Parameter setting method and device based on grid-following voltage source converter

Abstract

The application provides a parameter setting method and device based on a grid-following voltage source converter, comprising: determining a stability domain, a first key curve and a second key curve based on rated operating parameters of a grid system; calculating intersection points of the stability domain and the first key curve and intersection points of the stability domain and the second key curve; and determining the amplitude limit of the phase-locked loop frequency of the voltage source converter in the grid system according to each of the intersection points; wherein the amplitude limit of the phase-locked loop frequency comprises an upper limit and a lower limit. According to the rated operating parameters of the grid system, the application determines the amplitude limit of the phase-locked loop frequency of the voltage source converter in the grid system through the intersection points of the stability domain and the first key curve and the second key curve, and accurately sets the parameters of the grid-following voltage source converter, thereby improving the phase-locked loop frequency anti-saturation amplitude limit control of the global synchronization stability of the grid.

Description

Technical Field

[0001] This invention relates to the field of power system operation and control technology, and in particular to a parameter tuning method and apparatus based on a grid-following voltage source converter. Background Technology

[0002] With the increasing penetration rate of renewable energy sources such as wind power and photovoltaics, and the continuous commissioning of large-capacity DC projects, power electronic interface equipment is widely used. As a typical grid-connected interface for new energy generator sets, power electronic converters differ from traditional synchronous machines in that they generally achieve synchronization through a phase-locked loop (PLL) control loop. PLL synchronization is a type of "voltage-driven control synchronization," and its synchronization performance is closely related to the generator terminal voltage characteristics. However, the unstable output of new energy sources can cause significant fluctuations in the generator terminal voltage. Therefore, the synchronization stability problem caused by the PLL has become a major challenge for grid-following voltage source converters.

[0003] Phase-locked loops (PLLs) use PI (Proportional-Integral) controllers to achieve frequency tracking. A PI controller can control the controlled object by linearly combining the proportional and integral components of the control deviation between the setpoint and the actual output value. While the integral action in a PI controller can eliminate steady-state error, it can also lead to integral saturation. Integral saturation increases system overshoot, lengthens transition time, and worsens closed-loop response; in severe cases, it can even cause accidents.

[0004] Therefore, how to tune the parameters of the PI controller with anti-saturation limiting to achieve global synchronous and stable control of the grid-following voltage source converter has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides a parameter tuning method and apparatus for a grid-following voltage source converter, which enables the tuning of parameters of a PI controller with anti-saturation limiting, thereby achieving global synchronous and stable control of the grid-following voltage source converter.

[0006] In a first aspect, the present invention provides a parameter tuning method based on a grid follower voltage source converter, comprising:

[0007] Based on the rated operating parameters of the power grid system, the stability region, the first critical curve, and the second critical curve are determined.

[0008] Calculate the intersection of the stability region with the first critical curve and the intersection of the stability region with the second critical curve;

[0009] The frequency limiting of the phase-locked loop of the voltage source converter in the power grid system is determined based on each of the aforementioned intersection points;

[0010] The frequency limiting of the phase-locked loop includes an upper limit and a lower limit.

[0011] According to the present invention, a parameter tuning method for a grid-following voltage source converter is provided, which determines the stability region, the first critical curve, and the second critical curve based on the rated operating parameters of the power grid system, specifically including:

[0012] The stability region R is determined according to the first preset expression;

[0013] The first preset expression is:

[0014]

[0015] Where ω is the phase-locked loop angular frequency; δ is the phase-locked angle; A is a two-dimensional plane in Euclidean space; A, B, δ s V max R is the first intermediate variable; R is the expression for the stability region.

[0016] According to a parameter tuning method for a grid-following voltage source converter provided by the present invention, the first intermediate variable is calculated according to a first preset formula;

[0017] The first preset formula includes:

[0018]

[0019]

[0020]

[0021] δ s =arcsin(B / A)

[0022] V max =A(cosδ s -cosδ cri )-B(δ cri -δ s )

[0023] Among them, i d i is the system d-axis current command value; q k is the system q-axis current command value. p k is the proportional gain of the phase-locked loop PI controller. i ω0 is the integral coefficient of the phase-locked loop PI controller; R is the nominal angular frequency of the system. l The per-unit resistance value for the system connected to the power grid; L l U represents the per-unit value of the inductance of the system connected to the power grid; g This is the per-unit value of the grid connection point voltage; δcri It is an intermediate variable.

[0024] According to the present invention, a parameter tuning method for a grid-following voltage source converter is provided, which determines the stability region, the first critical curve, and the second critical curve based on the rated operating parameters of the power grid system, specifically including:

[0025] The first key curve C1 is determined according to the second preset expression;

[0026] The second preset expression is:

[0027]

[0028] in, δ is the phase-locked loop angular frequency; f The phase-locked angle; It is a two-dimensional plane in Euclidean space; It is the second intermediate variable.

[0029] According to a parameter tuning method for a grid-following voltage source converter provided by the present invention, the second intermediate variable is calculated according to a second preset formula;

[0030] The second preset formula includes:

[0031]

[0032]

[0033]

[0034] in, i is the phase-locked loop angular frequency; d i is the system d-axis current command value; q k is the system q-axis current command value. p k is the proportional gain of the phase-locked loop PI controller. i ω0 is the integral coefficient of the phase-locked loop PI controller; R is the nominal angular frequency of the system. l The per-unit resistance value for the system connected to the power grid; L l U represents the per-unit value of the inductance of the system connected to the power grid; g This is the per-unit value of the grid connection point voltage.

[0035] According to the present invention, a parameter tuning method for a grid-following voltage source converter is provided, which determines the stability region, the first critical curve, and the second critical curve based on the rated operating parameters of the power grid system, specifically including:

[0036] The second key curve C2 is determined according to the third preset expression;

[0037] The third preset expression is:

[0038]

[0039] in, δ is the phase-locked loop angular frequency; f The phase-locked angle; It is a two-dimensional plane in Euclidean space; It is the second intermediate variable; It is the third intermediate variable.

[0040] According to a parameter tuning method for a grid-following voltage source converter provided by the present invention, the third intermediate variable is calculated according to a third preset formula;

[0041] The third preset formula includes:

[0042]

[0043]

[0044] in, k is the phase-locked loop angular frequency; i The integral coefficients of the phase-locked loop PI controller are denoted as .

[0045] According to a parameter tuning method for a grid-following voltage source converter provided by the present invention, the method calculates the intersection points of the stability region with the first critical curve and the intersection points of the stability region with the second critical curve, and determines the limiting of the phase-locked loop frequency of the voltage source converter in the grid system based on each intersection point, specifically including:

[0046] Calculate the intersection points of the stability region and the first critical curve, and denote them as the first intersection point and the second intersection point; calculate the intersection points of the stability region and the second critical curve, and denote them as the third intersection point and the fourth intersection point;

[0047] The smaller value between the first intersection point and the second intersection point is used as the upper limit of the amplitude limit, and the larger value between the second intersection point and the fourth intersection point is used as the lower limit of the amplitude limit.

[0048] Secondly, the present invention also provides a parameter tuning device based on a grid-following voltage source converter, comprising:

[0049] The domain and curve determination unit is used to determine the stability domain, the first critical curve, and the second critical curve based on the rated operating parameters of the power grid system.

[0050] An intersection calculation unit is used to calculate the intersection points of the stability region with the first critical curve and the intersection points of the stability region with the second critical curve.

[0051] A limiting determination unit is used to determine the limiting of the phase-locked loop frequency of the voltage source converter in the power grid system based on each of the intersection points;

[0052] The frequency limiting of the phase-locked loop includes an upper limit and a lower limit.

[0053] Thirdly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the parameter tuning method based on a grid-following voltage source converter as described in the first aspect.

[0054] The present invention provides a parameter tuning method and apparatus for a grid-following voltage source converter. Based on the rated operating parameters of the power grid system, it determines a stability region, a first critical curve, and a second critical curve; calculates the intersection points of the stability region with the first critical curve and the second critical curve; and determines the limiting of the phase-locked loop (PLL) frequency of the voltage source converter in the power grid system based on each intersection point. The limiting of the PLL frequency includes an upper limit and a lower limit. By determining the limiting of the PLL frequency of the voltage source converter in the power grid system based on the rated operating parameters of the power grid system and through the intersection points of the stability region with the first and second critical curves, the present invention achieves parameter tuning for the PI controller with anti-saturation limiting, thereby realizing global synchronous stable control of the grid-following voltage source converter. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0056] Figure 1 This is a flowchart illustrating the parameter tuning method for a grid-following voltage source converter provided by the present invention.

[0057] Figure 2 This is a flowchart illustrating an embodiment of the parameter tuning method for a grid-following voltage source converter provided by the present invention;

[0058] Figure 3 This is a schematic diagram of the parameter tuning device based on a grid-following voltage source converter provided by the present invention;

[0059] Figure 4 This is a schematic diagram of the structure of the electronic device provided in an embodiment of the present invention;

[0060] Figure label:

[0061] 310: Domain and curve determination unit; 320: Intersection point calculation unit; 330: Amplitude limiting determination unit;

[0062] 410: Processor; 420: Communication interface; 430: Memory; 440: Communication bus. Detailed Implementation

[0063] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this 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 this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0064] The following is combined with Figures 1-2 This invention describes a parameter tuning method for a grid-following voltage source converter provided by an embodiment of the present invention.

[0065] Figure 1 This is a flowchart illustrating the parameter tuning method for a grid-following voltage source converter provided by the present invention, as shown below. Figure 1 As shown, this embodiment of the invention provides a parameter tuning method based on a grid follower voltage source converter, including:

[0066] Step 110: Based on the rated operating parameters of the power grid system, determine the stability region, the first critical curve, and the second critical curve.

[0067] The operating parameters of the power grid system include: the system d-axis current command value i d System q-axis current command value i q The system's nominal angular frequency ω0; the per-unit resistance R of the system connected to the power grid. l The per-unit value L of the inductance of the system connected to the power grid l The per-unit value U of the grid connection point voltage. g .

[0068] The stability region R, the first critical curve C1, and the second critical curve C2 are determined based on the rated operating parameters of the power grid system, as well as the first preset expression, the second preset expression, and the third preset expression.

[0069] Step 120: Calculate the intersection of the stability region with the first critical curve and the intersection of the stability region with the second critical curve.

[0070] Based on the expressions for the stability region R, the first critical curve C1, and the second critical curve C2, calculate the coordinates of the intersection points P, V, Q, and W of C1, C2, and R.

[0071] In this embodiment, the intersection of the stability region R and the first critical curve C1 can be denoted as the first intersection point (P) and the second intersection point (Q); the intersection of the stability region R and the second critical curve C2 can be denoted as the third intersection point (V) and the fourth intersection point (W).

[0072] Step 130: Determine the limiting of the phase-locked loop frequency of the voltage source converter in the power grid system based on each of the intersection points;

[0073] The frequency limiting of the phase-locked loop includes an upper limit and a lower limit.

[0074] In some embodiments, the upper limit of the phase-locked loop (PLL) frequency limiting should be the smaller value of the ordinates of the first intersection point (P) and the third intersection point (V). The lower limit of the PLL frequency limiting should be the larger value of the ordinates of the second intersection point (Q) and the fourth intersection point (W). This invention proposes for the first time a parameter tuning method for globally synchronous and stable PLL frequency anti-saturation limiting control of a grid-following voltage source converter, which can be used to guide and modify the design of the controller.

[0075] Based on the above embodiments, the method, which determines the stability region, the first critical curve, and the second critical curve based on the rated operating parameters of the power grid system, specifically includes:

[0076] The stability region R is determined according to the first preset expression;

[0077] The first preset expression is:

[0078]

[0079] Where ω is the phase-locked loop angular frequency; δ is the phase-locked angle; A is a two-dimensional plane in Euclidean space; A, B, δ s V max R is the first intermediate variable; R is the expression for the stability region.

[0080] Based on the above embodiments, in this method, the first intermediate variable is calculated according to a first preset formula;

[0081] The first preset formula includes:

[0082]

[0083]

[0084]

[0085] δ s =arcsin(B / A)

[0086] V max =A(cosδ s-cosδ cri )-B(δ cri -δ s )

[0087] Among them, i d i is the system d-axis current command value; q k is the system q-axis current command value. p k is the proportional gain of the phase-locked loop PI controller. i ω0 is the integral coefficient of the phase-locked loop PI controller; R is the nominal angular frequency of the system. l The per-unit resistance value for the system connected to the power grid; L l U represents the per-unit value of the inductance of the system connected to the power grid; g This is the per-unit value of the grid connection point voltage; δ cri It is an intermediate variable.

[0088] Specifically, based on the first intermediate variables A, B, and δ s V max Determine the stability region R.

[0089]

[0090] It is important to note that

[0091]

[0092]

[0093]

[0094] δ s =arcsin(B / A)

[0095] V max =A(cosδ s -cosδ cri )-B(δ cri -δ s )

[0096] Where ω is the phase-locked loop angular frequency; δ is the phase-locked angle; It is a two-dimensional plane in Euclidean space; i d i is the system d-axis current command value; q k is the system q-axis current command value. p k is the proportional gain of the phase-locked loop PI controller. i ω0 is the integral coefficient of the phase-locked loop PI controller; R is the nominal angular frequency of the system. l The per-unit resistance value for the system connected to the power grid; L l U represents the per-unit value of the inductance of the system connected to the power grid; g This is the per-unit value of the grid connection point voltage; δcri R is an intermediate variable; R is the expression for the stability region.

[0097] Based on the above embodiments, the method, which determines the stability region, the first critical curve, and the second critical curve based on the rated operating parameters of the power grid system, specifically includes:

[0098] The first key curve C1 is determined according to the second preset expression;

[0099] The second preset expression is:

[0100]

[0101] in, δ is the phase-locked loop angular frequency; f The phase-locked angle; It is a two-dimensional plane in Euclidean space; It is the second intermediate variable.

[0102] Based on the above embodiments, in this method, the second intermediate variable is calculated according to a second preset formula;

[0103] The second preset formula includes:

[0104]

[0105]

[0106]

[0107] in, i is the phase-locked loop angular frequency; d i is the system d-axis current command value; q k is the system q-axis current command value. p k is the proportional gain of the phase-locked loop PI controller. i ω0 is the integral coefficient of the phase-locked loop PI controller; R is the nominal angular frequency of the system. l The per-unit resistance value for the system connected to the power grid; L l U represents the per-unit value of the inductance of the system connected to the power grid; g This is the per-unit value of the grid connection point voltage.

[0108] Specifically, based on the second intermediate variable Determine the first critical curve C1.

[0109]

[0110] It is important to note that

[0111]

[0112]

[0113]

[0114] in, δ is the phase-locked loop angular frequency; f The phase-locked angle; It is a two-dimensional plane in Euclidean space; i d i is the system d-axis current command value; q k is the system q-axis current command value. p k is the proportional gain of the phase-locked loop PI controller. i ω0 is the integral coefficient of the phase-locked loop PI controller; R is the nominal angular frequency of the system. l The per-unit resistance value for the system connected to the power grid; L l U represents the per-unit value of the inductance of the system connected to the power grid; g This is the per-unit value of the grid connection point voltage.

[0115] Based on the above embodiments, the method, which determines the stability region, the first critical curve, and the second critical curve based on the rated operating parameters of the power grid system, specifically includes:

[0116] The second key curve C2 is determined according to the third preset expression;

[0117] The third preset expression is:

[0118]

[0119] in, δ is the phase-locked loop angular frequency; f The phase-locked angle; It is a two-dimensional plane in Euclidean space; It is the second intermediate variable; It is the third intermediate variable.

[0120] Based on the above embodiments, in this method, the third intermediate variable is calculated according to a third preset formula;

[0121] The third preset formula includes:

[0122]

[0123]

[0124] in, k is the phase-locked loop angular frequency; i The integral coefficients of the phase-locked loop PI controller are denoted as .

[0125] Specifically, based on the second intermediate variable and the third intermediate variable Determine the second critical curve C2.

[0126]

[0127] It is important to note that

[0128]

[0129]

[0130]

[0131]

[0132]

[0133] in, δ is the phase-locked loop angular frequency; f The phase-locked angle; It is a two-dimensional plane in Euclidean space; i d i is the system d-axis current command value; q k is the system q-axis current command value. p k is the proportional gain of the phase-locked loop PI controller. i ω0 is the integral coefficient of the phase-locked loop PI controller; R is the nominal angular frequency of the system. l The per-unit resistance value for the system connected to the power grid; L l U represents the per-unit value of the inductance of the system connected to the power grid; g This is the per-unit value of the grid connection point voltage.

[0134] Based on the above embodiments, in this method, calculating the intersection points of the stability region and the first critical curve and the intersection points of the stability region and the second critical curve, and determining the limiting of the phase-locked loop frequency of the voltage source converter in the power grid system based on each intersection point, specifically includes:

[0135] Calculate the intersection points of the stability region and the first critical curve, and denote them as the first intersection point and the second intersection point; calculate the intersection points of the stability region and the second critical curve, and denote them as the third intersection point and the fourth intersection point;

[0136] The smaller value between the first intersection point and the second intersection point is used as the upper limit of the amplitude limit, and the larger value between the second intersection point and the fourth intersection point is used as the lower limit of the amplitude limit.

[0137] Specifically, let the first critical curve C1 and the stability region R intersect at the first intersection point P(δ). p ,ω p ), second intersection point Q(δ) q ,ω qThe second critical curve C2 and the stability region R intersect at the third intersection point V(δ). v ,ω v ), fourth intersection point W(δ) w ,ω w Two points, where ω p >0,ω v >0, ω q <0,ω w <0.

[0138] Phase-locked loop frequency limiting upper limit ω M It should be taken as ω p and ω v The smaller value in the range. Lower limit of PLL frequency limiting ω L It should be taken as ω q and ω w The larger value in the range.

[0139] Based on the above embodiments, the present invention provides an example of completing a primary parameter tuning using the parameter tuning method based on a grid follower voltage source converter, such as... Figure 2 The present invention is implemented through the technical solutions described in the following steps S1 to S4:

[0140] S1: Determine the system stability region R;

[0141] S2: Determine the key curve C1;

[0142] S3: Determine the critical curve C2;

[0143] S4: Calculate the intersection points P, Q, V, and W of R with C1 and C2, and determine the frequency limiting of the phase-locked loop using a preset method.

[0144] In the above specific embodiments, the parameter tuning method for a grid-following voltage source converter provided by the present invention determines a stability region, a first critical curve, and a second critical curve based on the rated operating parameters of the power grid system; calculates the intersection points of the stability region with the first critical curve and the second critical curve; and determines the limiting of the phase-locked loop (PLL) frequency of the voltage source converter in the power grid system based on each intersection point; wherein the limiting of the PLL frequency includes an upper limit and a lower limit. The present invention determines the limiting of the PLL frequency of the voltage source converter in the power grid system based on the rated operating parameters of the power grid system and through the intersection points of the stability region with the first and second critical curves, thereby achieving parameter tuning of the PI controller with anti-saturation limiting, and thus realizing global synchronous stable control of the grid-following voltage source converter.

[0145] The parameter tuning device based on a grid-following voltage source converter provided by the present invention is described below. The parameter tuning device based on a grid-following voltage source converter described below and the parameter tuning method based on a grid-following voltage source converter described above can be referred to in correspondence with each other.

[0146] Figure 3 This is a schematic diagram of the parameter tuning device based on a grid-following voltage source converter provided by the present invention, as shown below. Figure 3 As shown, this embodiment of the invention provides a parameter tuning device based on a grid-following voltage source converter, including: a domain and curve determination unit 310, an intersection calculation unit 320, and a limiting determination unit 330;

[0147] in,

[0148] The domain and curve determination unit 310 is used to determine the stability domain, the first critical curve, and the second critical curve based on the rated operating parameters of the power grid system.

[0149] The intersection calculation unit 320 is used to calculate the intersection of the stability region with the first critical curve and the intersection of the stability region with the second critical curve.

[0150] The limiting determination unit 330 is used to determine the limiting of the phase-locked loop frequency of the voltage source converter in the power grid system based on each of the intersection points;

[0151] The frequency limiting of the phase-locked loop includes an upper limit and a lower limit.

[0152] Based on the above embodiments, in this device, the stability region, the first critical curve, and the second critical curve are determined based on the rated operating parameters of the power grid system, specifically including:

[0153] The stability region R is determined according to the first preset expression;

[0154] The first preset expression is:

[0155]

[0156] Where ω is the phase-locked loop angular frequency; δ is the phase-locked angle; A is a two-dimensional plane in Euclidean space; A, B, δ s V max R is the first intermediate variable; R is the expression for the stability region.

[0157] Based on the above embodiments, in this device, the first intermediate variable is calculated according to a first preset formula;

[0158] The first preset formula includes:

[0159]

[0160]

[0161]

[0162] δ s =arcsin(B / A)

[0163] V max =A(cosδ s -cosδ cri )-B(δ cri -δ s )

[0164] Among them, i d i is the system d-axis current command value; q k is the system q-axis current command value. p k is the proportional gain of the phase-locked loop PI controller. i ω0 is the integral coefficient of the phase-locked loop PI controller; R is the nominal angular frequency of the system. l The per-unit resistance value for the system connected to the power grid; L l U represents the per-unit value of the inductance of the system connected to the power grid; g This is the per-unit value of the grid connection point voltage; δ cri It is an intermediate variable.

[0165] Based on the above embodiments, in this device, the stability region, the first critical curve, and the second critical curve are determined based on the rated operating parameters of the power grid system, specifically including:

[0166] The first key curve C1 is determined according to the second preset expression;

[0167] The second preset expression is:

[0168]

[0169] in, δ is the phase-locked loop angular frequency; f The phase-locked angle; It is a two-dimensional plane in Euclidean space; It is the second intermediate variable.

[0170] Based on the above embodiments, in this device, the second intermediate variable is calculated according to a second preset formula;

[0171] The second preset formula includes:

[0172]

[0173]

[0174]

[0175] in, i is the phase-locked loop angular frequency; d i is the system d-axis current command value; q k is the system q-axis current command value. p k is the proportional gain of the phase-locked loop PI controller. i ω0 is the integral coefficient of the phase-locked loop PI controller; R is the nominal angular frequency of the system. l The per-unit resistance value for the system connected to the power grid; L l U represents the per-unit value of the inductance of the system connected to the power grid; g This is the per-unit value of the grid connection point voltage.

[0176] Based on the above embodiments, in this device, the stability region, the first critical curve, and the second critical curve are determined based on the rated operating parameters of the power grid system, specifically including:

[0177] The second key curve C2 is determined according to the third preset expression;

[0178] The third preset expression is:

[0179]

[0180] in, δ is the phase-locked loop angular frequency; f The phase-locked angle; It is a two-dimensional plane in Euclidean space; It is the second intermediate variable; It is the third intermediate variable.

[0181] Based on the above embodiments, in this device, the third intermediate variable is calculated according to a third preset formula;

[0182] The third preset formula includes:

[0183]

[0184]

[0185] in, k is the phase-locked loop angular frequency; i The integral coefficients of the phase-locked loop PI controller are denoted as .

[0186] Based on the above embodiments, in this device, calculating the intersection points of the stability region with the first critical curve and the intersection points of the stability region with the second critical curve, and determining the limiting of the phase-locked loop frequency of the voltage source converter in the power grid system based on each intersection point, specifically includes:

[0187] Calculate the intersection points of the stability region and the first critical curve, and denote them as the first intersection point and the second intersection point; calculate the intersection points of the stability region and the second critical curve, and denote them as the third intersection point and the fourth intersection point;

[0188] The smaller value between the first intersection point and the second intersection point is used as the upper limit of the amplitude limit, and the larger value between the second intersection point and the fourth intersection point is used as the lower limit of the amplitude limit.

[0189] In the above specific embodiments, the parameter tuning device for a grid-following voltage source converter provided by the present invention determines a stability region, a first critical curve, and a second critical curve based on the rated operating parameters of the power grid system; calculates the intersection points of the stability region with the first critical curve and the second critical curve; and determines the limiting of the phase-locked loop (PLL) frequency of the voltage source converter in the power grid system based on each intersection point; wherein the limiting of the PLL frequency includes an upper limit and a lower limit. The present invention determines the limiting of the PLL frequency of the voltage source converter in the power grid system based on the rated operating parameters of the power grid system and through the intersection points of the stability region with the first and second critical curves, thereby achieving parameter tuning of the PI controller with anti-saturation limiting, and thus realizing global synchronous stable control of the grid-following voltage source converter.

[0190] It should be noted that the apparatus provided in this embodiment of the invention can implement all the method steps implemented in the above method embodiment and can achieve the same technical effect. Therefore, the parts and beneficial effects that are the same as those in the method embodiment will not be described in detail here.

[0191] Figure 4 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 4 As shown, the electronic device may include a processor 410, a communication interface 420, a memory 430, and a communication bus 440, wherein the processor 410, the communication interface 420, and the memory 430 communicate with each other through the communication bus 440. The processor 410 can call logic instructions in the memory 430 to execute a parameter tuning method for a grid-following voltage source converter. The method includes: determining a stability region, a first critical curve, and a second critical curve based on the rated operating parameters of the power grid system; calculating the intersection points of the stability region and the first critical curve, and the intersection points of the stability region and the second critical curve; and determining the limiting of the phase-locked loop frequency of the voltage source converter in the power grid system based on each intersection point; wherein the limiting of the phase-locked loop frequency includes an upper limit and a lower limit.

[0192] Furthermore, the logical instructions in the aforementioned memory 430 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0193] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0194] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0195] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A parameter tuning method based on a grid-following voltage source converter, characterized in that, include: Based on the rated operating parameters of the power grid system, the stability region, the first critical curve, and the second critical curve are determined. Calculate the intersection of the stability region with the first critical curve and the intersection of the stability region with the second critical curve; The frequency limiting of the phase-locked loop of the voltage source converter in the power grid system is determined based on each of the aforementioned intersection points; The frequency limiting of the phase-locked loop includes an upper limit and a lower limit; Based on the rated operating parameters of the power grid system, the stability region, the first critical curve, and the second critical curve are determined, specifically including: The first key curve C1 is determined according to the second preset expression; The second preset expression is: ； in, The phase-locked loop angular frequency; The phase-locked angle; ; , , It is the second intermediate variable; The second intermediate variable is calculated according to the second preset formula; The second preset formula includes: ； ； ； in, The phase-locked loop angular frequency; This is the system's d-axis current command value; This is the system q-axis current command value; The proportional gain of the phase-locked loop PI controller; The integral coefficients of the phase-locked loop PI controller; The system's nominal angular frequency; This refers to the per-unit resistance value of the system connected to the power grid; This refers to the per-unit value of the inductance for the system connected to the power grid; This is the per-unit value of the grid connection point voltage; Based on the rated operating parameters of the power grid system, the stability region, the first critical curve, and the second critical curve are determined, specifically including: The second key curve C2 is determined according to the third preset expression; The third preset expression is: ； in, The phase-locked loop angular frequency; The phase-locked angle; It is a two-dimensional plane in Euclidean space; , , It is the second intermediate variable; , It is the third intermediate variable; The third intermediate variable is calculated according to the third preset formula; The third preset formula includes: ； ； in, The phase-locked loop angular frequency; The integral coefficients of the phase-locked loop PI controller; Calculate the intersection points of the stability region with the first critical curve and the stability region with the second critical curve, and determine the frequency limiting of the phase-locked loop of the voltage source converter in the power grid system based on each intersection point, specifically including: Calculate the intersection points of the stability region and the first critical curve, and denote them as the first intersection point and the second intersection point; calculate the intersection points of the stability region and the second critical curve, and denote them as the third intersection point and the fourth intersection point; The smaller value of the ordinate between the first intersection point and the third intersection point is used as the upper limit of the amplitude limit, and the larger value of the ordinate between the second intersection point and the fourth intersection point is used as the lower limit of the amplitude limit.

2. The parameter tuning method based on a grid-following voltage source converter according to claim 1, characterized in that, Based on the rated operating parameters of the power grid system, the stability region, the first critical curve, and the second critical curve are determined, specifically including: The stability region is determined according to the first preset expression. ; The first preset expression is: ； in, The phase-locked loop angular frequency; The phase-locked angle; It is a two-dimensional plane in Euclidean space; , , , As the first intermediate variable; This is the expression for the stability region.

3. The parameter tuning method based on a grid-following voltage source converter according to claim 2, characterized in that, The first intermediate variable is calculated according to the first preset formula; The first preset formula includes: ； ； ； ； ； in, This is the system's d-axis current command value; This is the system q-axis current command value; The proportional gain of the phase-locked loop PI controller; The integral coefficients of the phase-locked loop PI controller; The system's nominal angular frequency; This refers to the per-unit resistance value of the system connected to the power grid; This refers to the per-unit value of the inductance for the system connected to the power grid; This is the per-unit value of the grid connection point voltage; It is an intermediate variable.

4. A parameter tuning device based on a grid-following voltage source converter, characterized in that, The apparatus for the parameter tuning method based on a grid-following voltage source converter as described in any one of claims 1-3 comprises: The domain and curve determination unit is used to determine the stability domain, the first critical curve, and the second critical curve based on the rated operating parameters of the power grid system. An intersection calculation unit is used to calculate the intersection points of the stability region with the first critical curve and the intersection points of the stability region with the second critical curve. A limiting determination unit is used to determine the limiting of the phase-locked loop frequency of the voltage source converter in the power grid system based on each of the intersection points; The frequency limiting of the phase-locked loop includes an upper limit and a lower limit.

5. An electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the parameter tuning method based on the grid-following voltage source converter as described in any one of claims 1 to 3.

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