Transient power angle stability control method for grid-connected converters based on network disturbance response

Abstract

The present invention discloses a method for transient power angle stabilization control of a meshed converter based on network disturbance response, comprising: collecting real-time operating parameters of each branch and node in the meshed converter, and performing initial parameter setting on the meshed converter to determine the initial parameters of the meshed converter; judging whether the meshed converter meets the start criterion of transient power angle stabilization reshaping control of the meshed converter according to the real-time operating parameters; if so, executing transient power angle stabilization reshaping control of the meshed converter according to the initial parameters of the meshed converter, and executing the next real-time operating parameter collection if not satisfied; and determining whether to exit the transient power angle stabilization reshaping control of the meshed converter according to the control result of the transient power angle stabilization reshaping control of the meshed converter and the exit criterion of the transient power angle stabilization reshaping control of the meshed converter.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and more particularly to a method for controlling transient power angle stability of a grid-connected converter based on network disturbance response. Background Art

[0002] Currently, power systems characterized by "dual highs" (high-voltage, high-voltage, and high-voltage) both domestically and internationally face three threats to their safe and stable operation: the risk of transient overvoltages and voltage instability caused by a reduction in voltage support capability; the risk of frequency stability caused by a reduction in active power regulation capability; and the risk of broadband oscillations between power electronic devices in weak AC systems. Grid-connected converters (GCCs), a new type of device with frequency and voltage regulation capabilities similar to synchronous generators, possess active power regulation and inertia support capabilities, making them a crucial technology and foundational equipment supporting these new power systems. Compared to traditional synchronous units, they offer faster response times and rapid output stabilization. Grid-connected energy storage technology even outperforms synchronous generators in key performance areas such as frequency and voltage regulation, inertia damping, and system impedance. Grid-connected wind power, photovoltaic power generation, energy storage, and flexible direct current (HVDC) systems, using GCC control technology, are increasingly recognized as an effective technical measure to address the threats posed by "dual highs" (high-voltage, high-voltage, and high-voltage) power systems.

[0003] In traditional power systems dominated by synchronous generators, disturbed electrical quantities such as network node voltages, branch currents, and power contain information that can characterize transient stability. Building criteria based on this information and initiating emergency control accordingly can effectively reduce the risk of instability. Unlike traditional synchronous generators, the virtual power angle of a grid-connected converter can be directly reshaped and altered to improve stability. Due to the constraints of the converter's electrical quantities, the grid-connected converter based on the virtual synchronous generator control strategy responds differently to disturbances than the synchronous generator, and the network response of the grid-connected system after a disturbance will also be different. Therefore, the stable operation of the power grid cannot be guaranteed at present. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention provides a method for controlling transient power angle stability of a grid-connected converter based on network disturbance response.

[0005] According to one aspect of the present invention, a method for controlling transient power angle stability of a grid-connected converter based on network disturbance response is provided, comprising:

[0006] Collecting real-time operating parameters of each branch and node in the grid-type converter, setting initial parameters of the grid-type converter, and determining the initial parameters of the grid-type converter;

[0007] Judging whether the grid-type converter meets the grid-type converter transient power angle stability reshaping control start criterion according to real-time operating parameters;

[0008] If the conditions are met, the transient power angle stabilization reshaping control of the grid-type converter is performed according to the initial parameters of the grid-type converter. If the conditions are not met, the next real-time operation parameter acquisition is performed.

[0009] According to the control result of the transient power angle stabilization reshaping control of the grid-type converter and the exit criterion of the transient power angle stabilization reshaping control of the grid-type converter, it is determined whether to exit the transient power angle stabilization reshaping control of the grid-type converter.

[0010] Optionally, the real-time operating parameters include: the amplitude U of the voltage at both ends of the branch i im 、U in and phase θ im ,θ in , grid-type converter output voltage U v and output reactive power Q v .

[0011] Optionally, the initial parameters include: initial damping coefficient D of the grid-type converter orig ; Damping coefficient D of grid-type converter after reshaping control Emg ; Reshape control times n Emg ; Virtual power angle reshapes the control quantity δ Emg ; Reshape control to start BTTC index threshold value ε Lth , reshape the control start-up grid-type converter output node voltage threshold setting value U vLth ; Reshape the control exit BTTC index threshold value ε Hth And reshape the control exit grid-type converter output node voltage threshold setting value U vHth .

[0012] Optionally, judging whether the grid-type converter meets a start criterion for transient power angle stability remodeling control of the grid-type converter based on real-time operating parameters includes:

[0013] Determining whether the grid-type converter satisfies a first startup criterion of transient power angle stability reshaping control of the grid-type converter based on real-time operating parameters; or

[0014] Whether the grid-type converter meets the second starting criterion of the transient power angle stability reshaping control of the grid-type converter is determined according to the real-time operating parameters.

[0015] Optionally, judging whether the grid-type converter satisfies a first starting criterion of transient power angle stability reshaping control of the grid-type converter according to the real-time operating parameter includes:

[0016] Calculate the branch transient power transmission function index of each branch of the grid-type converter based on the real-time operating parameters of each branch and node;

[0017] Determine the key branches of the grid-type converter based on the DC transient power transmission function index of each branch;

[0018] Determine the key branch vertical foot voltage position coefficient of the key branch based on the voltage phasors at both ends of the key branch;

[0019] Determine the position of the key branch vertical foot voltage according to the key branch vertical foot voltage position coefficient;

[0020] If the position of the key branch vertical foot voltage is outside the branch, perform the next real-time operation parameter acquisition; if the position of the key branch vertical foot voltage is on the branch, determine whether the key branch meets the first startup criterion.

[0021] Optionally, the calculation formula of the branch transient transmission function index sBTTC is:

[0022]

[0023] The method for determining the critical branch k is:

[0024]

[0025] Where U im and θ im is the magnitude and phase of the voltage phasor at node m, U in and θ in is the amplitude and phase of the voltage phasor at node n, node m and node n correspond to the phase leading node and phase lagging node respectively, that is, θ im >θ in .

[0026] Optionally, determining a key branch vertical foot voltage position coefficient of the key branch according to the voltage phasors of the nodes at both ends of the key branch includes:

[0027] Calculate the vertical foot voltage of the key branch based on the voltage phasors of the two-end nodes of the key branch;

[0028] The key branch vertical foot voltage position coefficient of the key branch is determined according to the voltage phasors of the two end nodes of the key branch and the key branch vertical foot voltage.

[0029] Optionally, the key branch vertical foot voltage U kv The calculation formula is:

[0030] U kv =U kn sinγ

[0031] in,

[0032]

[0033] Where U km and U knis the voltage amplitude at the beginning and end of the key branch k, Δθ k is the voltage phase difference between the first and the last two ends of the key branch k, ΔU kmn is the amplitude of the voltage phasor difference between the nodes at both ends of the branch, and γ is the voltage phasor angle.

[0034] Optionally, the key branch vertical foot voltage position coefficient ξ kv The calculation formula is:

[0035]

[0036] Where, ΔU kmv , ΔU knv They are the node voltages at both ends of the branch and the vertical foot voltage of the key branch U kv The magnitude of the phasor difference.

[0037] Optionally, determining the position of the key branch vertical foot voltage according to the key branch vertical foot voltage position coefficient includes:

[0038] If the key branch vertical foot voltage position coefficient ξ kv Satisfying 1<ξ kv <2, the position of the critical branch vertical foot voltage is located on the branch;

[0039] If the key branch vertical foot voltage position coefficient ξ kv Satisfy ξ kv <1, the position of the critical branch vertical foot voltage is outside the branch.

[0040] Optionally, the first starting criterion is:

[0041] and And sBTTC k <ε LTH

[0042] Where Δθ k is the phase difference of the key branch, P k is the active power of key branches, sBTTC k is the branch transient transmission capability index of the critical branch, ε LTH To reshape the control start-up grid-type converter outlet node action threshold value, t is the time.

[0043] Optionally, the second starting criterion is:

[0044] Q v <0 and U v <U vLth and

[0045] Where U v is the grid-type converter output voltage, Qv is the output reactive power, U vLth To reshape the control startup grid-type converter output node voltage threshold setting value.

[0046] Optionally, performing transient power angle stabilization reshaping control of the grid-type converter according to initial parameters of the grid-type converter includes:

[0047] The reshaping control times n of the grid-type energy storage converter are Emg Increase once;

[0048] The damping coefficient of the grid-type energy storage converter is modified to the damping coefficient D after the grid-type converter is reshaped and controlled. Emg ;

[0049] The virtual power angle of the grid-type converter is modified to δ', where δ' = δ v -n Emg δ Emg , δ v is the virtual power angle before reshaping control, n Emg is the number of remodeling controls; δ Emg Reshape the control quantity for the virtual power angle;

[0050] The grid-type energy storage converter is controlled according to the modified grid-type converter virtual power angle δ'. Optionally, the grid-type converter transient power angle stability reshaping control exit criterion is:

[0051] U v >U vHth or sBTTC k >ε Hth

[0052] Where U v is the grid-type converter outlet voltage, sBTTC is the branch transient transmission function index, U vHth In order to reshape the control exit grid-type converter output node voltage threshold setting value, ε Hth To reshape the control exit threshold of BTTC index.

[0053] According to another aspect of the present invention, a transient power angle stabilization control device for a grid-connected converter based on a network disturbance response is provided, comprising:

[0054] The acquisition module is used to collect the real-time operating parameters of each branch and node in the meshed converter, and to set the initial parameters of the meshed converter to determine the initial parameters of the meshed converter;

[0055] A judgment module, used to judge whether the grid-type converter meets the grid-type converter transient power angle stability reshaping control start criterion according to real-time operating parameters;

[0056] A control module, configured to execute a transient power angle stabilization reshaping control of the grid-type converter according to the initial parameters of the grid-type converter if the conditions are met, and execute the next real-time operation parameter acquisition if the conditions are not met;

[0057] The determination module is used to determine whether to exit the transient power angle stabilization reshaping control of the grid-type converter according to the control result of the transient power angle stabilization reshaping control of the grid-type converter and the exit criterion of the transient power angle stabilization reshaping control of the grid-type converter.

[0058] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the storage medium stores a computer program, and the computer program is used to execute the method according to any one of the above aspects of the present invention.

[0059] According to another aspect of the present invention, an electronic device is provided, comprising: a processor; a memory for storing instructions executable by the processor; the processor for reading the executable instructions from the memory and executing the instructions to implement the method described in any one of the above aspects of the present invention.

[0060] Therefore, the present invention proposes a method for controlling transient power angle stability of a grid-type converter, which uses the wide-area measured network branch response as the information source to identify key branches. On the basis of determining the transient transmission capability index of the branch, a criterion for characterizing the deterioration trend of the power angle stability of the grid-type converter is constructed according to the branch voltage size and reactive power change trend that reflect the severity of the disturbance. When the criterion is met, the power angle state quantity of the grid-type converter is directly reshaped and controlled, which can effectively reduce the risk of transient power angle instability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0062] Figure 1 1 is a flow chart of a method for controlling transient power angle stabilization of a grid-connected converter based on network disturbance response according to an exemplary embodiment of the present invention;

[0063] Figure 2 1 is another flow chart of a method for controlling transient power angle stabilization of a grid-connected converter based on network disturbance response provided by an exemplary embodiment of the present invention;

[0064] Figure 3 1 is a schematic diagram of a grid-connected system of a single-machine grid-connected converter provided by an exemplary embodiment of the present invention;

[0065] Figure 4a and 4bThey are respectively a schematic diagram of a branch sBTTC index and a branch vertical foot voltage position coefficient of a power angle instability curve of a grid-type converter under weak system conditions provided by an exemplary embodiment of the present invention;

[0066] Figure 5a and 5b They are respectively schematic diagrams of the active power of the grid-type converter and the virtual power angle of the grid-type converter for the stable reshaping control effect of the power angle of the grid-type converter under weak system conditions provided by an exemplary embodiment of the present invention;

[0067] Figure 6a and Figure 6b They are respectively a schematic diagram of node voltage and branch reactive power of a power angle instability curve of a grid-type converter under strong system conditions provided by an exemplary embodiment of the present invention;

[0068] Figure 7a and Figure 7b They are respectively a schematic diagram of the active power of the grid-type converter and the virtual power angle of the grid-type converter, which provide a stable reshaping control effect of the power angle of the grid-type converter under strong system conditions provided by an exemplary embodiment of the present invention;

[0069] Figure 8 1 is a schematic structural diagram of a transient power angle stabilization control device for a grid-type converter based on network disturbance response provided by an exemplary embodiment of the present invention;

[0070] Figure 9 This is a structure of an electronic device provided by an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0071] Below, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0072] It should be noted that the relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

[0073] Those skilled in the art will understand that the terms "first" and "second" in the embodiments of the present invention are only used to distinguish different steps, devices or modules, and neither represent any specific technical meaning nor indicate the necessary logical order between them.

[0074] It should also be understood that, in the embodiments of the present invention, “a plurality of” may refer to two or more than two, and “at least one” may refer to one, two or more than two.

[0075] It should also be understood that any component, data or structure mentioned in the embodiments of the present invention can generally be understood as one or more, unless explicitly limited or otherwise indicated in the context.

[0076] In addition, the term "and / or" in this invention merely describes an association relationship between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Furthermore, the character " / " in this invention generally indicates that the related objects are in an "or" relationship.

[0077] It should also be understood that the description of the various embodiments of the present invention focuses on the differences between the various embodiments, and the same or similar aspects thereof can be referenced with each other. For the sake of brevity, they will not be described one by one.

[0078] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0079] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0080] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0081] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0082] Embodiments of the present invention can be applied to electronic devices such as terminal devices, computer systems, and servers, and can operate in conjunction with numerous other general-purpose or specialized computing system environments or configurations. Examples of well-known terminal devices, computing systems, environments, and / or configurations suitable for use with terminal devices, computer systems, servers, and other electronic devices include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, microprocessor-based systems, set-top boxes, programmable consumer electronics, network personal computers, minicomputer systems, mainframe computer systems, and distributed cloud computing technology environments including any of the above.

[0083] Electronic devices such as terminal devices, computer systems, and servers can be described in the general context of computer system-executable instructions (such as program modules) executed by a computer system. Generally, program modules can include routines, programs, object programs, components, logic, data structures, etc., which perform specific tasks or implement specific abstract data types. Computer systems / servers can be implemented in a distributed cloud computing environment, where tasks are performed by remote processing devices linked via a communication network. In a distributed cloud computing environment, program modules can be located on local or remote computing system storage media, including storage devices.

[0084] Exemplary Methods

[0085] Figure 1 This is a flow chart of a method for controlling transient power angle stability of a grid-connected converter based on network disturbance response according to an exemplary embodiment of the present invention. This embodiment can be applied to electronic devices, such as Figure 1 As shown, the transient power angle stabilization control method 100 of the grid-connected converter based on the network disturbance response includes the following steps:

[0086] Step 101: collecting real-time operating parameters of each branch and node in the meshed converter, and performing initial parameter setting on the meshed converter to determine the initial parameters of the meshed converter;

[0087] Step 102, judging whether the grid-type converter meets the grid-type converter transient power angle stability reshaping control start criterion based on the real-time operating parameters;

[0088] Step 103: If the conditions are met, then the transient power angle stabilization reshaping control of the grid-type converter is performed according to the initial parameters of the grid-type converter; if the conditions are not met, then the next real-time operation parameter acquisition is performed;

[0089] Step 104 : determining whether to exit the transient power angle stabilization reshaping control of the grid-type converter according to the control result of the transient power angle stabilization reshaping control of the grid-type converter and the exit criterion of the transient power angle stabilization reshaping control of the grid-type converter.

[0090] Specifically, in response to the shortcomings of the existing technology, the present invention provides a method for controlling the transient power angle stability of a grid-type converter based on the network disturbance response. The method uses the easily measurable amplitude and phase of the node voltage at both ends of the branch and the grid-type converter output voltage and reactive power as information sources, establishes a criterion for characterizing the deterioration trend of the transient power angle stability of the grid-type converter, and designs a reshaping control strategy to improve the power angle stability of the grid-type converter. This method has important theoretical and practical significance for ensuring the safe and stable operation of the power grid. Figure 2 As shown, the specific steps include:

[0091] (1) Obtaining the operating status information of the grid-connected converter

[0092] The wide area measurement system is used to collect the real-time operating parameters of all branches and nodes in the network, including the amplitude U of the node voltage at both ends of branch i. im 、U in and phase θ im ,θ in ; Grid-type converter output voltage U v and output reactive power Q v .

[0093] (2) Initial parameter setting

[0094] Set the initial damping coefficient D of the grid-type converter orig ; Damping coefficient D of grid-type converter after reshaping control Emg ; Reshape control times n Emg ; Virtual power angle reshapes the control quantity δ Emg ; Reshape control to start BTTC index threshold value ε Lth , reshape the control start-up grid-type converter output node voltage threshold setting value U vLth ; Reshape the control exit BTTC index threshold value ε Hth , reshape the control exit grid-type converter output node voltage threshold setting value U vHth .

[0095] (3) Determine whether the grid-type converter transient power angle stability reshaping control start-up criteria are met, including:

[0096] (3-1) Based on the voltage amplitude and phase dynamic parameters of the branch nodes, the efficiency index of the branch transient transmission capacity sBTTC index, which quantitatively characterizes the unbalanced power between the transmission groups of branch i, is defined as shown in formula (1).

[0097]

[0098] Where U im and θ im is the magnitude and phase of the voltage phasor at node m, U in and θ in is the magnitude and phase of the voltage phasor at node n. Nodes m and n correspond to the phase leading node and phase lagging node, i.e., θ im >θ in .

[0099] (3-2) Using formula (2), we can identify the key branch k with the smallest index value.

[0100]

[0101] (3-3) Using the node voltages at both ends of the key branch k obtained by the wide-area measurement system, determine the key branch vertical foot voltage U kv .U kv The calculation method is as follows:

[0102] U kv =U kn sinγ (3)

[0103]

[0104]

[0105] Where U km and U kn is the voltage amplitude at the beginning and end of the key branch k, Δθ k is the voltage phase difference between the first and the last two ends of the key branch k, ΔU kmn and ΔU kmv , ΔU knv They are the amplitude of the voltage phasor difference between the nodes at both ends of the branch and the voltage between the nodes at both ends of the branch and the vertical foot voltage of the key branch U kv The amplitude of the phasor difference, γ is the voltage phasor angle.

[0106] (3-4) Determine the vertical foot voltage position coefficient ξ of the key branch kv .

[0107]

[0108] If the branch vertical foot voltage is located on the branch, then ΔU knv <ΔU kmn And ΔU kmv <ΔU kmn , that is, 1<ξ kv <2, execute steps (3-5); if the branch vertical foot voltage is outside the branch, then ΔU knv >ΔU kmn And ΔU kmv >ΔU kmn , that is, ξ kv <1, execute the next wide-area measurement sampling.

[0109] (3-5) Determine the critical branch phase difference Δθ k , key branch active power P k And whether the sBTTC index meets the following criteria, if so, execute step (4), if not, execute the next wide-area measurement sampling.

[0110]

[0111] (3-6) Determine the output voltage U of the grid-type converter vand output reactive power Q v Whether the following criteria are met, if so, execute step (4), if not, execute the next wide-area measurement sampling.

[0112]

[0113] (4) Execute transient power angle stability reshaping control of the grid-connected converter, including:

[0114] (4-1) Reshape control times n Emg Increase once.

[0115] n Emg =n Emg +1 (11)

[0116] (4-2) The damping coefficient of the grid-type converter is modified to D Emg .

[0117] (4-3) The virtual power angle of the grid-type converter is modified to δ'.

[0118] δ'=δ v -n Emg δ Emg (12)

[0119] (5) Determine whether to exit the transient power angle stability remodeling control of the grid-connected converter, including:

[0120] Determine the output voltage U of the grid-connected converter v Or whether the sBTTC index meets the following criteria. If so, exit the reshaping control. If not, execute the next wide-area measurement sampling.

[0121] U v >U vHth or sBTTC k >ε Hth (13)

[0122] This embodiment takes a grid-connected system of a single-machine grid-connected grid-connected converter as an example to illustrate that a method for determining a grid-connected converter transient power angle stability control based on a network disturbance response includes the following steps:

[0123] (1) Obtaining the operating status information of the grid-connected converter

[0124] Taking the grid-connected system of a single-machine grid-connected converter as an example, the system network structure is as follows: Figure 3 The real-time operating parameters of the branches and nodes in the network are collected, including the amplitude and phase of the branch node voltage, as well as the output voltage and output reactive power of the grid-forming converter.

[0125] (2) Initial parameter setting

[0126] Parameter D in the control method orig 、D Emg 、n Emg , δ Emg , ε Lth 、U vLth , ε Hth 、U vHth They are 1.5, 10, 0, 10°, 0.4, 0.8pu, 0.7, and 0.9pu respectively.

[0127] (3) Determine whether the grid-type converter transient power angle stability reshaping control startup criteria are met

[0128] When the grid-connected system of the grid-connected converter is a weak system, the node n s A three-phase metallic short circuit fault occurs at 0.2s and lasts for 0.124s, causing the grid-type converter to experience power angle instability. The sBTTC index of each branch in the transmission network and the branch vertical foot voltage position coefficient ζ v Response such as Figure 4a and Figure 4b As shown in the figure, it can be seen that after the power angle swing stability deteriorates significantly, the sBTTC index of each branch decreases. Figure 4a and Figure 4b The time period shown [t a ,t b ], branch B 32 and B 43 have the minimum sBTTC index value and satisfy ζ v ∈(1,2), which are the key branches in the corresponding time period. At 0.57s, the key branch B 43 After satisfying the remodeling control start-up criterion of formula (9) and implementing the remodeling control strategy, the transient response of the grid-type converter is as follows: Figure 5a and Figure 5b As shown. In the key branch B 43 The sBTTC index begins to be less than ε Lth = 0.4 0.57s to implement reshaping control, virtual power angle δ v By reducing the power stepwise, the electromagnetic power can be maintained above the reference power. The continuous deceleration power acts on the damping rotor, braking it and restoring the power angle stability of the grid-type converter. Furthermore, increasing the grid-type converter's damping coefficient after a fault can accelerate oscillation decay and quickly restore the stable equilibrium point after the fault.

[0129] When the grid-connected system of the grid-connected converter is a strong system, the node n s A three-phase metallic short circuit fault occurred at 0.2s and lasted for 0.172s, causing transient power angle instability in the grid-connected converter. The transient responses of voltage and reactive power at each node in the transmission network are as follows: Figure 6a and Figure 6bAs shown. At 0.51s, the grid-type converter outputs reactive power Q v Starts to be less than zero and the terminal voltage U v Less than the set threshold value U vLth =0.8pu, which satisfies the remodeling control start criterion shown in formula (10), indicating that the power angle stability of the grid-type converter has deteriorated significantly. Starting the remodeling control reduces the virtual power angle δ of the grid-type converter. v , while increasing the damping coefficient to D Emg After implementing the remodeling control, the grid-type converter recovers the power angle stability, such as Figure 7a and Figure 7b Implementing grid-type converter emergency control according to this patent can improve system power angle stability.

[0130] Therefore, the present invention proposes a method for controlling transient power angle stability of a grid-type converter, which uses the wide-area measured network branch response as the information source to identify key branches. On the basis of determining the transient transmission capability index of the branch, a criterion for characterizing the deterioration trend of the power angle stability of the grid-type converter is constructed according to the branch voltage size and reactive power change trend that reflect the severity of the disturbance. When the criterion is met, the power angle state quantity of the grid-type converter is directly reshaped and controlled, which can effectively reduce the risk of transient power angle instability of the system.

[0131] Exemplary devices

[0132] Figure 8 FIG. 1 is a schematic diagram of a structure of a transient power angle stabilization control device for a grid-type converter based on a network disturbance response according to an exemplary embodiment of the present invention. Figure 8 As shown, the apparatus 800 includes:

[0133] The acquisition module 810 is used to collect real-time operating parameters of each branch and node in the meshed converter, and to set initial parameters of the meshed converter to determine the initial parameters of the meshed converter;

[0134] A judgment module 820 is configured to judge whether the grid-type converter satisfies a start criterion for transient power angle stability reshaping control of the grid-type converter based on the real-time operating parameters;

[0135] A control module 830 is configured to execute a transient power angle stabilization reshaping control of the grid-type converter according to the initial parameters of the grid-type converter if the conditions are met, and execute a next real-time operation parameter acquisition if the conditions are not met;

[0136] The determination module 840 is used to determine whether to exit the transient power angle stabilization reshaping control of the grid-type converter according to the control result of the transient power angle stabilization reshaping control of the grid-type converter and the exit criterion of the transient power angle stabilization reshaping control of the grid-type converter.

[0137] Optionally, the real-time operating parameters in the acquisition module 810 include: the amplitude U of the voltage at both ends of the branch i im 、U in and phase θ im ,θ in , grid-type converter output voltage U v and output reactive power Q v .

[0138] Optionally, the initial parameters include: initial damping coefficient D of the grid-type converter orig ; Damping coefficient D of grid-type converter after reshaping control Emg ; Reshape control times n Emg ; Virtual power angle reshapes the control quantity δ Emg ; Reshape control to start BTTC index threshold value ε Lth , reshape the control start-up grid-type converter output node voltage threshold setting value U vLth ; Reshape the control exit BTTC index threshold value ε Hth And reshape the control exit grid-type converter output node voltage threshold setting value U vHth .

[0139] Optionally, the judgment module 820 includes:

[0140] A first judgment submodule is configured to judge whether the grid-type converter satisfies a first starting criterion of transient power angle stability reshaping control of the grid-type converter according to the real-time operating parameter; or

[0141] The second judgment submodule is used to judge whether the grid-type converter meets the second starting criterion of the transient power angle stability reshaping control of the grid-type converter according to the real-time operating parameters.

[0142] Optionally, the first judgment submodule includes:

[0143] A calculation unit, configured to calculate a branch transient power transmission function index of each branch of the grid-connected converter based on the real-time operating parameters of each branch and node;

[0144] A first determining unit is configured to determine a key branch of the grid-connected converter according to the DC transient power transmission function index of each branch;

[0145] A second determining unit is configured to determine a key branch vertical foot voltage position coefficient of the key branch according to the voltage phasors of the two end nodes of the key branch;

[0146] a third determining unit, configured to determine the position of the key branch vertical foot voltage according to the key branch vertical foot voltage position coefficient;

[0147] The judgment unit is used to perform the next real-time operation parameter acquisition if the position of the key branch vertical foot voltage is outside the branch, and to judge whether the key branch meets the first starting criterion if the position of the key branch vertical foot voltage is on the branch.

[0148] Optionally, the calculation formula of the branch transient transmission function index sBTTC is:

[0149]

[0150] The method for determining the key branch k is:

[0151]

[0152] Where U im and θ im is the magnitude and phase of the voltage phasor at node m, U in and θ in is the amplitude and phase of the voltage phasor at node n, node m and node n correspond to the phase leading node and phase lagging node respectively, that is, θ im >θ in .

[0153] Optionally, the second determining unit includes:

[0154] a calculation subunit, configured to calculate a key branch vertical foot voltage of the key branch according to voltage phasors at both end nodes of the key branch;

[0155] The first determining subunit is configured to determine a key branch vertical foot voltage position coefficient of the key branch according to the voltage phasors of the two end nodes of the key branch and the key branch vertical foot voltage.

[0156] Optionally, the key branch vertical foot voltage U kv The calculation formula is:

[0157] U kv =U kn sinγ

[0158] in,

[0159]

[0160] Where U km and U kn is the voltage amplitude at the beginning and end of the key branch k, Δθ k is the voltage phase difference between the first and the last two ends of the key branch k, ΔU kmn is the amplitude of the voltage phasor difference between the nodes at both ends of the branch, and γ is the voltage phasor angle.

[0161] Optionally, the key branch vertical foot voltage position coefficient ξ kv The calculation formula is:

[0162]

[0163] Where, ΔU kmv , ΔU knv They are the node voltages at both ends of the branch and the vertical foot voltage of the key branch U kv The magnitude of the phasor difference.

[0164] Optionally, the third determining unit includes:

[0165] The second determining subunit is used to determine the key branch vertical foot voltage position coefficient ξ kv Satisfying 1<ξ kv <2, the position of the vertical foot voltage of the critical branch is located on the branch;

[0166] The third determining subunit is used to determine the key branch vertical foot voltage position coefficient ξ kv Satisfy ξ kv <1, the position of the vertical foot voltage of the critical branch is outside the branch.

[0167] Optionally, the first starting criterion is:

[0168] and And sBTTC k <ε LTH

[0169] Where Δθ k is the phase difference of the key branch, P k is the active power of key branches, sBTTC k is the branch transient transmission capability index of the critical branch, ε LTH To reshape the control start-up grid-type converter outlet node action threshold value, t is the time.

[0170] Optionally, the second starting criterion is:

[0171] Q v <0 and U v <U vLth and

[0172] Where U v is the grid-type converter output voltage, Q v is the output reactive power, U vLth To reshape the control startup grid-type converter output node voltage threshold setting value.

[0173] Optionally, the control module 830 includes:

[0174] The reshaping control times n of the grid-type energy storage converter are Emg Increase once;

[0175] The damping coefficient of the grid-type energy storage converter is modified to the damping coefficient D after the grid-type converter is reshaped and controlled. Emg ;

[0176] The virtual power angle of the grid-type converter is modified to δ', where δ'=δ v -n Emg δ Emg , δ v is the virtual power angle before reshaping control, n Emg is the number of remodeling controls; δ Emg Reshape the control quantity for the virtual power angle;

[0177] The grid-type energy storage converter is controlled according to the modified grid-type converter virtual power angle δ'.

[0178] Optionally, the grid-connected converter transient power angle stability remodeling control exit criterion is:

[0179] U v >U vHth or sBTTC k >ε Hth

[0180] Where U v is the grid-type converter outlet voltage, sBTTC is the branch transient transmission function index, U vHth In order to reshape the control exit grid-type converter output node voltage threshold setting value, ε Hth To reshape the control exit threshold of BTTC index.

[0181] Exemplary electronic devices

[0182] Figure 9 This is the structure of an electronic device provided by an exemplary embodiment of the present invention. Figure 9 As shown, the electronic device 90 includes one or more processors 91 and a memory 92 .

[0183] The processor 91 may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0184] The memory 92 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM) and / or cache memory (cache), etc. The non-volatile memory may, for example, include read-only memory (ROM), a hard disk, a flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 91 may execute the program instructions to implement the methods of the software programs of the various embodiments of the present invention described above and / or other desired functions. In one example, the electronic device may further include: an input device 93 and an output device 94, which are interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0185] In addition, the input device 93 may also include, for example, a keyboard, a mouse, and the like.

[0186] The output device 94 can output various information to the outside. The output device 94 can include, for example, a display, a speaker, a printer, a communication network and a remote output device connected thereto.

[0187] Of course, to simplify, Figure 9 Only some of the components related to the present invention in the electronic device are shown, and components such as a bus, an input / output interface, etc. are omitted. In addition, the electronic device may further include any other appropriate components according to specific application conditions.

[0188] Exemplary computer program products and computer-readable storage media

[0189] In addition to the above-mentioned methods and devices, an embodiment of the present invention may also be a computer program product, which includes computer program instructions, which, when executed by a processor, enable the processor to perform the steps of the method according to various embodiments of the present invention described in the above "Exemplary Method" section of this specification.

[0190] The computer program product may be written in any combination of one or more programming languages ​​to implement the operations of embodiments of the present invention, including object-oriented programming languages ​​such as Java, C++, and conventional procedural programming languages ​​such as C or similar programming languages. The program code may be executed entirely on the user's computing device, partially on the user's computing device, as a stand-alone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0191] In addition, an embodiment of the present invention may also be a computer-readable storage medium having computer program instructions stored thereon, which, when executed by a processor, causes the processor to execute the steps of the method according to various embodiments of the present invention described in the above "Exemplary Method" section of this specification.

[0192] The computer-readable storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can, for example, include but is not limited to a system, system or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination thereof. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable 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 device, a magnetic storage device, or any suitable combination thereof.

[0193] The basic principles of the present invention have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in the present invention are merely illustrative and non-limiting, and should not be construed as necessarily possessed by each embodiment of the present invention. Furthermore, the specific details disclosed above are provided for illustrative purposes and to facilitate understanding, and are not intended to be limiting. These details do not necessarily limit the present invention to being implemented using these specific details.

[0194] Each embodiment in this specification is described in a progressive manner, with each embodiment focusing on its differences from the other embodiments. References to the same or similar parts between the various embodiments are sufficient. For system embodiments, since they largely correspond to method embodiments, their description is relatively simple. For relevant parts, references to the description of the method embodiments are sufficient.

[0195] The block diagrams of the devices, systems, equipment, and systems involved in the present invention are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, systems, equipment, and systems can be connected, arranged, or configured in any manner. Words such as "including," "comprising," "having," and the like are open-ended words, meaning "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or" and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0196] The method and system of the present invention may be implemented in many ways. For example, the method and system of the present invention may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above sequence of steps for the method is for illustration only, and the steps of the method of the present invention are not limited to the sequence specifically described above, unless otherwise specified. In addition, in some embodiments, the present invention may also be implemented as a program recorded in a recording medium, which includes machine-readable instructions for implementing the method according to the present invention. Thus, the present invention also covers recording media that store programs for executing the method according to the present invention.

[0197] It should also be noted that, in the system, device and method of the present invention, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present invention. The above description of the disclosed aspects is provided to enable any technician in this field to make or use the present invention. Various modifications to these aspects will be very obvious to those skilled in the art, and the general principles defined here can be applied to other aspects without departing from the scope of the present invention. Therefore, the present invention is not intended to be limited to the aspects shown here, but according to the widest scope consistent with the principles disclosed here and novel features.

[0198] The above description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present invention to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A method for controlling transient power angle stability of a grid-connected converter based on network disturbance response, characterized in that: include: Collect the real-time operating parameters of each branch and node in the grid-type converter, and set the initial parameters of the grid-type converter to determine the initial parameters of the grid-type converter. The initial parameters include: the initial damping coefficient D of the grid-type converter orig ; Damping coefficient D of grid-type converter after reshaping control Emg ; Reshape control times n Emg ; Virtual power angle reshapes the control quantity δ Emg ; Reshape control to start BTTC index threshold value ε Lth , reshape the control start-up grid-type converter output node voltage threshold setting value U vLth ; Reshape the control exit BTTC index threshold value ε Hth And reshape the control exit grid-type converter output node voltage threshold setting value U vHth ; Determining whether the grid-type converter meets a grid-type converter transient power angle stability reshaping control start criterion based on the real-time operating parameters; If the conditions are met, the transient power angle stabilization reshaping control of the grid-type converter is performed according to the initial parameters of the grid-type converter; if the conditions are not met, the next real-time operation parameter acquisition is performed; Whether to exit the transient power angle stabilization reshaping control of the grid-type converter is determined according to the control result of the transient power angle stabilization reshaping control of the grid-type converter and the exit criterion of the transient power angle stabilization reshaping control of the grid-type converter. Judging whether the grid-type converter satisfies a grid-type converter transient power angle stability reshaping control start criterion based on the real-time operating parameters includes: Determining whether the grid-type converter satisfies a first starting criterion of transient power angle stability remodeling control of the grid-type converter according to the real-time operating parameter; or According to the real-time operating parameters, it is judged whether the grid-type converter meets the second starting criterion of the transient power angle stability reshaping control of the grid-type converter, wherein The first starting criterion is: and And sBTTC k <ε LTH Where Δθ k is the phase difference of the key branch, P k is the active power of key branches, sBTTC k is the branch transient transmission capability index of the critical branch, ε LTH To reshape the control start-up grid-type converter outlet node action threshold value, t is the time; The second starting criterion is: Q v <0 and U v <U vLth And Where U v is the grid-type converter output voltage, Q v is the output reactive power, U vLth To reshape the control startup grid-type converter output node voltage threshold setting value; The method further comprises: performing transient power angle stabilization reshaping control of the grid-type converter according to the initial parameters of the grid-type converter, comprising: The reshaping control times n of the grid-type energy storage converter are Emg Increase once; The damping coefficient of the grid-type energy storage converter is modified to the damping coefficient D after the grid-type converter is reshaped and controlled. Emg ; The virtual power angle of the grid-type converter is modified to δ', where δ'=δ v -n Emg δ Emg , δ v is the virtual power angle before reshaping control, n Emg is the number of remodeling controls; δ Emg Reshape the control quantity for the virtual power angle; Controlling the grid-type energy storage converter according to the modified grid-type converter virtual power angle δ'; The exit criterion for transient power angle stability remodeling control of grid-connected converter is: U v >U vHth sBTTC k >ε Hth Where U v is the grid-type converter outlet voltage, sBTTC is the branch transient transmission function index, U vHth In order to reshape the control exit grid-type converter output node voltage threshold setting value, ε Hth To reshape the control exit threshold of BTTC index.

2. The method according to claim 1, characterized in that The real-time operating parameters include: the amplitude U of the voltage at both ends of the branch i im 、U in and phase θ im ,θ in , grid-type converter output voltage U v and output reactive power Q v .

3. The method according to claim 1, characterized in that Judging whether the grid-type converter satisfies a first starting criterion of transient power angle stability reshaping control of the grid-type converter according to the real-time operating parameter includes: Calculating a branch transient power transmission function index of each branch of the grid-type converter according to the real-time operating parameters of each branch and node; Determining the key branches of the grid-type converter according to the branch transient power transmission function index of each branch; Determining a key branch vertical foot voltage position coefficient of the key branch according to the voltage phasors of the two end nodes of the key branch; Determining the position of the key branch vertical foot voltage according to the key branch vertical foot voltage position coefficient; If the position of the key branch vertical foot voltage is outside the branch, perform the next real-time operation parameter acquisition; if the position of the key branch vertical foot voltage is on the branch, determine whether the key branch meets the first startup criterion.

4. The method according to claim 3, characterized in that The calculation formula of the branch transient transmission function index sBTTC is: The method for determining the key branch k is: Where U im and θ im is the magnitude and phase of the voltage phasor at node m, U in and θ in is the amplitude and phase of the voltage phasor at node n, node m and node n correspond to the phase leading node and phase lagging node respectively, that is, θ im >θ in .

5. The method according to claim 4, characterized in that Determining a key branch vertical foot voltage position coefficient of the key branch according to the voltage phasors of the two end nodes of the key branch includes: Calculating the key branch vertical foot voltage of the key branch according to the voltage phasors of the two end nodes of the key branch; The key branch vertical foot voltage position coefficient of the key branch is determined according to the voltage phasors of the two end nodes of the key branch and the key branch vertical foot voltage.

6. The method according to claim 5, characterized in that The key branch vertical foot voltage U kv The calculation formula is: The kv =U kn sinγ in, Where U km and U kn is the voltage amplitude at the beginning and end of the key branch k, Δθ k is the voltage phase difference between the first and the last two ends of the key branch k, ΔU kmn is the amplitude of the voltage phasor difference between the nodes at both ends of the branch, and γ is the voltage phasor angle.

7. The method according to claim 6, characterized in that The key branch vertical foot voltage position coefficient ξ kv The calculation formula is: Where, ΔU kmv , ΔU knv They are the node voltages at both ends of the branch and the vertical foot voltage of the key branch U kv The magnitude of the phasor difference.

8. The method according to claim 3, characterized in that Determining the position of the key branch vertical foot voltage according to the key branch vertical foot voltage position coefficient includes: If the key branch vertical foot voltage position coefficient ξ kv Satisfying 1<ξ kv <2, the position of the vertical foot voltage of the critical branch is located on the branch; If the key branch vertical foot voltage position coefficient ξ kv Satisfy ξ kv <1, the position of the vertical foot voltage of the critical branch is outside the branch.

9. A transient power angle stabilization control device for a grid-connected converter based on network disturbance response, characterized in that: include: The acquisition module is used to collect the real-time operating parameters of each branch and node in the network-type converter, and to set the initial parameters of the network-type converter to determine the initial parameters of the network-type converter. The initial parameters include: the initial damping coefficient D of the network-type converter orig ; Damping coefficient D of grid-type converter after reshaping control Emg ; Reshape control times n Emg ; Virtual power angle reshapes the control quantity δ Emg ; Reshape control to start BTTC index threshold value ε Lth , reshape the control start-up grid-type converter output node voltage threshold setting value U vLth ; Reshape the control exit BTTC index threshold value ε Hth And reshape the control exit grid-type converter output node voltage threshold setting value U vHth ; A judgment module, configured to judge whether the grid-type converter satisfies a start criterion for transient power angle stability remodeling control of the grid-type converter according to the real-time operating parameters; A control module, configured to execute a transient power angle stabilization reshaping control of the grid-type converter according to the initial parameters of the grid-type converter if the conditions are met, and execute a next real-time operation parameter acquisition if the conditions are not met; a determination module, configured to determine whether to exit the transient power angle stabilization reshaping control of the grid-type converter according to a control result of the transient power angle stabilization reshaping control of the grid-type converter and an exit criterion of the transient power angle stabilization reshaping control of the grid-type converter; Judgment module, including: A first judgment submodule is configured to judge whether the grid-type converter satisfies a first starting criterion of transient power angle stability reshaping control of the grid-type converter according to the real-time operating parameter; or A second judgment submodule is used to judge whether the grid-type converter meets the second starting criterion of the transient power angle stability reshaping control of the grid-type converter according to the real-time operating parameter; The first starting criterion is: and And sBTTC k <ε LTH Where Δθ k is the phase difference of the key branch, P k is the active power of key branches, sBTTC k is the branch transient transmission capability index of the critical branch, ε LTH To reshape the control start-up grid-type converter outlet node action threshold value, t is the time; The second starting criterion is: Q v <0 and U v <U vLth And Where U v is the grid-type converter output voltage, Q v is the output reactive power, U vLth To reshape the control startup grid-type converter output node voltage threshold setting value; Control module, including: The reshaping control times n of the grid-type energy storage converter are Emg Increase once; The damping coefficient of the grid-type energy storage converter is modified to the damping coefficient D after the grid-type converter is reshaped and controlled. Emg ; The virtual power angle of the grid-type converter is modified to δ', where δ'=δ v -n Emg δ Emg , δ v is the virtual power angle before reshaping control, n Emg is the number of remodeling controls; δ Emg Reshape the control quantity for the virtual power angle; Controlling the grid-type energy storage converter according to the modified grid-type converter virtual power angle δ'; The exit criterion for transient power angle stability remodeling control of grid-connected converter is: U v >U vHth sBTTC k >ε Hth Where U v is the grid-type converter outlet voltage, sBTTC is the branch transient transmission function index, U vHth In order to reshape the control exit grid-type converter output node voltage threshold setting value, ε Hth To reshape the control exit threshold of BTTC index.

10. The device according to claim 9, characterized in that The real-time operating parameters in the acquisition module include: the amplitude U of the voltage at both ends of branch i im 、U in and phase θ im ,θ in , grid-type converter output voltage U v and output reactive power Q v .

11. The device according to claim 10, characterized in that The first judgment submodule includes: A calculation unit, configured to calculate a branch transient power transmission function index of each branch of the grid-connected converter based on the real-time operating parameters of each branch and node; A first determining unit is configured to determine a key branch of the grid-connected converter according to the branch transient power transmission function index of each branch; A second determining unit is configured to determine a key branch vertical foot voltage position coefficient of the key branch according to the voltage phasors of the two end nodes of the key branch; a third determining unit, configured to determine the position of the key branch vertical foot voltage according to the key branch vertical foot voltage position coefficient; The judgment unit is used to perform the next real-time operation parameter acquisition if the position of the vertical foot voltage of the key branch is outside the branch, and to judge whether the key branch meets the first starting criterion if the position of the vertical foot voltage of the key branch is on the branch.

12. The device according to claim 11, characterized in that The calculation formula of the branch transient transmission function index sBTTC is: The method for determining the key branch k is: Where U im and θ im is the magnitude and phase of the voltage phasor at node m, U in and θ in is the amplitude and phase of the voltage phasor at node n, node m and node n correspond to the phase leading node and phase lagging node respectively, that is, θ im >θ in .

13. The device according to claim 12, characterized in that The second determining unit includes: a calculation subunit, configured to calculate a key branch vertical foot voltage of the key branch according to voltage phasors at both end nodes of the key branch; The first determining subunit is configured to determine a key branch vertical foot voltage position coefficient of the key branch according to the voltage phasors of the two end nodes of the key branch and the key branch vertical foot voltage.

14. The device according to claim 13, characterized in that The key branch vertical foot voltage U kv The calculation formula is: The kv =U kn sinγ in, Where U km and U kn is the voltage amplitude at the beginning and end of the key branch k, Δθ k is the voltage phase difference between the first and the last two ends of the key branch k, ΔU kmn is the amplitude of the voltage phasor difference between the nodes at both ends of the branch, and γ is the voltage phasor angle.

15. The device according to claim 14, characterized in that The key branch vertical foot voltage position coefficient ξ kv The calculation formula is: Where, ΔU kmv , ΔU knv They are the node voltages at both ends of the branch and the vertical foot voltage of the key branch U kv The magnitude of the phasor difference.

16. The device according to claim 15, characterized in that The third determining unit includes: The second determining subunit is used to determine the key branch vertical foot voltage position coefficient ξ kv Satisfying 1<ξ kv <2, the position of the vertical foot voltage of the critical branch is located on the branch; The third determining subunit is used to determine the key branch vertical foot voltage position coefficient ξ kv Satisfy ξ kv <1, the position of the vertical foot voltage of the critical branch is outside the branch.

17. A computer-readable storage medium, characterized in that The storage medium stores a computer program, and the computer program is used to execute the method according to any one of claims 1 to 8.

18. An electronic device, characterized in that: The electronic device comprises: processor; a memory for storing instructions executable by the processor; The processor is configured to read the executable instructions from the memory and execute the instructions to implement the method according to any one of claims 1 to 8.

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