Method and apparatus for determining transient synchronization stability quantization margin

Abstract

This invention provides a method and apparatus for determining transient synchronization stability quantization margin, comprising: when a disturbance is detected in a multi-element heterogeneous parallel system, calculating the critical coefficients of each converter in the multi-element heterogeneous parallel system; based on the critical coefficients of each converter, selecting a critical converter set consisting of several converters from among the converters; calculating the transient synchronization stability quantization margin corresponding to each converter in the critical converter set; and setting the minimum transient synchronization stability quantization margin as the transient synchronization stability quantization margin of the multi-element heterogeneous parallel system. Using the method provided by this invention, the transient synchronization stability quantization margin of a multi-element heterogeneous parallel system can be quickly determined through the critical coefficients.

Description

Technical Field

[0001] This invention relates to the field of synchronous motor technology, and in particular to a method and apparatus for determining transient synchronous stability quantization margin. Background Technology

[0002] To ensure the stable operation of the power grid, converters can operate synchronously with the grid via phase-locked loops (PLLs). However, when a severe grid fault occurs, the PLL is prone to transient synchronization instability, causing the converter to trip and disconnect from the grid. To enable power electronic equipment to possess damping and rotational inertia similar to traditional synchronous generators, a virtual synchronous generator can be introduced into the power electronic converter control to simulate the operating characteristics of a synchronous generator, allowing the converter to be connected to the grid smoothly. However, distributed generation sources are often located at the end of weak grids with poor grid environments or distribution networks prone to short-circuit faults, making their transient operational stability a current research hotspot.

[0003] To ensure the stability of converters operating in the power grid, different types of converters, such as virtual synchronous converters and phase-locked loop converters, can be combined to form a multi-element heterogeneous parallel system. However, there is little research on multi-element heterogeneous parallel systems in the existing technology, and the transient synchronization stability quantization margin of multi-element heterogeneous parallel systems cannot be determined. Summary of the Invention

[0004] In view of this, the present invention provides a method and apparatus for determining transient synchronization stability quantization margin, for determining the transient synchronization stability quantization margin of a multi-element heterogeneous parallel system.

[0005] The present invention also provides a data processing apparatus to ensure the implementation and application of the above method in practice.

[0006] A method for determining transient synchronization stability quantization margin includes:

[0007] When a disturbance is detected in the multi-element heterogeneous parallel system, the critical coefficient of each converter in the multi-element heterogeneous parallel system is calculated. The critical coefficient is used to reflect the degree to which the converter is on the verge of instability after being disturbed. The multi-element heterogeneous parallel system contains multiple converters of different types.

[0008] Based on the critical coefficient of each converter, a critical converter set consisting of several converters is selected from each converter.

[0009] Calculate the transient synchronization stability quantization margin for each converter in the critical converter set;

[0010] The minimum transient synchronization stability quantization margin is set as the transient synchronization stability quantization margin of the multi-element heterogeneous parallel system.

[0011] Optionally, in the above method, calculating the critical coefficients of each converter in the multi-element heterogeneous parallel system includes:

[0012] Determine the capacity of each of the converters;

[0013] Real-time detection of the electrical distance between each converter and the PCC;

[0014] Detect the load on the interconnect line between each of the converters and the PCC;

[0015] For each converter, the criticality coefficient of the converter is calculated based on the converter's capacity, the electrical distance between the converter and the PCC, and the load on the tie line between the converter and the PCC.

[0016] Optionally, in the above method, the step of selecting multiple converters to form a critical converter set based on the critical coefficient of each converter includes:

[0017] Retrieve pre-set statistical values;

[0018] Determine whether the critical coefficient of each converter is greater than the statistical value;

[0019] If any converter has a critical coefficient greater than the statistical value, then all converters with critical coefficients greater than the statistical value are grouped into a critical converter cluster.

[0020] Optionally, in the above method, each of the converters includes at least one virtual synchronous machine converter and at least one phase-locked loop converter;

[0021] The calculation of the transient synchronization stability quantization margin for each converter in the critical converter set includes:

[0022] For the critical converter centralized virtual synchronous machine type converter, the first rotor motion equation and the first power flow equation of the virtual synchronous machine type converter are obtained; based on the first rotor motion equation and the first power flow equation, the first power angle characteristic curve corresponding to the virtual synchronous machine type converter is constructed; based on the first power angle characteristic curve, the first acceleration area and the first maximum deceleration area corresponding to the virtual synchronous machine type converter are obtained; based on the first acceleration area and the first maximum deceleration area, the transient synchronization stability quantization margin corresponding to the virtual synchronous machine type converter is calculated.

[0023] For the critical converter centralized phase-locked loop converter, the second rotor motion equation and the second power flow equation of the phase-locked loop converter are obtained; based on the second rotor motion equation and the second power flow equation, the second power angle characteristic curve corresponding to the phase-locked loop converter is constructed; based on the second power angle characteristic curve, the second acceleration area and the second maximum deceleration area corresponding to the phase-locked loop converter are obtained; based on the second acceleration area and the second maximum deceleration area, the transient synchronous stability quantization margin corresponding to the phase-locked loop converter is calculated.

[0024] Optionally, in the above method, obtaining the first rotor motion equation of the virtual synchronous converter includes:

[0025] Determine the moment of inertia, damping coefficient, power angle, angular velocity, output voltage, line reactance with the grid, and voltage amplitude of the virtual synchronous converter;

[0026] Based on the moment of inertia, damping coefficient, power angle, angular velocity, output voltage, line reactance with the grid, and voltage amplitude of the virtual synchronous converter, the first rotor motion equation of the virtual synchronous converter is obtained.

[0027] Optionally, in the above method, obtaining the second rotor motion equation of the phase-locked loop converter includes:

[0028] Determine the proportional gain, integral gain, total equivalent inductance with the grid, direct-axis current component, quadrature-axis total impedance voltage drop component, phase angle difference with grid voltage, angular velocity difference with grid voltage, and grid voltage of the phase-locked loop converter.

[0029] Based on the proportional gain, integral gain, total equivalent inductance with the grid, direct-axis current component, quadrature-axis total impedance voltage drop component, phase angle difference with grid voltage, angular velocity difference with grid voltage, and grid voltage of the phase-locked loop converter, the second rotor motion equation of the phase-locked loop converter is obtained.

[0030] A transient synchronization stability quantization margin determination device, comprising:

[0031] The first calculation unit is used to calculate the critical coefficient of each converter in the multi-element heterogeneous parallel system when a disturbance is detected. The critical coefficient is used to reflect the degree to which the converter is on the verge of instability after being disturbed. The multi-element heterogeneous parallel system contains multiple converters of different types.

[0032] A screening unit is used to screen out a critical converter set consisting of several converters from among the various converters based on the critical coefficient of each converter.

[0033] The second calculation unit is used to calculate the transient synchronization stability quantization margin corresponding to each converter in the critical converter set.

[0034] The setting unit is used to set the minimum transient synchronization stability quantization margin as the transient synchronization stability quantization margin of the multi-element heterogeneous parallel system.

[0035] Optionally, in the aforementioned apparatus, the first computing unit includes:

[0036] The first determining subunit is used to determine the capacity of each of the converters;

[0037] The first detection subunit is used to detect the electrical distance between each converter and the PCC in real time.

[0038] The second detection subunit is used to detect the load on the interconnect line between each converter and the PCC.

[0039] The first calculation subunit is used to calculate the critical coefficient of each converter based on the converter's capacity, the electrical distance between the converter and the PCC, and the load on the tie line between the converter and the PCC.

[0040] Optionally, in the aforementioned apparatus, the screening unit includes:

[0041] The first acquisition subunit is used to acquire pre-set statistical values;

[0042] A judgment subunit is used to determine whether the critical coefficient of each converter is greater than the statistical value;

[0043] The filtering subunit is used to form a critical converter cluster by combining all converters whose critical coefficients are greater than the statistical value if any converter has a critical coefficient greater than the statistical value.

[0044] Optionally, each of the aforementioned converters includes at least one virtual synchronous machine converter and at least one phase-locked loop converter.

[0045] The second computing unit includes:

[0046] The second calculation subunit is used to obtain, for the virtual synchronous converter in the critical converter cluster, the first rotor motion equation and the first power flow equation of the virtual synchronous converter; based on the first rotor motion equation and the first power flow equation, construct the first power angle characteristic curve corresponding to the virtual synchronous converter; based on the first power angle characteristic curve, obtain the first acceleration area and the first maximum deceleration area corresponding to the virtual synchronous converter; and based on the first acceleration area and the first maximum deceleration area, calculate the transient synchronization stability quantization margin corresponding to the virtual synchronous converter.

[0047] The second calculation subunit is used to obtain the second rotor motion equation and the second power flow equation of the phase-locked loop converter for the critical converter; construct the second power angle characteristic curve corresponding to the phase-locked loop converter based on the second rotor motion equation and the second power flow equation; obtain the second acceleration area and the second maximum deceleration area corresponding to the phase-locked loop converter based on the second power angle characteristic curve; and calculate the transient synchronous stability quantization margin corresponding to the phase-locked loop converter based on the second acceleration area and the second maximum deceleration area.

[0048] Optionally, in the aforementioned apparatus, the second computing subunit includes:

[0049] The second determining subunit is used to determine the moment of inertia, damping coefficient, power angle, angular velocity, output voltage, line reactance with the grid, and voltage amplitude of the virtual synchronous converter; based on the moment of inertia, damping coefficient, power angle, angular velocity, output voltage, line reactance with the grid, and voltage amplitude of the virtual synchronous converter, the first rotor motion equation of the virtual synchronous converter is obtained.

[0050] Optionally, in the aforementioned apparatus, the third computing subunit includes:

[0051] The third determining subunit is used to determine the proportional coefficient, integral coefficient, total equivalent inductance between the phase-locked loop converter and the grid, direct-axis current component, quadrature-axis total impedance voltage drop component, phase angle difference with grid voltage, angular velocity difference with grid voltage, and grid voltage of the phase-locked loop converter; based on the proportional coefficient, integral coefficient, total equivalent inductance between the phase-locked loop converter and the grid, direct-axis current component, quadrature-axis total impedance voltage drop component, phase angle difference with grid voltage, angular velocity difference with grid voltage, and grid voltage of the phase-locked loop converter, the second rotor motion equation of the phase-locked loop converter is obtained.

[0052] A storage medium comprising stored instructions, wherein, when the instructions are executed, the device in which the storage medium resides controls the execution of the data processing method described above.

[0053] An electronic device includes a memory and one or more instructions, wherein one or more instructions are stored in the memory and configured to be executed by one or more processors using the data processing method described above.

[0054] Compared with the prior art, the present invention has the following advantages:

[0055] This invention provides a method for determining transient synchronization stability quantization margin, comprising: when a disturbance is detected in a multi-element heterogeneous parallel system, calculating the critical coefficients of each converter in the multi-element heterogeneous parallel system, wherein the critical coefficients reflect the degree of disturbance to the converters; based on the critical coefficients of each converter, selecting multiple converters from the various converters to form a critical converter set; calculating the transient synchronization stability quantization margin corresponding to each converter in the critical converter set; and setting the minimum transient synchronization stability quantization margin as the transient synchronization stability quantization margin of the multi-element heterogeneous parallel system. Using the method provided by this invention, the transient synchronization stability quantization margin of a multi-element heterogeneous parallel system can be quickly determined through the critical coefficients. Attached Figure Description

[0056] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0057] Figure 1 A flowchart of a data processing method provided in an embodiment of the present invention;

[0058] Figure 2 Another flowchart of a data processing method provided in an embodiment of the present invention;

[0059] Figure 3 This is a structural diagram of a data processing apparatus provided in an embodiment of the present invention;

[0060] Figure 4 This is a schematic diagram of an electronic device structure provided in an embodiment of the present invention. Detailed Implementation

[0061] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] In this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0063] This invention can be used in a wide variety of general-purpose or special-purpose computing environments or configurations. For example: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor devices, distributed computing environments including any of the above devices, etc.

[0064] This invention provides a data processing method that can be applied to various system platforms. The executing entity can be a computer terminal or a processor of various mobile devices. The method flowchart is shown below. Figure 1 As shown, it specifically includes:

[0065] S101: When a disturbance is detected in the multi-element heterogeneous parallel system, calculate the critical coefficients of each converter in the multi-element heterogeneous parallel system.

[0066] It should be noted that the criticality coefficient is used to reflect the degree to which a converter is on the verge of instability after being subjected to disturbances. The criticality coefficient is based on parameters related to the converter's inherent characteristics and its geographical distribution; these parameters reflect the characteristics of the converter's critical state.

[0067] It should also be noted that a multi-type heterogeneous parallel system includes multiple different types of converters. Specifically, a multi-type heterogeneous parallel system includes at least one virtual synchronous machine converter and at least one phase-locked loop converter.

[0068] S102: Based on the critical coefficient of each converter, select a critical converter set consisting of several converters from each converter.

[0069] In this invention, the calculation range of the converter is narrowed by using a critical coefficient, thereby reducing the computational load on the computer.

[0070] S103: Calculate the transient synchronization stability quantization margin corresponding to each converter in the critical converter set.

[0071] It should be noted that the calculation methods for transient synchronous stability quantization margin differ for different types of converters. For different types of converters in the same multi-element heterogeneous parallel system, these converters influence each other. Therefore, when calculating the transient synchronous stability quantization margin for a converter, some parameters used in the calculation process will be affected by other types of converters.

[0072] S104: Set the minimum transient synchronization stability quantization margin as the transient synchronization stability quantization margin of the multi-element heterogeneous parallel system.

[0073] It should be noted that the minimum transient synchronization stability quantization margin reflects the most severe case of a disturbed converter in a multi-element heterogeneous parallel system. It can quantify the impact of different degrees of disturbance on the transient synchronization stability quantization margin of the system.

[0074] In the method provided by this invention, when a disturbance occurs in a multi-element heterogeneous parallel system, the critical coefficients of each converter in the multi-element heterogeneous parallel system under the disturbance state are calculated, and a set of critical converters is selected based on the critical coefficients. The transient synchronization stability quantization margin corresponding to each converter in the set of critical converters is calculated, and the smallest transient synchronization stability quantization margin is selected as the transient synchronization stability quantization margin of the multi-element heterogeneous parallel system.

[0075] By applying the method provided in the embodiments of the present invention, the transient synchronization stability quantization margin of a multi-element heterogeneous parallel system can be quickly determined through the critical coefficient.

[0076] In the method provided by this embodiment of the invention, based on the above-described S101, the process of calculating the critical coefficient of the converter when a disturbance occurs in a multi-element heterogeneous parallel system is as follows: Figure 2 The flowchart shown may specifically include:

[0077] S201: Determine the capacity of each converter.

[0078] S202: Real-time detection of the electrical distance between each converter and the PCC.

[0079] S203: Detect the load on the tie line between each converter and the PCC.

[0080] It should be noted that the tie line between the converter and the PCC (point of common coupling) refers to the tie line between the converter and the power grid.

[0081] For each converter, perform the steps shown in S204:

[0082] S204: Calculate the critical coefficient of the converter based on the converter's capacity, electrical distance to the PCC, and load on the tie line to the PCC.

[0083] It should be noted that the formula for calculating the critical coefficient of the converter is as follows:

[0084] C i,cr =D i-PCC *S i *L i-PCC

[0085] Among them, C i,cr D is the critical coefficient of converter i. i-PCC S is the electrical distance between converter i and PCC. i L represents the capacity of converter i. i-PCC This represents the load on the connection line between converter i and PCC.

[0086] In the method provided by this invention embodiment, after obtaining the critical coefficient of each converter, converters that meet the conditions are selected to form a critical converter set, specifically including:

[0087] Obtain the pre-set statistical values; determine whether the critical coefficient of each converter is greater than the statistical value; if any converter has a critical coefficient greater than the statistical value, then form a critical converter cluster with all converters whose critical coefficients are greater than the statistical value.

[0088] It should be noted that the statistical value ε was obtained from offline simulation. Using the statistical value as a screening criterion reduces the computational burden of calculating the transient synchronous stability quantization margin of the corresponding converters, allowing the solution to be performed only for converters that may be in a critical state, thus reducing computational costs.

[0089] Optionally, if critical converters are not selected, the transient synchronization stability quantization margin of each converter can be directly calculated.

[0090] The method provided in this embodiment of the invention, after selecting the critical converter set, calculates the transient synchronization stability quantization margin of each converter. If the multi-element heterogeneous parallel system contains multiple virtual synchronous converters and phase-locked loop converters, the corresponding transient synchronization stability quantization margin is calculated based on the virtual synchronous converters and phase-locked loop converters respectively.

[0091] For critical converters with centralized virtual synchronous machines, the specific process for calculating the transient synchronization stability quantization margin corresponding to the virtual synchronous machine converter may include:

[0092] Obtain the first rotor motion equation and the first power flow equation of the virtual synchronous converter; based on the first rotor motion equation and the first power flow equation, construct the first power angle characteristic curve corresponding to the virtual synchronous converter; based on the first power angle characteristic curve, obtain the first acceleration area and the first maximum deceleration area corresponding to the virtual synchronous converter; based on the first acceleration area and the first maximum deceleration area, calculate the transient synchronization stability quantization margin corresponding to the virtual synchronous converter.

[0093] Specifically, obtaining the first rotor motion equation of the virtual synchronous converter may include: determining the moment of inertia, damping coefficient, power angle, angular velocity, output voltage, line reactance with the grid, and voltage amplitude of the virtual synchronous converter; and obtaining the first rotor motion equation of the virtual synchronous converter based on the moment of inertia, damping coefficient, power angle, angular velocity, output voltage, line reactance with the grid, and voltage amplitude of the grid.

[0094] Therefore, the first rotor motion equation of the virtual synchronous converter j is:

[0095]

[0096] Among them, J j For the set moment of inertia, D j The damping coefficient δ is set. j ω j Let be the power angle and angular velocity of the virtual synchronous converter j. U g U represents the voltage amplitude of the power grid. j X is the output voltage of the virtual synchronous converter j. gj It is the line reactance between the virtual synchronous converter j and the power grid.

[0097] By combining the power flow equations of the power grid, solving the rotor motion equations, and plotting the p-δ curve, the acceleration area S is obtained. j,inc and maximum deceleration area S j,dec.max Then the transient synchronization stability quantization margin of the virtual synchronous converter j is:

[0098] For a critical converter with a centralized phase-locked loop (PLL) type, the specific process for calculating the transient synchronous stability quantization margin corresponding to the PLL converter can include:

[0099] Obtain the second rotor motion equation and the second power flow equation of the phase-locked loop converter; based on the second rotor motion equation and the second power flow equation, construct the second power angle characteristic curve corresponding to the phase-locked loop converter; based on the second power angle characteristic curve, obtain the second acceleration area and the second maximum deceleration area corresponding to the phase-locked loop converter; based on the second acceleration area and the second maximum deceleration area, obtain the transient synchronous stability quantization margin corresponding to the phase-locked loop converter.

[0100] Specifically, obtaining the second rotor motion equation of the phase-locked loop converter may include: determining the proportional gain, integral gain, total equivalent inductance between the phase-locked loop converter and the grid, direct-axis current component, quadrature-axis total impedance voltage drop component, phase angle difference with grid voltage, angular velocity difference with grid voltage, and grid voltage; and obtaining the second rotor motion equation of the phase-locked loop converter based on the proportional gain, integral gain, total equivalent inductance between the phase-locked loop converter and the grid, direct-axis current component, quadrature-axis total impedance voltage drop component, phase angle difference with grid voltage, angular velocity difference with grid voltage, and grid voltage.

[0101] Therefore, the first rotor motion equation of phase-locked loop converter i is:

[0102]

[0103] Among them, K p K i L represents the proportional and integral coefficients of the phase-locked loop control strategy. ti I is the total equivalent inductance between converter i and the power grid. di To convert converter i to the controlled current source current amplitude I i The d-axis (direct axis) component, U zqi U is the q-axis (quadrature axis) component of the total impedance voltage drop of converter i. g δ represents the voltage amplitude of the power grid. i , Δω i The phase angle difference and angular velocity difference between the phase-locked loop converter i and the grid voltage.

[0104] Solve the power flow equations of the combined power grid, solve the rotor motion equations, plot the u-δ curve (first power angle characteristic curve), and obtain the acceleration area S. i,inc and maximum deceleration area S i,dec.max Then the transient synchronization stability quantization margin of phase-locked loop converter i is:

[0105]

[0106] In the method provided by the embodiments of the present invention, the transient synchronization stability quantization margin of a multi-element heterogeneous parallel system including phase-locked loop type and virtual synchronous machine type converters can be obtained based on the above formulas. Before solving the transient synchronization stability quantization margin of the multi-element heterogeneous parallel system, a critical converter set is first screened according to the physical mechanism, and the transient synchronization stability quantization margin is calculated only for each selected converter, thus saving computational cost.

[0107] The specific implementation processes and derivative methods of the above embodiments are all within the protection scope of this invention.

[0108] and Figure 1 Corresponding to the method described above, embodiments of the present invention also provide a data processing apparatus for processing data... Figure 1 The specific implementation of the method, the data processing device provided in this embodiment of the invention can be applied to computer terminals or various mobile devices, and its structural schematic diagram is shown below. Figure 3 As shown, it specifically includes:

[0109] The first calculation unit 301 is used to calculate the critical coefficient of each converter in the multi-element heterogeneous parallel system when a disturbance is detected in the multi-element heterogeneous parallel system. The critical coefficient is used to reflect the degree to which the converter is on the verge of instability after being disturbed.

[0110] The screening unit 302 is used to select multiple converters from each of the converters to form a critical converter set based on the critical coefficient of each converter.

[0111] The second calculation unit 303 is used to calculate the transient synchronization stability quantization margin corresponding to each converter in the critical converter set.

[0112] Setting unit 304 is used to set the minimum transient synchronization stability quantization margin as the transient synchronization stability quantization margin of the multi-element heterogeneous parallel system.

[0113] In the apparatus provided in this embodiment of the invention, when a disturbance occurs in a multi-element heterogeneous parallel system, the critical coefficients of each converter in the multi-element heterogeneous parallel system under the disturbance state are calculated, and a set of critical converters is selected based on the critical coefficients. The transient synchronization stability quantization margin corresponding to each converter in the set of critical converters is calculated, and the smallest transient synchronization stability quantization margin is selected as the transient synchronization stability quantization margin of the multi-element heterogeneous parallel system.

[0114] Using the apparatus provided in the embodiments of the present invention, the transient synchronization stability quantization margin of a multi-element heterogeneous parallel system can be quickly determined by using the critical coefficient.

[0115] In the apparatus provided in this embodiment of the invention, the first computing unit 301 includes:

[0116] The first determining subunit is used to determine the capacity of each of the converters;

[0117] The first detection subunit is used to detect the electrical distance between each converter and the PCC in real time.

[0118] The second detection subunit is used to detect the load on the interconnect line between each converter and the PCC.

[0119] The first calculation subunit is used to calculate the critical coefficient of each converter based on the converter's capacity, the electrical distance between the converter and the PCC, and the load on the tie line between the converter and the PCC.

[0120] In the apparatus provided in this embodiment of the invention, the screening unit 302 includes:

[0121] The first acquisition subunit is used to acquire pre-set statistical values;

[0122] A judgment subunit is used to determine whether the critical coefficient of each converter is greater than the statistical value;

[0123] The filtering subunit is used to form a critical converter cluster by combining all converters whose critical coefficients are greater than the statistical value if any converter has a critical coefficient greater than the statistical value.

[0124] In the apparatus provided in this embodiment of the invention, each of the converters includes at least one virtual synchronous machine converter and at least one phase-locked loop converter;

[0125] The second calculation unit 303 includes:

[0126] The second calculation subunit is used to obtain, for the virtual synchronous converter in the critical converter cluster, the first rotor motion equation and the first power flow equation of the virtual synchronous converter; based on the first rotor motion equation and the first power flow equation, construct the first power angle characteristic curve corresponding to the virtual synchronous converter; based on the first power angle characteristic curve, obtain the first acceleration area and the first maximum deceleration area corresponding to the virtual synchronous converter; and based on the first acceleration area and the first maximum deceleration area, calculate the transient synchronization stability quantization margin corresponding to the virtual synchronous converter.

[0127] The second calculation subunit is used to obtain the second rotor motion equation and the second power flow equation of the phase-locked loop converter for the critical converter; construct the second power angle characteristic curve corresponding to the phase-locked loop converter based on the second rotor motion equation and the second power flow equation; obtain the second acceleration area and the second maximum deceleration area corresponding to the phase-locked loop converter based on the second power angle characteristic curve; and calculate the transient synchronous stability quantization margin corresponding to the phase-locked loop converter based on the second acceleration area and the second maximum deceleration area.

[0128] In the apparatus provided in this embodiment of the invention, the second computing subunit includes:

[0129] The second determining subunit is used to determine the moment of inertia, damping coefficient, power angle, angular velocity, output voltage, line reactance with the grid, and voltage amplitude of the virtual synchronous converter; based on the moment of inertia, damping coefficient, power angle, angular velocity, output voltage, line reactance with the grid, and voltage amplitude of the virtual synchronous converter, the first rotor motion equation of the virtual synchronous converter is obtained.

[0130] In the apparatus provided in this embodiment of the invention, the third computing subunit includes:

[0131] The third determining subunit is used to determine the proportional coefficient, integral coefficient, total equivalent inductance between the phase-locked loop converter and the grid, direct-axis current component, quadrature-axis total impedance voltage drop component, phase angle difference with grid voltage, angular velocity difference with grid voltage, and grid voltage of the phase-locked loop converter; based on the proportional coefficient, integral coefficient, total equivalent inductance between the phase-locked loop converter and the grid, direct-axis current component, quadrature-axis total impedance voltage drop component, phase angle difference with grid voltage, angular velocity difference with grid voltage, and grid voltage of the phase-locked loop converter, the second rotor motion equation of the phase-locked loop converter is obtained.

[0132] This invention also provides an electronic device, the structural schematic of which is shown below. Figure 4 As shown, it specifically includes a memory 401 and one or more instructions 402, wherein one or more instructions 402 are stored in the memory 401 and configured to be executed by one or more processors 403 to perform the following operations:

[0133] When a disturbance is detected in the multi-element heterogeneous parallel system, the critical coefficient of each converter in the multi-element heterogeneous parallel system is calculated. The critical coefficient is used to reflect the degree to which the converter is on the verge of instability after being disturbed. The multi-element heterogeneous parallel system contains multiple converters of different types.

[0134] Based on the critical coefficient of each converter, multiple converters are selected from each converter to form a critical converter set;

[0135] Calculate the transient synchronization stability quantization margin for each converter in the critical converter set;

[0136] The minimum transient synchronization stability quantization margin is set as the transient synchronization stability quantization margin of the multi-element heterogeneous parallel system.

[0137] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and relevant parts can be referred to the descriptions in the method embodiments. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0138] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both.

[0139] To clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been generally described in terms of functionality above. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0140] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for determining transient synchronization stability quantization margin, characterized in that, include: When a disturbance is detected in the multi-element heterogeneous parallel system, the critical coefficient of each converter in the multi-element heterogeneous parallel system is calculated. The critical coefficient is used to reflect the degree to which the converter is on the verge of instability after being disturbed. The multi-element heterogeneous parallel system includes at least one virtual synchronous machine type converter and at least one phase-locked loop type converter. Based on the critical coefficient of each converter, a critical converter set consisting of several converters is selected from each converter. Calculate the transient synchronization stability quantization margin for each converter in the critical converter set; Set the minimum transient synchronization stability quantization margin as the transient synchronization stability quantization margin of the multi-element heterogeneous parallel system. The calculation of the critical coefficients of each converter in the multi-element heterogeneous parallel system includes: Determine the capacity of each of the converters; Real-time detection of the electrical distance between each converter and the point of common coupling (PCC); Detect the load on the interconnect line between each of the converters and the PCC; For each converter, the criticality factor of the converter is calculated based on the converter's capacity, the electrical distance between the converter and the PCC, and the load on the tie line between the converter and the PCC.

2. The method according to claim 1, characterized in that, The step of selecting multiple converters from among the various converters to form a critical converter set based on the critical coefficient of each converter includes: Retrieve pre-set statistical values; Determine whether the critical coefficient of each converter is greater than the statistical value; If any converter has a critical coefficient greater than the statistical value, then all converters with critical coefficients greater than the statistical value are grouped into a critical converter set.

3. The method according to claim 1, characterized in that, The calculation of the transient synchronization stability quantization margin corresponding to each converter in the critical converter set includes: For the critical converter centralized virtual synchronous machine type converter, the first rotor motion equation and the first power flow equation of the virtual synchronous machine type converter are obtained; based on the first rotor motion equation and the first power flow equation, the first power angle characteristic curve corresponding to the virtual synchronous machine type converter is constructed; based on the first power angle characteristic curve, the first acceleration area and the first maximum deceleration area corresponding to the virtual synchronous machine type converter are obtained; based on the first acceleration area and the first maximum deceleration area, the transient synchronization stability quantization margin corresponding to the virtual synchronous machine type converter is calculated. For the critical converter centralized phase-locked loop converter, the second rotor motion equation and the second power flow equation of the phase-locked loop converter are obtained; based on the second rotor motion equation and the second power flow equation, the second power angle characteristic curve corresponding to the phase-locked loop converter is constructed; based on the second power angle characteristic curve, the second acceleration area and the second maximum deceleration area corresponding to the phase-locked loop converter are obtained; based on the second acceleration area and the second maximum deceleration area, the transient synchronous stability quantization margin corresponding to the phase-locked loop converter is calculated.

4. The method according to claim 3, characterized in that, The process of obtaining the first rotor motion equation of the virtual synchronous converter includes: Determine the moment of inertia, damping coefficient, power angle, angular velocity, output voltage, line reactance with the grid, and voltage amplitude of the virtual synchronous converter; Based on the moment of inertia, damping coefficient, power angle, angular velocity, output voltage, line reactance with the grid, and voltage amplitude of the virtual synchronous converter, the first rotor motion equation of the virtual synchronous converter is obtained.

5. The method according to claim 3, characterized in that, The process of obtaining the second rotor motion equation of the phase-locked loop converter includes: Determine the proportional gain, integral gain, total equivalent inductance with the grid, direct-axis current component, quadrature-axis total impedance voltage drop component, phase angle difference with grid voltage, angular velocity difference with grid voltage, and grid voltage of the phase-locked loop converter. Based on the proportional gain, integral gain, total equivalent inductance with the grid, direct-axis current component, quadrature-axis total impedance voltage drop component, phase angle difference with grid voltage, angular velocity difference with grid voltage, and grid voltage of the phase-locked loop converter, the second rotor motion equation of the phase-locked loop converter is obtained.

6. A device for determining transient synchronization stability quantization margin, characterized in that, include: The first calculation unit is used to calculate the critical coefficient of each converter in the multi-element heterogeneous parallel system when a disturbance is detected. The critical coefficient is used to reflect the degree to which the converter is on the verge of instability after being disturbed. The multi-element heterogeneous parallel system includes at least one virtual synchronous machine type converter and at least one phase-locked loop type converter. A screening unit is used to screen out a critical converter set consisting of several converters from among the various converters based on the critical coefficient of each converter. The second calculation unit is used to calculate the transient synchronization stability quantization margin corresponding to each converter in the critical converter set. The setting unit is used to set the minimum transient synchronization stability quantization margin as the transient synchronization stability quantization margin of the multi-element heterogeneous parallel system. The first computing unit includes: The first determining subunit is used to determine the capacity of each of the converters; The first detection subunit is used to detect the electrical distance between each converter and the PCC in real time. The second detection subunit is used to detect the load on the interconnect line between each converter and the PCC. The first calculation subunit is used to calculate the critical coefficient of each converter based on the converter's capacity, the electrical distance between the converter and the PCC, and the load on the tie line between the converter and the PCC.

7. The apparatus according to claim 6, characterized in that, The filtering unit includes: The first acquisition subunit is used to acquire pre-set statistical values; A judgment subunit is used to determine whether the critical coefficient of each converter is greater than the statistical value; The filtering subunit is used to form a critical converter set if any converter has a critical coefficient greater than the statistical value.

8. The apparatus according to claim 6, characterized in that, The second computing unit includes: The second calculation subunit is used to obtain, for the virtual synchronous converter in the critical converter cluster, the first rotor motion equation and the first power flow equation of the virtual synchronous converter; based on the first rotor motion equation and the first power flow equation, construct the first power angle characteristic curve corresponding to the virtual synchronous converter; based on the first power angle characteristic curve, obtain the first acceleration area and the first maximum deceleration area corresponding to the virtual synchronous converter; and based on the first acceleration area and the first maximum deceleration area, calculate the transient synchronization stability quantization margin corresponding to the virtual synchronous converter. The third calculation subunit is used to obtain the second rotor motion equation and the second power flow equation of the phase-locked loop converter for the critical converter; construct the second power angle characteristic curve corresponding to the phase-locked loop converter based on the second rotor motion equation and the second power flow equation; obtain the second acceleration area and the second maximum deceleration area corresponding to the phase-locked loop converter based on the second power angle characteristic curve; and calculate the transient synchronous stability quantization margin corresponding to the phase-locked loop converter based on the second acceleration area and the second maximum deceleration area.

9. The apparatus according to claim 8, characterized in that, The second computing subunit includes: The second determining subunit is used to determine the moment of inertia, damping coefficient, power angle, angular velocity, output voltage, line reactance with the grid, and voltage amplitude of the virtual synchronous converter; based on the moment of inertia, damping coefficient, power angle, angular velocity, output voltage, line reactance with the grid, and voltage amplitude of the virtual synchronous converter, the first rotor motion equation of the virtual synchronous converter is obtained.

10. The apparatus according to claim 8, characterized in that, The third computing subunit includes: The third determining subunit is used to determine the proportional coefficient, integral coefficient, total equivalent inductance between the phase-locked loop converter and the grid, direct-axis current component, quadrature-axis total impedance voltage drop component, phase angle difference with grid voltage, angular velocity difference with grid voltage, and grid voltage of the phase-locked loop converter; based on the proportional coefficient, integral coefficient, total equivalent inductance between the phase-locked loop converter and the grid, direct-axis current component, quadrature-axis total impedance voltage drop component, phase angle difference with grid voltage, angular velocity difference with grid voltage, and grid voltage of the phase-locked loop converter, the second rotor motion equation of the phase-locked loop converter is obtained.

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