Control method and device of wind turbine generator system under weak power grid based on full power converter

Abstract

The present disclosure proposes a control method and device for a wind turbine generator set based on a full-power converter under a weak power grid, the method includes obtaining a generator output power reference value, a DC voltage of a full-power converter, an AC side output power of a grid-side converter, an AC voltage and reactive power, a maximum current, a q-axis current component and a d-axis current component of a grid-side converter; obtaining a q-axis current reference value based on an AC voltage or reactive power; obtaining a d-axis current reference value based on a q-axis current reference value, a maximum current, a DC voltage, an AC side output power of a grid-side converter and an output power reference value; obtaining a d-axis voltage reference component and a q-axis voltage reference component based on a q-axis current reference value, a d-axis current reference value, a q-axis current component and a d-axis current component of a grid-side converter, and then generating a modulation wave to control the grid-side converter. According to the method disclosed in the present disclosure, when the access grid is a weak power grid, the control of the full-power converter can be optimized to better provide active and reactive support.

Description

Technical Field

[0001] The present disclosure relates to the field of wind power grid connection, and in particular to a control method and device for a wind turbine generator set under a weak power grid based on a full power converter. Background Art

[0002] With the rapid development of renewable energy generation, wind power generation has gradually occupied a large proportion in the power system. For wind power grid-connected systems, the system to which they are connected is usually a strong power grid, that is, the wind farm does not need to perform relevant active and reactive power regulation functions on the access grid. With the large-scale development of wind power, when a high proportion of wind power is connected to the power system, it will have a huge impact on the operation of the access grid, especially in the case of weak power grids, which also puts forward certain requirements on the active regulation ability of wind turbines. Therefore, there is an urgent need for an optimized control technology for full-power converter wind turbine controllers under the condition of weak power grid access. Summary of the invention

[0003] The present disclosure aims to solve one of the technical problems in the related art at least to some extent.

[0004] To this end, the first purpose of the present invention is to propose a control method for a wind turbine based on a full-power converter under a weak power grid. The main purpose is to optimize the control of the full-power converter to better provide certain active and reactive support when the access grid is a weak power grid.

[0005] The second objective of the present disclosure is to provide a control device for a wind turbine generator set under a weak power grid based on a full power converter.

[0006] The third objective of the present disclosure is to provide a control device for a wind turbine generator set under a weak power grid based on a full power converter.

[0007] To achieve the above-mentioned object, the first aspect of the present disclosure proposes a control method for a wind turbine generator set in a weak power grid based on a full-power converter, which is applied to a wind power grid-connected system. The wind power grid-connected system includes a wind turbine, a full-power converter and a transformer. The full-power converter includes a grid-side converter and a machine-side converter. The wind turbine is connected to the grid via the full-power converter and the transformer. The method includes:

[0008] Obtaining the DC voltage of the full-power converter, the AC voltage and reactive power of the grid-side converter, the generator output power reference value, the AC side output power of the grid-side converter, the maximum current of the full-power converter, and the q-axis current component and d-axis current component of the AC side of the grid-side converter;

[0009] Obtaining a q-axis current reference value based on the AC voltage or the reactive power;

[0010] Obtaining a d-axis current reference value based on the q-axis current reference value, the maximum current, the DC voltage, the AC-side output power of the grid-side converter, and the generator output power reference value;

[0011] Obtaining a d-axis voltage reference component and a q-axis voltage reference component based on the q-axis current reference value, the d-axis current reference value, and the q-axis current component and the d-axis current component on the AC side of the grid-side converter;

[0012] Pulse width modulation is performed based on the d-axis voltage reference component and the q-axis voltage reference component to generate a modulation wave, and the grid-side converter is controlled based on the modulation wave.

[0013] In one embodiment of the present disclosure, the d-axis current reference value is obtained based on the q-axis current reference value, the maximum current, the DC voltage, the AC side output power of the grid-side converter and the generator output power reference value, including: obtaining a first target d-axis current reference value based on the DC voltage, the AC side output power of the grid-side converter and the generator output power reference value; obtaining a second target d-axis current reference value based on the q-axis current reference value and the maximum current; and selecting the minimum value of the first target d-axis current reference value and the second target d-axis current reference value as the d-axis current reference value.

[0014] In one embodiment of the present disclosure, the DC voltage includes a DC voltage measurement value and a DC voltage rated value, and the first target d-axis current reference value is obtained based on the DC voltage, the AC side output power of the grid-side converter and the generator output power reference value, including: obtaining a first d-axis current intermediate value based on the DC voltage measurement value and the DC voltage rated value; obtaining a second d-axis current intermediate value based on the AC side output power of the grid-side converter and the generator output power reference value; and selecting the maximum value of the first d-axis current intermediate value and the second d-axis current intermediate value as the first target d-axis current reference value.

[0015] In one embodiment of the present disclosure, the second d-axis current intermediate value is obtained based on the AC side output power of the grid-side converter and the generator output power reference value, including: subtracting the AC side output power of the grid-side converter from the generator output power reference value to obtain a first difference, and sending the first difference to a PI regulator to calculate the second d-axis current intermediate value.

[0016] In one embodiment of the present disclosure, the generator speed and the DC voltage measurement value are detected; if at least one of the DC voltage measurement value or the generator speed does not meet the requirements, the generator output power reference value is updated based on the AC side output power or rated speed of the grid-side converter to generate a new first difference.

[0017] In one embodiment of the present disclosure, the DC voltage measurement value not meeting the requirement means that the DC voltage measurement value is greater than the DC voltage setting value; the generator speed not meeting the requirement means that the generator speed is not within the set safe operating range.

[0018] To achieve the above-mentioned purpose, the second aspect of the present disclosure proposes a control device for a wind turbine generator set in a weak power grid based on a full-power converter, which is applied to a wind power grid-connected system. The wind power grid-connected system includes a wind turbine, a full-power converter and a transformer. The full-power converter includes a grid-side converter and a machine-side converter. The wind turbine is connected to the power grid via the full-power converter and the transformer. The device includes:

[0019] An acquisition module is used to obtain the DC voltage of the full-power converter, the AC voltage and reactive power of the grid-side converter, the generator output power reference value, the AC side output power of the grid-side converter, the maximum current of the full-power converter, and the q-axis current component and d-axis current component of the AC side of the grid-side converter;

[0020] a calculation module, configured to obtain a q-axis current reference value based on the AC voltage or the reactive power; obtain a d-axis current reference value based on the q-axis current reference value, the maximum current, the DC voltage, the AC-side output power of the grid-side converter, and the generator output power reference value; and obtain a d-axis voltage reference component and a q-axis voltage reference component based on the q-axis current reference value, the d-axis current reference value, the q-axis current component and the d-axis current component on the AC side of the grid-side converter;

[0021] A control module is used to perform pulse width modulation based on the d-axis voltage reference component and the q-axis voltage reference component to generate a modulation wave, and control the grid-side converter based on the modulation wave.

[0022] In one embodiment of the present disclosure, the calculation module is specifically used to: obtain a first target d-axis current reference value based on the DC voltage, the AC side output power of the grid-side converter and the generator output power reference value; obtain a second target d-axis current reference value based on the q-axis current reference value and the maximum current; and select the minimum value between the first target d-axis current reference value and the second target d-axis current reference value as the d-axis current reference value.

[0023] In one embodiment of the present disclosure, the calculation module is specifically used to: obtain a first d-axis current intermediate value based on the DC voltage measurement value and the DC voltage rated value; obtain a second d-axis current intermediate value based on the AC side output power of the grid-side converter and the generator output power reference value; and select the maximum value of the first d-axis current intermediate value and the second d-axis current intermediate value as the first target d-axis current reference value.

[0024] To achieve the above-mentioned purpose, the third aspect embodiment of the present disclosure proposes a control device based on a full-power converter wind turbine under a weak power grid, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the control method based on the full-power converter wind turbine under a weak power grid of the first aspect embodiment of the present disclosure.

[0025] In one or more embodiments of the present disclosure, the present invention is applied to a wind power grid-connected system, the wind power grid-connected system includes a wind turbine, a full-power converter and a transformer, the full-power converter includes a grid-side converter and a machine-side converter, the wind turbine is connected to the grid via the full-power converter and the transformer, and the method includes: obtaining the DC voltage of the full-power converter, the AC voltage and reactive power of the grid-side converter, the generator output power reference value, the AC side output power of the grid-side converter, the maximum current of the full-power converter, the q-axis current component and the d-axis current of the AC side of the grid-side converter component; obtain a q-axis current reference value based on the AC voltage or reactive power; obtain a d-axis current reference value based on the q-axis current reference value, the maximum current, the DC voltage, the AC side output power of the grid-side converter and the generator output power reference value; obtain a d-axis voltage reference component and a q-axis voltage reference component based on the q-axis current reference value, the d-axis current reference value, the q-axis current component and the d-axis current component on the AC side of the grid-side converter; perform pulse width modulation based on the d-axis voltage reference component and the q-axis voltage reference component to generate a modulation wave, and control the grid-side converter based on the modulation wave. In this case, the DC voltage of the full-power converter, the AC voltage and reactive power of the grid-side converter, the generator output power reference value, the AC side output power of the grid-side converter, the maximum current of the full-power converter, the q-axis current component and the d-axis current component of the AC side of the grid-side converter are comprehensively obtained to obtain the d-axis voltage reference component and the q-axis voltage reference component, and then the modulation wave is obtained. The grid-side converter is controlled based on the modulation wave, which optimizes the control of the full-power converter when the grid is connected to a weak grid, improves the stability of the control of the grid-side converter, and better provides certain active and reactive power support for the grid.

[0026] Additional aspects and advantages of the present disclosure will be given in part in the following description and in part will be obvious from the following description or learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation of the present disclosure or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the specific implementation or prior art description. Obviously, the drawings described below are some implementations of the present disclosure. For ordinary technicians in this field, other drawings can also be obtained based on these drawings without creative work. The above and / or additional aspects and advantages of the present disclosure will become obvious and easy to understand from the following description of the embodiments in conjunction with the drawings, in which:

[0028] Figure 1 A schematic diagram of the topological structure of a wind power grid-connected system provided in an embodiment of the present disclosure;

[0029] Figure 2 A schematic flow chart of a control method for a wind turbine generator set in a weak power grid based on a full power converter provided in an embodiment of the present disclosure;

[0030] Figure 3 A control principle diagram of a grid-side converter provided in an embodiment of the present disclosure;

[0031] Figure 4 A block diagram of a control device for a wind turbine generator set in a weak power grid based on a full power converter provided by an embodiment of the present disclosure;

[0032] Figure 5 The present invention is a block diagram of a control device based on a full power converter wind turbine generator set under a weak power grid, which is used to implement the control method based on a full power converter wind turbine generator set under a weak power grid of the embodiment of the present disclosure. DETAILED DESCRIPTION

[0033] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the embodiments of the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the embodiments of the present disclosure as detailed in the appended claims.

[0034] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0035] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present disclosure, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. It should also be understood that the term "and / or" used in the present disclosure refers to and includes any or all possible combinations of one or more associated listed items.

[0036] Embodiments of the present disclosure are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present disclosure, and should not be construed as limiting the present disclosure.

[0037] The present invention provides a control method and device for a wind turbine generator set based on a full-power converter under weak power grid conditions, the main purpose of which is to optimize the control of the full-power converter to better provide certain active and reactive power support when the access grid is a weak power grid.

[0038] The control method and device of a wind turbine generator set under a weak power grid based on a full-power converter disclosed in the present invention are applied to a wind power grid-connected system. It is easy to understand that the wind power grid-connected system includes a wind turbine, a full-power converter and a transformer. The full-power converter includes a grid-side converter and a machine-side converter. The wind turbine is connected to the power grid via the full-power converter and the transformer.

[0039] Figure 1 Schematic diagram of the topological structure of the wind power grid-connected system provided by the embodiment of the present disclosure. Figure 1As shown, the wind power grid-connected system includes a wind turbine and a permanent magnet synchronous generator (PMSG). The wind turbine and the permanent magnet synchronous generator constitute a wind turbine unit. The wind power grid-connected system also includes a full-power converter and a step-up transformer. The full-power converter includes a grid-side converter and a machine-side converter. The grid-side converter is connected to the grid via a step-up transformer. The machine-side converter is connected to the permanent magnet synchronous generator. The full-power converter also includes a centralized capacitor connecting the DC side positive pole and the DC side negative pole of the grid-side converter.

[0040] In a first embodiment, Figure 2 The following is a flow chart of a control method for a wind turbine generator set in a weak power grid based on a full power converter according to an embodiment of the present disclosure. Figure 2 As shown, the control method of the wind turbine generator set based on the full power converter under weak power grid includes the following steps:

[0041] Step S11, obtaining the DC voltage of the full-power converter, the AC voltage and reactive power of the grid-side converter, the generator output power reference value, the AC side output power of the grid-side converter, the maximum current of the full-power converter, and the q-axis current component and d-axis current component of the AC side of the grid-side converter.

[0042] Specifically, in step S11, the DC voltage of the full power converter is obtained, including the DC voltage measurement value and the DC voltage rated value. The DC voltage measurement value can be represented by the symbol U dc The DC voltage rating can be represented by the symbol U dcref The AC voltage of the grid-side converter includes the AC voltage measurement value and the AC voltage rated value. The AC voltage measurement value can be represented by the symbol u g The AC voltage rating can be represented by the symbol u gref The reactive power of the grid-side converter includes the reactive power measurement value and the reactive power rating value. The reactive power measurement value can be represented by the symbol Q g The reactive power rating can be represented by the symbol Q gref The generator output power reference value can be represented by the symbol P sref The AC output power of the grid-side converter can be represented by the symbol P load Indicates the maximum current of a full power converter. The maximum current can be represented by the symbol i max The q-axis current component of the AC side of the grid-side converter can be represented by the symbol i gq The d-axis current component of the AC side of the grid-side converter can be represented by the symbol i gd express.

[0043] Step S12: obtaining a q-axis current reference value based on the AC voltage or reactive power.

[0044] In step S12, the q-axis current reference value may be obtained based on the AC voltage of the grid-side converter, or may be obtained based on the reactive power of the grid-side converter. gqref express.

[0045] In some embodiments, obtaining a q-axis current reference value based on the AC voltage of the grid-side converter includes obtaining the q-axis current reference value based on an AC voltage measurement value and an AC voltage rating. Obtaining a q-axis current reference value based on the reactive power of the grid-side converter includes obtaining the q-axis current reference value based on a reactive power measurement value and a reactive power rating.

[0046] Specifically, Figure 3 A control schematic diagram of a grid-side converter provided in an embodiment of the present disclosure.

[0047] like Figure 3 As shown, the q-axis current reference value i is generated gqref There are two ways. Method 1 is to calculate the reactive power measurement value Q g With reactive power rating Q gref The difference is sent to the PI regulator to calculate the q-axis current reference value i gqref Method 2 is to calculate the AC voltage rating u gref With the AC voltage measurement value u g The difference is sent to the PI regulator to calculate the q-axis current reference value i gqref Method 1 and method 2 can be selected based on needs.

[0048] Step S13, obtaining a d-axis current reference value based on the q-axis current reference value, the maximum current, the DC voltage, the AC side output power of the grid-side converter and the generator output power reference value.

[0049] Specifically, in step S13, the d-axis current reference value is obtained based on the q-axis current reference value, the maximum current, the DC voltage, the AC-side output power of the grid-side converter, and the generator output power reference value, including: obtaining a first target d-axis current reference value based on the DC voltage, the AC-side output power of the grid-side converter, and the generator output power reference value; obtaining a second target d-axis current reference value based on the q-axis current reference value and the maximum current; selecting the minimum value of the first target d-axis current reference value and the second target d-axis current reference value as the d-axis current reference value. The d-axis current reference value can be represented by the symbol i gdref The first target d-axis current reference value can be represented by the symbol i gdref1 The second target d-axis current reference value can be represented by the symbol i gdref2 express.

[0050] In step S13, a first target d-axis current reference value is obtained based on the DC voltage, the AC output power of the grid-side converter and the generator output power reference value, including: obtaining a first d-axis current intermediate value based on the DC voltage measurement value and the DC voltage rated value; obtaining a second d-axis current intermediate value based on the AC output power of the grid-side converter and the generator output power reference value; selecting the maximum value of the first d-axis current intermediate value and the second d-axis current intermediate value as the first target d-axis current reference value. The first d-axis current intermediate value can be represented by the symbol i gdref11 The intermediate value of the second d-axis current can be represented by the symbol i gdref12 express.

[0051] In step S13, a second d-axis current intermediate value is obtained based on the AC side output power of the grid-side converter and the generator output power reference value, including: subtracting the AC side output power of the grid-side converter from the generator output power reference value to obtain a first difference, and sending the first difference to a PI regulator to calculate the second d-axis current intermediate value.

[0052] In this embodiment, the first target d-axis current reference value i gdref1 satisfy:

[0053] i gdref1 =max(i gdref11 ,i gdref12 )

[0054] Among them, the first d-axis current intermediate value i gdref11 Satisfy i gdref11 =PI(U dcref -U dc ), the second d-axis current intermediate value i gdref12 Satisfy i gdref12 =PI(P load -P sref ). Among them, PI represents PI regulator, P load -P sref Get the first difference, that is, the DC voltage rated value U dcref With DC voltage measurement value U dc The difference is sent to the PI regulator to calculate the first d-axis current intermediate value i gdref11 The AC output power P of the grid-side converter load and the generator output power reference value P sref The difference is sent to the PI regulator to calculate the second d-axis current intermediate value i gdref12 .

[0055] The second target d-axis current reference value i gdref2 satisfy:

[0056]

[0057] like Figure 3 As shown, the minimum value of the first target d-axis current reference value and the second target d-axis current reference value is selected as the d-axis current reference value, that is, the d-axis current reference value i gdref satisfy:

[0058] i gdref =min(i gdref1 ,i gdref2 ).

[0059] In this embodiment, it also includes: detecting the generator speed and the DC voltage measurement value; if at least one of the DC voltage measurement value or the generator speed does not meet the requirements, updating the generator output power reference value based on the AC side output power or rated speed of the grid-side converter to generate a new first difference. The DC voltage measurement value not meeting the requirements means that the DC voltage measurement value is greater than the DC voltage setting value; the generator speed not meeting the requirements means that the generator speed is not within the set safe operation range. The DC voltage setting value is less than the DC voltage maximum value.

[0060] Specifically, considering that for the grid-side converter, the generator output power of the grid-side converter and the AC side output power of the grid-side converter satisfy the equation Among them, P s is the generator output power, C is the centralized capacitance value of the full power converter. t is the time. If the electrical and mechanical losses are ignored, the generator output power change satisfies the equation Among them, P wind is the power captured by the wind turbine, J is the generator moment of inertia, ω r is the generator speed. Based on the two equations satisfied by the generator output power, it can be seen that when P s >P load , U dc Reduce, otherwise U dc Increase; when P wind >P s ,ω r Increase, on the contrary r Since the DC voltage measurement value U dc There is a safe operating range, namely U min <U dc <U dcmax , where U dcmax is the maximum DC voltage (i.e. the maximum operating voltage), U min is the minimum value of DC voltage. The generator speed also has a set safe operating range, that is, ω rmin <ω r <ω rmax , where ω rmaxis the maximum speed of the generator, ω rmin Therefore, in the process of generating the first target d-axis current reference value in step S13, it is also necessary to determine whether the DC voltage measurement value or the generator speed meets the requirement.

[0061] If the DC voltage measurement value does not meet the requirement, but the generator speed meets the requirement, the generator output power reference value is updated to the AC side output power of the grid-side converter, and then the first difference is recalculated to obtain a new second d-axis current intermediate value i gdref12 .

[0062] If the DC voltage measurement value meets the requirement, but the generator speed does not meet the requirement, the generator output power reference value is updated based on the AC side output power and rated speed of the grid-side converter to generate a new first difference. Specifically, the target power is obtained based on the AC side output power and rated speed of the grid-side converter, and the target power satisfies -k(ω r -ω r0 )+P load , where k is the proportionality coefficient, ω r0 The target power is used to update the generator output power reference value, generate a new first difference value, and then obtain a new second d-axis current intermediate value i gdref12 It should be noted that in this embodiment, the generator speed is not within the set safe operation range (that is, the generator speed does not meet the requirements) mainly because the generator speed is greater than the maximum speed value of the generator operation. When the generator speed is less than the minimum speed value of the generator operation, the generator is directly shut down.

[0063] If the DC voltage measurement value and the generator speed do not meet the requirements, the target power is obtained based on the AC side output power and rated speed of the grid-side converter. The target power is used to update the generator output power reference value, generate a new first difference, and then obtain a new second d-axis current intermediate value i gdref12 .

[0064] In step S13, the d-axis current reference value is calculated by integrating the q-axis current reference value, the maximum current, the DC voltage, the AC side output power of the grid-side converter and the generator output power reference value, wherein the first d-axis current intermediate value i is generated in the voltage outer loop of the grid-side converter. gdref11 Based on this, a control link is added to generate the second d-axis current intermediate value i gdref12 , then the first d-axis current intermediate value i is integrated gdref11 and the second d-axis current intermediate value i gdref12The d-axis current reference value is used as the reference value of the inner loop current to participate in subsequent control, thereby enhancing the active regulation capability of the grid-side converter. The motor speed and DC voltage measurement values ​​are detected at the same time. If at least one of the motor speed or DC voltage measurement values ​​does not meet the requirements, the generator output power reference value is updated based on the AC side output power or rated speed of the grid-side converter, and a new second d-axis current intermediate value i is obtained. gdref12 , and then update the d-axis current reference value to participate in subsequent control, better optimize the control of the full-power converter fan controller, and further enhance the active regulation capability of the grid-side converter.

[0065] Step S14, obtaining a d-axis voltage reference component and a q-axis voltage reference component based on the q-axis current reference value, the d-axis current reference value, the q-axis current component and the d-axis current component on the AC side of the grid-side converter.

[0066] In step S14, specifically, the d-axis voltage component u is obtained based on the AC voltage measurement value. d and the q-axis voltage component u q .like Figure 3 As shown, calculate the d-axis current reference value i gdref The d-axis current component i of the AC side of the grid-side converter gd The difference is sent to the PI regulator (i.e., proportional integral controller) to calculate the first voltage V1, based on the q-axis current component i on the AC side of the grid-side converter gq , the inductive reactance value of the grid-side converter ω g L g Obtain the second voltage V2, and convert the d-axis voltage component u d Add the first voltage V1 and subtract the second voltage V2 to obtain the d-axis voltage reference component U gd . Calculate the q-axis current reference value i gqref The q-axis current component i of the AC side of the grid-side converter gq The difference is sent to the PI regulator (i.e., proportional integral controller) to calculate the third voltage V3, based on the d-axis current component i on the AC side of the grid-side converter gd , the inductive reactance value of the grid-side converter ω g L g The fourth voltage V4 is obtained by converting the q-axis voltage component u q After adding the third voltage V3, the fourth voltage V4 is added to obtain the q-axis voltage reference component U gq .

[0067] Step S15, performing pulse width modulation based on the d-axis voltage reference component and the q-axis voltage reference component to generate a modulation wave, and controlling the grid-side converter based on the modulation wave.

[0068] In step S15, Figure 3As shown, the d-axis voltage reference component U gd and the q-axis voltage reference component U gq Pulse width modulation is performed to generate a modulation wave, and the grid-side converter is controlled based on the modulation wave. This participates in the control and regulation of the DC voltage and reactive power of the grid-side converter, thereby ensuring the stability of the DC voltage.

[0069] In the control method of a wind turbine generator set under a weak power grid based on a full-power converter in an embodiment of the present disclosure, it is applied to a wind power grid-connected system, the wind power grid-connected system includes a wind turbine, a full-power converter and a transformer, the full-power converter includes a grid-side converter and a machine-side converter, the wind turbine is connected to the grid via the full-power converter and the transformer, and the method includes: obtaining the DC voltage of the full-power converter, the AC voltage and reactive power of the grid-side converter, the generator output power reference value, the AC side output power of the grid-side converter, the maximum current of the full-power converter, and the q-axis current of the AC side of the grid-side converter The invention relates to a method for controlling the grid-side converter by using a plurality of pulse width modulation (PWM) devices, comprising: obtaining a d-axis current component and a d-axis current component; obtaining a q-axis current reference value based on the AC voltage or reactive power; obtaining a d-axis current reference value based on the q-axis current reference value, the maximum current, the DC voltage, the AC-side output power of the grid-side converter and the generator output power reference value; obtaining a d-axis voltage reference component and a q-axis voltage reference component based on the q-axis current reference value, the d-axis current reference value, the q-axis current component and the d-axis current component on the AC side of the grid-side converter; performing pulse width modulation based on the d-axis voltage reference component and the q-axis voltage reference component to generate a modulation wave, and controlling the grid-side converter based on the modulation wave. In this case, the DC voltage of the full-power converter, the AC voltage and reactive power of the grid-side converter, the generator output power reference value, the AC side output power of the grid-side converter, the maximum current of the full-power converter, the q-axis current component and the d-axis current component of the AC side of the grid-side converter are comprehensively obtained to obtain the d-axis voltage reference component and the q-axis voltage reference component, and then the modulation wave is obtained. The grid-side converter is controlled based on the modulation wave, and the control of the full-power converter under the condition of weak grid access is optimized. Not only the active regulation capability of the grid-side converter is enhanced, but also the stability of the control of the grid-side converter is improved, and better active and reactive support is provided for the grid.

[0070] The following are embodiments of the device disclosed herein, which can be used to execute the method embodiments disclosed herein. For details not disclosed in the device embodiments disclosed herein, please refer to the method embodiments disclosed herein.

[0071] The present disclosure relates to a control device for a wind turbine generator set in a weak power grid based on a full-power converter. The control device for a wind turbine generator set in a weak power grid based on a full-power converter is used to optimize the control of the full-power converter when the access grid is a weak power grid, improve the stability of the control of the grid-side converter, and better provide certain active and reactive power support for the grid. The control device for a wind turbine generator set in a weak power grid based on a full-power converter is applied to a wind power grid-connected system, which includes a wind turbine, a full-power converter and a transformer, the full-power converter includes a grid-side converter and a machine-side converter, and the wind turbine is connected to the grid via the full-power converter and the transformer.

[0072] See also Figure 4 , Figure 4 The block diagram of a control device for a wind turbine generator set in a weak power grid based on a full power converter is provided in an embodiment of the present disclosure. The control device 10 for a wind turbine generator set in a weak power grid based on a full power converter comprises an acquisition module 11, a calculation module 12 and a control module 13, wherein:

[0073] An acquisition module 11 is used to obtain the DC voltage of the full-power converter, the AC voltage and reactive power of the grid-side converter, the generator output power reference value, the AC side output power of the grid-side converter, the maximum current of the full-power converter, and the q-axis current component and d-axis current component of the AC side of the grid-side converter;

[0074] A calculation module 12 is used to obtain a q-axis current reference value based on the AC voltage or reactive power; obtain a d-axis current reference value based on the q-axis current reference value, the maximum current, the DC voltage, the AC-side output power of the grid-side converter and the generator output power reference value; obtain a d-axis voltage reference component and a q-axis voltage reference component based on the q-axis current reference value, the d-axis current reference value, the q-axis current component and the d-axis current component on the AC side of the grid-side converter;

[0075] The control module 13 is used to perform pulse width modulation based on the d-axis voltage reference component and the q-axis voltage reference component to generate a modulation wave, and control the grid-side converter based on the modulation wave.

[0076] Optionally, the calculation module 12 is specifically used to: obtain a first target d-axis current reference value based on the DC voltage, the AC side output power of the grid-side converter and the generator output power reference value; obtain a second target d-axis current reference value based on the q-axis current reference value and the maximum current; and select the minimum value between the first target d-axis current reference value and the second target d-axis current reference value as the d-axis current reference value.

[0077] Optionally, the calculation module 12 is specifically used to: obtain a first d-axis current intermediate value based on a DC voltage measurement value and a DC voltage rated value; obtain a second d-axis current intermediate value based on an AC side output power of a grid-side converter and a generator output power reference value; and select a maximum value between the first d-axis current intermediate value and the second d-axis current intermediate value as a first target d-axis current reference value.

[0078] Optionally, the calculation module 12 is specifically used to: obtain a first difference by subtracting the AC side output power of the grid-side converter from a reference value of the generator output power, and send the first difference to a PI regulator to calculate a second d-axis current intermediate value.

[0079] Optionally, the control module 13 is also used to: detect the generator speed and DC voltage measurement value; if at least one of the DC voltage measurement value or the generator speed does not meet the requirements, update the generator output power reference value in the calculation module 12 based on the AC side output power or rated speed of the grid-side converter, so as to generate a new first difference using the calculation module 12.

[0080] Optionally, the DC voltage measurement value not meeting the requirement means that the DC voltage measurement value is greater than a DC voltage setting value; the generator speed not meeting the requirement means that the generator speed is not within a set safe operating range.

[0081] It should be noted that the above explanation of the control method embodiment of a wind turbine generator set based on a full power converter in a weak power grid is also applicable to the control device of a wind turbine generator set based on a full power converter in a weak power grid of this embodiment, which will not be repeated here.

[0082] In the control device for a wind turbine generator set under a weak power grid based on a full-power converter in an embodiment of the present disclosure, an acquisition module is used to acquire the DC voltage of the full-power converter, the AC voltage and reactive power of the grid-side converter, the generator output power reference value, the AC side output power of the grid-side converter, the maximum current of the full-power converter, and the q-axis current component and d-axis current component of the AC side of the grid-side converter; a calculation module is used to obtain the q-axis current reference value based on the AC voltage or reactive power; obtain the d-axis current reference value based on the q-axis current reference value, the maximum current, the DC voltage, the AC side output power of the grid-side converter, and the generator output power reference value; obtain the d-axis voltage reference component and the q-axis voltage reference component based on the q-axis current reference value, the d-axis current reference value, the q-axis current component and the d-axis current component of the AC side of the grid-side converter; and a control module is used to perform pulse width modulation based on the d-axis voltage reference component and the q-axis voltage reference component to generate a modulation wave, and control the grid-side converter based on the modulation wave. In this case, the DC voltage of the full-power converter, the AC voltage and reactive power of the grid-side converter, the generator output power reference value, the AC side output power of the grid-side converter, the maximum current of the full-power converter, the q-axis current component and the d-axis current component of the AC side of the grid-side converter are comprehensively obtained to obtain the d-axis voltage reference component and the q-axis voltage reference component, and then the modulation wave is obtained. The grid-side converter is controlled based on the modulation wave, and the control of the full-power converter under the condition of weak grid access is optimized. Not only the active regulation capability of the grid-side converter is enhanced, but also the stability of the control of the grid-side converter is improved, and better active and reactive support is provided for the grid.

[0083] According to an embodiment of the present disclosure, the present disclosure also provides a control device for a wind turbine generator set under a weak power grid based on a full power converter, a readable storage medium and a computer program product.

[0084] Figure 5 It is a block diagram of a control device based on a full power converter wind turbine under a weak power grid, which is used to implement the control method based on a full power converter wind turbine under a weak power grid of an embodiment of the present disclosure. The control device based on a full power converter wind turbine under a weak power grid is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The control device based on a full power converter wind turbine under a weak power grid can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable electronic devices and other similar computing devices. The components shown in the present disclosure, the connections and relationships of the components, and the functions of the components are merely examples and are not intended to limit the implementation of the present disclosure described and / or required in the present disclosure.

[0085] like Figure 5As shown, the control device 20 based on the weak grid of the full power converter wind turbine includes a computing unit 21, which can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 22 or the computer program loaded from the storage unit 28 to the random access memory (RAM) 23. In the RAM 23, various programs and data required for the operation of the control device 20 based on the weak grid of the full power converter wind turbine can also be stored. The computing unit 21, ROM 22 and RAM 23 are connected to each other through a bus 24. The input / output (I / O) interface 25 is also connected to the bus 24.

[0086] Multiple components in the control device 20 for a wind turbine generator set under a weak power grid based on a full power converter are connected to the I / O interface 25, including: an input unit 26, such as a keyboard, a mouse, etc.; an output unit 27, such as various types of displays, speakers, etc.; a storage unit 28, such as a disk, an optical disk, etc., which is in communication connection with the computing unit 21; and a communication unit 29, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 29 allows the control device 20 for a wind turbine generator set under a weak power grid based on a full power converter to exchange information / data with other control devices for a wind turbine generator set under a weak power grid based on a full power converter through a computer network such as the Internet and / or various telecommunication networks.

[0087] The computing unit 21 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 21 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 21 performs the various methods and processes described above, such as executing a control method based on a full power converter wind turbine under a weak grid. For example, in some embodiments, the control method based on a full power converter wind turbine under a weak grid can be implemented as a computer software program, which is tangibly included in a machine-readable medium, such as a storage unit 28. In some embodiments, part or all of the computer program can be loaded and / or installed on a control device 20 based on a full power converter wind turbine under a weak grid via a ROM 22 and / or a communication unit 29. When the computer program is loaded into the RAM 23 and executed by the computing unit 21, one or more steps of the control method based on a full power converter wind turbine under a weak grid described above can be executed. Alternatively, in other embodiments, the computing unit 21 may be configured to execute the control method for the wind turbine generator system under weak power grid based on a full power converter in any other appropriate manner (for example, by means of firmware).

[0088] Various embodiments of the systems and techniques described above in the present disclosure may be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0089] The program code for implementing the method of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0090] In the present disclosure, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or electronic device, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage electronic device, a magnetic storage electronic device, or any suitable combination of the foregoing.

[0091] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0092] The systems and techniques described herein can be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), the Internet, and a blockchain network.

[0093] A computer system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The relationship between the client and the server is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services ("Virtual Private Server", or "VPS" for short). The server may also be a server of a distributed system, or a server combined with a blockchain.

[0094] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and this disclosure is not limited here.

[0095] The above specific implementations do not constitute a limitation on the protection scope of the present disclosure. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A control method for a wind turbine generator set under weak power grid based on a full power converter, characterized in that: Applied to a wind power grid-connected system, the wind power grid-connected system includes a wind turbine, a full-power converter and a transformer, the full-power converter includes a grid-side converter and a machine-side converter, the wind turbine is connected to a power grid via the full-power converter and the transformer, and the method includes: Obtaining the DC voltage of the full-power converter, the AC voltage and reactive power of the grid-side converter, the generator output power reference value, the AC side output power of the grid-side converter, the maximum current of the full-power converter, and the q-axis current component and d-axis current component of the AC side of the grid-side converter; Obtaining a q-axis current reference value based on the AC voltage or the reactive power, wherein obtaining the q-axis current reference value comprises: calculating a difference between a reactive power measurement value and a reactive power rated value, and sending the difference to a PI regulator to obtain the q-axis current reference value, or calculating a difference between an AC voltage rated value and an AC voltage measurement value, and sending the difference to the PI regulator to obtain the q-axis current reference value; Obtaining a d-axis current reference value based on the q-axis current reference value, the maximum current, the DC voltage, the AC-side output power of the grid-side converter, and the generator output power reference value; A d-axis voltage reference component and a q-axis voltage reference component are obtained based on the q-axis current reference value, the d-axis current reference value, the q-axis current component and the d-axis current component on the AC side of the grid-side converter, wherein the difference between the d-axis current reference value and the d-axis current component on the AC side of the grid-side converter is calculated, and the difference is sent to the PI regulator to calculate and obtain a first voltage, a second voltage is obtained based on the product of the q-axis current component on the AC side of the grid-side converter and the inductive reactance value of the grid-side converter, and the d-axis voltage reference component is obtained by adding the first voltage to the d-axis voltage component and then subtracting the second voltage; the difference between the q-axis current reference value and the q-axis current component on the AC side of the grid-side converter is calculated, and the difference is sent to the PI regulator to calculate and obtain a third voltage, a fourth voltage is obtained based on the product of the d-axis current component on the AC side of the grid-side converter and the inductive reactance value of the grid-side converter, and the q-axis voltage reference component is obtained by adding the third voltage to the q-axis voltage component and then adding the fourth voltage; Performing pulse width modulation based on the d-axis voltage reference component and the q-axis voltage reference component to generate a modulation wave, and controlling the grid-side converter based on the modulation wave, wherein the DC voltage of the full-power converter, the AC voltage and reactive power of the grid-side converter, the generator output power reference value, the AC-side output power of the grid-side converter, the maximum current of the full-power converter, the q-axis current component and the d-axis current component of the AC side of the grid-side converter are comprehensively acquired to obtain the d-axis voltage reference component and the q-axis voltage reference component, and the modulation wave is obtained, and the grid-side converter is controlled based on the modulation wave; The step of obtaining the d-axis current reference value based on the q-axis current reference value, the maximum current, the DC voltage, the AC side output power of the grid-side converter and the generator output power reference value includes: The DC voltage includes a DC voltage measurement value and a DC voltage rated value, and a first d-axis current intermediate value is obtained based on the DC voltage measurement value and the DC voltage rated value; Obtaining a second d-axis current intermediate value based on the AC side output power of the grid-side converter and the generator output power reference value; selecting a maximum value between the first d-axis current intermediate value and the second d-axis current intermediate value as a first target d-axis current reference value; obtaining a second target d-axis current reference value based on the q-axis current reference value and the maximum current; selecting a minimum value between a first target d-axis current reference value and a second target d-axis current reference value as the d-axis current reference value; The d-axis current reference value is i gdref Indicates that the first target d-axis current reference value is i gdref1 Indicates that the second target d-axis current reference value is i gdref2 Indicates that the first d-axis current intermediate value is i gdref11 The second d-axis current intermediate value is represented by i gdref12 Indicates that the first target d-axis current reference value i gdref1 Satisfy: i gdref1 =max(i gdref11 ,i gdref12 ), the second target d-axis current reference value igdref2 satisfies: , d-axis current reference value i gdref Satisfy: i gdref =min(i gdref1 ,i gdref2 ), the first d-axis current intermediate value i gdref11 Satisfy i gdref11 =PI(U dcref —U dc ), the PI represents the PI regulator, U dcref is the DC voltage rating, U dc is the DC voltage measurement value, the second d-axis current intermediate value i gdref12 Satisfy i gdref12 =PI(P load —P sref ), the P load is the AC side output power of the grid-side converter, the P sref is the generator output power reference value, the generator output power of the grid-side converter and the AC side output power of the grid-side converter satisfy the equation , P s is the generator output power, C is the centralized capacitance value of the full power converter, and t is the time.

2. The control method of a wind turbine generator system based on a full power converter in a weak power grid according to claim 1, characterized in that: The obtaining a second d-axis current intermediate value based on the AC side output power of the grid-side converter and the generator output power reference value comprises: A first difference is obtained by subtracting the AC side output power of the grid-side converter from the reference value of the generator output power, and the first difference is sent to a PI regulator to calculate a second d-axis current intermediate value.

3. The control method of a wind turbine generator system based on a full power converter in a weak power grid according to claim 2, characterized in that: Also includes: Detect generator speed and DC voltage measurement values; If at least one of the DC voltage measurement value or the generator speed does not meet the requirements, the generator output power reference value is updated based on the AC side output power or the rated speed of the grid-side converter to generate a new first difference, including: if the DC voltage measurement value does not meet the requirements and the generator speed meets the requirements, the generator output power reference value is updated to the AC side output power of the grid-side converter; if the DC voltage measurement value meets the requirements and the generator speed does not meet the requirements, the generator output power reference value is updated based on the AC side output power of the grid-side converter and the rated speed.

4. The control method of a wind turbine generator system based on a full power converter in a weak power grid according to claim 3, characterized in that: The DC voltage measurement value not meeting the requirement means that the DC voltage measurement value is greater than the DC voltage setting value; the generator speed not meeting the requirement means that the generator speed is not within the set safe operating range.

5. A control device for a wind turbine generator set in a weak power grid based on a full power converter, characterized in that: Applicable to a wind power grid-connected system, the wind power grid-connected system includes a wind turbine, a full-power converter and a transformer, the full-power converter includes a grid-side converter and a machine-side converter, the wind turbine is connected to the grid via the full-power converter and the transformer, and the device includes: An acquisition module is used to obtain the DC voltage of the full-power converter, the AC voltage and reactive power of the grid-side converter, the generator output power reference value, the AC side output power of the grid-side converter, the maximum current of the full-power converter, and the q-axis current component and d-axis current component of the AC side of the grid-side converter; a calculation module, configured to obtain a q-axis current reference value based on the AC voltage or the reactive power, wherein obtaining the q-axis current reference value comprises: calculating the difference between the reactive power measurement value and the reactive power rated value, and sending the difference to the PI regulator to calculate and obtain the q-axis current reference value, or calculating the difference between the AC voltage rated value and the AC voltage measurement value, and sending the difference to the PI regulator to calculate and obtain the q-axis current reference value; obtaining a d-axis current reference value based on the q-axis current reference value, the maximum current, the DC voltage, the AC side output power of the grid-side converter, and the generator output power reference value; obtaining a d-axis voltage reference component and a q-axis voltage reference component based on the q-axis current reference value, the d-axis current reference value, the q-axis current component of the AC side of the grid-side converter, and the d-axis current component; The difference between the d-axis current reference value and the d-axis current component on the AC side of the grid-side converter is calculated, and the difference is sent to the PI regulator to calculate a first voltage, and a second voltage is obtained based on the product of the q-axis current component on the AC side of the grid-side converter and the inductive reactance value of the grid-side converter, and the d-axis voltage reference component is obtained by adding the first voltage to the d-axis voltage component and then subtracting the second voltage; the difference between the q-axis current reference value and the q-axis current component on the AC side of the grid-side converter is calculated, and the difference is sent to the PI regulator to calculate a third voltage, and a fourth voltage is obtained based on the product of the d-axis current component on the AC side of the grid-side converter and the inductive reactance value of the grid-side converter, and the q-axis voltage reference component is obtained by adding the third voltage to the q-axis voltage component and then adding the fourth voltage; A control module, configured to generate a modulation wave by pulse width modulation based on the d-axis voltage reference component and the q-axis voltage reference component, and control the grid-side converter based on the modulation wave, wherein the DC voltage of the full-power converter, the AC voltage and reactive power of the grid-side converter, the generator output power reference value, the AC-side output power of the grid-side converter, the maximum current of the full-power converter, the q-axis current component and the d-axis current component of the AC side of the grid-side converter are comprehensively acquired to obtain the d-axis voltage reference component and the q-axis voltage reference component, and the modulation wave is obtained, and the grid-side converter is controlled based on the modulation wave; Wherein, the computing module is specifically used for: The DC voltage includes a DC voltage measurement value and a DC voltage rated value, and a first d-axis current intermediate value is obtained based on the DC voltage measurement value and the DC voltage rated value; Obtaining a second d-axis current intermediate value based on the AC side output power of the grid-side converter and the generator output power reference value; selecting a maximum value between the first d-axis current intermediate value and the second d-axis current intermediate value as a first target d-axis current reference value; obtaining a second target d-axis current reference value based on the q-axis current reference value and the maximum current; selecting a minimum value between a first target d-axis current reference value and a second target d-axis current reference value as the d-axis current reference value; The d-axis current reference value is i gdref Indicates that the first target d-axis current reference value is i gdref1 Indicates that the second target d-axis current reference value is i gdref2 Indicates that the first d-axis current intermediate value is i gdref11 The second d-axis current intermediate value is represented by i gdref12 Indicates that the first target d-axis current reference value i gdref1 Satisfy: i gdref1 =max(i gdref11 ,i gdref12 ), the second target d-axis current reference value igdref2 satisfies: , d-axis current reference value i gdref Satisfy: i gdref =min(i gdref1 ,i gdref2 ), the first d-axis current intermediate value i gdref11 Satisfy i gdref11 =PI(U dcref —U dc ), the PI represents the PI regulator, U dcref is the DC voltage rating, U dc is the DC voltage measurement value, the second d-axis current intermediate value i gdref12 Satisfy i gdref12 =PI(P load —P sref ), the P load is the AC side output power of the grid-side converter, the P sref is the generator output power reference value, the generator output power of the grid-side converter and the AC side output power of the grid-side converter satisfy the equation , P s is the generator output power, C is the centralized capacitance value of the full power converter, and t is the time.

6. A control device for a wind turbine generator set under a weak power grid based on a full power converter, characterized in that: include: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the control method for a wind turbine generator set based on a full power converter in a weak power grid as described in any one of claims 1-4.

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