Double-fed asynchronous motor synchronous phase lock control method and device

Abstract

The invention discloses a double-fed asynchronous motor synchronous phase locking control method and device. The method comprises the steps that stator three-phase voltage, stator three-phase current instantaneous values and rotor three-phase current instantaneous values of a double-fed asynchronous motor are collected; acquiring a power grid voltage synchronous phase through a phase-locked loop; performing coordinate transformation on the stator three-phase current instantaneous value, the rotor three-phase current instantaneous value and the stator three-phase voltage based on the power grid voltage synchronous phase to obtain a coordinate transformation result; performing flux linkage calculation according to the coordinate transformation result to obtain a flux linkage calculation result; calculating a rotor voltage dynamic compensation item according to a coordinate transformation result and a flux linkage calculation result; performing power calculation according to a coordinate transformation result, and introducing a rotor voltage dynamic compensation item and a flux linkage calculation result according to a power calculation result to calculate and obtain a rotor target voltage reference value of the doubly-fed asynchronous motor; and generating a control signal according to the rotor target voltage reference value to control the doubly-fed asynchronous motor.

Description

Technical Field

[0001] The present invention relates to the field of motor control, and in particular to a method and device for synchronous phase-locked control of a double-fed asynchronous motor. Background Art

[0002] Gravity energy storage is an energy storage technology based on the conversion of gravitational potential energy. Excess electrical energy is used to drive the motor to lift heavy objects to a high place to store energy; when electricity is needed, the heavy objects are lowered and the gravitational potential energy is converted into electrical energy output through the generator. This energy storage method is not restricted by natural conditions and can operate stably in a variety of geographical environments; in addition, the gravity energy storage system can achieve flexible energy regulation and predictable power output by precisely controlling the lifting of heavy objects, which is particularly suitable for the frequency regulation and peak regulation of the power grid.

[0003] At present, most gravity energy storage systems use synchronous motors as generator motors, and realize the conversion of mechanical energy and electrical energy through the synchronous rotation of the motor rotor and the stator magnetic field. For example, patent text CN118783650A discloses a highly efficient gravity energy storage system and its control method, including a synchronous motor, a wound asynchronous motor, and a lifting shaft. Both the synchronous motor and the wound asynchronous motor can be connected to the lifting shaft in a transmission manner. In the power generation system, the synchronous motor is used as the main motor to drive the lifting shaft to release the weight, and in the electric system, the wound asynchronous motor is used as the main motor to drive the lifting shaft to lift the weight. Patent text CN116979843A provides a stable operation control method and system for a gravity energy storage system, which relates to the technical field of ramp-type gravity energy storage systems, including: collecting data for preprocessing and real-time monitoring of the signals sent by the sensor; increasing the excitation voltage of the synchronous motor to adjust the excitation current to the maximum, and judging the duration of the maximum excitation voltage; judging whether PI control of the excitation voltage output is required according to the angular acceleration state of the motor rotor; judging whether to restore to fixed excitation control according to the speed difference.

[0004] However, synchronous motors have some limitations. For example, they are prone to impact the mechanical transmission and power grid systems during starting, stopping and switching, resulting in power intermittent and fluctuations. Summary of the invention

[0005] The present invention provides a doubly-fed asynchronous motor synchronous phase-locked control method and device, which are particularly suitable for a gravity energy storage system and can avoid impact on mechanical transmission and power grid systems.

[0006] A synchronous phase-locked control method for a double-fed asynchronous motor, comprising: Collect the stator three-phase voltage, stator three-phase current instantaneous value and rotor three-phase current instantaneous value of the double-fed asynchronous motor; Obtain the grid voltage synchronization phase through a phase-locked loop; Based on the synchronous phase of the grid voltage, perform coordinate transformation on the instantaneous values of the stator three-phase current, the rotor three-phase current, and the stator three-phase voltage to obtain the coordinate transformation result; Perform flux linkage calculation according to the coordinate transformation result to obtain the flux linkage calculation result; Calculate the rotor voltage dynamic compensation term according to the coordinate transformation result and the flux linkage calculation result; Perform power calculation according to the coordinate transformation result, and introduce the rotor voltage dynamic compensation term and the flux linkage calculation result according to the power calculation result to calculate and obtain the rotor target voltage reference value of the doubly-fed induction motor; Generate a control signal according to the rotor target voltage reference value to control the doubly-fed induction motor.

[0007] Further, after collecting the stator three-phase voltage of the doubly-fed induction motor, it further includes: Perform filtering processing on the stator three-phase voltage based on a power frequency band-pass filter.

[0008] Further, the coordinate transformation result includes the stator voltage d-axis component, the stator voltage q-axis component, the stator current d-axis component, the stator current q-axis component, the rotor current d-axis component, and the rotor current q-axis component.

[0009] Further, based on the synchronous phase of the grid voltage, performing coordinate transformation on the instantaneous values of the stator three-phase current and the stator three-phase voltage includes: Perform Clarke transformation on the instantaneous values of the stator three-phase current and the stator three-phase voltage to obtain the stator voltage components and the stator current components in the two-phase stationary coordinate system; Based on the synchronous phase of the grid voltage, perform Park transformation on the component results in the two-phase stationary coordinate system to obtain the stator voltage components and the stator current components in the two-phase rotating coordinate system.

[0010] Further, the stator voltage component results and the stator current components in the two-phase stationary coordinate system include the stator voltage α component, the stator voltage β component, the stator current α component, and the stator current β component; Based on the synchronous phase of the grid voltage, performing Park transformation on the component results in the two-phase stationary coordinate system to obtain the stator voltage components and the stator current components in the two-phase rotating coordinate system includes: Establish a first Park transformation matrix according to the synchronous phase of the grid voltage, and calculate and obtain the stator voltage d-axis component, the stator voltage q-axis component, the stator current d-axis component, and the stator current q-axis component according to the stator voltage α component, the stator voltage β component, the stator current α component, the stator current β component, and the first Park transformation matrix.

[0011] Further, based on the synchronous phase of the grid voltage, performing a coordinate transformation on the instantaneous values of the three-phase rotor current, including: Performing a Clarke transformation on the instantaneous values of the three-phase rotor current to obtain the rotor current component results in a two-phase stationary coordinate system; Collecting the rotor position angle of the doubly-fed induction motor, and based on the rotor position angle and the synchronous phase of the grid voltage, performing a Park transformation on the rotor current component results in a two-phase stationary coordinate system to obtain the rotor current component results in a two-phase rotating coordinate system.

[0012] Further, the rotor current component results in a two-phase stationary coordinate system include a rotor current α component and a rotor current β component; Based on the rotor position angle and the synchronous phase of the grid voltage, performing a Park transformation on the rotor current component results in a two-phase stationary coordinate system, including: Based on the rotor position angle and the synchronous phase of the grid voltage, establishing a second Park transformation matrix; Based on the rotor current α component, the rotor current β component, and the second Park transformation matrix, calculating to obtain a rotor current d-axis component and a rotor current q-axis component.

[0013] Further, the flux linkage calculation results include a stator flux linkage d-axis component and a stator flux linkage q-axis component; Performing a flux linkage calculation based on the coordinate transformation results to obtain flux linkage calculation results, including: Based on the stator current d-axis component and the stator current q-axis component, obtaining a stator current vector; Based on the rotor current d-axis component and the rotor current q-axis component, obtaining a rotor current vector; Based on the stator current vector, the rotor current vector, the self-inductance of the stator, and the mutual inductance between the rotor and the stator, obtaining a stator flux linkage vector; Performing a coordinate transformation on the stator flux linkage vector to obtain a stator flux linkage d-axis component and a stator flux linkage q-axis component.

[0014] Further, performing a coordinate transformation on the stator flux linkage vector to obtain a stator flux linkage d-axis component and a stator flux linkage q-axis component, including: Based on the stator flux linkage vector, performing a Clarke transformation to obtain a stator flux linkage α component and a stator flux linkage β component; Based on the synchronous phase of the grid voltage, performing a Park transformation on the stator flux linkage α component and the stator flux linkage β component to obtain a stator flux linkage d-axis component and a stator flux linkage q-axis component.

[0015] Further, calculating a rotor voltage dynamic compensation term based on the coordinate transformation results and the flux linkage calculation results, including: Obtain the stator voltage vector based on the d-axis component and q-axis component of the stator voltage; Obtain the synchronous electrical angular velocity of the doubly-fed induction motor; Calculate and obtain the d-axis stator resistance voltage drop and q-axis stator resistance voltage drop respectively according to the d-axis component of the stator current, the q-axis component of the stator current and the stator resistance; Calculate and obtain the d-axis compensation term of the rotor voltage according to the mutual inductance between the rotor and the stator, the self-inductance of the stator, the stator voltage vector, the d-axis stator resistance voltage drop, the synchronous electrical angular velocity and the d-axis component of the stator flux linkage; Calculate and obtain the q-axis compensation term of the rotor voltage according to the mutual inductance between the rotor and the stator, the self-inductance of the stator, the q-axis stator resistance voltage drop, the synchronous electrical angular velocity and the q-axis component of the stator flux linkage.

[0016] Further, perform power calculation according to the coordinate transformation result, including: Calculate the actual active power of the stator and the actual reactive power of the stator according to the coordinate transformation result; Obtain the rotor angular velocity according to the rotor position angle of the doubly-fed induction motor; Calculate the speed difference according to the rotor angular velocity and the rotor speed reference value, and input the speed difference into the speed PI controller to obtain the reference value of the stator active power; Input the difference between the reference value of the stator active power and the actual active power of the stator into the active power PI controller to obtain the reference value of the d-axis component of the rotor current; Adopt a reactive power closed-loop to calculate and obtain the reference value of the q-axis component of the rotor current according to the actual reactive power of the stator.

[0017] Further, according to the power calculation result, introduce the rotor voltage dynamic compensation term and the flux linkage calculation result to calculate and obtain the reference value of the target voltage of the rotor of the doubly-fed induction motor, including: Introduce an integral link to calculate and obtain the d-axis component and q-axis component of the rotor voltage according to the reference value of the d-axis component of the rotor current, the reference value of the q-axis component of the rotor current, the d-axis component of the rotor current and the q-axis component of the rotor current; Calculate the d-axis leakage inductance voltage drop of the rotor current and the q-axis leakage inductance voltage drop of the rotor current according to the flux linkage calculation result; Add the d-axis component of the rotor voltage, the d-axis leakage inductance voltage drop of the rotor current and the d-axis compensation term of the rotor voltage to obtain the reference value of the target voltage of the d-axis of the rotor; Add the q-axis component of the rotor voltage, the q-axis leakage inductance voltage drop of the rotor current and the q-axis compensation term of the rotor voltage to obtain the reference value of the target voltage of the q-axis of the rotor.

[0018] Further, the d-axis leakage inductance voltage drop of the rotor current is the voltage drop generated by the d-axis component of the rotor current across the rotor resistance, minus the coupling voltage generated by the q-axis component of the rotor current and the induced voltage generated by the slip of the q-axis component of the stator magnetic flux; The q-axis leakage inductance voltage drop of the rotor current is the sum of the voltage drop generated by the q-axis component of the rotor current across the rotor resistance, the coupling voltage generated by the d-axis component of the rotor current, and the induced voltage generated by the slip of the d-axis component of the stator magnetic flux.

[0019] Further, generating a control signal according to the rotor target voltage reference value to control the doubly-fed induction motor includes: Performing an inverse Park transformation on the rotor d-axis target voltage reference value and the rotor q-axis target voltage reference value to obtain the rotor α-target voltage component and the rotor β-target voltage component; Performing space vector modulation according to the rotor α-target voltage component and the rotor β-target voltage component to generate the switching signals required by the rotor-side PWM converter, and controlling the voltage on the rotor side of the doubly-fed induction motor according to the switching signals.

[0020] A synchronous phase-locked control device for a doubly-fed induction motor includes: An acquisition module, configured to acquire the instantaneous values of the stator three-phase voltage, the stator three-phase current, and the rotor three-phase current of the doubly-fed induction motor; A phase-locked loop control module, configured to obtain the synchronous phase of the grid voltage through a phase-locked loop; A coordinate transformation module, configured to perform coordinate transformation on the instantaneous values of the stator three-phase current, the rotor three-phase current, and the stator three-phase voltage based on the synchronous phase of the grid voltage to obtain a coordinate transformation result; A magnetic flux calculation module, configured to perform magnetic flux calculation according to the coordinate transformation result to obtain a magnetic flux calculation result; A compensation calculation module, configured to calculate the rotor voltage dynamic compensation term according to the coordinate transformation result and the magnetic flux calculation result; A target voltage calculation module, configured to perform power calculation according to the coordinate transformation result, and calculate and obtain the rotor target voltage reference value of the doubly-fed induction motor by introducing the rotor voltage dynamic compensation term and the magnetic flux calculation result according to the power calculation result; A control module, configured to generate a control signal according to the rotor target reference value to control the doubly-fed induction motor.

[0021] Further, after the acquisition module acquires the stator three-phase voltage of the doubly-fed induction motor, it further includes: Filtering the stator three-phase voltage based on a power frequency band-pass filter.

[0022] Further, the coordinate transformation results include the stator voltage d-axis component, the stator voltage q-axis component, the stator current d-axis component, the stator current q-axis component, the rotor current d-axis component, and the rotor current q-axis component.

[0023] Further, the coordinate transformation module performs coordinate transformation on the instantaneous values of the stator three-phase current and the stator three-phase voltage based on the synchronous phase of the grid voltage, including: Performing Clarke transformation on the instantaneous values of the stator three-phase current and the stator three-phase voltage to obtain the stator voltage components and the stator current components in the two-phase stationary coordinate system; Based on the synchronous phase of the grid voltage, performing Park transformation on the component results in the two-phase stationary coordinate system to obtain the stator voltage components and the stator current components in the two-phase rotating coordinate system.

[0024] Further, the stator voltage component results and the stator current components in the two-phase stationary coordinate system include the stator voltage α component, the stator voltage β component, the stator current α component, and the stator current β component; The coordinate transformation module performs Park transformation on the component results in the two-phase stationary coordinate system based on the synchronous phase of the grid voltage to obtain the stator voltage components and the stator current components in the two-phase rotating coordinate system, including: Establishing a first Park transformation matrix according to the synchronous phase of the grid voltage, and calculating the stator voltage d-axis component, the stator voltage q-axis component, the stator current d-axis component, and the stator current q-axis component based on the stator voltage α component, the stator voltage β component, the stator current α component, the stator current β component, and the first Park transformation matrix.

[0025] Further, the coordinate transformation module performs coordinate transformation on the instantaneous values of the rotor three-phase current based on the synchronous phase of the grid voltage, including: Performing Clarke transformation on the instantaneous values of the rotor three-phase current to obtain the rotor current component results in the two-phase stationary coordinate system; Collecting the rotor position angle of the doubly-fed induction motor, and performing Park transformation on the rotor current component results in the two-phase stationary coordinate system according to the rotor position angle and the synchronous phase of the grid voltage to obtain the rotor current component results in the two-phase rotating coordinate system.

[0026] Further, the rotor current component results in the two-phase stationary coordinate system include the rotor current α component and the rotor current β component; The coordinate transformation module performs Park transformation on the rotor current component results in the two-phase stationary coordinate system according to the rotor position angle and the synchronous phase of the grid voltage, including: Establish a second Park transformation matrix according to the rotor position angle and the synchronous phase of the grid voltage; Calculate the d-axis component and q-axis component of the rotor current based on the α-component of the rotor current, the β-component of the rotor current, and the second Park transformation matrix.

[0027] Furthermore, the flux linkage calculation result includes the d-axis component and q-axis component of the stator flux linkage; The flux linkage calculation module performs flux linkage calculation according to the coordinate transformation result to obtain a flux linkage calculation result, including: Obtain the stator current vector based on the d-axis component and q-axis component of the stator current; Obtain the rotor current vector based on the d-axis component and q-axis component of the rotor current; Obtain the stator flux linkage vector based on the stator current vector, the rotor current vector, the self-inductance of the stator, and the mutual inductance between the rotor and the stator; Perform coordinate transformation on the stator flux linkage vector to obtain the d-axis component and q-axis component of the stator flux linkage.

[0028] Furthermore, the flux linkage calculation module performs coordinate transformation on the stator flux linkage vector to obtain the d-axis component and q-axis component of the stator flux linkage, including: Perform Clarke transformation based on the stator flux linkage vector to obtain the α-component and β-component of the stator flux linkage; Perform Park transformation on the α-component and β-component of the stator flux linkage according to the synchronous phase of the grid voltage to obtain the d-axis component and q-axis component of the stator flux linkage.

[0029] Furthermore, the compensation calculation module calculates the rotor voltage dynamic compensation term according to the coordinate transformation result and the flux linkage calculation result, including: Obtain the stator voltage vector based on the d-axis component and q-axis component of the stator voltage; Obtain the synchronous electrical angular velocity of the doubly-fed induction motor; Calculate the d-axis stator resistance voltage drop and q-axis stator resistance voltage drop respectively based on the d-axis component of the stator current, the q-axis component of the stator current, and the stator resistance; Calculate the d-axis compensation term of the rotor voltage based on the mutual inductance between the rotor and the stator, the self-inductance of the stator, the stator voltage vector, the d-axis stator resistance voltage drop, the synchronous electrical angular velocity, and the d-axis component of the stator flux linkage; Calculate the q-axis compensation term of the rotor voltage based on the mutual inductance between the rotor and the stator, the self-inductance of the stator, the q-axis stator resistance voltage drop, the synchronous electrical angular velocity, and the q-axis component of the stator flux linkage.

[0030] Further, the target voltage calculation module calculates power according to the coordinate transformation result, including: Calculating the actual active power of the stator and the actual reactive power of the stator according to the coordinate transformation result; Calculating the rotor angular velocity based on the rotor position angle of the doubly-fed induction motor; Calculating the speed difference according to the rotor angular velocity and the rotor speed reference value, and inputting the speed difference into a speed PI controller to obtain the reference value of the stator active power; Inputting the difference between the reference value of the stator active power and the actual active power of the stator into an active power PI controller to obtain the reference value of the d-axis component of the rotor current; Adopting a reactive power closed loop to calculate the reference value of the q-axis component of the rotor current according to the actual reactive power of the stator.

[0031] Further, the target voltage calculation module calculates the reference value of the rotor target voltage of the doubly-fed induction motor according to the power calculation result, introducing the rotor voltage dynamic compensation term and the magnetic flux calculation result, including: Introducing an integral link according to the reference value of the d-axis component of the rotor current, the reference value of the q-axis component of the rotor current, the d-axis component of the rotor current, and the q-axis component of the rotor current to calculate the d-axis component of the rotor voltage and the q-axis component of the rotor voltage; Calculating the d-axis leakage inductance voltage drop of the rotor current and the q-axis leakage inductance voltage drop of the rotor current according to the magnetic flux calculation result; Adding the d-axis component of the rotor voltage, the d-axis leakage inductance voltage drop of the rotor current, and the d-axis compensation term of the rotor voltage to obtain the reference value of the d-axis target voltage of the rotor; Adding the q-axis component of the rotor voltage, the q-axis leakage inductance voltage drop of the rotor current, and the q-axis compensation term of the rotor voltage to obtain the reference value of the q-axis target voltage of the rotor.

[0032] Further, the d-axis leakage inductance voltage drop of the rotor current is the voltage drop generated by the d-axis component of the rotor current on the rotor resistance, minus the coupling voltage generated by the q-axis component of the rotor current and the induced voltage generated by the slip of the q-axis component of the stator magnetic flux; The q-axis leakage inductance voltage drop of the rotor current is the sum of the voltage drop generated by the q-axis component of the rotor current on the rotor resistance, the coupling voltage generated by the d-axis component of the rotor current, and the induced voltage generated by the slip of the d-axis component of the stator magnetic flux.

[0033] Further, the control module generates a control signal according to the reference value of the rotor target voltage to control the doubly-fed induction motor, including: Performing an inverse Park transformation on the reference value of the d-axis target voltage of the rotor and the reference value of the q-axis target voltage of the rotor to obtain the α-target voltage component of the rotor and the β-target voltage component of the rotor; Perform space vector modulation based on the rotor α target voltage component and the rotor β target voltage component to generate the switching signals required by the rotor-side PWM converter, and control the voltage on the rotor side of the doubly-fed induction motor according to the switching signals.

[0034] The synchronous phase-locked control method and device for a doubly-fed induction motor provided by the present invention at least include the following beneficial effects: (1) Through the coordinated control of the stator side and the rotor side, directly control the rotor voltage. When applied to a gravity energy storage system, it can quickly adjust the output power at the moment when gravitational potential energy is released, avoiding power intermittency and fluctuations caused by impacting the power grid system. It is particularly suitable for gravity energy storage systems. Based on synchronous phase-locked control, it can automatically synchronize with the grid frequency, eliminating the excitation regulation device of the synchronous motor, simplifying the control system, and effectively improving the system operation stability and energy conversion efficiency; (2) Introduce a rotor voltage dynamic compensation term and a leakage inductance voltage drop to correct the rotor voltage, which can dynamically cancel the coupled voltage component, further reduce power fluctuations, and improve the dynamic performance, robustness, and control accuracy of the system. Description of the Drawings

[0035] Figure 1 It is a flowchart of an embodiment of the synchronous phase-locked control method for a doubly-fed induction motor provided by the present invention.

[0036] Figure 2 It is a schematic structural diagram of an embodiment of the synchronous phase-locked control device for a doubly-fed induction motor provided by the present invention. Detailed Embodiments

[0037] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in conjunction with the accompanying drawings of the specification and specific embodiments.

[0038] Refer to Figure 1 , in some embodiments, a synchronous phase-locked control method for a doubly-fed induction motor is provided, including: S1. Collect the instantaneous values of the stator three-phase voltage, stator three-phase current, and rotor three-phase current of the doubly-fed induction motor; S2. Obtain the synchronous phase of the grid voltage through a phase-locked loop; S3. Based on the synchronous phase of the grid voltage, perform coordinate transformation on the instantaneous values of the stator three-phase current, rotor three-phase current, and stator three-phase voltage to obtain a coordinate transformation result; S4. Calculate the magnetic flux according to the coordinate transformation result to obtain a magnetic flux calculation result; S5. Calculate the rotor voltage dynamic compensation term according to the coordinate transformation result and the magnetic flux calculation result; S6. Calculate the power according to the coordinate transformation result. Based on the power calculation result, introduce the rotor voltage dynamic compensation term and the magnetic flux calculation result to calculate the rotor target voltage reference value of the doubly-fed induction motor; S7. Generate a control signal according to the rotor target voltage reference value to control the doubly-fed induction motor.

[0039] Specifically, in step S1, through a sensor, collect the stator three-phase voltages u sa_mea , u sb_mea , u sc_mea , the instantaneous values of the stator three-phase currents i sa_mea , i sb_mea , i sc_mea and the instantaneous values of the rotor three-phase currents i ra_mea , i rb_mea , i rc_mea .

[0040] Further, in some embodiments, after collecting the stator three-phase voltages of the doubly-fed induction motor, it further includes: Perform filtering processing on the stator three-phase voltages based on a power frequency band-pass filter.

[0041] In step S2, obtain the grid voltage synchronous phase q l .

[0042] Further, in step S3, the coordinate transformation result includes the d-axis component of the stator voltage, the q-axis component of the stator voltage, the d-axis component of the stator current, the q-axis component of the stator current, the d-axis component of the rotor current, and the q-axis component of the rotor current.

[0043] In step S3, based on the grid voltage synchronous phase, perform coordinate transformation on the instantaneous values of the stator three-phase currents and the filtered stator three-phase voltages, including: S31. Perform Clarke transformation on the instantaneous values of the stator three-phase currents and the stator three-phase voltages to obtain the stator voltage components and stator current components in the two-phase stationary coordinate system; S32. According to the grid voltage synchronous phase, perform Park transformation based on the component results in the two-phase stationary coordinate system to obtain the stator voltage components and stator current components in the two-phase rotating coordinate system.

[0044] Specifically, in step S31, perform Clarke transformation on the instantaneous values of the stator three-phase currents and the stator three-phase voltages to obtain the stator voltage component results and stator current components in the two-phase stationary coordinate system. The stator voltage component results and stator current components in the two-phase stationary coordinate system include the stator voltage α component, the stator voltage β component, the current α component, and the stator current β component, as shown respectively below: ; (1) ; (2) Among them, u sα represents the α-component of the stator voltage, u sβ represents the β-component of the stator voltage, k mea represents the conversion coefficient, 0 ≤ k mea ≤ 1, and appropriate parameters can be selected according to the control requirements. u sa_mea , u sb_mea , u sc_mea are the three-phase stator voltages, and i sα represents the α-component of the stator current, i sβ represents the β-component of the stator current, i sa_mea , i sb_mea , i sc_mea represent the instantaneous values of the three-phase stator currents.

[0045] Furthermore, in step S32, according to the synchronous phase of the grid voltage, Park transformation is performed based on the component results in the two-phase stationary coordinate system to obtain the stator voltage components and stator current components in the two-phase rotating coordinate system, including:[[]] Establish a first Park transformation matrix according to the synchronous phase of the grid voltage, and calculate the d-axis component of the stator voltage, the q-axis component of the stator voltage, the d-axis component of the stator current, and the q-axis component of the stator current based on the α-component of the stator voltage, the β-component of the stator voltage, the α-component of the stator current, the β-component of the stator current, and the first Park transformation matrix.

[0046] Specifically, the first Park transformation matrix is as follows:[[]] ; (3) Among them, θ l represents the synchronous phase of the grid voltage.

[0047] The d-axis component of the stator voltage, the q-axis component of the stator voltage, the d-axis component of the stator current, and the q-axis component of the stator current are calculated by the following formulas:[[]] ; (4) ; (5) Among them, u sd is the d-axis component of the stator voltage, u sq is the q-axis component of the stator voltage, i sd is the d-axis component of the stator current, i sq is the q-axis component of the stator current, u sα represents the α-component of the stator voltage, u sβ represents the β-component of the stator voltage, i sα represents the α-component of the stator current, i sβrepresents the β - component of the stator current, θ l represents the synchronous phase of the grid voltage.

[0048] Furthermore, in step S3, based on the synchronous phase of the grid voltage, a coordinate transformation is performed on the instantaneous values of the rotor three - phase current, including: S33. Perform a Clarke transformation on the instantaneous values of the rotor three - phase current to obtain the rotor current component results in the two - phase stationary coordinate system; S34. Collect the rotor position angle of the doubly - fed induction motor, and based on the rotor position angle and the synchronous phase of the grid voltage, perform a Park transformation on the rotor current component results in the two - phase stationary coordinate system to obtain the rotor current component results in the two - phase rotating coordinate system.

[0049] Specifically, in step S33, the rotor current component results in the two - phase stationary coordinate system include the rotor current α - component and the rotor current β - component, and the specific calculation formula is: ; (6) where, i rα represents the rotor current α - component, i rβ represents the rotor current β - component, i ra_mea , i rb_mea , i rc_mea represent the instantaneous values of the rotor three - phase current.

[0050] Furthermore, in step S34, the rotor current component results in the two - phase stationary coordinate system include the rotor current α - component and the rotor current β - component.

[0051] Collect the rotor position angle of the doubly - fed induction motor, and based on the rotor position angle and the synchronous phase of the grid voltage, perform a Park transformation on the rotor current component results in the two - phase stationary coordinate system to obtain the rotor current component results in the two - phase rotating coordinate system, including: Based on the rotor position angle and the synchronous phase of the grid voltage, establish a second Park transformation matrix; Based on the rotor current α - component, the rotor current β - component and the second Park transformation matrix, calculate the rotor current d - axis component and the rotor current q - axis component.

[0052] Specifically, the second Park transformation matrix is shown as follows: ; (7) where, θ l represents the synchronous phase of the grid voltage, θr represents the rotor position angle, which is obtained through an optical encoder.

[0053] Furthermore, the rotor current d - axis component and the rotor current q - axis component are calculated by the following formula: ; (8) Among them, θ l represents the synchronous phase of the grid voltage, θr represents the rotor position angle, and i rα represents the α component of the rotor current, and i rβ represents the β component of the rotor current, and i rd represents the d-axis component of the rotor current, and i rq represents the q-axis component of the rotor current.

[0054] Furthermore, in step S4, the magnetic flux calculation result includes the d-axis component and the q-axis component of the stator magnetic flux.

[0055] Specifically, according to the coordinate transformation result, magnetic flux calculation is performed to obtain the magnetic flux calculation result, including: S41. Obtain the stator current vector according to the d-axis component and the q-axis component of the stator current; S42. Obtain the rotor current vector according to the d-axis component and the q-axis component of the rotor current; S43. Obtain the stator magnetic flux vector according to the stator current vector, the rotor current vector, the self-inductance of the stator, and the mutual inductance between the rotor and the stator; S44. Perform coordinate transformation on the stator magnetic flux vector to obtain the d-axis component and the q-axis component of the stator magnetic flux.

[0056] Specifically, in step S41, the stator current vector is calculated according to the following formula: I s = i sd + j * i sq ; (9) Among them, I s represents the stator current vector, i sd represents the d-axis component of the stator current, and i sq represents the q-axis component of the stator current.

[0057] Furthermore, in step S42, the rotor current vector is calculated according to the following formula: I r = i rd + j * i rq ; (10) Among them, I r represents the rotor current vector, i rd represents the d-axis component of the rotor current, and i rq represents the q-axis component of the rotor current.

[0058] Furthermore, in step S43, the stator magnetic flux vector is calculated according to the following formula: ; (11) Wherein, represents the stator flux linkage vector, I s represents the stator current vector, I r represents the rotor current vector, L s represents the self - inductance of the stator, L m represents the mutual inductance between the rotor and the stator.

[0059] Furthermore, in step S44, a coordinate transformation is performed on the stator flux linkage vector to obtain the d - axis component and the q - axis component of the stator flux linkage, which specifically includes: Performing a Clarke transformation based on the stator flux linkage vector to obtain the α - component and the β - component of the stator flux linkage; Performing a Park transformation on the α - component and the β - component of the stator flux linkage according to the synchronous phase of the grid voltage to obtain the d - axis component and the q - axis component of the stator flux linkage.

[0060] The specific calculation formulas are as follows: ; (12) ; (13) Wherein, represents the d - axis component of the stator flux linkage, represents the q - axis component of the stator flux linkage, represents the α - component of the stator flux linkage, represents the β - component of the stator flux linkage, θ l represents the synchronous phase of the grid voltage.

[0061] Furthermore, in step S5, the rotor voltage dynamic compensation term is calculated according to the coordinate transformation result and the flux linkage calculation result, including: S51. Obtaining the stator voltage vector according to the d - axis component and the q - axis component of the stator voltage; S52. Obtaining the synchronous electrical angular velocity of the doubly - fed induction motor; S53. Respectively calculating and obtaining the d - axis stator resistance voltage drop and the q - axis stator resistance voltage drop according to the d - axis component of the stator current, the q - axis component of the stator current, and the stator resistance; S54. Calculating and obtaining the d - axis compensation term of the rotor voltage according to the mutual inductance between the rotor and the stator, the self - inductance of the stator, the stator voltage vector, the d - axis stator resistance voltage drop, the synchronous electrical angular velocity, and the d - axis component of the stator flux linkage; S55. Calculating and obtaining the q - axis compensation term of the rotor voltage according to the mutual inductance between the rotor and the stator, the self - inductance of the stator, the q - axis stator resistance voltage drop, the synchronous electrical angular velocity, and the q - axis component of the stator flux linkage.

[0062] Specifically, in step S51, the stator voltage vector is calculated according to the following formula: U s =u sd +j*u sq ; (14) Wherein, U s represents the stator voltage vector, u sd represents the d-axis component of the stator voltage, and u sq represents the q-axis component of the stator voltage.

[0063] Furthermore, in step S52, the synchronous electrical angular velocity of the doubly-fed induction motor is obtained .

[0064] Furthermore, in step S53, the d-axis stator resistance voltage drop is the product of the stator resistance R s and the d-axis component i sd of the stator current, and the q-axis stator resistance voltage drop is the product of the stator resistance R s and the q-axis component i sq of the stator current.

[0065] Furthermore, in steps S54 and S55, the d-axis compensation term and the q-axis compensation term of the rotor voltage are calculated according to the following formula: ; (15) Wherein, v rdl is the d-axis compensation term of the rotor voltage, v rql is the q-axis compensation term of the rotor voltage, L m is the mutual inductance between the stator and the rotor, L s is the self-inductance of the stator, R s is the stator resistance, U s is the stator voltage vector, i sd is the d-axis component of the stator current, i sq is the q-axis component of the stator current, represents the synchronous electrical angular velocity, represents the d-axis component of the stator flux linkage, represents the q-axis component of the stator flux linkage.

[0066] Furthermore, in step S6, power calculation is performed according to the coordinate transformation result, including: S61. Calculate the actual active power and the actual reactive power of the stator according to the coordinate transformation result; S62. Calculate the rotor angular velocity based on the rotor position angle of the doubly-fed induction motor; S63. Calculate the speed difference according to the rotor angular velocity and the rotor speed reference value, and input the speed difference into the speed PI controller to obtain the reference value of the stator active power; S64. Input the difference between the stator active power reference value and the actual stator active power into the active power PI controller to obtain the reference value of the d-axis component of the rotor current; S65. Adopt a reactive power closed-loop to calculate the reference value of the q-axis component of the rotor current according to the actual stator reactive power.

[0067] Specifically, in step S61, the actual stator active power and the actual stator reactive power are calculated by the following formulas: ; (16) where, P s represents the actual stator active power, Q s represents the actual stator reactive power, U s represents the stator voltage vector, i rd is the d-axis component of the rotor current, i rq is the q-axis component of the rotor current, represents the synchronous electrical angular velocity, L m is the mutual inductance between the stator and the rotor, L s is the self-inductance of the stator.

[0068] It can be seen that when the d-axis stator voltage orientation is adopted, the d-axis component i rd of the rotor current is the active current component, while the q-axis component i rq of the rotor current is the reactive current component. Then, the active and reactive powers output by the stator can be decoupled by independently adjusting the d- and q-axis currents of the rotor.

[0069] Based on this, for the reference value of the d-axis component of the rotor current, the speed error formed by comparing the rotor speed reference value with the actual rotor angular velocity can be input into the speed PI controller to obtain the stator active power reference value P s_ref .

[0070] Specifically, in step S62, the rotor angular velocity is calculated according to the rotor position angle of the doubly-fed induction motor.

[0071] In step S63, the speed difference is calculated according to the rotor angular velocity and the rotor speed reference value , and the speed difference is input into the speed PI controller to obtain the stator active power reference value P s_ref .

[0072] In step S64, then the stator active power reference value P s_ref is compared with the actual stator active power P sThe error between them is input into the active power PI controller to obtain the reference value of the d-axis component of the rotor current.

[0073] In step S65, the reactive power reference value Qs_ref is adjusted according to the requirements of the power grid. Generally, it is set to 0, and the reference value of the q-axis component of the rotor current is obtained through the reactive power closed-loop.

[0074] Further, in step S6, according to the power calculation result, the rotor target voltage reference value of the doubly-fed induction motor is calculated by introducing the rotor voltage dynamic compensation term and the magnetic flux calculation result, including: S66. According to the reference value of the d-axis component of the rotor current, the reference value of the q-axis component of the rotor current, the d-axis component of the rotor current, and the q-axis component of the rotor current, an integral link is introduced to calculate the d-axis component and the q-axis component of the rotor voltage; S67. Calculate the d-axis leakage inductance voltage drop of the rotor current and the q-axis leakage inductance voltage drop of the rotor current according to the magnetic flux calculation result; S68. Add the d-axis component of the rotor voltage, the d-axis leakage inductance voltage drop of the rotor current, and the d-axis compensation term of the rotor voltage to obtain the reference value of the d-axis target voltage of the rotor; S69. Add the q-axis component of the rotor voltage, the q-axis leakage inductance voltage drop of the rotor current, and the q-axis compensation term of the rotor voltage to obtain the reference value of the q-axis target voltage of the rotor.

[0075] Specifically, in step S66, the d-axis component and the q-axis component of the rotor voltage are calculated by the following formulas: ; (17) Wherein, represents the d-axis component of the rotor voltage, represents the q-axis component of the rotor voltage, represents the leakage magnetic coefficient, L r represents the self-inductance of the rotor, represents the reference value of the d-axis component of the rotor current, represents the reference value of the q-axis component of the rotor current, k irp represents the proportional coefficient of the rotor current controller, k iri represents the integral coefficient of the rotor current controller, i rd represents the d-axis component of the rotor current, i rq represents the q-axis component of the rotor current.

[0076] Further, in step S67, the d-axis leakage inductance voltage drop of the rotor current is the voltage drop generated by the d-axis component of the rotor current on the rotor resistance, minus the coupling voltage generated by the q-axis component of the rotor current and the induced voltage generated by the q-axis component of the stator magnetic flux due to slip, that is , in this formula, the first term is the voltage drop generated by the d-axis component of the rotor current across the rotor resistance, the second term is the coupling voltage generated by the q-axis component of the rotor current, and the third term is the induced voltage generated by the q-axis component of the stator flux due to the slip. R r represents the rotor resistance, i rd represents the d-axis component of the rotor current, represents the slip electrical angular velocity, represents the leakage magnetic coefficient, L r represents the self-inductance of the rotor, i rq represents the q-axis component of the rotor current, L m represents the mutual inductance between the rotor and the stator, and Ls represents the self-inductance of the stator, represents the q-axis component of the stator flux.

[0077] The q-axis leakage inductance voltage drop of the rotor current is the sum of the voltage drop generated by the q-axis component of the rotor current across the rotor resistance, the coupling voltage generated by the d-axis component of the rotor current, and the induced voltage generated by the d-axis component of the stator flux due to the slip, that is , in this calculation formula, the first term is the voltage drop generated by the q-axis component of the rotor current across the rotor resistance, the second term is the coupling voltage generated by the d-axis component of the rotor current, and the third term is the induced voltage generated by the d-axis component of the stator flux due to the slip. Among them, R r represents the rotor resistance, i rq represents the q-axis component of the rotor current, represents the slip electrical angular velocity, represents the leakage magnetic coefficient, L r represents the self-inductance of the rotor, i rd represents the d-axis component of the rotor current, L m represents the mutual inductance between the rotor and the stator, and Ls represents the self-inductance of the stator, represents the d-axis component of the stator flux.

[0078] Furthermore, in steps S68 and S69, the target voltage reference value of the rotor d-axis and the target voltage reference value of the rotor q-axis are calculated by the following formula: ; (18) Among them, represents the d-axis component of the rotor voltage, represents the q-axis component of the rotor voltage, represents the target voltage reference value of the rotor d-axis, represents the target voltage reference value of the rotor q-axis, R r represents the rotor resistance, i rd represents the d-axis component of the rotor current, represents the slip electrical angular velocity, represents the leakage magnetic coefficient, L r represents the self-inductance of the rotor, irq represents the q-axis component of the rotor current, L m represents the mutual inductance between the rotor and the stator, Ls represents the self-inductance of the stator, represents the q-axis component of the stator flux linkage, represents the d-axis component of the stator flux linkage, v rdl is the d-axis compensation term of the rotor voltage, v rql is the q-axis compensation term of the rotor voltage.

[0079] Further, in step S7, generating a control signal according to the rotor target voltage reference value to control the doubly-fed induction motor includes: Performing an inverse Park transformation on the rotor d-axis target voltage reference value and the rotor q-axis target voltage reference value to obtain the rotor α-axis target voltage component and the rotor β-axis target voltage component; Performing space vector modulation according to the rotor α-axis target voltage component and the rotor β-axis target voltage component to generate the switching signals required for the rotor-side PWM converter, and controlling the voltage on the rotor side of the doubly-fed induction motor according to the switching signals.

[0080] Reference Figure 2 , in some embodiments, a synchronous phase-locked control device for a doubly-fed induction motor is provided, including: An acquisition module 201, configured to acquire the instantaneous values of the stator three-phase voltage, the stator three-phase current, and the rotor three-phase current of the doubly-fed induction motor; A phase-locked loop control module 202, configured to obtain the synchronous phase of the grid voltage through a phase-locked loop; A coordinate transformation module 203, configured to perform a coordinate transformation on the instantaneous values of the stator three-phase current, the rotor three-phase current, and the stator three-phase voltage based on the synchronous phase of the grid voltage to obtain a coordinate transformation result; A flux linkage calculation module 204, configured to perform a flux linkage calculation according to the coordinate transformation result to obtain a flux linkage calculation result; A compensation calculation module 205, configured to calculate the rotor voltage dynamic compensation term according to the coordinate transformation result and the flux linkage calculation result; A target voltage calculation module 206, configured to perform a power calculation according to the coordinate transformation result, and calculate and obtain the rotor target voltage reference value of the doubly-fed induction motor by introducing the rotor voltage dynamic compensation term and the flux linkage calculation result according to the power calculation result; A control module 207, configured to generate a control signal according to the rotor target reference value to control the doubly-fed induction motor.

[0081] Further, after the acquisition module 201 acquires the stator three-phase voltage of the doubly-fed induction motor, it further includes: Performing a filtering process on the stator three-phase voltage based on an industrial frequency band-pass filter Further, the coordinate transformation result includes the stator voltage d-axis component, the stator voltage q-axis component, the stator current d-axis component, the stator current q-axis component, the rotor current d-axis component, and the rotor current q-axis component.

[0082] Further, the coordinate transformation module 203 performs coordinate transformation on the instantaneous values of the stator three-phase current and the stator three-phase voltage based on the synchronous phase of the grid voltage, including: Performing Clarke transformation on the instantaneous values of the stator three-phase current and the stator three-phase voltage to obtain the stator voltage component result and the stator current component in the two-phase stationary coordinate system; Based on the synchronous phase of the grid voltage, performing Park transformation on the component results in the two-phase stationary coordinate system to obtain the stator voltage component and the stator current component in the two-phase rotating coordinate system.

[0083] Further, the stator voltage component result and the stator current component in the two-phase stationary coordinate system include the stator voltage α component, the stator voltage β component, the stator current α component, and the stator current β component; They are respectively as follows: ; (1) ; (2) where u sα represents the stator voltage α component, u sβ represents the stator voltage β component, k mea represents the conversion coefficient, 0 ≤ k mea ≥ 1, and appropriate parameters can be selected according to the control requirements. u sa_mea , u sb_mea , u sc_mea are the stator three-phase voltages, i sα represents the stator current α component, i sβ represents the stator current β component, i sa_mea , i sb_mea , i sc_mea represent the instantaneous values of the stator three-phase current.

[0084] The coordinate transformation module performs Park transformation on the component results in the two-phase stationary coordinate system based on the synchronous phase of the grid voltage to obtain the stator voltage component and the stator current component in the two-phase rotating coordinate system, including: Establishing a first Park transformation matrix according to the synchronous phase of the grid voltage, and calculating the stator voltage d-axis component, the stator voltage q-axis component, the stator current d-axis component, and the stator current q-axis component based on the stator voltage α component, the stator voltage β component, the stator current α component, the stator current β component, and the first Park transformation matrix.

[0085] Specifically, the first Park transformation matrix is as follows: ; (3) where θ l represents the synchronous phase of the grid voltage.

[0086] The d-axis component of the stator voltage, the q-axis component of the stator voltage, the d-axis component of the stator current, and the q-axis component of the stator current are calculated by the following formulas: ; (4) ; (5) where u sd is the d-axis component of the stator voltage, u sq is the q-axis component of the stator voltage, i sd is the d-axis component of the stator current, i sq is the q-axis component of the stator current, u sα represents the α-component of the stator voltage, u sβ represents the β-component of the stator voltage, i sα represents the α-component of the stator current, i sβ represents the β-component of the stator current, θ l represents the synchronous phase of the grid voltage.

[0087] Furthermore, the coordinate transformation module 203 performs coordinate transformation on the instantaneous values of the rotor three-phase current based on the synchronous phase of the grid voltage, including: Performing Clarke transformation on the instantaneous values of the rotor three-phase current to obtain the rotor current component results in the two-phase stationary coordinate system; Collecting the rotor position angle of the doubly-fed induction motor, and performing Park transformation on the rotor current component results in the two-phase stationary coordinate system according to the rotor position angle and the synchronous phase of the grid voltage to obtain the rotor current component results in the two-phase rotating coordinate system.

[0088] Furthermore, the rotor current component results in the two-phase stationary coordinate system include the rotor current α-component and the rotor current β-component; the calculation formulas are as follows: ; (6) where i rα represents the rotor current α-component, i rβ represents the rotor current β-component, i ra_mea , i rb_mea , i rc_mea represent the instantaneous values of the rotor three-phase current.

[0089] The coordinate transformation module 203 performs Park transformation on the rotor current component results in the two-phase stationary coordinate system according to the rotor position angle and the synchronous phase of the grid voltage, including: Establish a second Park transformation matrix according to the rotor position angle and the synchronous phase of the grid voltage; Calculate and obtain the d-axis component and q-axis component of the rotor current according to the α-component of the rotor current, the β-component of the rotor current, and the second Park transformation matrix.

[0090] Specifically, the second Park transformation matrix is shown as follows: ; (7) Wherein, θ l represents the synchronous phase of the grid voltage, θr represents the rotor position angle, and is obtained through an optical encoder disk.

[0091] Furthermore, the d-axis component and q-axis component of the rotor current are calculated through the following formula: ; (8) Wherein, θ l represents the synchronous phase of the grid voltage, θr represents the rotor position angle, i rα represents the α-component of the rotor current, i rβ represents the β-component of the rotor current, i rd represents the d-axis component of the rotor current, i rq represents the q-axis component of the rotor current.

[0092] Furthermore, the flux linkage calculation result includes the d-axis component and q-axis component of the stator flux linkage; The flux linkage calculation module 204 performs flux linkage calculation according to the coordinate transformation result to obtain the flux linkage calculation result, including: Obtain the stator current vector according to the d-axis component and q-axis component of the stator current; Obtain the rotor current vector according to the d-axis component and q-axis component of the rotor current; Obtain the stator flux linkage vector according to the stator current vector, the rotor current vector, the self-inductance of the stator, and the mutual inductance between the rotor and the stator; Perform coordinate transformation on the stator flux linkage vector to obtain the d-axis component and q-axis component of the stator flux linkage.

[0093] The stator current vector is calculated according to the following formula: I s = i sd + j * i sq ; (9) Wherein, I s represents the stator current vector, i sd represents the d-axis component of the stator current, i sqRepresents the q-axis component of the stator current.

[0094] The rotor current vector is calculated according to the following formula: I r = i rd + j * i rq ; (10) Where, I r represents the rotor current vector, i rd represents the d-axis component of the rotor current, i rq represents the q-axis component of the rotor current.

[0095] The stator flux linkage vector is calculated according to the following formula: ; (11) Where, represents the stator flux linkage vector, I s represents the stator current vector, I r represents the rotor current vector, L s represents the self-inductance of the stator, L m represents the mutual inductance between the rotor and the stator.

[0096] Furthermore, the flux linkage calculation module performs a coordinate transformation on the stator flux linkage vector to obtain the d-axis component and the q-axis component of the stator flux linkage, including: Performing a Clarke transformation based on the stator flux linkage vector to obtain the α-component and the β-component of the stator flux linkage; Performing a Park transformation on the α-component and the β-component of the stator flux linkage according to the synchronous phase of the grid voltage to obtain the d-axis component and the q-axis component of the stator flux linkage.

[0097] The specific calculation formula is as follows: ; (12) ; (13) Where, represents the d-axis component of the stator flux linkage, represents the q-axis component of the stator flux linkage, represents the α-component of the stator flux linkage, represents the β-component of the stator flux linkage, θ l represents the synchronous phase of the grid voltage.

[0098] Furthermore, the compensation calculation module 205 calculates the rotor voltage dynamic compensation term according to the coordinate transformation result and the flux linkage calculation result, including: Obtaining the stator voltage vector according to the d-axis component and the q-axis component of the stator voltage; Obtaining the synchronous electrical angular velocity of the doubly-fed induction motor; Calculate the d-axis stator resistance voltage drop and the q-axis stator resistance voltage drop respectively based on the d-axis component of the stator current, the q-axis component of the stator current, and the stator resistance; Calculate the d-axis compensation term of the rotor voltage based on the mutual inductance between the rotor and the stator, the self-inductance of the stator, the stator voltage vector, the d-axis stator resistance voltage drop, the synchronous electrical angular velocity, and the d-axis component of the stator flux linkage; Calculate the q-axis compensation term of the rotor voltage based on the mutual inductance between the rotor and the stator, the self-inductance of the stator, the q-axis stator resistance voltage drop, the synchronous electrical angular velocity, and the q-axis component of the stator flux linkage.

[0099] The stator voltage vector is calculated according to the following formula: U s =u sd +j*u sq ; (14) Among them, U s represents the stator voltage vector, u sd represents the d-axis component of the stator voltage, u sq represents the q-axis component of the stator voltage.

[0100] The d-axis stator resistance voltage drop is the product of the stator resistance R s and the d-axis component i sd of the stator current, and the q-axis stator resistance voltage drop is the product of the stator resistance R s and the q-axis component i sq of the stator current.

[0101] The d-axis compensation term of the rotor voltage and the q-axis compensation term of the rotor voltage are calculated according to the following formula: ; (15) Among them, v rdl is the d-axis compensation term of the rotor voltage, v rql is the q-axis compensation term of the rotor voltage, L m is the mutual inductance between the stator and the rotor, L s is the self-inductance of the stator, R s is the stator resistance, U s is the stator voltage vector, i sd is the d-axis component of the stator current, i sq is the q-axis component of the stator current, represents the synchronous electrical angular velocity, represents the d-axis component of the stator flux linkage, represents the q-axis component of the stator flux linkage.

[0102] Furthermore, the target voltage calculation module 206 performs power calculation according to the coordinate transformation result, including: Calculate the actual active power of the stator and the actual reactive power of the stator according to the coordinate transformation result; The rotor angular velocity is calculated based on the rotor position angle of the doubly-fed induction motor; The speed difference is calculated according to the rotor angular velocity and the reference value of the rotor speed, and the speed difference is input into the speed PI controller to obtain the reference value of the stator active power; The difference between the reference value of the stator active power and the actual stator active power is input into the active power PI controller to obtain the reference value of the d-axis component of the rotor current; The closed-loop reactive power is adopted, and the reference value of the q-axis component of the rotor current is calculated according to the actual stator reactive power.

[0103] The actual stator active power and the actual stator reactive power are calculated by the following formula: ; (16) where, P s represents the actual stator active power, Q s represents the actual stator reactive power, U s represents the stator voltage vector, i rd is the d-axis component of the rotor current, i rq is the q-axis component of the rotor current, represents the synchronous electrical angular velocity, L m is the mutual inductance between the stator and the rotor, L s is the self-inductance of the stator.

[0104] Furthermore, the target voltage calculation module 206 calculates the reference value of the rotor target voltage of the doubly-fed induction motor according to the power calculation result, introducing the rotor voltage dynamic compensation term and the magnetic flux calculation result, including: According to the reference value of the d-axis component of the rotor current, the reference value of the q-axis component of the rotor current, the d-axis component of the rotor current, and the q-axis component of the rotor current, an integral link is introduced to calculate the d-axis component and the q-axis component of the rotor voltage; Calculate the d-axis leakage inductance voltage drop of the rotor current and the q-axis leakage inductance voltage drop of the rotor current according to the magnetic flux calculation result; Add the d-axis component of the rotor voltage, the d-axis leakage inductance voltage drop of the rotor current, and the d-axis compensation term of the rotor voltage to obtain the reference value of the d-axis target voltage of the rotor; Add the q-axis component of the rotor voltage, the q-axis leakage inductance voltage drop of the rotor current, and the q-axis compensation term of the rotor voltage to obtain the reference value of the q-axis target voltage of the rotor.

[0105] The d-axis component and the q-axis component of the rotor voltage are calculated by the following formula: ; (17) where, represents the d-axis component of the rotor voltage, represents the q-axis component of the rotor voltage, represents the leakage magnetic coefficient, L r represents the self-inductance of the rotor, represents the reference value of the d-axis component of the rotor current, represents the reference value of the q-axis component of the rotor current, k irp represents the proportional coefficient of the rotor current controller, k iri represents the integral coefficient of the rotor current controller, i rd represents the d-axis component of the rotor current, i rq represents the q-axis component of the rotor current.

[0106] Furthermore, the d-axis leakage inductance voltage drop of the rotor current is the voltage drop generated by the d-axis component of the rotor current on the rotor resistance, minus the coupling voltage generated by the q-axis component of the rotor current and the induced voltage generated by the q-axis component of the stator magnetic flux due to slip; The q-axis leakage inductance voltage drop of the rotor current is the sum of the voltage drop generated by the q-axis component of the rotor current on the rotor resistance, the coupling voltage generated by the d-axis component of the rotor current, and the induced voltage generated by the d-axis component of the stator magnetic flux due to slip.

[0107] The reference values of the d-axis target voltage and the q-axis target voltage of the rotor are calculated by the following formula: ; (18) Wherein, represents the d-axis component of the rotor voltage, represents the q-axis component of the rotor voltage, represents the reference value of the d-axis target voltage of the rotor, represents the reference value of the q-axis target voltage of the rotor, R r represents the rotor resistance, i rd represents the d-axis component of the rotor current, represents the slip electrical angular velocity, represents the leakage magnetic coefficient, L r represents the self-inductance of the rotor, i rq represents the q-axis component of the rotor current, L m represents the mutual inductance between the rotor and the stator, Ls represents the self-inductance of the stator, represents the q-axis component of the stator magnetic flux, represents the d-axis component of the stator magnetic flux, v rdl is the d-axis compensation term of the rotor voltage, v rql is the q-axis compensation term of the rotor voltage.

[0108] Furthermore, the control module 207 generates a control signal according to the reference value of the rotor target voltage to control the doubly-fed induction motor, including: Perform Park inverse transformation on the rotor d-axis target voltage reference value and the rotor q-axis target voltage reference value to obtain the rotor α-target voltage component and the rotor β-target voltage component; Perform space vector modulation based on the rotor α-target voltage component and the rotor β-target voltage component to generate the switching signals required by the rotor-side PWM converter, and control the voltage on the rotor side of the doubly-fed induction motor according to the switching signals.

[0109] The method and device provided in the above embodiments have at least the following beneficial effects: (1) Through the coordinated control of the stator side and the rotor side, the rotor voltage is directly controlled. When applied to the gravity energy storage system, the output power can be quickly adjusted at the moment when the gravitational potential energy is released, avoiding power intermittency and fluctuations caused by impacting the power grid system. It is particularly suitable for the gravity energy storage system. Based on synchronous phase-locked control, it can automatically synchronize with the power grid frequency, eliminating the excitation regulation device of the synchronous motor, simplifying the control system, and effectively improving the system operation stability and energy conversion efficiency; (2) Introducing the rotor voltage dynamic compensation term and the leakage inductance voltage drop to correct the rotor voltage can dynamically cancel the coupling voltage component, further reducing the power fluctuation and improving the dynamic performance, robustness and control accuracy of the system.

[0110] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present invention. Obviously, those skilled in the art can make various changes and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A doubly-fed asynchronous motor synchronous phase-locked control method, characterized in that: include: Collect the stator three-phase voltage, stator three-phase current instantaneous value and rotor three-phase current instantaneous value of the double-fed asynchronous motor; Obtain the grid voltage synchronization phase through a phase-locked loop; Based on the grid voltage synchronization phase, coordinate transformation is performed on the instantaneous value of the stator three-phase current, the instantaneous value of the rotor three-phase current and the stator three-phase voltage to obtain a coordinate transformation result; Performing magnetic flux calculation according to the coordinate transformation result to obtain a magnetic flux calculation result; Calculate the rotor voltage dynamic compensation term according to the coordinate transformation result and the flux calculation result; Perform power calculation according to the coordinate transformation result, and according to the power calculation result, introduce the rotor voltage dynamic compensation term and the flux calculation result to calculate and obtain the rotor target voltage reference value of the doubly-fed asynchronous motor; A control signal is generated according to the rotor target voltage reference value to control the double-fed asynchronous motor.

2. The method according to claim 1, characterized in that After collecting the stator three-phase voltage of the double-fed asynchronous motor, it also includes: The stator three-phase voltage is filtered based on an industrial frequency bandpass filter.

3. The method according to claim 1, characterized in that The coordinate transformation result includes a stator voltage d-axis component, a stator voltage q-axis component, a stator current d-axis component, a stator current q-axis component, a rotor current d-axis component, and a rotor current q-axis component.

4. The method according to claim 1 or 3, characterized in that: Based on the grid voltage synchronization phase, coordinate transformation is performed on the instantaneous value of the stator three-phase current and the stator three-phase voltage, including: Perform Clarke transformation on the instantaneous value of the stator three-phase current and the stator three-phase voltage to obtain the stator voltage component and the stator current component in the two-phase stationary coordinate system; According to the grid voltage synchronization phase, Park transformation is performed based on the component results in the two-phase stationary coordinate system to obtain the stator voltage component and the stator current component in the two-phase rotating coordinate system.

5. The method according to claim 4, characterized in that The stator voltage component results and stator current components in the two-phase stationary coordinate system include a stator voltage α component, a stator voltage β component, a stator current α component and a stator current β component; According to the grid voltage synchronization phase, Park transformation is performed based on the component results in the two-phase stationary coordinate system to obtain the stator voltage component and the stator current component in the two-phase rotating coordinate system, including: A first Park transformation matrix is ​​established according to the synchronous phase of the grid voltage, and a stator voltage d-axis component, a stator voltage q-axis component, a stator current d-axis component and a stator current q-axis component are calculated according to the stator voltage α component, the stator voltage β component, the stator current α component, the stator current β component and the first Park transformation matrix.

6. The method according to claim 1 or 3, characterized in that: Based on the grid voltage synchronization phase, coordinate transformation is performed on the instantaneous value of the rotor three-phase current, including: Performing Clarke transformation on the instantaneous value of the rotor three-phase current to obtain the rotor current component results in a two-phase stationary coordinate system; The rotor position angle of the doubly-fed asynchronous motor is collected, and according to the rotor position angle and the grid voltage synchronization phase, a Park transformation is performed on the rotor current component result in a two-phase stationary coordinate system to obtain the rotor current component result in a two-phase rotating coordinate system.

7. The method according to claim 6, characterized in that The rotor current component results in the two-phase stationary coordinate system include the rotor current α component and the rotor current β component; According to the rotor position angle and the grid voltage synchronization phase, a Park transformation is performed on the rotor current component result in the two-phase stationary coordinate system, including: Establishing a second Park transformation matrix according to the rotor position angle and the grid voltage synchronization phase; The rotor current d-axis component and the rotor current q-axis component are calculated according to the rotor current α component, the rotor current β component and the second Park transformation matrix.

8. The method according to claim 3, characterized in that The flux calculation result includes a stator flux d-axis component and a stator flux q-axis component; Performing magnetic flux calculation according to the coordinate transformation result to obtain the magnetic flux calculation result includes: Obtaining a stator current vector according to the stator current d-axis component and the stator current q-axis component; Obtaining a rotor current vector according to the rotor current d-axis component and the rotor current q-axis component; Obtaining a stator flux vector according to the stator current vector, the rotor current vector, the self-inductance of the stator, and the mutual inductance between the rotor and the stator; The stator flux vector is subjected to coordinate transformation to obtain a stator flux d-axis component and a stator flux q-axis component.

9. The method according to claim 8, characterized in that Performing coordinate transformation on the stator flux vector to obtain a stator flux d-axis component and a stator flux q-axis component includes: Performing Clarke transformation based on the stator flux vector to obtain a stator flux α component and a stator flux β component; Park transformation is performed on the stator flux α component and the stator flux β component according to the grid voltage synchronization phase to obtain the stator flux d-axis component and the stator flux q-axis component.

10. The method according to claim 8, characterized in that The rotor voltage dynamic compensation term is calculated according to the coordinate transformation result and the flux calculation result, including: Obtaining a stator voltage vector according to a stator voltage d-axis component and a stator voltage q-axis component; Obtain the synchronous electrical angular velocity of the doubly-fed asynchronous motor; According to the stator current d-axis component, the stator current q-axis component and the stator resistance, respectively calculating and obtaining a d-axis stator resistance voltage drop and a q-axis stator resistance voltage drop; The rotor voltage d-axis compensation term is calculated based on the mutual inductance between the rotor and the stator, the self-inductance of the stator, the stator voltage vector, the d-axis stator resistance voltage drop, the synchronous electrical angular velocity, and the stator flux d-axis component; The rotor voltage q-axis compensation term is calculated based on the mutual inductance between the rotor and the stator, the self-inductance of the stator, the q-axis stator resistance voltage drop, the synchronous electrical angular velocity, and the q-axis component of the stator flux.

11. The method according to claim 10, characterized in that The power calculation is performed according to the coordinate transformation result, including: According to the coordinate transformation result, calculating the actual active power of the stator and the actual reactive power of the stator; The rotor angular velocity is obtained according to the rotor position angle of the doubly-fed asynchronous motor; Calculating a speed difference value according to the rotor angular velocity and the rotor speed reference value, and inputting the speed difference value into a speed PI controller to obtain a stator active power reference value; The difference between the stator active power reference value and the stator actual active power is input into the active power PI controller to obtain a reference value of the rotor current d-axis component; A reactive power closed loop is adopted to calculate the reference value of the q-axis component of the rotor current according to the actual reactive power of the stator.

12. The method according to claim 11, characterized in that According to the power calculation result, the rotor voltage dynamic compensation term and the flux calculation result are introduced to calculate and obtain the rotor target voltage reference value of the doubly-fed asynchronous motor, including: According to the reference value of the rotor current d-axis component, the reference value of the rotor current q-axis component, the rotor current d-axis component and the rotor current q-axis component, an integral link is introduced to calculate and obtain the rotor voltage d-axis component and the rotor voltage q-axis component; Calculate the rotor current d-axis leakage inductance voltage drop and the rotor current q-axis leakage inductance voltage drop according to the flux calculation result; Adding the rotor voltage d-axis component, the rotor current d-axis leakage inductance voltage drop and the rotor voltage d-axis compensation term to obtain a rotor d-axis target voltage reference value; The rotor voltage q-axis component, the rotor current q-axis leakage inductance voltage drop and the rotor voltage q-axis compensation term are added together to obtain a rotor q-axis target voltage reference value.

13. The method according to claim 12, characterized in that The rotor current d-axis leakage inductance voltage drop is the voltage drop generated by the rotor current d-axis component on the rotor resistance, minus the coupling voltage generated by the rotor current q-axis component and the induced voltage generated by the stator flux q-axis component due to slip; The rotor current q-axis leakage inductance voltage drop is the sum of the voltage drop caused by the rotor current q-axis component on the rotor resistance, the coupling voltage generated by the rotor current d-axis component, and the induced voltage generated by the stator flux d-axis component due to slip.

14. The method according to claim 12, characterized in that Generating a control signal according to the rotor target voltage reference value to control the double-fed asynchronous motor includes: Performing Park inverse transformation on the rotor d-axis target voltage reference value and the rotor q-axis target voltage reference value to obtain a rotor α target voltage component and a rotor β target voltage component; Space vector modulation is performed according to the rotor α target voltage component and the rotor β target voltage component to generate a switching signal required by the rotor-side PWM converter, and the voltage on the rotor side of the double-fed asynchronous motor is controlled according to the switching signal.

15. A doubly-fed asynchronous motor synchronous phase-locked control device, characterized in that: include: An acquisition module is used to acquire the instantaneous value of the stator three-phase voltage, the stator three-phase current and the rotor three-phase current of the double-fed asynchronous motor; A phase-locked loop control module, used for obtaining a synchronous phase of a power grid voltage through a phase-locked loop; A coordinate transformation module, used to perform coordinate transformation on the instantaneous value of the stator three-phase current, the instantaneous value of the rotor three-phase current and the stator three-phase voltage based on the synchronous phase of the grid voltage to obtain a coordinate transformation result; A flux calculation module, used to perform flux calculation according to the coordinate transformation result to obtain a flux calculation result; A compensation calculation module, used for calculating a rotor voltage dynamic compensation term according to the coordinate transformation result and the flux calculation result; A target voltage calculation module is used to perform power calculation according to the coordinate transformation result, and introduce the rotor voltage dynamic compensation term and the flux calculation result to calculate and obtain a rotor target voltage reference value of the doubly-fed asynchronous motor according to the power calculation result; A control module is used to generate a control signal according to the rotor target reference value to control the double-fed asynchronous motor.

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