:

[0071]

[0072] Among them, ψ fa represents the flux component on the a-axis of the three-phase stationary coordinate system, ψ fb represents the flux component on the b-axis of the three-phase stationary coordinate system, ψ fc represents the flux component on the c-axis of the three-phase stationary coordinate system, ψ f represents the amplitude value of the rotor permanent magnet flux linkage, and its magnitude can be regarded as an invariant. θ is the electrical angle between the axis of the A-phase winding of the synchronous motor and the axis of the rotor fundamental magnetic flux.

[0073] 2) Based on the three-phase stator current equations, three-phase flux equations in the three-phase stationary coordinate system, and the self-inductance and mutual-inductance coefficients of the winding coils, determine the three-phase flux linkage equations of the synchronous motor;

[0074] The three-phase stator current equations are:

[0075]

[0076] Among them, i a represents the stator current on the a-axis of the three-phase stationary coordinate system, i b represents the stator current on the b-axis of the three-phase stationary coordinate system, i c represents the stator current on the c-axis of the three-phase stationary coordinate system, ω represents the rotation angular velocity of the three-phase stator current, t represents time, and ωt represents frequency.

[0077] The three-phase flux linkage equations are as follows:

[0078]

[0079] Among them, ψ a , ψ b , ψ c respectively represent the flux linkages generated by the magnetic field in the three-phase winding coils A, B, and C, L aa , L bb , L cc respectively represent the self-inductance coefficients of each winding coil, M ab , M ac , M ba , M bc , M ca , M cb respectively represent the mutual inductance coefficients between the ABC three-phase winding coils, i a , i b , i c respectively represent the three-phase stator currents, ψ fa , ψ fb , ψ fc respectively represent the three-phase magnetic fluxes.

[0080] 3) Based on the three-phase stator current equations and the three-phase flux linkage equations, determine the stator voltage equation of the synchronous motor in the three-phase stationary coordinate system.

[0081] The stator voltage equation is as follows:

[0082]

[0083] Among them, u a , u b , u c respectively represent the three-phase stator voltages, R represents the stator armature resistance, ψ f represents the amplitude value of the rotor permanent magnet flux linkage, the magnitude of which can be regarded as an invariant, ω e represents the magnetic flux rotation speed.

[0084] 4) Based on the stator voltage equation, determine the first electromagnetic torque equation of the synchronous motor in the three-phase stationary coordinate system.

[0085] The first electromagnetic torque equation is as follows:

[0086]

[0087] Among them, T e1 represents the first electromagnetic torque of the synchronous motor, P n represents the number of pole pairs of the synchronous motor.

[0088] Step 2: Use the Clark transformation to convert the three-phase stationary coordinate system into a two-phase stationary coordinate system, and determine the second electromagnetic torque equation in the two-phase stationary coordinate system based on the first electromagnetic torque equation.

[0089] Specifically, use the Clark transformation to convert the three-phase stationary coordinate system into a two-phase αβ stationary coordinate system. The Clark transformation formula is as follows:

[0090]

[0091] where f α and f β represent the α-axis and β-axis of the two-phase αβ stationary coordinate system respectively, and f a and f b and f c represent the a-axis, b-axis, and c-axis of the three-phase stationary coordinate system respectively.

[0092] where Step 2 specifically includes:

[0093] 1) Determine the flux linkage equation and voltage equation in the two-phase stationary coordinate system;

[0094] After the Clark transformation, the flux linkage equation of the synchronous motor in the two-phase αβ stationary coordinate system is:

[0095]

[0096] where ψ α and ψ β represent the stator flux linkage components on the α-axis and β-axis respectively, i α and i β represent the stator current components on the α-axis and β-axis respectively, L represents the inductance coefficient, and ψ f represents the amplitude value of the rotor permanent magnet flux linkage.

[0097] After the Clark transformation, the voltage equation of the synchronous motor is:

[0098]

[0099] where u α and u β represent the voltage components on the α-axis and β-axis respectively, ψ α and ψ β represent the stator flux linkage components on the α-axis and β-axis respectively, i α and i β represent the stator current components on the α-axis and β-axis respectively, and R represents the stator armature resistance.

[0100] 2) Determine the second electromagnetic torque equation in the two-phase stationary coordinate system based on the first electromagnetic torque equation, the flux linkage equation, and the voltage equation.

[0101] The second electromagnetic torque equation is:

[0102]

[0103] where, T e2 represents the second electromagnetic torque in the two-phase stationary coordinate system, and P n represents the number of pole pairs of the synchronous motor.

[0104] Step 3: Use Park transformation to convert the two-phase stationary coordinate system to the dq coordinate system, and determine the third electromagnetic torque equation in the dq coordinate system based on the second electromagnetic torque equation.

[0105] Among them, the rotational angular velocity of the dq coordinate system is the same as the rotor angular velocity. Therefore, the d-axis is in the same direction as the fundamental magnetic field direction of the rotor flux linkage, and the q-axis is in the direction 90° ahead of the d-axis. In the dq coordinate system, the field current and torque current can be independently controlled to achieve decoupling. The transformation formula of Park transformation is:

[0106]

[0107] where, f d , f q respectively represent the d-axis and q-axis of the dq coordinate system, and f α , f β respectively represent the α-axis and β-axis of the two-phase αβ stationary coordinate system.

[0108] Step 3 specifically includes:

[0109] 1) Determine the voltage equation in the dq coordinate system based on the d-axis flux linkage and q-axis flux linkage of the dq coordinate system, specifically as follows:

[0110]

[0111] where, u d , u q respectively represent the voltage components on the d-axis and q-axis, ψ d , ψ q respectively represent the stator flux linkage components on the d-axis and q-axis, L d , L q respectively represent the model equivalent inductances on the d-axis and q-axis, ψ f represents the amplitude value of the rotor permanent magnet flux linkage, and i d , i q respectively represent the current components on the d-axis and q-axis.

[0112] 2) Based on the second electromagnetic torque equation and the voltage equation in the dq coordinate system, determine the third electromagnetic torque equation in the dq coordinate system, which is specifically as follows:

[0113]

[0114] Where, T e3 represents the third electromagnetic torque, L d and L q represent the model equivalent inductances on the d-axis and q-axis respectively, i d and i q represent the current components on the d-axis and q-axis respectively, P n represents the number of pole pairs of the synchronous motor, and ψ f represents the amplitude value of the rotor permanent magnet flux linkage.

[0115] Step 4: Based on the third electromagnetic torque equation, construct an equivalent model of the synchronous motor in the dq coordinate system.

[0116] S102: Based on the equivalent model, obtain the resistance voltage drop and inductance voltage drop of the synchronous motor in the dq coordinate system.

[0117] Specifically, the resistance voltage drop includes the d-axis resistance voltage drop and the q-axis resistance voltage drop, and the inductance voltage drop includes the d-axis inductance voltage drop and the q-axis inductance voltage drop. The formulas are as follows:

[0118]

[0119] Where, u Ld and u Lq represent the inductance voltage drops of the winding coil on the d-axis and q-axis respectively, u Rd and u Rq represent the resistance voltage drops of the winding coil on the d-axis and q-axis respectively, L d and L q represent the model equivalent inductances on the d-axis and q-axis respectively, R d and R q represent the model equivalent resistances on the d-axis and q-axis respectively, i d and i q represent the current components on the d-axis and q-axis respectively.

[0120] S103: Based on the resistance voltage drop and inductance voltage drop, obtain the error speed of the synchronous motor.

[0121] Specifically, it includes: based on the resistance voltage drop and inductance voltage drop, calculate the error voltage:

[0122] u err = u d - u Rd - u Ld + ωL q iq

[0123] Among them, u err represents the error voltage, u d represents the voltage component of the winding coil on the d-axis, u Rd represents the resistance voltage drop of the winding coil on the d-axis, u Ld represents the inductance voltage drop of the winding coil on the d-axis, L q represents the model equivalent inductance on the q-axis, i q represents the current component on the q-axis.

[0124] Based on the error voltage, using a proportional-integral controller, the error speed of the synchronous motor is obtained, and the formula is as follows:

[0125] ω err = k p (sign(u q - u Eq - u Lq ))u err + k p k i ∫(sign(u q - u Rq - u Lq ))u err dt

[0126] Among them, ω err represents the error speed of the synchronous motor, k p represents the proportional coefficient of the proportional-integral controller, k i represents the integral coefficient of the proportional-integral controller.

[0127] S104: Based on the d-axis magnetic flux and q-axis voltage equation in the obtained dq coordinate system, calculate the estimated speed of the synchronous motor.

[0128] Specifically, it includes: determining the q-axis voltage equation based on the q-axis voltage component, q-axis resistance voltage drop, and q-axis inductance voltage drop in the dq coordinate system, and obtaining the d-axis magnetic flux in the dq coordinate system;

[0129] Based on the ratio of the q-axis voltage equation to the d-axis magnetic flux, calculate the estimated speed of the synchronous motor, and the formula is as follows:

[0130]

[0131] Among them, ω 0 represents the estimated speed of the synchronous motor, (u q - u Rq - u Lq ) represents the q-axis voltage equation, represents the d-axis magnetic flux.

[0132] S105: Calculate the difference between the estimated rotational speed and the error speed, take the derivative of the difference, and determine the true observed angle of the synchronous motor. The formula is as follows:

[0133] angle = ∫(ω 0 - ω err )dt

[0134] where angle represents the true observed angle.

[0135] S106: Based on the true observed angle, perform phase tracking on the synchronous motor.

[0136] The PLL design method proposed in this embodiment is essentially a state reconstruction of a state observer, that is, reconstruct a system, use the variables that can be directly measured in the original system as input signals, and make the reconstructed state equivalent to the state of the original system under certain conditions. The equivalence principle is that the error between the two can asymptotically and stably approach zero during dynamic changes (ω err approaches zero). Therefore, the PLL design method proposed in this embodiment has the advantages of good dynamic performance, high stability, wide adaptability, etc.

[0137] As Figure 2 shown, it is another flowchart of the PLL design method provided by the embodiment of the present disclosure. The electromagnetic relationship inside the permanent magnet synchronous motor is very complex and is a non-linear control system with multi-parameter coupling. It is very difficult to analyze using traditional control methods. Therefore, when establishing an equivalent model for the synchronous motor, appropriate assumptions need to be made for the motor to facilitate subsequent analysis and research. For example: assume that the synchronous motor satisfies the following conditions:

[0138] 1. Assume that the magnetic circuit is linear, without considering magnetic circuit saturation, hysteresis, and eddy current losses;

[0139] 2. Assume that the magnetic permeability inside the permanent magnet is the same as that of air, and the conductivity of the permanent magnet material is zero;

[0140] 3. The stator windings satisfy three-phase symmetry and are completely the same, with a phase difference of 120° between each phase, and the damper windings of the rotor are not considered;

[0141] 4. When the motor runs without load, the induced back electromotive force is a sine wave, without high-order harmonic distribution, and the excitation current basically has no fluctuation.

[0142] The coordinate transformation of the synchronous motor is divided into two exchange methods: power invariant and amplitude invariant. Since overmodulation will occur when using the power invariant transformation method, the coordinate transformation of this solution is carried out on the premise of amplitude invariant. The method includes S201 - S209:

[0143] S201: Determine the first electromagnetic torque equation of the synchronous motor in the three-phase stationary coordinate system.

[0144] First, as Figure 3 shown, it is a schematic diagram of a synchronous motor system model. In the three-phase stationary coordinate system, the three-phase stator current equations of the PMSM (Permanent Magnet Synchronous Motor) are:

[0145]

[0146] where, i a represents the stator current on the a-axis of the three-phase stationary coordinate system, i b represents the stator current on the b-axis of the three-phase stationary coordinate system, i c represents the stator current on the c-axis of the three-phase stationary coordinate system, ω represents the rotational angular velocity of the three-phase stator current, t represents, ωt represents the frequency.

[0147] According to the electromagnetic relationship, the initial stator voltage equation in the three-phase stationary coordinate system is:

[0148]

[0149] where, u a , u b , u c respectively represent the three-phase stator voltages, R represents the stator armature resistance, ψ a , ψ b , ψ c respectively represent the magnetic fluxes generated by the magnetic field in the three-phase winding coils A, B, and C. Specifically, ψ a , ψ b , ψ c The three-phase magnetic flux equations are:

[0150]

[0151] where, L aa , L bb , L cc respectively represent the self-inductance coefficients of each winding coil, M ab , M ac , M ba , M bc , M ca , M cb respectively represent the mutual inductance coefficients between any two of the ABC three-phase winding coils, i a , i b , i c respectively represent the three-phase stator currents, ψ fa , ψ fb , ψ fcThey represent the three-phase fluxes respectively. Since the magnetic field of a synchronous motor is jointly generated by the permanent magnets on the rotor and the stator windings, and the change in the rotor position will affect the distribution of the magnetic field, thereby affecting the magnitude and direction of the magnetic flux linkage, there are a large number of coupling terms in the three-phase stationary coordinate system, which increases the difficulty of system control.

[0152] Due to the circuit reciprocity and the symmetrical distribution of the three-phase windings of the motor, the following can be obtained:

[0153]

[0154] Therefore, ψ fa 、ψ fb 、ψ fc The three-phase flux equations can be expressed as:

[0155]

[0156] Among them, ψ fa represents the flux component on the a-axis of the three-phase stationary coordinate system, ψ fb represents the flux component on the b-axis of the three-phase stationary coordinate system, ψ fc represents the flux component on the c-axis of the three-phase stationary coordinate system, ψ f represents the amplitude value of the rotor permanent magnet flux linkage, the magnitude of which can be regarded as an invariant, and θ is the electrical angle between the axis of the A-phase winding of the synchronous motor and the axis of the rotor fundamental flux linkage.

[0157] Since the motor is star-connected, the phases of its three-phase currents are 120° out of phase with each other and the sum of the three-phase currents is zero. Therefore, there are the following relationships:

[0158]

[0159] Among them, ψ A 、ψ B 、ψ C represent the ABC three-phase fluxes respectively.

[0160] Combining the initial stator voltage equation and the above three-phase flux equations, the stator voltage equation can be determined as follows:

[0161]

[0162] Among them, u a 、u b 、u c represent the three-phase stator voltages respectively, R represents the stator armature resistance, ψ f represents the amplitude value of the rotor permanent magnet flux linkage, the magnitude of which can be regarded as an invariant, and ω e represents the magnetic flux rotation speed.

[0163] Therefore, the first electromagnetic torque equation of the synchronous motor in the three-phase stationary coordinate system can be determined as follows:

[0164]

[0165] Among them, T e1 represents the first electromagnetic torque of the synchronous motor, and P n represents the number of pole pairs of the synchronous motor.

[0166] S202: Use the Clark transformation to convert the three-phase stationary coordinate system into a two-phase αβ stationary coordinate system.

[0167] As Figure 4 shown, it is a schematic diagram of the αβ-axis decomposition system of the synchronous motor system. The Clark transformation can be expressed as:

[0168]

[0169] Among them, f α and f β represent the α-axis and β-axis of the two-phase αβ stationary coordinate system respectively, and f s , f b , f v represent the a-axis, b-axis, and c-axis of the three-phase stationary coordinate system respectively.

[0170] S203: Based on the first electromagnetic torque equation, determine the second electromagnetic torque equation in the two-phase αβ stationary coordinate system.

[0171] After the Clark transformation, the flux linkage equation of the synchronous motor in the two-phase αβ stationary coordinate system is:

[0172]

[0173] Among them, ψ α and ψ β represent the stator flux linkage components on the α-axis and β-axis respectively, i α and i β represent the stator current components on the α-axis and β-axis respectively, L represents the inductance coefficient, and ψ f represents the amplitude value of the rotor permanent magnet flux linkage.

[0174] After the Clark transformation, the voltage equation of the synchronous motor is:

[0175]

[0176] Among them, u α and u β represent the voltage components on the α-axis and β-axis respectively, ψ α and ψ βrespectively represent the stator flux linkage components on the α-axis and β-axis, and i α , i β respectively represent the stator current components on the α-axis and β-axis, and R represents the stator armature resistance.

[0177] Based on the first electromagnetic torque equation, flux linkage equation, and voltage equation, the second electromagnetic torque equation in the two-phase αβ stationary coordinate system can be determined as follows:

[0178]

[0179] where, T r2 represents the second electromagnetic torque in the two-phase stationary coordinate system, and P n represents the number of pole pairs of the synchronous motor.

[0180] S204: Use Park transformation to convert the two-phase stationary coordinate system to the dq coordinate system.

[0181] As Figure 5 shown, it is a schematic diagram of the dq-axis decomposition system of the synchronous motor system. The rotational angular velocity of the dq coordinate system is the same as the rotor angular velocity. Therefore, the d-axis is in the same direction as the fundamental magnetic field direction of the rotor flux linkage, and the q-axis is in the direction 90° ahead of the d-axis.

[0182] Park transformation can be expressed as:

[0183]

[0184] where, f d , f q respectively represent the d-axis and q-axis of the dq coordinate system, and f α , f β respectively represent the α-axis and β-axis of the two-phase αβ stationary coordinate system.

[0185] After Clark and Park transformations, the three-phase AC system can be converted into a two-phase DC system in the dq coordinate system, thus realizing a control strategy similar to that of a DC motor. In the dq coordinate system, the field current and torque current can be independently controlled to achieve decoupling. Specifically, the field current is usually used to control the magnetic field strength of the synchronous motor, while the torque current is used to control the output torque of the synchronous motor. By independently controlling these two current components, precise control of the motor can be achieved and decoupling is realized.

[0186] Based on the d-axis flux linkage and q-axis flux linkage in the dq coordinate system, the voltage equation in the dq coordinate system can be determined as follows:

[0187]

[0188] where, u d , u qrespectively represent the voltage components on the d-axis and q-axis, ψ d , ψ q respectively represent the stator flux linkage components on the d-axis and q-axis, L d , L q respectively represent the model equivalent inductances on the d-axis and q-axis, ψ f represents the amplitude value of the rotor permanent magnet flux linkage, i d , i q respectively represent the current components on the d-axis and q-axis.

[0189] Based on the second electromagnetic torque equation and the voltage equation in the dq coordinate system, the third electromagnetic torque equation in the dq coordinate system can be determined as follows:

[0190]

[0191] Among them, T e3 represents the third electromagnetic torque, L d , L q respectively represent the model equivalent inductances on the d-axis and q-axis, i d , i q respectively represent the current components on the d-axis and q-axis, P n represents the number of pole pairs of the synchronous motor, ψ f represents the amplitude value of the rotor permanent magnet flux linkage.

[0192] S205: Based on the third electromagnetic torque equation, construct an equivalent model of the synchronous motor in the dq coordinate system.

[0193] As Figure 6 shown, it is a system schematic diagram of the equivalent model in the dq coordinate system, and the equivalent model is the complete mathematical model of the synchronous motor.

[0194] S206: Based on the equivalent model, calculate the resistance voltage drop and inductance voltage drop of the synchronous motor in the dq coordinate system.

[0195] By constructing the equivalent model, the q-axis equivalent circuit is used to estimate the speed of the synchronous motor and used as the input of the d-axis equivalent circuit. Finally, the error amplifier amplifies the error value calculated in the d-axis equation and subtracts the output from the estimated speed. Therefore, the measured voltage and current in the dq system coordinates, as well as the permanent magnet flux linkage and winding resistance, will be fed back into the d-axis and q-axis machine equations, and after being amplified by the error amplifier, the estimated speed difference calculated from the d-axis equation and q-axis equation will be minimized.

[0196] First, calculate the resistance voltage drops of the winding coils on the d-axis and q-axis:

[0197]

[0198] Among them, u Rd, u Rq respectively represent the resistance voltage drops of the winding coil on the d-axis and q-axis, R d , R q respectively represent the model equivalent resistances on the d-axis and q-axis, i d , i q respectively represent the current components on the d-axis and q-axis.

[0199] Then calculate the inductance voltage drops of the winding coil on the d-axis and q-axis:

[0200]

[0201] where, u Ld , u Lq respectively represent the inductance voltage drops of the winding coil on the d-axis and q-axis, L d , L q respectively represent the model equivalent inductances on the d-axis and q-axis, i d , i q respectively represent the current components on the d-axis and q-axis.

[0202] S207: Calculate the error speed of the synchronous motor based on the resistance voltage drop and inductance voltage drop.

[0203] Apply KVL on the d-axis loop. Combining the resistance voltage drops and inductance voltage drops on the dq axes, the error voltage can be calculated. The error voltage expression is:

[0204] u err = u d - u Rd - u Ld + ωL q i q

[0205] where, u err represents the error voltage, u d represents the voltage component of the winding coil on the d-axis, u Rd represents the resistance voltage drop of the winding coil on the d-axis, u Ld represents the inductance voltage drop of the winding coil on the d-axis, L q represents the model equivalent inductance on the q-axis, i q represents the current component on the q-axis.

[0206] Using the error voltage value u err as the input of the PI controller (proportional-integral controller), the output value of the PI controller can be obtained:

[0207] ω err = k p (sign(u q - u Rq - uLq ))u err +k p k i ∫(sign(u q -u Rq -u Lq ))u err dt

[0208] where ω err represents the error speed of the synchronous motor, k p represents the proportional coefficient of the proportional-integral controller, k i represents the integral coefficient of the proportional-integral controller.

[0209] S208: Based on the obtained d-axis magnetic flux and q-axis voltage equations in the dq coordinate system, calculate the estimated speed of the synchronous motor.

[0210] Specifically, by constructing an equivalent model, use the q-axis equivalent circuit to estimate the speed of the synchronous motor, and use it as the input of the d-axis equivalent circuit. Substitute the limited d-axis magnetic flux into the q-axis model, and initially calculate the estimated speed by solving the PMSM voltage equation on the q-axis. Understanding the PMSM as an electrically excited synchronous generator, the d-axis magnetic flux can be calculated. The expression of the d-axis magnetic flux is:

[0211]

[0212] where i d is the d-axis current, i f is the value of the equivalent electrical excitation current. The limitation of the d-axis magnetic flux is:

[0213]

[0214] Substitute the limited d-axis magnetic flux into the q-axis model, and calculate the estimated speed by solving the PMSM voltage equation on the q-axis. The expression of the estimated speed is as follows:

[0215]

[0216] where ω 0 represents the estimated speed of the synchronous motor, (u q -u Rq -u Lq ) represents the q-axis voltage equation, represents the d-axis magnetic flux.

[0217] S209: Calculate the difference between the estimated speed and the error speed, take the derivative of the difference, determine the true observation angle of the synchronous motor, and based on the true observation angle, perform phase tracking on the synchronous motor to implement a phase-locked loop adapted to the variable frequency output of the synchronous motor.

[0218] The error amplifier (PI controller) amplifies the error value calculated in the d-axis equation and subtracts the output from the estimated rotational speed. The measured voltage and current in the dq coordinate system, as well as the permanent magnet flux linkage and winding resistance, are fed back into the machine equations of the d-axis and q-axis. And through the amplification of the error amplifier, the estimated rotational speed difference calculated from the d-axis equation and the q-axis equation will be minimized, and finally the electrical angular velocity of the PMSM is observed. Subtracting the estimated rotational speed of the q-axis voltage equation from the output of the error amplifier, the true observed angle of the synchronous motor can be calculated through the calculated generator angular velocity. The expression of the true observed angle angle is:

[0219]

[0220] The PLL design method proposed in this embodiment is essentially a state reconstruction of a state observer, that is, a system is reconstructed, using the variables that can be directly measured in the original system as input signals, and making the reconstructed state equivalent to the state of the original system under certain conditions. The equivalence principle is that the error between the two can asymptotically and stably approach zero during dynamic changes (ω err approaches zero). Therefore, the PLL design method proposed in this embodiment has the advantages of good dynamic performance, high stability, wide adaptability, etc.

[0221] To prove the reliability of the PLL design method proposed in this scheme, a simulation experiment was carried out, and the synchronous motor was used for variable frequency testing. The parameters of the synchronous motor are shown in Table 1:

[0222] Table 1 Motor Parameters

[0223] Name Parameter Number of pole pairs 4 pairs <![CDATA[L d > 0.00068H <![CDATA[L q > 0.00068H R 0.26 Ω Sampling time 8.7 μs

[0224] To verify the feasibility of the scheme, this scheme respectively sets the output AC frequency of the synchronous motor to 50Hz, 100Hz, and 200Hz for simulation experiment verification. The experimental results are respectively as Figures 7 - 9 shown:

[0225] As Figure 7 shown, a sawtooth-shaped phase waveform can be output, the waveform range is [-π, π], and the waveform spacing with the same amplitude is 0.02s, proving that the PLL designed in this scheme can perform phase tracking.

[0226] As Figure 8 shown, a sawtooth-shaped phase waveform can be output, the waveform range is [-π, π], and the waveform spacing with the same amplitude is 0.01s, proving that the PLL designed in this scheme can perform phase tracking.

[0227] As Figure 9As shown, a sawtooth-shaped phase waveform can be output, with the waveform range being [-π, π], and the waveform spacing with the same amplitude being 0.005 s, proving that the phase-locked loop designed by this solution can perform phase tracking.

[0228] According to another aspect of the embodiments of the present disclosure, a phase-locked loop design device is provided, as Figure 10 shown, the device includes:

[0229] A model construction module 101 for constructing an equivalent model of a synchronous motor in the dq coordinate system;

[0230] A first acquisition module 102 for acquiring the resistance voltage drop and inductance voltage drop of the synchronous motor in the dq coordinate system based on the equivalent model;

[0231] A second acquisition module 103 for obtaining the error speed of the synchronous motor based on the resistance voltage drop and the inductance voltage drop;

[0232] A first calculation module 104 for calculating the estimated speed of the synchronous motor based on the d-axis magnetic flux and q-axis voltage equation of the acquired dq coordinate system;

[0233] A second calculation module 105 for calculating the difference between the estimated speed and the error speed, taking the derivative of the difference to determine the true observed angle of the synchronous motor;

[0234] A phase tracking module 106 for performing phase tracking on the synchronous motor based on the true observed angle.

[0235] In one or more embodiments, the model construction module 101 is used to:

[0236] Determine the first electromagnetic torque equation of the synchronous motor in the three-phase stationary coordinate system;

[0237] Use the Clarke transformation to convert the three-phase stationary coordinate system into a two-phase stationary coordinate system, and based on the first electromagnetic torque equation, determine the second electromagnetic torque equation in the two-phase stationary coordinate system;

[0238] Use the Park transformation to convert the two-phase stationary coordinate system into the dq coordinate system, and based on the second electromagnetic torque equation, determine the third electromagnetic torque equation in the dq coordinate system;

[0239] Based on the third electromagnetic torque equation, construct an equivalent model of the synchronous motor in the dq coordinate system.

[0240] In one or more embodiments, the second acquisition module 103 is used to:

[0241] Calculate the error voltage based on the resistance voltage drop and the inductance voltage drop;

[0242] Based on the error voltage, the error speed of the synchronous motor is obtained by using a proportional-integral controller.

[0243] In one or more embodiments, the first calculation module 104 is configured to:

[0244] Based on the q-axis voltage component, q-axis resistance voltage drop, and q-axis inductance voltage drop in the dq coordinate system, determine the q-axis voltage equation, and obtain the d-axis magnetic flux in the dq coordinate system;

[0245] Calculate the estimated speed of the synchronous motor based on the ratio of the q-axis voltage equation to the d-axis magnetic flux.

[0246] In one or more embodiments, the model construction module 101 is further configured to:

[0247] Based on the circuit reciprocity of the three-phase stationary coordinate system, determine the three-phase magnetic flux equation;

[0248] Based on the three-phase stator current equation in the three-phase stationary coordinate system, the three-phase magnetic flux equation, and the self-inductance coefficient and mutual-inductance coefficient of the winding coils, determine the three-phase magnetic linkage equation of the synchronous motor;

[0249] Based on the three-phase stator current equation and the three-phase magnetic linkage equation, determine the stator voltage equation of the synchronous motor in the three-phase stationary coordinate system;

[0250] Based on the stator voltage equation, determine the first electromagnetic torque equation of the synchronous motor in the three-phase stationary coordinate system.

[0251] In one or more embodiments, the model construction module 101 is further configured to:

[0252] Determine the magnetic linkage equation and voltage equation in the two-phase stationary coordinate system;

[0253] Based on the first electromagnetic torque equation, the magnetic linkage equation, and the voltage equation, determine the second electromagnetic torque equation in the two-phase stationary coordinate system.

[0254] In one or more embodiments, the model construction module 101 is further configured to:

[0255] Based on the d-axis magnetic linkage and q-axis magnetic linkage in the dq coordinate system, determine the voltage equation in the dq coordinate system;

[0256] Based on the second electromagnetic torque equation and the voltage equation in the dq coordinate system, determine the third electromagnetic torque equation in the dq coordinate system.

[0257] The phase-locked loop design device provided by the embodiments of the present disclosure and the phase-locked loop design method provided by the embodiments of the present disclosure are based on the same inventive concept and have the same beneficial effects as the methods adopted, run, or implemented by them.

[0258] The embodiments of the present disclosure also provide a computer device to execute the above-mentioned phase-locked loop design method. Please refer to Figure 11 It shows a schematic diagram of a computer device provided by some embodiments of the present disclosure. As Figure 11 shown, the computer device 8 includes: a processor 800, a memory 801, a bus 802, and a communication interface 803. The processor 800, the communication interface 803, and the memory 801 are connected through the bus 802; a computer program that can run on the processor 800 is stored in the memory 801, and when the processor 800 runs the computer program, it executes the phase-locked loop design method provided by any of the foregoing embodiments of the present disclosure.

[0259] Among them, the memory 801 may include a high-speed random access memory (RAM: Random Access Memory), and may also include a non-volatile memory, such as at least one disk memory. Through at least one communication interface 803 (which can be wired or wireless), the communication connection between this device network element and at least one other network element can be realized, and the Internet, wide area network, local area network, metropolitan area network, etc. can be used.

[0260] The bus 802 can be an ISA bus, a PCI bus, an EISA bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. Among them, the memory 801 is used to store programs, and after receiving the execution instruction, the processor 800 executes the program. The phase-locked loop design method disclosed in any of the foregoing embodiments of the present disclosure can be applied to the processor 800 or implemented by the processor 800.

[0261] The processor 800 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the integrated logic circuit of the hardware in the processor 800 or the instructions in the form of software. The above-mentioned processor 800 may be a general-purpose processor, including a central processing unit (CPU for short), a network processor (NP for short), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPTA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present disclosure. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in combination with the embodiments of the present disclosure can be directly embodied as being executed by the hardware decoding processor, or executed by a combination of the hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. This storage medium is located in the memory 801, and the processor 800 reads the information in the memory 801 and combines its hardware to complete the steps of the above method.

[0262] The computer device provided by the embodiments of the present disclosure and the phase-locked loop design method provided by the embodiments of the present disclosure are based on the same inventive concept and have the same beneficial effects as the methods adopted, run, or implemented by them.

[0263] The embodiments of the present disclosure also provide a computer-readable storage medium corresponding to the phase-locked loop design method provided by the foregoing embodiments. The computer-readable storage medium is an optical disc, on which a computer program (i.e., a computer program product) is stored. When the computer program is run by a processor, it will execute the phase-locked loop design method provided by any of the foregoing embodiments.

[0264] It should be noted that examples of the computer-readable storage medium may also include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory, or other optical and magnetic storage media, which will not be elaborated here one by one.

[0265] The computer-readable storage medium provided by the above embodiments of the present disclosure and the phase-locked loop design method provided by the embodiments of the present disclosure are based on the same inventive concept and have the same beneficial effects as the methods adopted, run, or implemented by the application programs stored in it.

[0266] Embodiments of the present disclosure also provide a computer program product. Please refer to Figure 12 , the computer program product 600 carries program code, that is, computer program 601. The instructions included in the computer program 601 can be used to execute the steps of the phase-locked loop design method described in the above method embodiments. For details, please refer to the above method embodiments and will not be elaborated here.

[0267] Among them, the above computer program product can be specifically implemented in the form of hardware, software, or a combination thereof. In an alternative embodiment, the computer program product is specifically embodied as a computer storage medium. In another alternative embodiment, the computer program product is specifically embodied as a software product, such as a Software Development Kit (SDK), etc.

[0268] The basic principles of the present disclosure have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, benefits, effects, etc. mentioned in the present disclosure are only examples and not limitations. It cannot be considered that these advantages, benefits, effects, etc. are essential for each embodiment of the present disclosure. In addition, the above disclosed specific details are only for illustrative and easy-to-understand purposes, rather than limitations. The above details do not limit the present disclosure to necessarily adopt the above specific details for implementation.

[0269] The block diagrams of the devices, apparatuses, equipment, and systems involved in the present disclosure are only illustrative examples and do not intend to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open-ended words, meaning "including but not limited to", and can be used interchangeably with each other. The words "or" and "and" used here refer to "and / or", and can be used interchangeably with each other unless the context clearly indicates otherwise. The word "such as" used here refers to the phrase "such as but not limited to", and can be used interchangeably with each other.

[0270] In addition, as used herein, the "or" in the listing of items starting with "at least one" indicates a separate listing, so that for example, the listing of "at least one of A, B, or C" means A or B or C, or AB or AC or BC, or ABC (that is, A and B and C). In addition, the term "exemplary" does not mean that the described examples are preferred or better than other examples.

[0271] It should also be noted that in the systems and methods of the present disclosure, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent solutions of the present disclosure.

[0272] Various changes, substitutions, and alterations to the technology described herein can be made without departing from the teachings defined by the appended claims. Additionally, the scope of the claims of this disclosure is not limited to the specific aspects of the processes, machines, manufactures, compositions of events, means, methods, and acts described above. Processes, machines, manufactures, compositions of events, means, methods, or acts that are currently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding aspects described herein can be utilized. Accordingly, the appended claims include such processes, machines, manufactures, compositions of events, means, methods, or acts within their scope.

[0273] The foregoing description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the aspects shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0274] The foregoing description has been presented for purposes of illustration and description. Additionally, this description is not intended to limit the embodiments of the present disclosure to the forms disclosed herein. Although numerous example aspects and embodiments have been discussed above, those skilled in the art will recognize some of their variations, modifications, alterations, additions, and subcombinations.

Claims

1. A phase-locked loop design method, characterized in that: include: Construct an equivalent model of the synchronous motor in the dq coordinate system; Based on the equivalent model, obtaining the resistance voltage drop and the inductance voltage drop of the synchronous motor in the dq coordinate system; Obtaining an error speed of the synchronous motor based on the resistance voltage drop and the inductance voltage drop; Calculating an estimated rotation speed of the synchronous motor based on the acquired d-axis magnetic flux and q-axis voltage equations of the dq coordinate system; Calculating a difference between the estimated rotation speed and the error speed, taking a derivative of the difference, and determining a true observation angle of the synchronous motor; Based on the real observation angle, phase tracking is performed on the synchronous motor.

2. The phase-locked loop design method according to claim 1, characterized in that: Construct an equivalent model of the synchronous motor in the dq coordinate system, including: Determine the first electromagnetic torque equation of the synchronous motor in a three-phase stationary coordinate system; The three-phase stationary coordinate system is converted into a two-phase stationary coordinate system by using Clarke transformation, and a second electromagnetic torque equation in the two-phase stationary coordinate system is determined based on the first electromagnetic torque equation; The two-phase stationary coordinate system is converted into a dq coordinate system by using Park transformation, and a third electromagnetic torque equation in the dq coordinate system is determined based on the second electromagnetic torque equation; Based on the third electromagnetic torque equation, an equivalent model of the synchronous motor in the dq coordinate system is constructed.

3. The phase-locked loop design method according to claim 1, characterized in that: The resistance voltage drop includes a d-axis resistance voltage drop and a q-axis resistance voltage drop, and the inductance voltage drop includes a d-axis inductance voltage drop and a q-axis inductance voltage drop; Obtaining an error speed of the synchronous motor based on the resistance voltage drop and the inductance voltage drop, comprising: Calculating an error voltage based on the resistor voltage drop and the inductor voltage drop; Based on the error voltage, an error speed of the synchronous motor is obtained by using a proportional-integral controller.

4. The phase-locked loop design method according to claim 1, characterized in that: Calculating the estimated speed of the synchronous motor based on the acquired d-axis magnetic flux and q-axis voltage equations of the dq coordinate system includes: Determine a q-axis voltage equation based on a q-axis voltage component, a q-axis resistance voltage drop, and a q-axis inductance voltage drop of the dq coordinate system, and obtain a d-axis magnetic flux of the dq coordinate system; Based on a ratio of the q-axis voltage equation to the d-axis magnetic flux, an estimated rotation speed of the synchronous motor is calculated.

5. The phase-locked loop design method according to claim 2, characterized in that: Determine the first electromagnetic torque equation of the synchronous motor in the three-phase stationary coordinate system, including: Based on the circuit reciprocity of the three-phase stationary coordinate system, the three-phase flux equation is determined; Determine the three-phase flux equation of the synchronous motor based on the three-phase stator current equation in the three-phase stationary coordinate system, the three-phase flux equation and the self-inductance coefficient and mutual inductance coefficient of the winding coil; Based on the three-phase stator current equation and the three-phase flux equation, determining the stator voltage equation of the synchronous motor in a three-phase stationary coordinate system; Based on the stator voltage equation, a first electromagnetic torque equation of the synchronous motor in a three-phase stationary coordinate system is determined.

6. The phase-locked loop design method according to claim 2, characterized in that: Based on the first electromagnetic torque equation, a second electromagnetic torque equation in a two-phase stationary coordinate system is determined, including: Determine the flux equation and voltage equation in the two-phase stationary coordinate system; Determine a second electromagnetic torque equation in a two-phase stationary coordinate system based on the first electromagnetic torque equation, the flux equation and the voltage equation; Based on the second electromagnetic torque equation, a third electromagnetic torque equation in the dq coordinate system is determined, including: Determining a voltage equation in the dq coordinate system based on the d-axis magnetic flux and the q-axis magnetic flux of the dq coordinate system; Based on the second electromagnetic torque equation and the voltage equation in the dq coordinate system, a third electromagnetic torque equation in the dq coordinate system is determined.

7. A phase-locked loop design device, characterized in that: include: A model building module is used to build an equivalent model of the synchronous motor in the dq coordinate system; A first acquisition module, configured to acquire a resistance voltage drop and an inductance voltage drop of the synchronous motor in a dq coordinate system based on the equivalent model; A second acquisition module, configured to obtain an error speed of the synchronous motor based on the resistance voltage drop and the inductance voltage drop; A first calculation module, configured to calculate an estimated rotation speed of the synchronous motor based on the obtained d-axis magnetic flux and q-axis voltage equations of the dq coordinate system; a second calculation module, configured to calculate a difference between the estimated rotational speed and the error speed, and to differentiate the difference to determine a true observation angle of the synchronous motor; A phase tracking module is used to perform phase tracking on the synchronous motor based on the real observation angle.

8. A computer embedded device, comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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