Shafting oscillation suppression method based on dq-axis voltage instruction mixed resistance increase for grid-forming type doubly-fed wind turbine generator

Abstract

The invention discloses a shafting oscillation suppression method for a grid-forming doubly-fed wind turbine generator based on dq-axis voltage instruction mixed resistance increase, and the method comprises the steps: 1, collecting the current and voltage of a stator and a rotor of the doubly-fed wind turbine generator, and calculating the dq-axis component of the current and voltage of the stator and the rotor through coordinate transformation; 2, calculating a resistance increasing power instruction Pdref by using a damping controller, and superposing the resistance increasing power instruction Pdref with the active instruction Pref to obtain a new active instruction Pref1; 3, calculating a stator coordinate transformation angle theta s and a slip angle theta sl; 4, voltage resistance increasing instructions udrefsd and udrefsq of the d axis and the q axis of the stator are calculated according to the Pdref, and new stator voltage instructions usdref1 and usqref1 are obtained after the reactive droop voltage instructions are superposed; and 5, calculating by using the stator voltage loop and the rotor current loop to obtain a rotor voltage instruction, and modulating to generate a rotor side converter driving signal. According to the invention, the shafting oscillation of the grid-forming type doubly-fed wind turbine generator under the weak power grid can be suppressed, so that the electromechanical stability of the grid-forming type doubly-fed wind turbine generator can be improved.

Description

Technical Field

[0001] The present invention relates to the field of renewable energy power generation, and in particular to a method for suppressing shaft oscillation of a grid-forming doubly-fed wind turbine generator set under a weak power grid based on a dq axis voltage command hybrid resistance. Background Art

[0002] As the installed capacity of wind power and photovoltaic power generation continues to increase, the new energy power generation equipment that uses grid-connected converters as the grid interface will profoundly change the characteristics of the grid due to its inherent characteristics. The traditional power system dominated by synchronous generators is gradually transforming into a new power system with a high proportion of new energy access and a high proportion of power electronic equipment application. Wind power has also received widespread attention as the main energy source in the future new power system. With the further development of high-proportion wind power, the strong power grid originally dominated by synchronous machines is gradually transforming into a weak power grid or even an extremely weak power grid. In a weak power grid environment, the stable operation capability of the electromechanical system of the doubly-fed wind turbine will face great challenges.

[0003] The mechanical part of a doubly-fed wind turbine includes a wind turbine, a variable speed gearbox, and a transmission system. Among them, due to the low inherent damping of the mechanical transmission system, it is easy to cause torsional vibration of the transmission system of the system when subjected to mechanical and electromagnetic disturbances. In response to the problem of shaft oscillation, the existing solution uses a damping controller, which uses the generator speed feedback input bandpass filter to extract the natural frequency component in the speed, and generates the corresponding electromagnetic damping torque through the converter to attenuate the speed oscillation component, thereby providing damping compensation at the system's natural frequency. The effectiveness of the above damping controller has been effectively verified on grid-following wind turbines, but its applicability to grid-forming wind turbines has not yet been deeply studied. Therefore, suppressing the shaft oscillation of grid-forming doubly-fed wind turbines under weak power grids is still a core difficulty, which needs further research and breakthrough. Summary of the invention

[0004] In order to overcome the disadvantage that the inherent damping of the mechanical transmission system of the doubly-fed wind turbine set is low in a weak grid environment, and the system's transmission system torsional vibration is easily caused when subjected to mechanical and electromagnetic disturbances, the present invention proposes a method for suppressing the shaft system oscillation of a grid-type doubly-fed wind turbine set based on a mixed resistance of dq axis voltage instructions, in order to solve the problem of transmission chain oscillation of the grid-type doubly-fed wind turbine set under a weak grid, and at the same time improve the bidirectional demand that the grid-type control under a weak grid cannot take into account both the rapidity of power response and the stability, so as to realize the suppression of the shaft system oscillation of the grid-type doubly-fed wind turbine set under a weak grid, thereby improving the stability of the electromechanical system of the grid-type doubly-fed wind turbine set.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme:

[0006] The invention discloses a method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine generator set based on mixed resistance of dq axis voltage instructions. The method is characterized in that the method is applied to a doubly-fed wind power generation system composed of a doubly-fed generator and a machine-side converter under a weak power grid, and is performed according to the following steps:

[0007] Step 1: Collect the three-phase voltage and three-phase current on the stator and rotor sides and obtain the d-axis DC component u of the stator voltage in the synchronous rotating coordinate system through coordinate transformation. sd , q-axis DC component u sq and the d-axis DC component i of the stator current in the synchronous rotating coordinate system sd , q-axis DC component i sq And the d-axis DC component i of the rotor current in the synchronous rotating coordinate system rd , q-axis DC component i rq ;

[0008] Step 2: According to the rotor speed instruction ω rref and speed feedback value ω r The deviation between them is used to calculate the active power command P output by the speed loop. ref , and according to the transmission chain natural oscillation frequency ω in the rotor speed signal ntf The component at which the resistance power command P is calculated dref ;

[0009] Step 3: The active power command P output by the speed loop ref With the resistance power command P dref After superposition, the new active power command P is obtained. ref1 ;

[0010] Step 4: According to the active power P f and stator angular frequency ω s The droop relationship between them is used to calculate the stator coordinate transformation angle θ s and slip angle θ sl ;

[0011] Step 5: According to the resistance power instruction P dref Calculate the stator d-axis voltage resistance command u in the synchronous rotating coordinate system dref_sd and stator q-axis voltage resistance command u dref_sq ;

[0012] Step 6: Output reactive power Q of the double-fed generator and filtered reactive power Q f , calculate the stator d-axis voltage loop command value u in the synchronous rotating coordinate system sdref and q-axis voltage loop command value u sqref ;

[0013] Step 7: sdref with udref_sd After superposition, the new d-axis stator voltage command u is obtained. sdref1 ; will u sqref and u dref_sq After superposition, the new q-axis stator voltage command u is obtained sqref1 ;

[0014] Step 8: According to u sdref1 With d-axis stator feedback u sd The deviation and u sqref1 With q-axis stator feedback u sq The deviation is used to calculate the d-axis rotor current command i in the synchronous rotating coordinate system. rdref , q-axis rotor current command i rqref ;

[0015] Step 9: According to i rdref With the d-axis rotor current feedback i rd The deviation and i rqref With q-axis rotor current feedback i rq The deviation is used to calculate the d-axis rotor voltage command u in the synchronous rotating coordinate system. rdref , q-axis rotor voltage command u rqref :

[0016] Step 10: d-axis rotor voltage command u rdref , q-axis rotor voltage command u rqref After modulation by the SVPWM link, the rotor-side converter switch control signals S1-S6 are generated to achieve shaft oscillation suppression control of the grid-type doubly-fed wind turbine in a weak power grid.

[0017] The method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine generator set based on mixed resistance of dq axis voltage instructions according to the present invention is also characterized in that step 1 comprises:

[0018] Sampling the stator three-phase voltage u of the doubly fed generator sa 、u sb 、u sc and the stator three-phase current i sa 、i sb 、i sc , and is brought into the coordinate transformation link shown in equation (1) to obtain the d-axis DC component u of the stator voltage in the synchronous rotating coordinate system sd , q-axis DC component u sq And the d-axis DC component i of the stator current in the synchronous rotating coordinate system sd , q-axis DC component i sq :

[0019] (1)

[0020] In formula (1), θ s is the stator coordinate transformation angle, x A 、x B 、x C represents the three-phase stator voltage / current of the doubly-fed generator set in the three-phase stationary coordinate system, x d 、x q Represents the d-axis and q-axis DC components of the stator voltage / current in the synchronous rotating coordinate system;

[0021] Collect the three-phase rotor current i of the doubly fed generator set ra 、i rb 、i rc , and is brought into the coordinate transformation link shown in equation (2) to obtain the d-axis DC component i of the rotor current in the synchronous rotating coordinate system rd , q-axis DC component i rq :

[0022] (2)

[0023] In formula (2), θ sl Indicates the slip angle.

[0024] Furthermore, the step 2 comprises:

[0025] Calculate the rotor speed command ω rref and speed feedback value ω r The deviation between them is input into the PI regulator of the rotor speed outer loop for processing, so that the active power command P is obtained by using formula (3): ref :

[0026] (3)

[0027] In formula (3), T ref is the torque command, K pω and K iω They represent the proportional coefficient and integral coefficient of the rotor speed outer loop PI regulator, and s represents the Laplace operator;

[0028] Using the damping controller G in equation (4) bpf Extract the transmission chain natural oscillation frequency ω from the rotor speed signal ntf The component at which the resistance power command P is calculated dref :

[0029] (4)

[0030] In formula (4), K dω represents the damping coefficient, ω c represents the center frequency of the bandpass filter, and ω c = ωntf , ξ represents the bandwidth ratio, ω r Indicates the rotor electrical angular velocity.

[0031] Further, the step 4 comprises:

[0032] Use formula (5) to calculate the active power P output by the doubly fed generator set and the filtered active power P f :

[0033] (5)

[0034] In formula (5), G f represents the transfer function of the low-pass filter, and G f =ω f / (s + ω f ),ω f is the cutoff frequency of the low-pass filter;

[0035] According to the active power P f and stator angular frequency ω s The droop relationship between them is used to calculate the stator coordinate transformation angle θ using formula (6): s and slip angle θ sl :

[0036] (6)

[0037] In formula (6), m p Represents the active power droop coefficient, ω n Indicates the rated angular frequency, ω s represents the stator output angular frequency, θ r Indicates the rotor electrical angle.

[0038] Furthermore, in step 5, equation (7) is used to obtain the stator d-axis voltage resistance instruction u dref_sd and stator q-axis voltage resistance command u dref_sq :

[0039] (7)

[0040] In formula (7), U s represents the stator voltage amplitude, θ0 represents the power angle value, X g Indicates the grid inductive reactance, E g Indicates the grid voltage amplitude.

[0041] Further, the step 6 comprises:

[0042] The output reactive power Q of the doubly-fed generator and the filtered reactive power Q are calculated using formula (8): f :

[0043] (8)

[0044] Use formula (9) to calculate the stator d-axis voltage loop command value u sdref and q-axis voltage loop command value u sqref :

[0045] (9)

[0046] In formula (9), n q Represents the reactive power droop coefficient, U n Indicates the rated stator voltage amplitude.

[0047] Furthermore, in step 8, u sdref1 With d-axis stator voltage feedback u sd The deviation and u sqref1 With q-axis stator voltage feedback u sq The deviation is input into the PI regulator of the stator voltage inner loop for processing, so that the d-axis and q-axis rotor current instructions i in the synchronous rotating coordinate system are obtained using formula (10): rdref 、i rqref :

[0048] (10)

[0049] In formula (10), K pv and K iv They represent the proportional coefficient and integral coefficient of the PI regulator of the stator voltage inner loop respectively;

[0050] Furthermore, step 9 is to calculate i rdref With the d-axis rotor current feedback i rd The deviation and i rqref With q-axis rotor current feedback i rq The deviation is input into the PI regulator of the rotor current inner loop for processing, so that the d-axis rotor voltage command u in the synchronous rotating coordinate system is obtained by using formula (11): rdref , q-axis rotor voltage command u rqref :

[0051] (11)

[0052] In formula (11), K pi and K ii They are the proportional coefficient and integral coefficient of the PI regulator of the rotor current inner loop respectively.

[0053] An electronic device of the present invention includes a memory and a processor, wherein the memory is used to store a program that supports the processor to execute the method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine set, and the processor is configured to execute the program stored in the memory.

[0054] The present invention provides a computer-readable storage medium, wherein a computer program is stored on the computer-readable storage medium, and the computer program, when executed by a processor, executes the steps of the method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine set.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] 1. The present invention proposes a dq axis voltage command mixed resistance structure, which effectively solves the problem of difficulty in coordinating the speed loop bandwidth and the electrical system stability compared with the traditional solution, suppresses the shaft system oscillation and improves the speed loop response speed and the electromechanical stability of the grid-type doubly-fed wind turbine in weak grid conditions;

[0057] 2. The present invention derives the expression of the dq axis voltage resistance command in the synchronous rotating coordinate system through the relative relationship between the system output power and the power angle, wherein the grid impedance and the power angle can be measured and estimated using the existing detection technology, which simplifies the calculation difficulty of the axis resistance command and effectively reduces the application difficulty of the method of the present invention in engineering practice;

[0058] 3. The present invention extracts the component at the transmission chain natural oscillation frequency in the rotor speed signal through the damping controller, reduces the adverse effect of noise signals outside the transmission chain natural oscillation frequency band on system control, improves the calculation accuracy of the resistance power instruction, and enhances the control accuracy of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a diagram of a mixed resistance-adding structure based on dq axis voltage instructions in the present invention;

[0060] Figure 2 This is a structural diagram of the shaft oscillation suppression control of a grid-connected doubly-fed wind turbine generator set under a weak power grid according to the present invention. DETAILED DESCRIPTION

[0061] The specific implementation modes of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0062] In this embodiment, a method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine generator set based on mixed resistance of dq axis voltage instructions is applied to a doubly-fed wind power generation system composed of a doubly-fed generator and a machine-side converter under a weak power grid, and is used to solve the contradiction between shaft oscillation suppression and electrical stability of a grid-type doubly-fed wind turbine generator set under a weak power grid, and improve the electromechanical and electrical stability of the system, and is performed according to the following steps:

[0063] Step 1: Data collection and coordinate transformation calculation on the stator and rotor sides;

[0064] like Figure 2 As shown, the stator three-phase voltage u of the doubly fed generator is sampled sa 、u sb 、u sc and the stator three-phase current i sa 、i sb 、i sc , and bring it into the coordinate transformation link shown in equation (1) to obtain the d-axis and q-axis DC components u of the stator voltage in the synchronous rotating coordinate system sd 、u sq And the d-axis and q-axis DC components i of the stator current in the synchronous rotating coordinate system sd 、i sq :

[0065] (1)

[0066] In formula (1), θ s is the stator coordinate transformation angle, x A 、x B 、x C represents the three-phase stator voltage / current of the doubly-fed generator in the three-phase stationary coordinate system, x d 、x q Represents the d-axis and q-axis DC components of the stator voltage / current in the synchronous rotating coordinate system.

[0067] Collect the three-phase rotor current i of the doubly fed generator ra 、i rb 、i rc , and bring it into the coordinate transformation link shown in equation (2) to obtain the d-axis and q-axis DC components i of the rotor current in the synchronous rotating coordinate system rd 、i rq :

[0068] (2)

[0069] In formula (2), θ sl Indicates the slip angle.

[0070] Step 2: Calculate the active power command P output by the speed loop ref And resistance power command P dref ;

[0071] like Figure 1 As shown, calculate the rotor speed command ω rref and speed feedback value ω rThe deviation between them is input into the PI regulator of the rotor speed outer loop for processing, and the active power command P is obtained using formula (3): ref :

[0072] (3)

[0073] In formula (3), T ref is the torque command, K pω and K iω They represent the proportional coefficient and integral coefficient of the rotor speed outer loop PI regulator respectively, and s represents the Laplace operator.

[0074] Using the damping controller G in equation (4) bpf Extract the transmission chain natural oscillation frequency ω from the rotor speed signal ntf The components at the resistance and the resistance power command P are calculated. dref :

[0075] (4)

[0076] In formula (4), K dω represents the damping coefficient, ω c represents the center frequency of the bandpass filter, and ω c = ω ntf , ξ represents the bandwidth ratio, ω r Indicates the rotor electrical angular velocity.

[0077] Step 3: Figure 1 As shown, the power command P output by the speed loop is ref With the resistance power command P dref After superposition, the new active power command P is obtained. ref1 .

[0078] Step 4: Calculate the stator coordinate transformation angle θ s and slip angle θ sl ;

[0079] like Figure 2 As shown, the output active power P of the doubly fed generator and the filtered active power P are calculated using formula (5). f :

[0080] (5)

[0081] In formula (5), G f represents the transfer function of the low-pass filter, and G f = ω f / (s + ω f ),ω f is the cutoff frequency of the low-pass filter.

[0082] According to the active power P f and stator angular frequency ω s The downward relationship between Figure 2 As shown, the stator coordinate transformation angle θ is calculated using formula (6) s and slip angle θ sl :

[0083] (6)

[0084] In formula (6), m p Represents the active power droop coefficient, ω n Indicates the rated angular frequency, ω s represents the stator output angular frequency, θ r Indicates the rotor electrical angle.

[0085] Step 5: Figure 1 As shown, the stator d-axis and q-axis voltage resistance instructions u in the synchronous rotating coordinate system are calculated using formula (7): dref_sd and u dref_sq :

[0086] (7)

[0087] In formula (7), U s represents the stator voltage amplitude, θ0 represents the power angle value, X g Indicates the grid inductive reactance, E g Indicates the grid voltage amplitude.

[0088] Step 6: Calculate the stator d-axis and q-axis voltage loop command values ​​u in the synchronous rotating coordinate system sdref and u sqref ;

[0089] like Figure 2 As shown, the output reactive power Q of the doubly-fed generator and the filtered reactive power Q are calculated using formula (8): f :

[0090] (8)

[0091] Use equation (9) to calculate the stator d-axis and q-axis voltage loop command value u sdref and u sqref :

[0092] (9)

[0093] In formula (9), n q Represents the reactive power droop coefficient, U n Indicates the rated stator voltage amplitude.

[0094] Step 7: Figure 2 As shown, the stator voltage loop command value u is calculated by using formula (10): sdref and u sqref With the voltage resistance instruction u dref_sd and u dref_sq After superposition, the new stator voltage command u is obtained sdref1 and u sqref1 :

[0095] (10)

[0096] Step 8: Calculate the d-axis and q-axis stator voltage instructions u in the synchronous rotating coordinate system sdref1 、u sqref1 Respectively with the d-axis and q-axis stator feedback u sd 、u sq The deviation is input into the PI regulator of the stator voltage inner loop for processing, and the d-axis and q-axis rotor current instructions i in the synchronous rotating coordinate system are obtained using formula (11): rdref 、i rqref :

[0097] (11)

[0098] In formula (11), K pv and K iv They represent the proportional coefficient and integral coefficient of the stator voltage inner loop PI regulator respectively.

[0099] Step 9: Calculate the d-axis and q-axis rotor current instructions i in the synchronous rotating coordinate system rdref 、i rqref Respectively with the d-axis and q-axis rotor current feedback i rd 、i rq The deviation is input into the PI regulator of the rotor current inner loop for processing, so that the d-axis and q-axis rotor voltage instructions u in the synchronous rotating coordinate system are obtained by using formula (12): rdref 、u rqref :

[0100] (12)

[0101] In formula (12), K pi and K ii They are the proportional coefficient and integral coefficient of the rotor current inner loop PI regulator respectively.

[0102] Step 10: d-axis and q-axis rotor voltage command u rdref 、u rqref After modulation by the SVPWM link, the rotor-side converter switch control signals S1-S6 are generated to realize the shaft oscillation suppression control of the grid-connected doubly-fed wind turbine in a weak power grid.

[0103] In this embodiment, an electronic device includes a memory and a processor, wherein the memory is used to store a program that supports the processor to execute the method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine set, and the processor is configured to execute the program stored in the memory.

[0104] A computer-readable storage medium stores a computer program on the computer-readable storage medium. When the computer program is run by a processor, the steps of the method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine set are executed.

[0105] Figure 1 This is the mixed resistance structure diagram based on dq axis voltage command corresponding to step 2 and step 3. Figure 2 This is the structure diagram of the shaft oscillation suppression control of the grid-type doubly fed wind turbine under weak power grid. The five PI controllers of the rotor speed outer loop and the stator voltage and rotor current double closed loop are used to realize the fast zero-static error tracking control of the rotor speed, stator voltage and rotor current. The resistance voltage command u superimposed by the stator voltage loop command dref_sd and u dref_sq It is used to suppress the shaft oscillation of the electromechanical system of the grid-type doubly-fed wind turbine set and improve the electromechanical stability of the grid-type doubly-fed wind turbine set in a weak power grid.

Claims

1. A method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine generator system based on mixed resistance of dq axis voltage instructions, characterized in that: It is applied to the doubly-fed wind power generation system composed of doubly-fed generator and machine-side converter under weak power grid, and is carried out in the following steps: Step 1: Collect the three-phase voltage and three-phase current on the stator and rotor sides and obtain the d-axis DC component u of the stator voltage in the synchronous rotating coordinate system through coordinate transformation. sd , q-axis DC component u sq and the d-axis DC component i of the stator current in the synchronous rotating coordinate system sd , q-axis DC component i sq And the d-axis DC component i of the rotor current in the synchronous rotating coordinate system rd , q-axis DC component i rq ; Step 2: According to the rotor speed instruction ω rref and speed feedback value ω r The deviation between them is used to calculate the active power command P output by the speed loop. ref , and according to the transmission chain natural oscillation frequency ω in the rotor speed signal ntf The component at which the resistance power command P is calculated dref ; Step 3: The active power command P output by the speed loop ref With the resistance power command P dref After superposition, the new active power command P is obtained. ref1 ; Step 4: According to the active power P f and stator angular frequency ω s The droop relationship between them is used to calculate the stator coordinate transformation angle θ s and slip angle θ sl ; Step 5: According to the resistance power instruction P dref Calculate the stator d-axis voltage resistance command u in the synchronous rotating coordinate system dref_sd and stator q-axis voltage resistance command u dref_sq ; Step 6: Output reactive power Q of the double-fed generator and filtered reactive power Q f , calculate the stator d-axis voltage loop command value u in the synchronous rotating coordinate system sdref and q-axis voltage loop command value u sqref ; Step 7: sdref with u dref_sd After superposition, the new d-axis stator voltage command u is obtained. sdref1 ; will u sqref and u dref_sq After superposition, the new q-axis stator voltage command u is obtained sqref1 ; Step 8: According to u sdref1 With d-axis stator feedback u sd The deviation and u sqref1 With q-axis stator feedback u sq The deviation is used to calculate the d-axis rotor current command i in the synchronous rotating coordinate system. rdref , q-axis rotor current command i rqref ; Step 9: According to i rdref With the d-axis rotor current feedback i rd The deviation and i rqref With q-axis rotor current feedback i rq The deviation is used to calculate the d-axis rotor voltage command u in the synchronous rotating coordinate system. rdref , q-axis rotor voltage command u rqref : Step 10: d-axis rotor voltage command u rdref , q-axis rotor voltage command u rqref After modulation by the SVPWM link, the rotor-side converter switch control signals S1-S6 are generated to achieve shaft oscillation suppression control of the grid-type doubly-fed wind turbine in a weak power grid.

2. According to claim 1, a method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine generator system based on mixed resistance of dq axis voltage instructions, characterized in that: The step 1 comprises: Sampling the stator three-phase voltage u of the doubly fed generator sa 、u sb 、u sc and the stator three-phase current i sa 、i sb 、i sc , and is brought into the coordinate transformation link shown in equation (1) to obtain the d-axis DC component u of the stator voltage in the synchronous rotating coordinate system sd , q-axis DC component u sq And the d-axis DC component i of the stator current in the synchronous rotating coordinate system sd , q-axis DC component i sq : (1) In formula (1), θ s is the stator coordinate transformation angle, x A 、x B 、x C represents the three-phase stator voltage / current of the doubly-fed generator set in the three-phase stationary coordinate system, x d 、x q Represents the d-axis and q-axis DC components of the stator voltage / current in the synchronous rotating coordinate system; Collect the three-phase rotor current i of the doubly fed generator set ra 、i rb 、i rc , and is brought into the coordinate transformation link shown in equation (2) to obtain the d-axis DC component i of the rotor current in the synchronous rotating coordinate system rd , q-axis DC component i rq : (2) In formula (2), θ sl Indicates the slip angle.

3. A method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine generator system based on mixed resistance of dq axis voltage instructions according to claim 2, characterized in that: The step 2 comprises: Calculate the rotor speed command ω rref and speed feedback value ω r The deviation between them is input into the PI regulator of the rotor speed outer loop for processing, so that the active power command P is obtained by using formula (3): ref : (3) In formula (3), T ref is the torque command, K pω and K iω They represent the proportional coefficient and integral coefficient of the rotor speed outer loop PI regulator, and s represents the Laplace operator; Using the damping controller G in equation (4) bpf Extract the transmission chain natural oscillation frequency ω from the rotor speed signal ntf The component at which the resistance power command P is calculated dref : (4) In formula (4), K dω represents the damping coefficient, ω c represents the center frequency of the bandpass filter, and ω c = ω ntf , ξ represents the bandwidth ratio, ω r Indicates the rotor electrical angular velocity.

4. A method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine generator system based on mixed resistance of dq axis voltage instructions according to claim 3, characterized in that: The step 4 comprises: Use formula (5) to calculate the active power P output by the doubly fed generator set and the filtered active power P f : (5) In formula (5), G f represents the transfer function of the low-pass filter, and G f =ω f / (s + ω f ),ω f is the cutoff frequency of the low-pass filter; According to the active power P f and stator angular frequency ω s The droop relationship between them is used to calculate the stator coordinate transformation angle θ using formula (6): s and slip angle θ sl : (6) In formula (6), m p Represents the active power droop coefficient, ω n Indicates the rated angular frequency, ω s represents the stator output angular frequency, θ r Indicates the rotor electrical angle.

5. A method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine generator system based on mixed resistance of dq axis voltage instructions according to claim 4, characterized in that: In step 5, equation (7) is used to obtain the stator d-axis voltage resistance instruction u dref_sd and stator q-axis voltage resistance command u dref_sq : (7) In formula (7), U s represents the stator voltage amplitude, θ0 represents the power angle value, X g Indicates the grid inductive reactance, E g Indicates the grid voltage amplitude.

6. A method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine generator system based on mixed resistance of dq axis voltage instructions according to claim 5, characterized in that: The step 6 comprises: The output reactive power Q of the doubly-fed generator and the filtered reactive power Q are calculated using formula (8): f : (8) Use formula (9) to calculate the stator d-axis voltage loop command value u sdref and q-axis voltage loop command value u sqref : (9) In formula (9), n q Represents the reactive power droop coefficient, U n Indicates the rated stator voltage amplitude.

7. A method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine generator system based on mixed resistance of dq axis voltage instructions according to claim 6, characterized in that: In step 8, u sdref1 With d-axis stator voltage feedback u sd The deviation and u sqref1 With q-axis stator voltage feedback u sq The deviation is input into the PI regulator of the stator voltage inner loop for processing, so that the d-axis and q-axis rotor current instructions i in the synchronous rotating coordinate system are obtained using formula (10): rdref 、i rqref : (10) In formula (10), K pv and K iv They respectively represent the proportional coefficient and integral coefficient of the PI regulator of the stator voltage inner loop.

8. A method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine generator system based on mixed resistance of dq axis voltage instructions according to claim 7, characterized in that: Step 9 is to calculate i rdref With the d-axis rotor current feedback i rd The deviation and i rqref With q-axis rotor current feedback i rq The deviation is input into the PI regulator of the rotor current inner loop for processing, so that the d-axis rotor voltage command u in the synchronous rotating coordinate system is obtained by using formula (11): rdref , q-axis rotor voltage command u rqref : (11) In formula (11), K pi and K ii They are the proportional coefficient and integral coefficient of the PI regulator of the rotor current inner loop respectively.

9. An electronic device, comprising a memory and a processor, characterized in that: The memory is used to store a program that supports the processor to execute the method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine set as described in any one of claims 1-8, and the processor is configured to execute the program stored in the memory.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for suppressing shaft oscillation of a grid-type doubly-fed wind turbine set described in any one of claims 1 to 8 are executed.

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