Power and current prediction control method and system of doubly-fed motor grid-side converter

Abstract

The invention discloses a power and current prediction control method and system for a doubly-fed motor grid-side converter, and relates to the technical field of converter monitoring, and the method comprises the steps: predicting a current value, an active power value and a reactive power value of the doubly-fed motor grid-side converter in a next control period according to a power prediction model and a current prediction model; designing an improved value function by considering active power, reactive power and a current component of a dq axis under a dq coordinate system, and obtaining the action duration of a voltage vector in a next control period by minimizing the value function; and based on the action duration of the voltage vector in the next control period, controlling the power switch of the grid-side converter of the doubly-fed motor. According to the method, power and current parameter control of the doubly-fed motor grid-side converter under the three-phase balance working condition is considered, and efficient control of the doubly-fed motor grid-side converter under the three-phase power grid voltage balance condition is achieved.

Description

Technical Field

[0001] This invention relates to the field of converter monitoring technology, and in particular to a power and current prediction control method and system for a doubly fed motor grid-side converter. Background Technology

[0002] With the continuous increase in the proportion of new energy sources in the energy structure, the traditional coal-fired power industry faces new challenges in transformation and upgrading. In the operation of coal-fired power units, over 80% of energy consumption is consumed by rotating auxiliary equipment such as fans and pumps. Therefore, optimizing the energy efficiency of these auxiliary equipment is a core aspect of improving the performance of coal-fired power units. Compared to the traditional method of controlling flow by adjusting dampers or gate valves, the rapid development of modern variable frequency speed control technology has enabled auxiliary equipment such as fans and pumps to achieve energy savings of over 50%, effectively improving energy utilization and power quality.

[0003] Doubly fed induction generator (DFIG) speed control systems play a crucial role in speed regulation of equipment such as fans and pumps. They achieve motor speed regulation and energy conversion through two-stage power conversion circuits, helping to adapt to different loads and improve system conversion efficiency. However, even when the power grid is in a relatively ideal three-phase voltage balance state, inappropriate control methods can lead to distortion of the rectifier input current in the power conversion circuit, resulting in unstable output DC voltage. This, in turn, leads to poor power quality transmitted to the grid, severe harmonic interference, and reduced overall system operating efficiency and performance. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the prior art by providing a power and current prediction control method and system for a doubly-fed induction generator grid-side converter, thereby solving the problems of the prior art.

[0005] This invention specifically provides the following technical solution: a power and current prediction control method for a doubly-fed induction generator grid-side converter, comprising the following steps: Establish the power and current models of the grid-side converter of the doubly-fed induction generator under the voltage balance state of a three-phase power grid; Based on the voltage vector of the power model and the current model, a power prediction model and a current prediction model are constructed, and the current value, active power and reactive power value of the grid-side converter of the doubly-fed motor in the next control cycle are predicted according to the power prediction model and the current prediction model. Considering active power, reactive power and dq coordinate system dq The current component of the shaft is used to design an improved value function, and the duration of the voltage vector action in the next control cycle is obtained by minimizing the value function. Based on the duration of the voltage vector action in the next control cycle, space vector pulse width modulation technology is used to generate the switching state of the doubly fed motor grid-side converter in the next control cycle, and power and current predictive control is performed.

[0006] Preferably, the design improves the value function, and obtains the duration of the voltage vector action in the next control cycle by minimizing the value function, specifically as follows: Considering active power, reactive power and dq coordinate system dq The current components of the axis are used to construct a value function of power and current. J value function J As shown in the following formula: ; in P r 、Q r 、I dr 、I qr They are active power, reactive power and dq coordinate system dq Active and reactive current components of the shaft P, Q, I d 、I q Reference value, k Indicates the current sampling period. k+ 1 indicates the next sampling period; By calculating the partial derivative of the value function with respect to the voltage application time, the voltage vector application time that minimizes the value function is obtained. T 0 、T 1 and T 2, of which, T 0 indicates zero vector action time. T 1 and T 2 represents the effective vector action time, in... T 0 、T 1 and T The sum of 2 is used as the entire sampling period.

[0007] Preferably, the establishment of the power model and current model of the doubly-fed induction generator grid-side converter under the three-phase power grid voltage balance state specifically includes: The active and reactive voltage components in the dq coordinate system and dq The relationship between the current components of the shaft is used to construct a current model, the specific expression of which is: ; in, This represents the angular frequency of the input sinusoidal voltage. U d and U q These represent the active and reactive voltage components in the dq coordinate system, respectively. Id and I q These represent the active and reactive current components in the dq coordinate system, respectively. R This is the estimated equivalent resistance value of the grid-side converter circuit for the doubly-fed motor. L The estimated value of the input filter inductance for the grid-side converter of the doubly-fed induction generator; S d , S q These represent the three-phase bridge arm switching states of the doubly-fed induction generator grid-side converter. S a , S b , S c Switching components in the dq coordinate system U dc Indicates the DC bus output voltage; In grid voltage When oriented towards the d-axis, Through grid voltage Calculate active power P and reactive power Q The specific expression is: ; Active power P and reactive power Q This indicates that, in conjunction with the current model, the power model of the doubly-fed induction generator (DFIG) grid-side converter is obtained, and the specific expression is as follows: .

[0008] Preferably, the step of predicting the current value, active power, and reactive power value of the doubly-fed induction generator grid-side converter for the next control cycle based on the power prediction model and the current prediction model specifically involves: by U rd = S d U dc , U rq =S q U dc As the control variables of the dq axis, the predictive model equations for current and power are obtained, as well as the rate of change of current and power of the dq axis; Based on the prediction model equations for current and power, the initial values ​​of current and power in the current sampling period are obtained, and the initial values, the dq-axis current change rate, and the power change rate are plotted in the voltage vector. U m After action T 1 andT 2. During this time, the current value, active power, and reactive power values ​​of the grid-side converter of the doubly fed motor are obtained.

[0009] Preferably, the step of using space vector pulse width modulation technology to generate the switching state of the doubly-fed induction generator grid-side converter for the next control cycle, and performing power and current predictive control, specifically involves: In a sampling period T s Three consecutive voltage vectors are selected to define different three-phase arm switching states of the doubly-fed induction generator (DFIG) grid-side converter, and the voltage vectors of the three-phase arm switching states of the DFIG grid-side converter under different combinations of conditions are obtained. V n ; One three-phase voltage cycle input to the AC side of the doubly-fed motor grid-side converter is divided into six sectors at 60-degree intervals. The sector to which the current sector belongs is determined based on the current state of the three-phase AC voltage input to the doubly-fed motor grid-side converter, and the voltage vector of the current sector operation is obtained. Based on the voltage vector duration of the next control cycle, and using the obtained voltage vector, the switching state of the doubly-fed motor grid-side converter for the next control cycle is generated through vector pulse width modulation (VPWM) technology, enabling predictive control of the power and current of the doubly-fed motor grid-side converter.

[0010] This invention provides a power and current prediction control system for a doubly-fed induction generator grid-side converter, comprising: The model building module is used to establish the power and current models of the doubly fed motor grid-side converter under the three-phase grid voltage balance state. The power prediction module is used to construct power prediction models and current prediction models based on the voltage vector of the power model and current model, and predict the current value, active power and reactive power value of the grid-side converter of the doubly-fed motor in the next control cycle according to the power prediction model and current prediction model. The duration acquisition module is used to consider active power, reactive power, and dq coordinate system dq The current component of the shaft is used to design an improved value function, and the duration of the voltage vector action in the next control cycle is obtained by minimizing the value function. The control module is used to generate the switching state of the doubly-fed motor grid-side converter for the next control cycle based on the duration of the voltage vector action in the next control cycle, using space vector pulse width modulation technology, and to perform power and current predictive control.

[0011] The present invention provides a computer device, including a memory and a processor. The memory stores a program, and when the program is executed by the processor, the processor performs the steps of the power and current prediction control method for a doubly fed motor grid-side converter.

[0012] The present invention provides a storage medium storing a computer program thereon, wherein when the computer program is executed by a processor, the steps of the power and current prediction control method for a doubly fed motor grid-side converter are implemented.

[0013] Compared with the prior art, the present invention has the following significant advantages: This invention establishes power and current models respectively to predict the current, active power, and reactive power values ​​of the doubly-fed induction generator (DFIG) grid-side converter in the next control cycle. It also combines the current, active power, and reactive power values ​​to obtain the voltage vector duration for the next control cycle, thus achieving an accurate description of the DFIG grid-side converter's operating state. Furthermore, it employs space vector pulse width modulation (SVM) technology for power switching control of the DFIG grid-side converter, enabling predictive control of the converter's switching state in the next control cycle. This improves the quality of power transmitted to the grid and enhances the overall system operating efficiency. Attached Figure Description

[0014] Figure 1 This is a diagram of the control structure of the doubly fed motor grid-side converter in the doubly fed motor control structure mentioned in the embodiments of the present invention; Figure 2 This is a sector division diagram obtained by inputting three-phase AC voltage to the grid-side converter of the doubly fed motor mentioned in the embodiments of the present invention; Figure 3 The simulated three-phase input AC voltage waveform of the doubly fed motor grid-side converter using the method of the present invention under the three-phase grid voltage balance condition mentioned in the embodiments of the present invention; Figure 4 The simulated three-phase input AC current waveform of the doubly fed motor grid-side converter using the method of the present invention under the three-phase grid voltage balance condition mentioned in the embodiments of the present invention; Figure 5 The active and reactive power simulation waveforms of the doubly fed motor grid-side converter using the method of the present invention under the three-phase power grid voltage balance condition mentioned in the embodiments of the present invention are shown. Figure 6 The simulated waveforms of the d-axis and q-axis currents of the doubly fed motor grid-side converter using the method of the present invention under the three-phase grid voltage balance condition mentioned in the embodiments of the present invention are shown in the dq coordinate system. Figure 7 The above describes the simulated DC bus voltage waveform of the doubly fed motor grid-side converter under the three-phase grid voltage balance condition mentioned in this embodiment of the invention. Figure 8 The image shows the FFT analysis results of the A-phase current of the three-phase input AC current of the doubly fed motor grid-side converter under the three-phase grid voltage balance condition mentioned in the embodiments of the present invention. Figure 9 A flowchart of the power and current prediction control method for the grid-side converter of the doubly fed motor provided by the present invention. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0016] like Figure 9 As shown, this invention proposes a power and current prediction control method for a doubly-fed induction generator (DFIG) grid-side converter, which specifically includes the following steps: Step S1: Establish the power model and current model of the doubly fed motor grid-side converter under the three-phase grid voltage balance state.

[0017] The following current model is established for the grid-side converter of a doubly-fed induction generator under three-phase grid voltage balance conditions, expressed as follows: (1); in, ω This represents the angular frequency of the input sinusoidal voltage. U d and U q They represent dq Active and reactive voltage components in the coordinate system; I d and I q They represent dq Active and reactive current components in the coordinate system; R This is the estimated equivalent resistance value of the grid-side converter circuit for the doubly-fed motor. L The estimated value of the input filter inductance for the grid-side converter of the doubly-fed induction generator; S d ，S q These represent the three-phase bridge arm switching states of the doubly-fed induction generator grid-side converter. S a , S b , S c In two-phase rotation ( dq Switching components in the coordinate system.

[0018] Doubly fed motor grid-side converter topology as follows Figure 1 As shown, its three-phase AC input voltage is U a, U b , U c The three-phase AC input current is I a , I b , I c ; R This is the estimated equivalent resistance value of the grid-side converter circuit for the doubly-fed motor. L The estimated value of the input filter inductance for the grid-side converter of the doubly-fed induction generator; U dc This is the DC bus output voltage.

[0019] When the grid voltage is oriented d In the case of shaft ( Active power P and reactive power Q It can be represented as: (2); Based on the current model established by equation (1), the power model of the doubly-fed induction generator grid-side converter can be obtained as follows: (3); Step S2: Construct power prediction model and current prediction model based on the voltage vector of the power model and current model, and predict the current value, active power and reactive power value of the doubly fed motor grid-side converter in the next control cycle according to the power prediction model and current prediction model.

[0020] Based on the changing patterns of current and power under different voltage vectors, several consecutive voltage vectors are selected as the acting vectors within a certain time interval. Therefore, in conjunction with the traditional SVPWM modulation method, within one sampling period... T s Three voltage vectors are selected: one zero vector and two effective vectors. The selection method depends on the different sectors.

[0021] Define the state of the three-phase bridge arm switch as S a , S b , S c ,when S i =1 ( i = a , b , c When ), it means i When the upper switch on the bridge arm is turned on, the lower switch is turned off, and when... S i =0 (i = a , b , c When ), it means i The upper switch on the bridge arm is off, and the lower switch is on. Obtain the three-phase bridge arm switch status of the doubly-fed induction generator grid-side converter. S a , S b , S c Voltage vector under different combinations of conditions V n , can be defined as V n =[ S a S b S c (n=1,2,…,8), then V 1 = [0 0 0], V 2 = [0 0 1], V 3 = [0 1 0], V 4 = [0 1 1], V 5 = [1 00], V 6 = [1 0 1], V 7 = [1 1 0], V 8 =[1 1 1], where V 2 to V 7 represents a non-zero voltage vector. V 1 and V 8 represents the zero voltage vector.

[0022] Table 1. Voltage Vector Table of Doubly Fed Motor Grid-Side Converter One three-phase voltage cycle of the AC input to the grid-side converter of the doubly-fed induction generator is divided into six sectors at 60-degree intervals, as defined in Table 2. The sector division diagram is shown below. Figure 2 As shown, where U a， U b， U c This refers to the three-phase input voltage on the AC side.

[0023] Table 2 Sector Division and Corresponding Voltage Vector Table Based on the current and power models established by equations (1) and (3), U rd=S d U dc , U rq =S q U dc As the control variables for the dq axis, the prediction model equations for current and power are obtained, along with the dq axis current change rate and power change rate; the prediction model equations for current and power are as follows: (4); Let the voltage vector U m Under its influence, then its dq Shaft current change rate and power change rate e dm 、e qm 、e ppm and e qqm It can be written as: (5); Among them, different voltage vectors U j (j=0,1,2) can be divided into sectors by the input three-phase AC voltage of the doubly-fed motor grid-side converter, and from 8 voltage vectors V n (n=1, 2, ..., 8) are selected. In equation (6) , Control Quantity U rd , U rq Different voltage vectors U j The value under the influence is described in detail as follows:

[0024] ,in U rα and U rβ The values ​​under different voltage vectors are shown in Table 3.

[0025] Table 3 U rα and U rβ Table of values ​​under different voltage vectors Based on the above correspondence, we can obtain the voltage vector... Um Under the influence of, dq Shaft current change rate and power change rate e dm 、e qm 、e ppm and e qqm .

[0026] Under the condition of three-phase grid voltage balance, the doubly-fed induction generator grid-side converter, based on the prediction model equations of current and power, assumes that in the first phase... K At the start of each sampling period, the initial values ​​of current and power for the current sampling period are obtained as follows: I d 、I q P, Q And the initial values, dq-axis current change rate, and power change rate are plotted in the voltage vector. U m (in the six non-zero voltage vectors of the corresponding sector) V 2~ V (Select from 7) After the action T 1 and T 2. During this time period, obtain the current, active power, and reactive power values ​​of the doubly-fed induction generator (DFIG) grid-side converter. The d-axis and q-axis current and power values ​​are shown below. P, Q It will become:

[0027] (6); Similarly, the voltage vector can be calculated. U n (in the six non-zero voltage vectors of the corresponding sector) V 2~ V Select from 7) under the action dq Shaft current change rate and power change rate e dn ，e qn ，e ppn ，e qqn ; and voltage vector U 0 (by zero voltage vector) V 1 and V 8 Select (under the action) dq Shaft current change rate and power change rate e d0 ，e q0 ，e pp0，e qq0 .

[0028] Let the current sampling period be K Then the next sampling period dq The shaft current and power can be expressed as, where T s = T 0 +T 1 +T 2 To control the cycle.

[0029] (7); Step S3: Consider active power, reactive power, and dq coordinate system dq The current component of the shaft is used to design an improved value function, and the duration of the voltage vector action in the next control cycle is obtained by minimizing the value function.

[0030] The definition considers active power, reactive power, and dq coordinate system dq Value function of the current component of the axis J As shown in the following formula: (8); in P r ，Q r ，I dr ，I qr They are active power, reactive power and dq coordinate system dq Active and reactive current components of the shaft P, Q, I d ，I q Reference values.

[0031] By analyzing the value function J The calculation minimizes this value by calculating the partial derivative of the value function with respect to the voltage action time to obtain the voltage vector action time that minimizes the value function. T 0 ，T 1 and T 2 , represented as: (9); in Represents the time of action of the value function on the voltage vector. T 1. Find the partial derivative. Indicates the duration of action of the voltage vector T 2. Find the partial derivatives. Based on formulas (7), (8), and (9), we obtain: (10); in: Step S4: Based on the duration of the voltage vector action in the next control cycle, the switching state of the doubly fed motor grid-side converter in the next control cycle is generated using space vector pulse width modulation technology, and power and current predictive control is performed.

[0032] The sector to which the current sector belongs is determined based on the current three-phase AC voltage state input to the grid-side converter of the doubly-fed induction generator, and the operating voltage vector of the current sector is obtained. U 0 ，U 1 ，U 2 The sector determination process is as follows: the three-phase input voltage on the AC side is... U a > U b >0> U c Status is sector 1; AC three-phase input voltage is U b > U a >0> U c Status: Sector 2; AC three-phase input voltage: U b > U c >0> U a Status: Sector 3; AC three-phase input voltage: U c > U b >0> U a Status: Sector 4; AC three-phase input voltage: U c > U a >0> Ub Status: Sector 5; AC three-phase input voltage: U a > U c >0> U b The status is sector 6.

[0033] In short, based on the current three-phase AC input values ​​of the doubly-fed induction generator's grid-side converter, the current sector can be determined. N And obtain the operating voltage vector corresponding to the current sector from it. U 0, U m and U n The specific sector determination process is as follows: Pick ,like ,but ,otherwise ,like ,but ,otherwise ,like ,but ,otherwise Therefore, there are sectors: .

[0034] in U ab , U bc , U ca These represent the AC side of the grid-side converter of the doubly-fed motor. a and b , b and c ,as well as c and a The line voltage between; intermediate parameters A, B, and C required for the calculation process, which have no actual physical meaning; N The calculated sector number.

[0035] Based on the duration of the voltage vector action in the next control cycle obtained in step 3 T 0 ，T 1 ，T 2Based on the obtained voltage vector, the switching state of the doubly-fed induction generator (DFIG) grid-side converter for the next control cycle is generated using space vector pulse width modulation (SVM) technology, enabling predictive control of the DFIG grid-side converter's power and current. This invention comprehensively considers the power and current parameter control of the DFIG grid-side converter under three-phase balanced operating conditions, achieving efficient control of the DFIG grid-side converter under three-phase grid voltage balance conditions.

[0036] Simulation verification: A Matlab / Simulink simulation model and a 1200W experimental prototype were built to simulate the control method used in this invention. The topology current parameters of the doubly-fed induction generator grid-side converter are: the effective value of the three-phase input voltage is 220V, and the angular frequency of the input sinusoidal voltage is... Input filter inductor L=0.0015H Inductance and equivalent resistance of the circuit R =3 ohms, DC bus output filter capacitor C=1500uF DC bus output load R L =300 Ohm. The simulation and experimental parameters for the doubly-fed induction generator grid-side converter are: control cycle. T s =0.0001 Seconds, outer loop voltage, active power PI control parameters K p =0.0365, K i =0.04.

[0037] Figure 3 The three-phase input AC voltage of the doubly fed motor grid-side converter using the method of this invention is given under the condition of three-phase grid voltage balance.

[0038] Figure 4 This document presents the simulation waveforms of the three-phase input AC current of the doubly-fed induction generator grid-side converter using the method of this invention under three-phase grid voltage balance conditions. Figure 4 As can be seen from the method of the present invention, the grid-side converter of the doubly fed motor achieves the control of the input three-phase current following the three-phase input voltage, and the waveform of the input three-phase AC current exhibits sinusoidal variation with balanced amplitude and no distortion.

[0039] Figure 5 The simulation waveforms of active and reactive power of the doubly-fed induction generator grid-side converter using the method of this invention are shown in the figure under three-phase grid voltage balance conditions. As can be seen from the figure, the active and reactive power fluctuations are small and the waveforms are stable.

[0040] Figure 6 For doubly-fed generator grid-side converters using the method of this invention under three-phase grid voltage balance conditions dq coordinate system dshaft current and q Simulated waveform of shaft current. As can be seen from the figure, the current waveform has small ripple and is stable.

[0041] Figure 7 The figure shows the simulated DC bus voltage of the doubly-fed induction generator grid-side converter using the method of this invention under three-phase grid voltage balance conditions. As can be seen from the figure, the system can output a stable 600V DC voltage within a short time, demonstrating good rectification performance.

[0042] Figure 8 The image shows the FFT analysis results of the A-phase current of the three-phase input AC current of the doubly-fed induction generator grid-side converter using the method of this invention under three-phase grid voltage balance conditions. It can be seen that the total harmonic content of the A-phase input current is 1.63%, which meets the requirement of the "Power Quality Public Grid Harmonics" standard that the total harmonic content should not exceed 5%.

[0043] The above experimental results verify the feasibility and effectiveness of the power and current prediction control method for a doubly fed motor grid-side converter mentioned in this invention.

[0044] Based on the same inventive concept, this invention provides a power and current prediction control system for a doubly fed motor grid-side converter, comprising: a model building module, a power prediction module, an operation duration acquisition module, and a control module.

[0045] The model building module is used to establish the power and current models of the doubly-fed induction generator (DFIG) grid-side converter under three-phase grid voltage balance conditions. The power prediction module is used to construct power and current prediction models based on the voltage vectors of the power and current models, and to predict the current, active power, and reactive power values ​​of the DFIG grid-side converter in the next control cycle based on these models. The duration acquisition module considers active power, reactive power, and... dq coordinate system dq The current component of the shaft is used to design an improved value function, and the duration of the voltage vector action in the next control cycle is obtained by minimizing the value function. The control module is used to generate the switching state of the doubly-fed motor grid-side converter in the next control cycle based on the duration of the voltage vector action in the next control cycle, using space vector pulse width modulation technology, and to perform power and current predictive control.

[0046] The present invention also provides a computer device, including a memory and a processor. The memory stores a program, and when the program is executed by the processor, the processor performs the steps of a power and current prediction control method for a doubly-fed motor grid-side converter.

[0047] According to the disclosed embodiments, the computer device can communicate with one or more external devices (e.g., keyboard, pointing device, Bluetooth communication, etc.) or with any device that enables the computing device to communicate with one or more other computing devices (e.g., router, demodulator, etc.).

[0048] The present invention also provides a storage medium storing a computer program thereon, wherein the computer program, when executed by a processor, implements the steps of a power and current prediction control method for a doubly-fed induction generator grid-side converter.

[0049] According to the disclosed embodiments, the storage medium can be a non-volatile computer-readable storage medium, such as, but not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this invention, the storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0050] The above description, in conjunction with specific preferred embodiments, provides a more detailed explanation of the present invention. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the scope of protection of the present invention.

Claims

1. A power and current prediction control method for a doubly-fed induction generator grid-side converter, characterized in that, include: Establish the power and current models of the grid-side converter of the doubly-fed induction generator under the voltage balance state of a three-phase power grid; Based on the voltage vector of the power model and the current model, a power prediction model and a current prediction model are constructed, and the current value, active power and reactive power value of the grid-side converter of the doubly-fed motor in the next control cycle are predicted according to the power prediction model and the current prediction model. Considering active power, reactive power and dq coordinate system dq The current component of the shaft is used to design an improved value function, and the duration of the voltage vector action in the next control cycle is obtained by minimizing the value function. Based on the duration of the voltage vector action in the next control cycle, space vector pulse width modulation technology is used to generate the switching state of the doubly fed motor grid-side converter in the next control cycle, and power and current predictive control is performed.

2. The power and current prediction control method for a doubly-fed induction generator grid-side converter as described in claim 1, characterized in that, The design improves the value function, and obtains the duration of the voltage vector action in the next control cycle by minimizing the value function. Specifically: Considering active power, reactive power and dq coordinate system dq The current components of the axis are used to construct a value function of power and current. J value function J As shown in the following formula: ； in P r 、Q r 、I dr 、I qr They are active power, reactive power and dq coordinate system dq Active and reactive current components of the shaft P, Q, I d 、I q Reference value, k Indicates the current sampling period. k+ 1 indicates the next sampling period; By calculating the partial derivative of the value function with respect to the voltage application time, the voltage vector application time that minimizes the value function is obtained. T 0 、T 1 and T 2, of which, T 0 indicates zero vector action time. T 1 and T 2 represents the effective vector action time, in... T 0 、T 1 and T The sum of 2 is used as the entire sampling period.

3. The power and current prediction control method for a doubly-fed induction generator grid-side converter as described in claim 1, characterized in that, The establishment of the power model and current model of the doubly-fed induction generator grid-side converter under the three-phase power grid voltage balance state is specifically as follows: The active and reactive voltage components in the dq coordinate system and dq The relationship between the current components of the shaft is used to construct a current model, the specific expression of which is: ； in, This represents the angular frequency of the input sinusoidal voltage. U d and U q These represent the active and reactive voltage components in the dq coordinate system, respectively. I d and I q These represent the active and reactive current components in the dq coordinate system, respectively. R This is the estimated equivalent resistance value of the grid-side converter circuit for the doubly-fed motor. L The estimated value of the input filter inductance for the grid-side converter of the doubly-fed induction generator; S d , S q These represent the three-phase bridge arm switching states of the doubly-fed induction generator grid-side converter. S a , S b , S c Switching components in the dq coordinate system U dc Indicates the DC bus output voltage; In grid voltage When oriented towards the d-axis, Through grid voltage Calculate active power P and reactive power Q The specific expression is: ； Active power P and reactive power Q This indicates that, in conjunction with the current model, the power model of the doubly-fed induction generator (DFIG) grid-side converter is obtained, and the specific expression is as follows: 。 4. The power and current prediction control method for a doubly-fed induction generator grid-side converter as described in claim 3, characterized in that, The prediction of the current, active power, and reactive power values ​​of the doubly-fed induction generator grid-side converter for the next control cycle based on the power prediction model and the current prediction model is as follows: by U rd = S d U dc , U rq =S q U dc As the control variables of the dq axis, the predictive model equations for current and power are obtained, as well as the rate of change of current and power of the dq axis; Based on the prediction model equations for current and power, the initial values ​​of current and power in the current sampling period are obtained, and the initial values, the dq-axis current change rate, and the power change rate are plotted in the voltage vector. U m After action T 1 and T 2. During this time, the current value, active power, and reactive power values ​​of the grid-side converter of the doubly fed motor are obtained.

5. The power and current prediction control method for a doubly-fed induction generator grid-side converter as described in claim 4, characterized in that, The method of using space vector pulse width modulation technology to generate the switching state of the doubly-fed induction generator grid-side converter for the next control cycle, and performing power and current predictive control, specifically involves: In a sampling period T s Three consecutive voltage vectors are selected to define different three-phase arm switching states of the doubly-fed induction generator (DFIG) grid-side converter, and the voltage vectors of the three-phase arm switching states of the DFIG grid-side converter under different combinations of conditions are obtained. V n ; One three-phase voltage cycle input to the AC side of the doubly-fed motor grid-side converter is divided into six sectors at 60-degree intervals. The sector to which the current sector belongs is determined based on the current state of the three-phase AC voltage input to the doubly-fed motor grid-side converter, and the voltage vector of the current sector operation is obtained. Based on the voltage vector duration of the next control cycle, and using the obtained voltage vector, the switching state of the doubly-fed motor grid-side converter for the next control cycle is generated through vector pulse width modulation (VPWM) technology, enabling predictive control of the power and current of the doubly-fed motor grid-side converter.

6. A power and current prediction control system for a doubly-fed induction generator grid-side converter, characterized in that, include: The model building module is used to establish the power and current models of the doubly fed motor grid-side converter under the three-phase grid voltage balance state. The power prediction module is used to construct power prediction models and current prediction models based on the voltage vector of the power model and current model, and predict the current value, active power and reactive power value of the grid-side converter of the doubly-fed motor in the next control cycle according to the power prediction model and current prediction model. The duration acquisition module is used to consider active power, reactive power, and dq coordinate system dq The current component of the shaft is used to design an improved value function, and the duration of the voltage vector action in the next control cycle is obtained by minimizing the value function. The control module is used to generate the switching state of the doubly-fed motor grid-side converter for the next control cycle based on the duration of the voltage vector action in the next control cycle, using space vector pulse width modulation technology, and to perform power and current predictive control.

7. A computer device, characterized in that, The system includes a memory and a processor, wherein the memory stores a program that, when executed by the processor, causes the processor to perform the steps of a power and current prediction control method for a doubly fed motor grid-side converter as described in any one of claims 1 to 5.

8. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the power and current prediction control method for a doubly fed motor grid-side converter according to any one of claims 1 to 5.

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