Low voltage ride through protection threshold value setting method and device

Abstract

The embodiment of the invention provides a low-voltage ride-through protection threshold value setting method and device. The method comprises the steps that the power grid strength and equivalent impedance of an alternating current power grid connected with a grid-connected point in a power system are determined; obtaining grid-connected impedance and equivalent transmission power of an energy system connected to a new energy side in the power system; determining the new energy permeability in the power system; constructing a voltage stability analysis model according to the actual power grid parameters of the power system and a preset interface equation; and processing the power grid strength, the equivalent impedance, the grid-connected impedance, the equivalent transmission power and the new energy permeability by using the voltage stability analysis model to obtain a low voltage ride through protection threshold setting value. The method provided by the invention comprehensively considers the power grid strength and the new energy permeability, and is suitable for most new energy grid-connected scenes.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of new energy power transmission technology, and in particular to a method and device for setting the low voltage ride-through protection threshold. Background Technology

[0002] Against the backdrop of promoting the large-scale application of renewable energy, the power system is transforming into a new structure dominated by renewable energy, which has become a clear goal for industry development. As a key link in the concentrated power consumption area and renewable energy absorption, the voltage stability level of the receiving-end power grid directly affects the operational reliability of the entire new power system. Taking the East China Power Grid as a typical receiving-end power grid as an example, its total installed capacity of renewable energy will exceed 180 million kW. However, with the significant increase in renewable energy penetration, traditional synchronous generators are gradually being replaced, the system's operating inertia is decreasing accordingly, and the voltage support capacity is weakening. When a grid fault occurs, it can easily cause a sudden drop in voltage and repeated participation of generating units in the low voltage ridethrough (LVRT) process, posing a significant threat to the voltage stability of the receiving-end power grid and increasing the difficulty of system safety control.

[0003] Currently, the academic community has conducted multi-faceted modeling analysis and empirical research on LVRT and power system voltage stability. Existing results have preliminarily clarified the key role of LVRT control strategies in the transient voltage support and recovery process. However, there is a lack of systematic theoretical explanation and modeling analysis for the frequent low voltage ride-through phenomenon caused by a high proportion of renewable energy grid connection, and existing low voltage ride-through protection threshold setting methods do not comprehensively consider this issue. Summary of the Invention

[0004] To address the aforementioned issues, this application proposes a method and apparatus for setting the low voltage ride-through protection threshold that comprehensively considers grid strength and renewable energy penetration rate.

[0005] To address the aforementioned technical problems, embodiments of the present invention provide a method for setting a low-voltage ride-through protection threshold, comprising: Determine the grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system; Obtain the grid connection impedance and equivalent transmission power of the energy system connected to the new energy side in the power system; Determine the penetration rate of new energy sources in the power system; A voltage stability analysis model is constructed based on the actual grid parameters of the power system and the preset interface equations. The voltage stability analysis model is used to process the grid strength, equivalent impedance, grid connection impedance, equivalent transmission power, and new energy penetration rate to obtain the low voltage ride-through protection threshold setting value.

[0006] In one embodiment, determining the grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system includes: The grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system are calculated based on the Thevenin model.

[0007] In one embodiment, the calculation of the grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system based on the Thevenin model includes: The grid strength and equivalent impedance are calculated based on the Thevenin model and the following formula:

[0008] in, P dc The rated DC power of the converter station, U s The rated AC voltage amplitude at point PCC. Z g The equivalent impedance is SCR, and the grid strength is SCR.

[0009] In one embodiment, determining the penetration rate of new energy sources in the power system includes: Determine the transmission power of new energy sources and the total transmission power of the power system; Calculate the ratio between the new energy transmission power and the total transmission power, and determine the new energy penetration rate based on the ratio.

[0010] In one embodiment, the preset interface equation, which involves constructing a voltage stability analysis model based on the actual grid parameters of the power system and the preset interface equation, includes: The voltage stability analysis model is constructed with the help of the actual power grid parameters of the power system and the new energy load model formed by some preset interface equations. The new energy load model adopts active current control mode for current control.

[0011] In one embodiment, the method further includes: During low-voltage ride-through, current control is performed based on active and reactive power commands:

[0012] in, V t , K v , I P0 , K I , I PSET , I PrefThese are, respectively, the terminal voltage amplitude, the voltage-active current correlation coefficient, the steady-state active current before the fault, the initial active current weighting coefficient, the active current offset, and the active current reference value. V SET , K v , I Q0 , K I , I QSET , I Qref These are, respectively, the voltage reference value, the voltage-reactive current correlation coefficient, the steady-state reactive current before the fault, the initial reactive current weighting coefficient, the reactive current offset, and the reactive current reference value.

[0013] In one embodiment, the method further includes: The voltage stability analysis model is constructed based on the synchronous machine model formed by some of the preset interface equations, and the synchronous machine model is a motor load model.

[0014] In one embodiment, the motor load model includes:

[0015] in, T e The mechanical torque of the motor load. T L For load torque, ω For rotational speed, J It represents mechanical inertia.

[0016] Another embodiment of the present invention also provides a low voltage ride-through protection threshold setting device, comprising: The first determining module is used to determine the grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system. The acquisition module is used to obtain the grid connection impedance and equivalent transmission power of the energy system connected to the new energy side in the power system. The second determining module is used to determine the penetration rate of new energy sources in the power system; The construction module is used to construct a voltage stability analysis model based on the actual grid parameters of the power system and preset interface equations; The processing module is used to process the grid strength, equivalent impedance, grid-connected impedance, equivalent transmission power and new energy penetration rate using the voltage stability analysis model to obtain the low voltage ride-through protection threshold setting value.

[0017] Another embodiment of the present invention provides an electronic device, including a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor executes the program to implement the low voltage ride-through protection threshold setting method as described in any of the embodiments herein.

[0018] As can be seen from the above, the method in the embodiments of the present invention obtains actual power grid parameters, constructs a simplified voltage stability analysis model, comprehensively considers the impact of power grid strength and new energy penetration rate on system voltage stability, and finally obtains the low voltage ride-through protection threshold setting value. The overall process is simple, easy to implement, and highly accurate, and is applicable to most new energy grid connection scenarios.

[0019] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0020] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a flowchart of the low voltage ride-through protection threshold setting method in an embodiment of the present invention.

[0023] Figure 2 This is a flowchart illustrating the application of the low voltage ride-through protection threshold setting method in this embodiment of the invention.

[0024] Figure 3 This is a schematic diagram of the first tuning process in an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of the second tuning process in an embodiment of the present invention.

[0026] Figure 5 This is a diagram illustrating the architecture of the voltage stability analysis model in this embodiment of the invention.

[0027] Figure 6 This is a structural block diagram of the low voltage ride-through protection threshold setting device in an embodiment of the present invention. Detailed Implementation

[0028] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but these are not intended to limit the scope of the invention.

[0029] It should be understood that various modifications can be made to the embodiments disclosed herein. Therefore, the following description should not be considered as limiting, but merely as an example of embodiments. Other modifications within the scope of this disclosure will be apparent to those skilled in the art.

[0030] The accompanying drawings, which are included in and form part of this specification, illustrate embodiments of the present disclosure and, together with the general description of the disclosure given above and the detailed description of the embodiments given below, serve to explain the principles of the disclosure.

[0031] These and other features of the invention will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0032] It should also be understood that although the invention has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of the invention, which have the features described in the claims and are therefore all within the scope of protection defined herein.

[0033] The above and other aspects, features and advantages of this disclosure will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0034] Specific embodiments of the present disclosure are described thereafter with reference to the accompanying drawings; however, it should be understood that the disclosed embodiments are merely examples of the present disclosure, which may be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that could obscure the present disclosure. Therefore, the specific structural and functional details disclosed herein are not intended to be limiting, but merely to serve as the basis and representative basis for the claims to teach those skilled in the art to use the present disclosure in a variety of substantially any suitable detailed structures.

[0035] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in other embodiments,” all of which may refer to one or more of the same or different embodiments according to this disclosure.

[0036] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0037] like Figure 1 As shown, this embodiment of the invention provides a method for setting a low voltage ride-through protection threshold, including: S1: Determine the grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system; S2: Obtain the grid connection impedance and equivalent transmission power of the energy system connected to the new energy side in the power system; S3: Determine the penetration rate of new energy sources in the power system; S4: Construct a voltage stability analysis model based on the actual grid parameters of the power system and the preset interface equations; S5: The voltage stability analysis model is used to process the grid strength, equivalent impedance, grid-connected impedance, equivalent transmission power and new energy penetration rate to obtain the low voltage ride-through protection threshold setting value.

[0038] Based on the above, the low voltage ride-through protection threshold setting method introduced in this embodiment obtains actual power grid parameters, constructs a simplified voltage stability analysis model, and comprehensively considers the impact of power grid strength and new energy penetration rate on system voltage stability, ultimately obtaining a low voltage ride-through protection threshold setting method. This method comprehensively considers power grid strength and new energy penetration rate, overcoming the shortcomings of existing low voltage ride-through threshold setting methods.

[0039] In one embodiment, determining the grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system includes: S101: The grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system are calculated based on the Thevenin model.

[0040] Furthermore, the grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system, calculated based on the Thevenin model, include: S102: The grid strength and equivalent impedance are calculated based on the Thevenin model and the following formula:

[0041] in, P dc The rated DC power of the converter station, U s The rated AC voltage amplitude at point PCC. Z g The equivalent impedance is SCR, and the grid strength is SCR.

[0042] Based on the above, it can be seen that in this embodiment, the value of the power grid strength is calculated from the equivalent AC power grid short-circuit ratio.

[0043] The grid connection impedance and equivalent transmission power of the energy system connected to the new energy side in the power system can be directly determined through the actual collected parameters.

[0044] Furthermore, determining the penetration rate of new energy sources in the power system includes: S301: Determine the transmission power of new energy sources and the total transmission power of the power system; S302: Calculate the ratio between the new energy transmission power and the total transmission power, and determine the new energy penetration rate based on the ratio.

[0045] For example, based on formula To calculate the penetration rate of new energy sources, the aforementioned New energy transmission power, Total refers to the total transmission power.

[0046] Furthermore, the preset interface equation, which constructs a voltage stability analysis model based on the actual power grid parameters and the preset interface equation, includes: S401: The voltage stability analysis model is constructed with the help of the actual power grid parameters of the power system and the new energy load model formed by some preset interface equations. The new energy load model adopts active current control mode for current control.

[0047] Specifically, the method further includes: S402: During low-voltage ride-through, current control is performed based on active and reactive power commands.

[0048] in, V t , K v , I P0 , K I , I PSET , I Pref These are, respectively, the terminal voltage amplitude, the voltage-active current correlation coefficient, the steady-state active current before the fault, the initial active current weighting coefficient, the active current offset, and the active current reference value. V SET , K v , I Q0 , K I , I QSET , I Qref These are, respectively, the voltage reference value, the voltage-reactive current correlation coefficient, the steady-state reactive current before the fault, the initial reactive current weighting coefficient, the reactive current offset, and the reactive current reference value.

[0049] Furthermore, the method also includes: S403: The voltage stability analysis model is constructed based on the synchronous machine model formed by some of the preset interface equations, and the synchronous machine model is a motor load model.

[0050] Specifically, the motor load model includes:

[0051] in, T e The mechanical torque of the motor load. T L For load torque, ω For rotational speed, J It represents mechanical inertia.

[0052] After constructing the analysis model based on the above embodiments, the model is used to set the low-voltage ride-through protection threshold, such as... Figure 2 As shown: Set the low-pressure cross-entry threshold step size With exit threshold step size Next, it is determined whether the grid strength index is the primary indicator. If so, it is determined whether the SCR of the power system is low, i.e., whether the preset SCR value condition has been triggered. If not, the preset first setting procedure is executed; if so, the preset second setting procedure is executed. Regardless of whether the first or second setting procedure is used, the low-voltage ride-through threshold corresponding to the current power system state will ultimately be obtained. and the exit threshold V M .

[0053] Furthermore, if it is determined that the main indicator is not the power grid strength index, but the new energy penetration rate, then it is determined whether the new energy penetration rate is high, that is, whether the preset new energy penetration rate value condition is triggered. If not, the preset first setting procedure is executed; if not, the preset second setting procedure is executed.

[0054] In another embodiment, such as Figure 3 As shown, the first tuning process includes setting a lower initial low-voltage crossover threshold. and a higher exit threshold V M The terms "lower" and "higher" are relative values ​​and are not fixed. After setting the threshold, a simulation analysis is performed, recording the duration t1 of repeatedly entering the low-voltage ride-through state and the time t2 of exiting the low-voltage ride-through mode. Then, it is determined whether t1 and t2 meet the preset requirements. If so, the entry threshold is directly output. With exit threshold V M If the preset requirements are not met, then let , Reduce the entry threshold step size VMstep and exit threshold step size V Lstep These two step sizes are preset. Then, it is determined whether the current two thresholds satisfy V. M Greater than V L If so, re-execute the simulation process and again determine whether t1 and t2 meet the preset requirements. If V M Less than V L If so, then adjust other parameters and no longer adjust the entry and exit thresholds.

[0055] In another embodiment, such as Figure 4 As shown, a lower initial low-pressure cross-through threshold is set. and a higher exit threshold And satisfy Greater than Next, simulation analysis is performed, recording the duration t1 of repeatedly entering the low-voltage ride-through mode and the time t2 of exiting the low-voltage ride-through mode. Then, it is determined whether t1 and t2 meet the preset requirements. If so, the entry threshold is directly output. With exit threshold V M If the preset requirements are not met, then let , Reduce the entry threshold step size V Mstep and exit threshold step size V Lstep These two step sizes are preset. Afterwards, it is determined whether the power system operates stably after the thresholds are modified. If so, the simulation process is re-executed, and it is again determined whether t1 and t2 meet the preset requirements. If the operation is unstable, other parameters are tuned, but the entry and exit thresholds are not tuned.

[0056] When applying the voltage stability analysis model in this embodiment, the specific structural configuration can be found in [reference needed]. Figure 5 As shown, but not limited to Figure 5 The structure shown.

[0057] like Figure 6 As shown, another embodiment of the present invention also provides a low voltage ride-through protection threshold setting device, comprising: The first determining module is used to determine the grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system. The acquisition module is used to obtain the grid connection impedance and equivalent transmission power of the energy system connected to the new energy side in the power system. The second determining module is used to determine the penetration rate of new energy sources in the power system; The construction module is used to construct a voltage stability analysis model based on the actual grid parameters of the power system and preset interface equations; The processing module is used to process the grid strength, equivalent impedance, grid-connected impedance, equivalent transmission power and new energy penetration rate using the voltage stability analysis model to obtain the low voltage ride-through protection threshold setting value.

[0058] In one embodiment, determining the grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system includes: The grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system are calculated based on the Thevenin model.

[0059] In one embodiment, the calculation of the grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system based on the Thevenin model includes: The grid strength and equivalent impedance are calculated based on the Thevenin model and the following formula:

[0060] in, P dc The rated DC power of the converter station, U s The rated AC voltage amplitude at point PCC. Z g The equivalent impedance is SCR, and the grid strength is SCR.

[0061] In one embodiment, determining the penetration rate of new energy sources in the power system includes: Determine the transmission power of new energy sources and the total transmission power of the power system; Calculate the ratio between the new energy transmission power and the total transmission power, and determine the new energy penetration rate based on the ratio.

[0062] In one embodiment, the preset interface equation, which involves constructing a voltage stability analysis model based on the actual grid parameters of the power system and the preset interface equation, includes: The voltage stability analysis model is constructed with the help of the actual power grid parameters of the power system and the new energy load model formed by some preset interface equations. The new energy load model adopts active current control mode for current control.

[0063] In one embodiment, the device further includes: During low-voltage ride-through, current control is performed based on active and reactive power commands:

[0064] in, V t , K v , IP0 , K I , I PSET , I Pref These are, respectively, the terminal voltage amplitude, the voltage-active current correlation coefficient, the steady-state active current before the fault, the initial active current weighting coefficient, the active current offset, and the active current reference value. V SET , K v , I Q0 , K I , I QSET , I Qref These are, respectively, the voltage reference value, the voltage-reactive current correlation coefficient, the steady-state reactive current before the fault, the initial reactive current weighting coefficient, the reactive current offset, and the reactive current reference value.

[0065] In one embodiment, the building module is further configured to: The voltage stability analysis model is constructed based on the synchronous machine model formed by some of the preset interface equations, and the synchronous machine model is a motor load model.

[0066] In one embodiment, the motor load model includes:

[0067] in, T e The mechanical torque of the motor load. T L For load torque, ω For rotational speed, J It represents mechanical inertia.

[0068] Furthermore, one embodiment of the present invention also provides an electronic device, including a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor executes the program to implement the low voltage ride-through protection threshold setting method as described in any of the embodiments above.

[0069] Furthermore, one embodiment of the present invention also provides a storage medium storing a computer program, which, when executed by a processor, implements the low-voltage ride-through protection threshold setting method as described above. It should be understood that the various solutions in this embodiment have the corresponding technical effects in the above-described method embodiments, and will not be repeated here.

[0070] Furthermore, embodiments of the present invention also provide a computer program product tangibly stored on a computer-readable medium and comprising computer-readable instructions that, when executed, cause at least one processor to perform a low-voltage ride-through protection threshold setting method such as in the embodiments described above.

[0071] It should be noted that the computer storage medium of the present invention can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, system, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access storage medium (RAM), a read-only storage medium (ROM), an erasable programmable read-only storage medium (EPROM or flash memory), an optical fiber, a portable compact disk read-only storage medium (CD-ROM), an optical storage medium, a magnetic storage medium, or any suitable combination thereof. In the present invention, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. In the present invention, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media can also be any computer-readable medium other than computer-readable storage media, which can send, propagate, or transmit a program configured for use by or in connection with an instruction execution system, system, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wireless, antenna, optical fiber, RF, etc., or any suitable combination thereof.

[0072] Furthermore, those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0073] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A system that specifies functions in one or more boxes.

[0074] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including an instruction set implemented in a process. Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0075] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.

Claims

1. A method for setting a low voltage ride-through protection threshold, characterized in that, include: Determine the grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system; Obtain the grid connection impedance and equivalent transmission power of the energy system connected to the new energy side in the power system; Determine the penetration rate of new energy sources in the power system; A voltage stability analysis model is constructed based on the actual grid parameters of the power system and the preset interface equations. The voltage stability analysis model is used to process the grid strength, equivalent impedance, grid connection impedance, equivalent transmission power, and new energy penetration rate to obtain the low voltage ride-through protection threshold setting value.

2. The low voltage ride-through protection threshold setting method according to claim 1, characterized in that, Determining the grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system includes: The grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system are calculated based on the Thevenin model.

3. The low voltage ride-through protection threshold setting method according to claim 2, characterized in that, The grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system, calculated based on the Thevenin model, include: The grid strength and equivalent impedance are calculated based on the Thevenin model and the following formula: in, P dc The rated DC power of the converter station, U s The rated AC voltage amplitude at point PCC. Z g The equivalent impedance is SCR, and the grid strength is SCR.

4. The low voltage ride-through protection threshold setting method according to claim 1, characterized in that, Determining the penetration rate of new energy sources in the power system includes: Determine the transmission power of new energy sources and the total transmission power of the power system; Calculate the ratio between the new energy transmission power and the total transmission power, and determine the new energy penetration rate based on the ratio.

5. The low voltage ride-through protection threshold setting method according to claim 1, characterized in that, The preset interface equations refer to the construction of a voltage stability analysis model based on the actual power grid parameters and preset interface equations of the power system, including: The voltage stability analysis model is constructed with the help of the actual power grid parameters of the power system and the new energy load model formed by some preset interface equations. The new energy load model adopts active current control mode for current control.

6. The low voltage ride-through protection threshold setting method according to claim 5, characterized in that, The method further includes: During low-voltage ride-through, current control is performed based on active and reactive power commands: in, V t , K v , I P0 , K I , I PSET , I Pref These are, respectively, the terminal voltage amplitude, the voltage-active current correlation coefficient, the steady-state active current before the fault, the initial active current weighting coefficient, the active current offset, and the active current reference value. V SET , K v , I Q0 , K I , I QSET , I Qref These are, respectively, the voltage reference value, the voltage-reactive current correlation coefficient, the steady-state reactive current before the fault, the initial reactive current weighting coefficient, the reactive current offset, and the reactive current reference value.

7. The low voltage ride-through protection threshold setting method according to claim 5, characterized in that, The method further includes: The voltage stability analysis model is constructed based on the synchronous machine model formed by some of the preset interface equations, and the synchronous machine model is a motor load model.

8. The low voltage ride-through protection threshold setting method according to claim 7, characterized in that, The motor load model includes: in, T e The mechanical torque of the motor load. T L For load torque, ω For rotational speed, J It represents mechanical inertia.

9. A low voltage ride-through protection threshold setting device, characterized in that, include: The first determining module is used to determine the grid strength and equivalent impedance of the AC grid connected to the grid connection point in the power system. The acquisition module is used to obtain the grid connection impedance and equivalent transmission power of the energy system connected to the new energy side in the power system. The second determining module is used to determine the penetration rate of new energy sources in the power system; The construction module is used to construct a voltage stability analysis model based on the actual grid parameters of the power system and preset interface equations; The processing module is used to process the grid strength, equivalent impedance, grid-connected impedance, equivalent transmission power and new energy penetration rate using the voltage stability analysis model to obtain the low voltage ride-through protection threshold setting value.

10. An electronic device, characterized in that, It includes a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor executes the program to implement the low voltage ride-through protection threshold setting method as described in any one of claims 1-8.

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