A synchronous phase-locked control method and device for a doubly-fed asynchronous motor

Abstract

The present invention discloses a synchronous phase-locked control method and device for a doubly-fed asynchronous motor. The method comprises: collecting stator three-phase voltage, stator three-phase current instantaneous value and rotor three-phase current instantaneous value of the doubly-fed asynchronous motor; obtaining grid voltage synchronization phase through a phase-locked loop; performing coordinate transformation on stator three-phase current instantaneous value, rotor three-phase current instantaneous value and stator three-phase voltage based on grid voltage synchronization phase to obtain coordinate transformation result; performing magnetic flux calculation according to the coordinate transformation result to obtain magnetic flux calculation result; calculating rotor voltage dynamic compensation item according to the coordinate transformation result and magnetic flux calculation result; performing power calculation according to the coordinate transformation result, introducing rotor voltage dynamic compensation item and magnetic flux calculation result according to the power calculation result to calculate 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 synchronous phase-locked control method and device for a doubly-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 a motor, lifting a heavy object to a height to store energy. When electricity is needed, the object is lowered, and a generator converts the gravitational potential energy into electrical output. This energy storage method is not restricted by natural conditions and can operate stably in a variety of geographical environments. Furthermore, by precisely controlling the lifting and lowering of the object, the gravity energy storage system enables flexible energy regulation and predictable power output, making it particularly suitable for grid frequency regulation and peak load regulation.

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

[0004] However, synchronous motors have some limitations. For example, they are prone to impacting the mechanical transmission and power grid systems during start-up, shutdown and switching, resulting in power intermittence and fluctuation. Summary of the Invention

[0005] The present invention provides a synchronous phase-locked control method and device for a doubly-fed asynchronous motor, which is 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 doubly-fed asynchronous motor, comprising:

[0007] Collect the stator three-phase voltage, stator three-phase current instantaneous value and rotor three-phase current instantaneous value of the doubly-fed asynchronous motor;

[0008] Obtain the grid voltage synchronization phase through a phase-locked loop;

[0009] 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;

[0010] Performing magnetic flux calculation according to the coordinate transformation result to obtain a magnetic flux calculation result;

[0011] Calculating a rotor voltage dynamic compensation term according to the coordinate transformation result and the flux calculation result;

[0012] Performing power calculation according to the coordinate transformation result, and introducing 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;

[0013] A control signal is generated according to the rotor target voltage reference value to control the doubly-fed asynchronous motor.

[0014] Furthermore, after collecting the stator three-phase voltage of the doubly-fed asynchronous motor, the method further includes:

[0015] The stator three-phase voltage is filtered based on an industrial frequency bandpass filter.

[0016] Furthermore, 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.

[0017] Furthermore, 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:

[0018] 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 stator current component in the two-phase stationary coordinate system;

[0019] 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.

[0020] Furthermore, the stator voltage component results and the stator current component 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;

[0021] 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:

[0022] A first Park transformation matrix is ​​established according to the grid voltage synchronization phase, 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 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.

[0023] Furthermore, based on the grid voltage synchronization phase, coordinate transformation is performed on the instantaneous value of the rotor three-phase current, including:

[0024] Performing Clarke transformation on the instantaneous value of the rotor three-phase current to obtain rotor current component results in a two-phase stationary coordinate system;

[0025] The rotor position angle of the doubly-fed asynchronous motor is collected, and a Park transformation is performed on the rotor current component results in a two-phase stationary coordinate system according to the rotor position angle and the grid voltage synchronization phase to obtain the rotor current component results in a two-phase rotating coordinate system.

[0026] Furthermore, the rotor current component results in the two-phase stationary coordinate system include a rotor current α component and a rotor current β component;

[0027] Performing a Park transformation on the rotor current component results in a two-phase stationary coordinate system according to the rotor position angle and the grid voltage synchronization phase, including:

[0028] Establishing a second Park transformation matrix according to the rotor position angle and the grid voltage synchronization phase;

[0029] The rotor current d-axis component and the rotor current q-axis component are calculated based on the rotor current α component, the rotor current β component and the second Park transformation matrix.

[0030] Furthermore, the flux calculation result includes a stator flux d-axis component and a stator flux q-axis component;

[0031] Performing magnetic flux calculation according to the coordinate transformation result to obtain a magnetic flux calculation result includes:

[0032] Obtaining a stator current vector according to the stator current d-axis component and the stator current q-axis component;

[0033] Obtaining a rotor current vector according to the rotor current d-axis component and the rotor current q-axis component;

[0034] 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;

[0035] Coordinate transformation is performed on the stator flux vector to obtain a stator flux d-axis component and a stator flux q-axis component.

[0036] Furthermore, coordinate transformation is performed on the stator flux vector to obtain a stator flux d-axis component and a stator flux q-axis component, including:

[0037] Performing Clarke transformation based on the stator flux vector to obtain a stator flux α component and a stator flux β component;

[0038] 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.

[0039] Furthermore, the rotor voltage dynamic compensation term is calculated according to the coordinate transformation result and the flux calculation result, including:

[0040] Obtaining a stator voltage vector according to a stator voltage d-axis component and a stator voltage q-axis component;

[0041] Get the synchronous electrical angular velocity of the doubly-fed asynchronous motor;

[0042] Calculating a d-axis stator resistance voltage drop and a q-axis stator resistance voltage drop according to the stator current d-axis component, the stator current q-axis component, and the stator resistance respectively;

[0043] The rotor voltage d-axis compensation term is calculated based on the mutual inductance between the rotor and stator, the stator self-inductance, the stator voltage vector, the d-axis stator resistance voltage drop, the synchronous electrical angular velocity, and the stator flux d-axis component;

[0044] The q-axis compensation term of the rotor voltage is calculated based on the mutual inductance between the rotor and 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.

[0045] Furthermore, power calculation is performed according to the coordinate transformation result, including:

[0046] Calculating the actual active power and the actual reactive power of the stator according to the coordinate transformation result;

[0047] The rotor angular velocity is obtained according to the rotor position angle of the doubly-fed asynchronous motor;

[0048] Calculating a speed difference based on the rotor angular velocity and the rotor speed reference value, and inputting the speed difference into a speed PI controller to obtain a stator active power reference value;

[0049] Inputting the difference between the stator active power reference value and the stator actual active power into the active power PI controller to obtain a reference value of the rotor current d-axis component;

[0050] A reactive power closed loop is adopted to calculate the reference value of the rotor current q-axis component according to the actual reactive power of the stator.

[0051] Furthermore, according to the power calculation result, the rotor voltage dynamic compensation term and the flux calculation result are introduced to calculate the rotor target voltage reference value of the doubly-fed asynchronous motor, including:

[0052] 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 the rotor voltage d-axis component and the rotor voltage q-axis component;

[0053] Calculating 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;

[0054] 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;

[0055] 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 to obtain a rotor q-axis target voltage reference value.

[0056] Furthermore, 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;

[0057] 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 caused by the rotor current d-axis component, and the induced voltage caused by the stator flux d-axis component due to slip.

[0058] Furthermore, generating a control signal according to the rotor target voltage reference value to control the doubly-fed asynchronous motor includes:

[0059] Performing a Park inverse transform 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;

[0060] 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 doubly-fed asynchronous motor is controlled according to the switching signal.

[0061] A doubly-fed asynchronous motor synchronous phase-locked control device, comprising:

[0062] An acquisition module is used 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 asynchronous motor;

[0063] A phase-locked loop control module is used to obtain the grid voltage synchronization phase through a phase-locked loop;

[0064] A coordinate transformation module is 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;

[0065] A magnetic flux calculation module, configured to perform magnetic flux calculation according to the coordinate transformation result to obtain a magnetic flux calculation result;

[0066] A compensation calculation module, configured to calculate a rotor voltage dynamic compensation term based on the coordinate transformation result and the flux calculation result;

[0067] a target voltage calculation module, configured to perform power calculation according to the coordinate transformation result, and introduce the rotor voltage dynamic compensation term and the flux calculation result according to the power calculation result to obtain a rotor target voltage reference value of the doubly-fed asynchronous motor;

[0068] A control module is used to generate a control signal according to the rotor target reference value to control the doubly-fed asynchronous motor.

[0069] Furthermore, after the acquisition module acquires the stator three-phase voltage of the doubly-fed asynchronous motor, it further includes:

[0070] The stator three-phase voltage is filtered based on an industrial frequency bandpass filter.

[0071] Furthermore, 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.

[0072] Furthermore, the coordinate transformation module performs coordinate transformation on the instantaneous value of the stator three-phase current and the stator three-phase voltage based on the grid voltage synchronization phase, including:

[0073] 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 stator current component in the two-phase stationary coordinate system;

[0074] 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.

[0075] Furthermore, the stator voltage component results and the stator current component 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;

[0076] The coordinate transformation module performs Park transformation based on the component results in the two-phase stationary coordinate system according to the grid voltage synchronization phase to obtain the stator voltage component and the stator current component in the two-phase rotating coordinate system, including:

[0077] A first Park transformation matrix is ​​established according to the grid voltage synchronization phase, 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 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.

[0078] Furthermore, the coordinate transformation module performs coordinate transformation on the instantaneous value of the rotor three-phase current based on the grid voltage synchronization phase, including:

[0079] Performing Clarke transformation on the instantaneous value of the rotor three-phase current to obtain rotor current component results in a two-phase stationary coordinate system;

[0080] The rotor position angle of the doubly-fed asynchronous motor is collected, and a Park transformation is performed on the rotor current component results in a two-phase stationary coordinate system according to the rotor position angle and the grid voltage synchronization phase to obtain the rotor current component results in a two-phase rotating coordinate system.

[0081] Furthermore, the rotor current component results in the two-phase stationary coordinate system include a rotor current α component and a rotor current β component;

[0082] 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 grid voltage synchronization phase, including:

[0083] Establishing a second Park transformation matrix according to the rotor position angle and the grid voltage synchronization phase;

[0084] The rotor current d-axis component and the rotor current q-axis component are calculated based on the rotor current α component, the rotor current β component and the second Park transformation matrix.

[0085] Furthermore, the flux calculation result includes a stator flux d-axis component and a stator flux q-axis component;

[0086] The magnetic flux calculation module performs magnetic flux calculation according to the coordinate transformation result to obtain a magnetic flux calculation result, including:

[0087] Obtaining a stator current vector according to the stator current d-axis component and the stator current q-axis component;

[0088] Obtaining a rotor current vector according to the rotor current d-axis component and the rotor current q-axis component;

[0089] 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;

[0090] Coordinate transformation is performed on the stator flux vector to obtain a stator flux d-axis component and a stator flux q-axis component.

[0091] Furthermore, the flux calculation module performs coordinate transformation on the stator flux vector to obtain a stator flux d-axis component and a stator flux q-axis component, including:

[0092] Performing Clarke transformation based on the stator flux vector to obtain a stator flux α component and a stator flux β component;

[0093] 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.

[0094] Furthermore, the compensation calculation module calculates the rotor voltage dynamic compensation term according to the coordinate transformation result and the flux calculation result, including:

[0095] Obtaining a stator voltage vector according to a stator voltage d-axis component and a stator voltage q-axis component;

[0096] Get the synchronous electrical angular velocity of the doubly-fed asynchronous motor;

[0097] Calculating a d-axis stator resistance voltage drop and a q-axis stator resistance voltage drop according to the stator current d-axis component, the stator current q-axis component, and the stator resistance respectively;

[0098] The rotor voltage d-axis compensation term is calculated based on the mutual inductance between the rotor and stator, the stator self-inductance, the stator voltage vector, the d-axis stator resistance voltage drop, the synchronous electrical angular velocity, and the stator flux d-axis component;

[0099] The q-axis compensation term of the rotor voltage is calculated based on the mutual inductance between the rotor and 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.

[0100] Furthermore, the target voltage calculation module performs power calculation according to the coordinate transformation result, including:

[0101] Calculating the actual active power and the actual reactive power of the stator according to the coordinate transformation result;

[0102] The rotor angular velocity is obtained according to the rotor position angle of the doubly-fed asynchronous motor;

[0103] Calculating a speed difference based on the rotor angular velocity and the rotor speed reference value, and inputting the speed difference into a speed PI controller to obtain a stator active power reference value;

[0104] Inputting the difference between the stator active power reference value and the stator actual active power into the active power PI controller to obtain a reference value of the rotor current d-axis component;

[0105] A reactive power closed loop is adopted to calculate the reference value of the rotor current q-axis component according to the actual reactive power of the stator.

[0106] Furthermore, the target voltage calculation module introduces the rotor voltage dynamic compensation term and the flux calculation result to calculate the rotor target voltage reference value of the doubly-fed asynchronous motor according to the power calculation result, including:

[0107] 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 the rotor voltage d-axis component and the rotor voltage q-axis component;

[0108] Calculating 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;

[0109] 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;

[0110] 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 to obtain a rotor q-axis target voltage reference value.

[0111] Furthermore, 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;

[0112] 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 caused by the rotor current d-axis component, and the induced voltage caused by the stator flux d-axis component due to slip.

[0113] Furthermore, the control module generates a control signal according to the rotor target voltage reference value to control the doubly-fed asynchronous motor, including:

[0114] Performing a Park inverse transform 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;

[0115] 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 doubly-fed asynchronous motor is controlled according to the switching signal.

[0116] The method and device for synchronous phase-locked control of a doubly-fed asynchronous motor provided by the present invention have at least the following beneficial effects:

[0117] (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 of gravitational potential energy release to avoid power interruption and fluctuation caused by the impact on the power grid system. It is particularly suitable for gravity energy storage systems. Based on synchronous phase-locked control, it can automatically synchronize the grid frequency, eliminate the excitation regulation device of the synchronous motor, simplify the control system, and effectively improve the system operation stability and energy conversion efficiency.

[0118] (2) The introduction of rotor voltage dynamic compensation terms and leakage inductance voltage drop correction to the rotor voltage can dynamically offset the coupled voltage component, further reduce power fluctuations, and improve the dynamic performance, robustness, and control accuracy of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0119] Figure 1 The present invention provides a flowchart of a method for synchronous phase-locked control of a doubly-fed asynchronous motor according to an embodiment of the present invention.

[0120] Figure 2 This is a structural schematic diagram of an embodiment of a synchronous phase-locked control device for a doubly-fed asynchronous motor provided by the present invention. DETAILED DESCRIPTION

[0121] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0122] refer to Figure 1 In some embodiments, a method for synchronous phase-locked control of a doubly-fed asynchronous motor is provided, comprising:

[0123] S1, collecting the instantaneous values ​​of the stator three-phase voltage, stator three-phase current and rotor three-phase current of the doubly-fed asynchronous motor;

[0124] S2, obtaining the grid voltage synchronization phase through a phase-locked loop;

[0125] S3. Based on the grid voltage synchronization phase, performing 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 to obtain a coordinate transformation result;

[0126] S4, performing magnetic flux calculation according to the coordinate transformation result to obtain a magnetic flux calculation result;

[0127] S5. Calculating a rotor voltage dynamic compensation term according to the coordinate transformation result and the flux calculation result;

[0128] S6. Perform power calculation according to the coordinate transformation result, and introduce the rotor voltage dynamic compensation term and the flux calculation result according to the power calculation result to calculate a rotor target voltage reference value of the doubly-fed asynchronous motor;

[0129] S7. Generate a control signal according to the rotor target voltage reference value to control the doubly-fed asynchronous motor.

[0130] Specifically, in step S1, the stator three-phase voltage u of the doubly fed asynchronous motor is collected by a sensor. sa_mea 、u sb_mea 、u sc_mea , stator three-phase current instantaneous value i sa_mea 、i sb_mea 、i sc_mea And the instantaneous value of the rotor three-phase current i ra_mea 、i rb_mea 、i rc_mea .

[0131] Furthermore, in some embodiments, after collecting the stator three-phase voltage of the doubly-fed asynchronous motor, the method further includes:

[0132] The stator three-phase voltage is filtered based on an industrial frequency bandpass filter.

[0133] In step S2, the grid voltage synchronization phase q is obtained through the phase-locked loop l .

[0134] Further, in step S3, 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.

[0135] In step S3, coordinate transformation is performed on the instantaneous value of the stator three-phase current and the stator three-phase voltage after filtering based on the grid voltage synchronization phase, including:

[0136] S31. 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 a two-phase stationary coordinate system;

[0137] S32. Perform Park transformation based on the component results in the two-phase stationary coordinate system according to the grid voltage synchronization phase to obtain the stator voltage component and the stator current component in the two-phase rotating coordinate system.

[0138] Specifically, in step S31, Clarke transformation is performed on the instantaneous value 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. 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 current α component, and the stator current β component, which are respectively as follows:

[0139] ; (1)

[0140] ; (2)

[0141] Among them, u sα represents the stator voltage α component, u sβ represents the stator voltage β component, k mea Indicates the conversion coefficient, 0≤k mea ≥1, you can select appropriate parameters according to control requirements, u sa_mea 、u sb_mea 、u sc_mea is the stator three-phase voltage, 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 Indicates the instantaneous value of the stator three-phase current.

[0142] Furthermore, in step S32, 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:

[0143] A first Park transformation matrix is ​​established according to the grid voltage synchronization phase, 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 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.

[0144] Specifically, the first Park transformation matrix is ​​as follows:

[0145] ; (3)

[0146] Among them, θ l Indicates the grid voltage synchronization phase.

[0147] The stator voltage d-axis component, stator voltage q-axis component, stator current d-axis component, and stator current q-axis component are calculated using the following formulas:

[0148] ; (4)

[0149] ; (5)

[0150] 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 stator voltage α component, u sβ represents the stator voltage β component, i sα represents the stator current α component, i sβ represents the stator current β component, θ l Indicates the grid voltage synchronization phase.

[0151] Furthermore, in step S3, coordinate transformation is performed on the instantaneous value of the rotor three-phase current based on the grid voltage synchronization phase, including:

[0152] S33, 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;

[0153] S34. Collect the rotor position angle of the doubly-fed asynchronous motor, and perform Park transformation on the rotor current component results in the two-phase stationary coordinate system according to the rotor position angle and the grid voltage synchronization phase to obtain the rotor current component results in the two-phase rotating coordinate system.

[0154] 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:

[0155] ; (6)

[0156] Among them, 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 Indicates the instantaneous value of the rotor three-phase current.

[0157] Furthermore, in step S34 , the rotor current component results in the two-phase stationary coordinate system include a rotor current α component and a rotor current β component.

[0158] The rotor position angle of the doubly-fed asynchronous motor is collected, and a Park transform is performed on the rotor current component results in a two-phase stationary coordinate system according to the rotor position angle and the grid voltage synchronization phase to obtain the rotor current component results in a two-phase rotating coordinate system, including:

[0159] Establishing a second Park transformation matrix according to the rotor position angle and the grid voltage synchronization phase;

[0160] The rotor current d-axis component and the rotor current q-axis component are calculated based on the rotor current α component, the rotor current β component and the second Park transformation matrix.

[0161] Specifically, the second Park transformation matrix is ​​as follows:

[0162] ; (7)

[0163] Among them, θ l It represents the synchronous phase of the grid voltage, and θr represents the rotor position angle, which is obtained through the optical encoder.

[0164] Furthermore, the rotor current d-axis component and the rotor current q-axis component are calculated using the following formulas:

[0165] ; (8)

[0166] in, θ l represents the grid voltage synchronization phase, θr represents the rotor position angle, i rα represents the rotor current α component, i rβ represents the rotor current β component, i rd represents the d-axis component of the rotor current, i rq Represents the q-axis component of the rotor current.

[0167] Furthermore, in step S4, the flux calculation result includes a stator flux d-axis component and a stator flux q-axis component.

[0168] Specifically, performing magnetic flux calculation according to the coordinate transformation result to obtain the magnetic flux calculation result includes:

[0169] S41. Obtaining a stator current vector according to the stator current d-axis component and the stator current q-axis component;

[0170] S42, obtaining a rotor current vector according to the rotor current d-axis component and the rotor current q-axis component;

[0171] S43, 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;

[0172] S44 . Perform coordinate transformation on the stator flux vector to obtain a stator flux d-axis component and a stator flux q-axis component.

[0173] Specifically, in step S41, the stator current vector is calculated according to the following formula:

[0174] I s =i sd +j*i sq ; (9)

[0175] Among them, I s represents the stator current vector, i sd represents the d-axis component of the stator current, i sq Represents the q-axis component of the stator current.

[0176] Furthermore, in step S42, the rotor current vector is calculated according to the following formula:

[0177] I r =i rd +j*i rq ; (10)

[0178] Among them, 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.

[0179] Furthermore, in step S43, the stator flux vector is calculated according to the following formula:

[0180] ; (11)

[0181] in, represents the stator flux vector, I s Represents the stator current vector, I r Represents the rotor current vector, L s represents the stator's self-inductance, L m represents the mutual inductance between the rotor and stator.

[0182] Furthermore, in step S44, coordinate transformation is performed on the stator flux vector to obtain a stator flux d-axis component and a stator flux q-axis component, which specifically includes:

[0183] Performing Clarke transformation based on the stator flux vector to obtain a stator flux α component and a stator flux β component;

[0184] 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.

[0185] The specific calculation formula is as follows:

[0186] ; (12)

[0187] ; (13)

[0188] in, represents the d-axis component of the stator flux, represents the q-axis component of the stator flux, represents the stator flux α component, represents the stator flux β component, θ l Indicates the grid voltage synchronization phase.

[0189] Furthermore, in step S5, a rotor voltage dynamic compensation term is calculated according to the coordinate transformation result and the flux calculation result, including:

[0190] S51. Obtaining a stator voltage vector according to a stator voltage d-axis component and a stator voltage q-axis component;

[0191] S52, obtaining the synchronous electrical angular velocity of the doubly-fed asynchronous motor;

[0192] S53, calculating a d-axis stator resistance voltage drop and a q-axis stator resistance voltage drop according to the stator current d-axis component, the stator current q-axis component, and the stator resistance;

[0193] S54, calculating a rotor voltage d-axis compensation term 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;

[0194] S55. Calculate and obtain a rotor voltage q-axis compensation term 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.

[0195] Specifically, in step S51, the stator voltage vector is calculated according to the following formula:

[0196] U s =u sd +j*u sq ; (14)

[0197] 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.

[0198] Furthermore, in step S52, the synchronous electrical angular velocity of the doubly-fed asynchronous motor is obtained. .

[0199] Furthermore, in step S53, the d-axis stator resistance voltage drop is the stator resistance R s and the stator current d-axis component i sd The product of the q-axis stator resistance voltage drop is the stator resistance R s and the stator current q-axis component i sq The product of .

[0200] Furthermore, in step S54 and step S55, the rotor voltage d-axis compensation term and the rotor voltage q-axis compensation term are calculated according to the following formula:

[0201] ; (15)

[0202] Among them, v rdl is the rotor voltage d-axis compensation term, v rql is the rotor voltage q-axis compensation term, L m is the mutual inductance between the stator and the rotor, L s is the stator's self-inductance, 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, Represents the q-axis component of the stator flux.

[0203] Furthermore, in step S6, power calculation is performed according to the coordinate transformation result, including:

[0204] S61. Calculating the stator actual active power and the stator actual reactive power according to the coordinate transformation result;

[0205] S62, calculating and obtaining a rotor angular velocity according to a rotor position angle of the doubly-fed asynchronous motor;

[0206] S63, calculating a 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 a stator active power reference value;

[0207] S64, inputting the difference between the stator active power reference value and the stator actual active power into an active power PI controller to obtain a reference value of the rotor current d-axis component;

[0208] S65 , using a reactive power closed loop, and calculating a reference value of the rotor current q-axis component according to the actual reactive power of the stator.

[0209] Specifically, in step S61, the stator actual active power and the stator actual reactive power are calculated using the following formula:

[0210] ; (16)

[0211] Among them, P s Indicates the actual active power of the stator, Q s Indicates the actual reactive power of the stator, 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.

[0212] It can be seen that when the d-axis stator voltage orientation is adopted, the d-axis component of the rotor current i rd is the active current component, and the rotor current q-axis component i rq If it is the reactive current component, the stator output active and reactive power can be decoupled by independently adjusting the rotor d-axis and q-axis currents respectively.

[0213] Based on this, for the rotor current d-axis component reference value, the rotor speed reference value can be converted to The actual rotor angular velocity The speed error formed by comparison is input into the speed PI controller to obtain the stator active power reference value P s_ref .

[0214] Specifically, in step S62, the rotor angular velocity is calculated based on the rotor position angle of the doubly fed asynchronous motor. .

[0215] In step S63, according to the rotor angular velocity and rotor speed reference Calculate the speed difference and input it into the speed PI controller to obtain the stator active power reference value P s_ref .

[0216] In step S64, the stator active power reference value P s_ref and the actual active power P of the stator s The error between them is input to the active power PI controller to obtain the reference value of the rotor current d-axis component.

[0217] In step S65 , the reactive power reference value Qs_ref is adjusted according to the demand of the power grid and is generally set to 0. The reference value of the q-axis component of the rotor current is obtained through the reactive power closed loop.

[0218] Furthermore, in step S6, based on 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:

[0219] S66, introducing an integration link based on 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, to calculate and obtain the rotor voltage d-axis component and the rotor voltage q-axis component;

[0220] S67, calculating 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;

[0221] S68, 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;

[0222] S69: Add the rotor voltage q-axis component, the rotor current q-axis leakage inductance voltage drop, and the rotor voltage q-axis compensation term to obtain a rotor q-axis target voltage reference value.

[0223] Specifically, in step S66, the rotor voltage d-axis component and the rotor voltage q-axis component are calculated using the following formula:

[0224] ; (17)

[0225] in, represents the d-axis component of the rotor voltage, represents the q-axis component of the rotor voltage, Indicates the magnetic flux leakage coefficient, L r represents the self-inductance of the rotor, represents the reference value of the d-axis component of the rotor current, Indicates 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 Indicates 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.

[0226] Furthermore, in step S67, 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, that is, In this formula, the first term is the voltage drop caused by the d-axis component of the rotor current on 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 slip. r represents the rotor resistance, i rd represents the d-axis component of the rotor current, represents the slip electrical angular velocity, Indicates the magnetic flux leakage coefficient, L r represents the rotor's self-inductance, 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 flux.

[0227] 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, that is, In this calculation formula, the first term is the voltage drop caused by the q-axis component of the rotor current on 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 slip. r represents the rotor resistance, i rq represents the q-axis component of the rotor current, represents the slip electrical angular velocity, Indicates the magnetic flux leakage coefficient, L r represents the rotor's self-inductance, i rd represents the d-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 d-axis component of the stator flux.

[0228] Furthermore, in step S68 and step S69, the rotor d-axis target voltage reference value and the rotor q-axis target voltage reference value are calculated using the following formula:

[0229] ; (18)

[0230] in, represents the d-axis component of the rotor voltage, represents the q-axis component of the rotor voltage, Indicates the rotor d-axis target voltage reference value, Indicates the rotor q-axis target voltage reference value, R r represents the rotor resistance, i rd represents the d-axis component of the rotor current, represents the slip electrical angular velocity, Indicates the magnetic leakage coefficient, Lr represents the rotor's self-inductance, 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 flux, represents the d-axis component of the stator flux, v rdl is the rotor voltage d-axis compensation term, v rql is the rotor voltage q-axis compensation term.

[0231] Furthermore, in step S7, generating a control signal according to the rotor target voltage reference value to control the doubly-fed asynchronous motor includes:

[0232] Performing a Park inverse transform 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;

[0233] 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 doubly-fed asynchronous motor is controlled according to the switching signal.

[0234] refer to Figure 2 In some embodiments, a doubly-fed asynchronous motor synchronous phase-locked control device is provided, comprising:

[0235] The acquisition module 201 is used 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 asynchronous motor;

[0236] A phase-locked loop control module 202 is configured to obtain a synchronous phase of a power grid voltage through a phase-locked loop;

[0237] A coordinate transformation module 203 is configured 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;

[0238] A magnetic flux calculation module 204 is configured to perform magnetic flux calculation according to the coordinate transformation result to obtain a magnetic flux calculation result;

[0239] A compensation calculation module 205 is configured to calculate a rotor voltage dynamic compensation term based on the coordinate transformation result and the flux calculation result;

[0240] a target voltage calculation module 206 for performing power calculation according to the coordinate transformation result, and introducing the rotor voltage dynamic compensation term and the flux calculation result to calculate a rotor target voltage reference value of the doubly-fed asynchronous motor according to the power calculation result;

[0241] The control module 207 is configured to generate a control signal according to the rotor target reference value to control the doubly-fed asynchronous motor.

[0242] Furthermore, after the acquisition module 201 acquires the stator three-phase voltage of the doubly-fed asynchronous motor, the acquisition module 201 further includes:

[0243] The stator three-phase voltage is filtered based on the power frequency bandpass filter

[0244] Furthermore, 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.

[0245] Furthermore, the coordinate transformation module 203 performs coordinate transformation on the instantaneous value of the stator three-phase current and the stator three-phase voltage based on the grid voltage synchronization phase, including:

[0246] 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 results and stator current component results in the two-phase stationary coordinate system;

[0247] 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.

[0248] Furthermore, the stator voltage component results and the stator current component 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;

[0249] They are as follows:

[0250] ; (1)

[0251] ; (2)

[0252] Among them, u sα represents the stator voltage α component, u sβ represents the stator voltage β component, k mea Indicates the conversion coefficient, 0≤k mea ≥1, you can select appropriate parameters according to control requirements, u sa_mea 、u sb_mea 、u sc_mea is the stator three-phase voltage, 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 Indicates the instantaneous value of the stator three-phase current.

[0253] The coordinate transformation module performs Park transformation based on the component results in the two-phase stationary coordinate system according to the grid voltage synchronization phase to obtain the stator voltage component and the stator current component in the two-phase rotating coordinate system, including:

[0254] A first Park transformation matrix is ​​established according to the grid voltage synchronization phase, 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 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.

[0255] Specifically, the first Park transformation matrix is ​​as follows:

[0256] ; (3)

[0257] Among them, θ l Indicates the grid voltage synchronization phase.

[0258] The stator voltage d-axis component, stator voltage q-axis component, stator current d-axis component, and stator current q-axis component are calculated using the following formulas:

[0259] ; (4)

[0260] ; (5)

[0261] 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 stator voltage α component, u sβ represents the stator voltage β component, i sα represents the stator current α component, i sβ represents the stator current β component, θ l Indicates the grid voltage synchronization phase.

[0262] Furthermore, the coordinate transformation module 203 performs coordinate transformation on the instantaneous value of the rotor three-phase current based on the grid voltage synchronization phase, including:

[0263] Performing Clarke transformation on the instantaneous value of the rotor three-phase current to obtain rotor current component results in a two-phase stationary coordinate system;

[0264] The rotor position angle of the doubly-fed asynchronous motor is collected, and a Park transformation is performed on the rotor current component results in a two-phase stationary coordinate system according to the rotor position angle and the grid voltage synchronization phase to obtain the rotor current component results in a two-phase rotating coordinate system.

[0265] 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 formula is as follows:

[0266] ; (6)

[0267] Among them, 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 Indicates the instantaneous value of the rotor three-phase current.

[0268] 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 grid voltage synchronization phase, including:

[0269] Establishing a second Park transformation matrix according to the rotor position angle and the grid voltage synchronization phase;

[0270] The rotor current d-axis component and the rotor current q-axis component are calculated based on the rotor current α component, the rotor current β component and the second Park transformation matrix.

[0271] Specifically, the second Park transformation matrix is ​​as follows:

[0272] ; (7)

[0273] in, θ l It represents the synchronous phase of the grid voltage, and θr represents the rotor position angle, which is obtained through the optical encoder.

[0274] Furthermore, the rotor current d-axis component and the rotor current q-axis component are calculated using the following formulas:

[0275] ; (8)

[0276] in, θ l represents the grid voltage synchronization phase, θr represents the rotor position angle, i rα represents the rotor current α component, i rβ represents the rotor current β component, i rd represents the d-axis component of the rotor current, i rqRepresents the q-axis component of the rotor current.

[0277] Furthermore, the flux calculation results include the stator flux d-axis component and the stator flux q-axis component;

[0278] The magnetic flux calculation module 204 performs magnetic flux calculation according to the coordinate transformation result to obtain a magnetic flux calculation result, including:

[0279] Obtaining a stator current vector according to the stator current d-axis component and the stator current q-axis component;

[0280] Obtaining a rotor current vector according to the rotor current d-axis component and the rotor current q-axis component;

[0281] 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;

[0282] Coordinate transformation is performed on the stator flux vector to obtain a stator flux d-axis component and a stator flux q-axis component.

[0283] The stator current vector is calculated according to the following formula:

[0284] I s =i sd +j*i sq ; (9)

[0285] Among them, I s represents the stator current vector, i sd represents the d-axis component of the stator current, i sq Represents the q-axis component of the stator current.

[0286] The rotor current vector is calculated according to the following formula:

[0287] I r =i rd +j*i rq ; (10)

[0288] Among them, 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.

[0289] The stator flux vector is calculated according to the following formula:

[0290] ; (11)

[0291] in, represents the stator flux vector, I s Represents the stator current vector, I rRepresents the rotor current vector, L s represents the stator's self-inductance, L m represents the mutual inductance between the rotor and stator.

[0292] Furthermore, the flux calculation module performs coordinate transformation on the stator flux vector to obtain a stator flux d-axis component and a stator flux q-axis component, including:

[0293] Performing Clarke transformation based on the stator flux vector to obtain a stator flux α component and a stator flux β component;

[0294] 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.

[0295] The specific calculation formula is as follows:

[0296] ; (12)

[0297] ; (13)

[0298] in, represents the d-axis component of the stator flux, represents the q-axis component of the stator flux, represents the stator flux α component, represents the stator flux β component, θ l Indicates the grid voltage synchronization phase.

[0299] Furthermore, the compensation calculation module 205 calculates the rotor voltage dynamic compensation term according to the coordinate transformation result and the flux calculation result, including:

[0300] Obtaining a stator voltage vector according to a stator voltage d-axis component and a stator voltage q-axis component;

[0301] Get the synchronous electrical angular velocity of the doubly-fed asynchronous motor;

[0302] Calculating a d-axis stator resistance voltage drop and a q-axis stator resistance voltage drop according to the stator current d-axis component, the stator current q-axis component, and the stator resistance respectively;

[0303] The rotor voltage d-axis compensation term is calculated based on the mutual inductance between the rotor and stator, the stator self-inductance, the stator voltage vector, the d-axis stator resistance voltage drop, the synchronous electrical angular velocity, and the stator flux d-axis component;

[0304] The q-axis compensation term of the rotor voltage is calculated based on the mutual inductance between the rotor and 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.

[0305] The stator voltage vector is calculated according to the following formula:

[0306] U s =u sd +j*u sq ; (14)

[0307] 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.

[0308] The d-axis stator resistance voltage drop is the stator resistance R s and the stator current d-axis component i sd The product of the q-axis stator resistance voltage drop is the stator resistance R s and the stator current q-axis component i sq The product of .

[0309] The rotor voltage d-axis compensation term and the rotor voltage q-axis compensation term are calculated according to the following formula:

[0310] ; (15)

[0311] Among them, v rdl is the rotor voltage d-axis compensation term, v rql is the rotor voltage q-axis compensation term, L m is the mutual inductance between the stator and the rotor, L s is the stator's self-inductance, 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, Represents the q-axis component of the stator flux.

[0312] Furthermore, the target voltage calculation module 206 performs power calculation according to the coordinate transformation result, including:

[0313] Calculating the actual active power and the actual reactive power of the stator according to the coordinate transformation result;

[0314] The rotor angular velocity is obtained according to the rotor position angle of the doubly-fed asynchronous motor;

[0315] Calculating a speed difference based on the rotor angular velocity and the rotor speed reference value, and inputting the speed difference into a speed PI controller to obtain a stator active power reference value;

[0316] Inputting the difference between the stator active power reference value and the stator actual active power into the active power PI controller to obtain a reference value of the rotor current d-axis component;

[0317] A reactive power closed loop is adopted to calculate the reference value of the rotor current q-axis component according to the actual reactive power of the stator.

[0318] The stator actual active power and stator actual reactive power are calculated using the following formulas:

[0319] ; (16)

[0320] Among them, P s Indicates the actual active power of the stator, Q s Indicates the actual reactive power of the stator, 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.

[0321] Furthermore, the target voltage calculation module 206 calculates the rotor target voltage reference value of the doubly-fed asynchronous motor by introducing the rotor voltage dynamic compensation term and the flux calculation result according to the power calculation result, including:

[0322] 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 the rotor voltage d-axis component and the rotor voltage q-axis component;

[0323] Calculating 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;

[0324] 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;

[0325] 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 to obtain a rotor q-axis target voltage reference value.

[0326] The rotor voltage d-axis component and the rotor voltage q-axis component are calculated using the following formulas:

[0327] ; (17)

[0328] in, represents the d-axis component of the rotor voltage, represents the q-axis component of the rotor voltage, Indicates the magnetic flux leakage coefficient, L r represents the self-inductance of the rotor, represents the reference value of the d-axis component of the rotor current, Indicates 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 Indicates 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.

[0329] Furthermore, 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;

[0330] 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 caused by the rotor current d-axis component, and the induced voltage caused by the stator flux d-axis component due to slip.

[0331] The rotor d-axis target voltage reference value and the rotor q-axis target voltage reference value are calculated using the following formulas:

[0332] ; (18)

[0333] in, represents the d-axis component of the rotor voltage, represents the q-axis component of the rotor voltage, Indicates the rotor d-axis target voltage reference value, Indicates the rotor q-axis target voltage reference value, R r represents the rotor resistance, i rd represents the d-axis component of the rotor current, represents the slip electrical angular velocity, Indicates the magnetic leakage coefficient, L r represents the rotor's self-inductance, 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 flux, represents the d-axis component of the stator flux, v rdl is the rotor voltage d-axis compensation term, v rql is the rotor voltage q-axis compensation term.

[0334] Furthermore, the control module 207 generates a control signal according to the rotor target voltage reference value to control the doubly-fed asynchronous motor, including:

[0335] Performing a Park inverse transform 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;

[0336] 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 doubly-fed asynchronous motor is controlled according to the switching signal.

[0337] The methods and devices provided in the above embodiments have at least the following beneficial effects:

[0338] (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 of gravitational potential energy release to avoid power interruption and fluctuation caused by the impact on the power grid system. It is particularly suitable for gravity energy storage systems. Based on synchronous phase-locked control, it can automatically synchronize the grid frequency, eliminate the excitation regulation device of the synchronous motor, simplify the control system, and effectively improve the system operation stability and energy conversion efficiency.

[0339] (2) The introduction of rotor voltage dynamic compensation terms and leakage inductance voltage drop correction to the rotor voltage can dynamically offset the coupled voltage component, further reduce power fluctuations, and improve the dynamic performance, robustness, and control accuracy of the system.

[0340] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the invention. Thus, the present invention is intended to include such changes and modifications as fall within the scope of the claims and their equivalents.

Claims

1. A synchronous phase-locked control method for a doubly-fed asynchronous motor, 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 doubly-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; Calculating a rotor voltage dynamic compensation term based on the coordinate transformation result and the flux calculation result; Performing power calculation according to the coordinate transformation result, and introducing 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 signal is generated according to the rotor target voltage reference value to control the doubly-fed asynchronous motor.

2. The method according to claim 1, characterized in that After collecting the stator three-phase voltage of the doubly-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 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 component results 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; 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 grid voltage synchronization phase, 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 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.

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 rotor current component results in a two-phase stationary coordinate system; The rotor position angle of the doubly-fed asynchronous motor is collected, and a Park transformation is performed on the rotor current component results in a two-phase stationary coordinate system according to the rotor position angle and the grid voltage synchronization phase to obtain the rotor current component results 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; Performing a Park transformation on the rotor current component results in a two-phase stationary coordinate system according to the rotor position angle and the grid voltage synchronization phase, 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 based on 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 results include the stator flux d-axis component and the stator flux q-axis component; Performing magnetic flux calculation according to the coordinate transformation result to obtain a 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; Coordinate transformation is performed on the stator flux vector 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 Calculating the rotor voltage dynamic compensation term according to the coordinate transformation result and the flux calculation result includes: Obtaining a stator voltage vector according to a stator voltage d-axis component and a stator voltage q-axis component; Get the synchronous electrical angular velocity of the doubly-fed asynchronous motor; Calculating a d-axis stator resistance voltage drop and a q-axis stator resistance voltage drop according to the stator current d-axis component, the stator current q-axis component, and the stator resistance respectively; The rotor voltage d-axis compensation term is calculated based on the mutual inductance between the rotor and stator, the stator self-inductance, the stator voltage vector, the d-axis stator resistance voltage drop, the synchronous electrical angular velocity, and the stator flux d-axis component; The q-axis compensation term of the rotor voltage is calculated based on the mutual inductance between the rotor and 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 Performing power calculation according to the coordinate transformation result includes: Calculating the actual active power and the actual reactive power of the stator according to the coordinate transformation result; The rotor angular velocity is obtained according to the rotor position angle of the doubly-fed asynchronous motor; Calculating a speed difference based on the rotor angular velocity and the rotor speed reference value, and inputting the speed difference into a speed PI controller to obtain a stator active power reference value; Inputting the difference between the stator active power reference value and the stator actual active power 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 rotor current q-axis component 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 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 the rotor voltage d-axis component and the rotor voltage q-axis component; Calculating 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 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 caused by the rotor current d-axis component, and the induced voltage caused 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 doubly-fed asynchronous motor includes: Performing a Park inverse transform 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 doubly-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 values ​​of the stator three-phase voltage, the stator three-phase current and the rotor three-phase current of the doubly-fed asynchronous motor; A phase-locked loop control module is used to obtain the grid voltage synchronization phase through a phase-locked loop; A coordinate transformation module is 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 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 a rotor voltage dynamic compensation term based on the coordinate transformation result and the flux calculation result; a target voltage calculation module, configured to perform power calculation according to the coordinate transformation result, and introduce the rotor voltage dynamic compensation term and the flux calculation result according to the power calculation result to obtain a rotor target voltage reference value of the doubly-fed asynchronous motor; A control module is used to generate a control signal according to the rotor target voltage reference value to control the doubly-fed asynchronous motor.

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