Transient stability improvement control method and system adapted for new energy power system

Abstract

Disclosed are a transient stability improvement control method and system adapted for a new energy power system. The method comprises: constructing and acquiring an external subsystem model corresponding to a new energy power system, and creating first matrix data corresponding to the external subsystem model on the basis of a voltage control method; generating and acquiring second matrix data corresponding to the new energy power system, and in combination with the first matrix data, constructing in real time a transient stability Lyapunov function corresponding to the new energy power system; on the basis of Lyapunov's second method, generating and acquiring first control signal data corresponding to the new energy power system, and controlling and improving a transient stability of the new energy power system in real time according to the first control signal data; and a system corresponding to the method improves the transient stability of the system by means of modifying a voltage instruction value of an inverter.

Description

Control method and system for improving transient stability of new energy power system TECHNICAL FIELD

[0001] The present application belongs to the technical field of new energy power system, and particularly relates to a control method and system for improving transient stability of new energy power system. BACKGROUND

[0002] In recent years, extreme weather has occurred frequently worldwide, and the construction of a low-carbon society is urgent. Increasing the proportion of renewable energy in primary energy is of great significance to reducing carbon emissions of the power system. Unlike fossil fuels, renewable energy represented by wind and solar energy is usually connected to the grid through inverters, not synchronous machines. Therefore, as the proportion of renewable energy increases, synchronous machines will gradually be replaced by inverters. In order to promote mankind to a low-carbon or even zero-carbon society, the power grid needs to have the ability to operate in the form of 100% new energy power system. Since there are great differences between the IBG-dominated 100% new energy power system and the traditional power system dominated by synchronous machines, the connection of IBG will inevitably bring great challenges to the transient stability analysis and control of the system.

[0003] In the synchronous machine-dominated power system, the synchronization between units is achieved by the spontaneous movement of the rotor, which is a natural physical property. However, in the 100% new energy power system, the synchronization between inverters is related to their output electrical quantities, and needs to be ensured by setting a reasonable control strategy. In the synchronous machine-dominated power system, the transient stability of the system can be improved by the strong excitation function of the excitation system. The basic idea of strong excitation control is to increase the terminal voltage as much as possible during and after the fault, thereby providing damping torque for the synchronous machine. By changing the voltage reference value of the inverter, the transient stability of the system can be effectively improved by learning from the control experience of synchronous machine strong excitation. However, for the 100% new energy power system, the bus voltage of the inverter cannot remain constant under severe faults, and the inverter will switch to constant current control.

[0004] Therefore, in view of the above technical problems and defects, there is an urgent need to design and develop a control method and system for improving the transient stability of new energy power system.

[0005] SUMMARY

[0006] In order to overcome the deficiencies and difficulties existing in the prior art, the purpose of the present application is to provide a control method and system for improving the transient stability of new energy power system, so as to improve the transient stability of the system by modifying the voltage instruction value of the inverter.

[0007] The first object of the present application is to provide a method for improving transient stability control suitable for a new energy power system; and the second object of the present application is to provide a system for improving transient stability control suitable for a new energy power system.

[0008] The first object of the present application is achieved by the method comprising the following steps:

[0009] An external subsystem model corresponding to the new energy power system is constructed and obtained, and first matrix data corresponding to the external subsystem model is created based on a voltage control mode; wherein the first matrix data is external subsystem matrix expression data of the new energy power system under an ideal voltage control mode;

[0010] Second matrix data corresponding to the new energy power system is generated and obtained, and a transient stability Lyapunov function corresponding to the new energy power system is constructed in real time in combination with the first matrix data; wherein the second matrix data is actual external subsystem matrix expression data of the new energy power system;

[0011] First control signal data corresponding to the new energy power system is generated and obtained based on the second Lyapunov method, and the transient stability of the new energy power system is controlled in real time according to the first control signal data; wherein the first control signal data is adaptive voltage control signal data of the new energy power system.

[0012] Further, the construction and acquisition of the external subsystem model corresponding to the new energy power system, and the creation of the first matrix data corresponding to the external subsystem model based on the voltage control mode further comprise:

[0013] A grid-connected inverter model corresponding to the new energy power system is constructed, and at least three control loops corresponding to the grid-connected inverter are created; wherein the control loops include a virtual synchronous loop, an inner current loop and an outer current loop;

[0014] Output current function data corresponding to grid-connected inverter output power data is generated and obtained, and a nonlinear system model corresponding to the new energy power system is established based on the output current function data.

[0015] Further, the grid-connected inverter output power data is obtained by the following equation:

[0016] wherein i sdi and i sqi are actual output d-axis and q-axis currents of the inverter i, u sdi and u sqi are dq-axis components of the outlet bus voltage of the inverter i, Rij and X ij are the real and imaginary parts of the element of the impedance matrix in the i-th row and j-th column, respectively, and ij = δ i - δ j represents the phase difference between inverter i and inverter j.

[0017] Further, the external subsystem model corresponding to the new energy power system is constructed and obtained, and a first matrix data corresponding to the external subsystem model is created based on a voltage control mode, and the method further comprises:

[0018] obtaining ideal control signal data corresponding to the external subsystem of the new energy power system and under an ideal voltage control mode; the ideal control signal data is obtained by calculation through the following equation:

[0019] wherein K a and K c are coefficient matrices of the ideal control scheme.

[0020] Further, the relationship of the external subsystem model is specifically as follows:

[0021] wherein ξ is an external subsystem variable of the new energy power system, A, B and C are coefficient matrices, and v is an auxiliary control signal of each inverter in the system.

[0022] Further, the first control signal data corresponding to the new energy power system is generated and obtained based on the Lyapunov second method, and the transient stability of the new energy power system is controlled in real time according to the first control signal data to improve the transient stability of the new energy power system, and the method further comprises:

[0023] the first control signal data is obtained by calculation through the following equation:

[0024] wherein the coefficient matrices and satisfy the Lyapunov stability condition.

[0025] Further, after the first control signal data corresponding to the new energy power system is generated and obtained based on the Lyapunov second method, and the transient stability of the new energy power system is controlled in real time according to the first control signal data to improve the transient stability of the new energy power system, the method further comprises:

[0026] short-circuit fault data corresponding to the new energy power system is generated and obtained, and the transient stability of the new energy power system is verified in real time based on the short-circuit fault data.

[0027] The second object of the present application is achieved in that the system is applied to the transient stability control method, and the system comprises:

[0028] The first data construction unit is configured to construct and acquire an external subsystem model corresponding to the new energy power system, and create first matrix data corresponding to the external subsystem model based on a voltage control mode, wherein the first matrix data is ideal voltage control mode new energy power system external subsystem matrix expression data.

[0029] The second data construction unit is configured to generate and acquire second matrix data corresponding to the new energy power system, and combine the first matrix data to construct a transient stability Lyapunov function corresponding to the new energy power system in real time, wherein the second matrix data is actual new energy power system external subsystem matrix expression data.

[0030] The first data generation unit is configured to generate and acquire first control signal data corresponding to the new energy power system based on the Lyapunov second method, and control the transient stability of the new energy power system in real time according to the first control signal data, wherein the first control signal data is new energy power system adaptive voltage control signal data.

[0031] Further, the grid-forming inverter output power data is calculated by the following equation:

[0032] Wherein, i sdi and i sqi are the actual output d-axis and q-axis currents of the inverter i, u sdi and u sqi are the dq-axis components of the outlet bus voltage of the inverter i, R ij and X ij are the real part and imaginary part of the element in the i-th row and j-th column of the impedance matrix, δ ij = δ i - δ j , representing the phase difference between the inverter i and the inverter j.

[0033] The first data construction unit further comprises:

[0034] The first construction module is configured to construct a grid-forming inverter model corresponding to the new energy power system, and create at least three control loops corresponding to the grid-forming inverter, wherein the control loops include a virtual synchronous loop, an inner current loop and an outer current loop.

[0035] The first data generation module is configured to generate and acquire output current function data corresponding to the output power data of the grid-forming inverter, and establish a nonlinear system model corresponding to the new energy power system based on the output current function data.

[0036] And / or, the first data construction unit further comprises:

[0037] The first data acquisition module is configured to acquire ideal control signal data corresponding to an external subsystem of the new energy power system and under an ideal voltage control mode; the ideal control signal data is obtained by calculation through the following equation:

[0038] Wherein: K a And K c is the coefficient matrix of the ideal control scheme.

[0039] And / or, the first data generation unit further comprises:

[0040] The first calculation module is configured to calculate and generate first control signal data; the first control signal data is obtained by calculation through the following equation:

[0041] Wherein, the coefficient matrix And satisfies the Lyapunov stability condition.

[0042] And / or, the system further comprises:

[0043] The generation verification module is configured to generate and acquire short-circuit fault data corresponding to the new energy power system, and verify the transient stability of the new energy power system in real time based on the short-circuit fault data.

[0044] Further, the relationship of the external subsystem model is specifically as follows:

[0045] Wherein: ξ is the external subsystem variable of the new energy power system, A, B and C are coefficient matrices, and v is the auxiliary control signal of each inverter in the system.

[0046] The application constructs and obtains an external subsystem model corresponding to a new energy power system by a method, and creates first matrix data corresponding to the external subsystem model based on a voltage control mode; the first matrix data is external subsystem matrix expression data of the new energy power system under an ideal voltage control mode; second matrix data corresponding to the new energy power system is generated and obtained, and a transient stability Lyapunov function corresponding to the new energy power system is constructed in real time by combining the first matrix data; the second matrix data is actual external subsystem matrix expression data of the new energy power system; first control signal data corresponding to the new energy power system is generated and obtained based on the Lyapunov second method, and the transient stability of the new energy power system is controlled in real time according to the first control signal data; the first control signal data is adaptive voltage control signal data of the new energy power system; and a system corresponding to the method is used to improve the transient stability of the system by modifying the voltage instruction value of the inverter.

[0047] That is, by the application scheme, the external subsystem of the 100% new energy power system is constructed, and the analytical expression of the inverter voltage control signal is derived based on the Lyapunov theory, so that the transient stability of the system is improved by modifying the voltage instruction value of the inverter. BRIEF DESCRIPTION OF DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0049] Fig. 1 is a schematic diagram of an inverter model of a transient stability improvement control method suitable for a new energy power system;

[0050] Fig. 2 is a schematic diagram of a 100% new energy penetration 11-node system of a transient stability improvement control method suitable for a new energy power system of the application;

[0051] Fig. 3 is a schematic diagram of an instability phenomenon of a system before applying an adaptive voltage control method of a transient stability improvement control method suitable for a new energy power system of the application;

[0052] Fig. 4 is a schematic diagram of a stable result of a system after applying an adaptive voltage control method of a transient stability improvement control method suitable for a new energy power system of the application;

[0053] Fig. 5 is a flowchart of a transient stability improvement control method suitable for a new energy power system of the application;

[0054] Fig. 6 is a schematic diagram of a control system architecture for improving transient stability of a new energy power system according to the present application;

[0055] The purposes, technical solutions and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0056] In order to better understand the purposes, technical solutions and advantages of the present application, the present application will be further described with reference to the embodiments and the accompanying drawings. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the present specification.

[0057] The present application can also be implemented or applied through other different specific examples, and each detail in the present specification can be modified and changed in various ways based on different views and applications without departing from the spirit of the present application.

[0058] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications will also change accordingly.

[0059] In addition, if the embodiments of the present application involve descriptions of "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. Secondly, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions appears to be contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection claimed by the present application.

[0060] The present application will be further described in detail below with reference to the accompanying drawings. As shown in Figs. 1-5, the present application provides a method for improving transient stability of a new energy power system, which comprises the following steps:

[0061] S1, constructing and obtaining an external subsystem model corresponding to the new energy power system, and creating first matrix data corresponding to the external subsystem model based on a voltage control mode; wherein the first matrix data is the matrix expression data of the external subsystem of the new energy power system under the ideal voltage control mode;

[0062] S2, generate and acquire second matrix data corresponding to the new energy power system, and combine the first matrix data to construct a transient stability Lyapunov function corresponding to the new energy power system in real time; wherein the second matrix data is actual new energy power system external subsystem matrix expression data;

[0063] S3, based on the Lyapunov second method, generate and acquire first control signal data corresponding to the new energy power system, and control the transient stability of the new energy power system in real time according to the first control signal data; wherein the first control signal data is new energy power system adaptive voltage control signal data.

[0064] The external subsystem model corresponding to the new energy power system is constructed and acquired, and based on the voltage control mode, first matrix data corresponding to the external subsystem model is created, and the method further comprises:

[0065] S11, construct a grid-connected inverter model corresponding to the new energy power system, and create at least three control loops corresponding to the grid-connected inverter; wherein the control loop includes a virtual synchronous loop, an inner current loop and an outer current loop;

[0066] S12, generate and acquire output current function data corresponding to grid-connected inverter output power data, and based on the output current function data, establish a nonlinear system model corresponding to the new energy power system.

[0067] The grid-connected inverter output power data is calculated by the following equation:

[0068] Wherein, i sdi and i sqi are the actual output d-axis and q-axis currents of the inverter i, u sdi and u sqi are the dq-axis components of the outlet bus voltage of the inverter i, R ij and X ij are the real part and imaginary part of the impedance matrix element in the i-th row and j-th column, δ ij = δ i - δ j , representing the phase difference between inverter i and inverter j.

[0069] The external subsystem model corresponding to the new energy power system is constructed and acquired, and based on the voltage control mode, first matrix data corresponding to the external subsystem model is created, and the method further comprises:

[0070] S13, acquire ideal control signal data corresponding to the external subsystem of the new energy power system and under ideal voltage control mode; the ideal control signal data is obtained by calculation through the following equation:

[0071] Wherein: K a and K c is the coefficient matrix of the ideal control scheme.

[0072] The relationship of the external subsystem model is specifically as follows:

[0073] Wherein: ξ is the external subsystem variable of the new energy power system, A, B and C are coefficient matrixes, and v is the auxiliary control signal of each inverter in the system.

[0074] The first control signal data corresponding to the new energy power system is generated and acquired based on the second Lyapunov method, and the transient stability of the new energy power system is controlled in real time according to the first control signal data, and the method further comprises the following steps of:

[0075] S31, the first control signal data is calculated and generated, and the first control signal data is obtained by calculation through the following equation:

[0076] Wherein, the coefficient matrix and satisfy the Lyapunov stability condition.

[0077] The first control signal data corresponding to the new energy power system is generated and acquired based on the second Lyapunov method, and the transient stability of the new energy power system is controlled in real time according to the first control signal data, and the method further comprises the following steps of:

[0078] S40, generate and acquire short-circuit fault data corresponding to the new energy power system, and verify the transient stability of the new energy power system in real time based on the short-circuit fault data.

[0079] Specifically, in the embodiment of the application, an adaptive voltage control method for 100% new energy power system transient stability improvement is provided, first, the external subsystem model of the 100% new energy power system is obtained through input-output linearization, an ideal voltage control structure with unknown parameters is assumed, and the external subsystem expression is derived under the control structure. According to the difference between the actual 100% new energy power system external subsystem expression and the ideal expression, a Lyapunov function for evaluating the transient stability of the system is constructed, and the adaptive voltage control signal of the 100% new energy power system is obtained.

[0080] The method comprises the following steps: (1) obtaining an external subsystem model of a 100% new energy power system through input-output linearization; (2) deriving an external subsystem expression of the 100% new energy power system under an ideal voltage control mode; (3) constructing a Lyapunov function for evaluating transient stability of the system according to the difference between an actual external subsystem expression of the 100% new energy power system and the ideal expression; and (4) obtaining an adaptive voltage control signal of the 100% new energy power system according to the second Lyapunov method.

[0081] The external subsystem model of the 100% new energy power system is obtained through the following formula in the step (1):

[0082] Wherein, ξ is an external subsystem variable of the 100% new energy power system, A, B and C are coefficient matrices, and v is an auxiliary control signal of each inverter in the system.

[0083] The external subsystem expression of the 100% new energy power system under the ideal voltage control mode is derived through the following formula in the step (2):

[0084] The ideal control signal is:

[0085] The ideal external subsystem is:

[0086] Wherein: K a and K c are coefficient matrices of the ideal control scheme

[0087] The Lyapunov function for evaluating transient stability of the system is constructed through the following formula in the step (3).

[0088] The feasible solution of the controller is:

[0089] The external subsystem under the feasible solution is:

[0090] The Lyapunov function is:

[0091] Wherein, and are coefficient matrices in the feasible solution, ΔK a is the difference between the coefficient matrix K a of the ideal control scheme and the coefficient matrix K of the feasible solution control scheme, ΔK c is the difference between the coefficient matrix K c of the ideal control scheme and the coefficient matrix K where e is the error vector between the feasible solution of the external subsystem variables and the ideal external subsystem variables, P is a positive definite matrix, and Γ a and Γ c are diagonal matrices with all elements greater than 0.

[0092] The adaptive voltage control signal of the 100% new energy power system in step (4) is obtained by the following formula.

[0093] The change rate of the coefficient matrix in the feasible solution is:

[0094] The final control law of the system is:

[0095] where u is the voltage reference value of each inverter in the system.

[0096] That is, in the scheme of the present application, a transient stability control method suitable for a new energy power system is provided, which is specifically as follows:

[0097] (1) Obtain the external subsystem model of the 100% new energy power system through input-output linearization

[0098] The composition of the grid-forming inverter model is shown in FIG. 1, and the controller of the inverter includes three control loops, a virtual synchronous loop, an inner current loop, and an outer loop. In FIG. 1, P s and P sref represent the actual value and the reference value of the active power output by the inverter, respectively, U s and U sref represent the actual value and the reference value of the bus voltage of the inverter, respectively, and u sq represents the q-axis component of the bus voltage.

[0099] The output power of the inverter i can be written as:

[0100] In the formula, i sdi and i sqi are the actual output d-axis and q-axis currents of the inverter i, respectively, u sdi and u sqi are the dq-axis components of the outlet bus voltage of the inverter i, R ij and X ij are the real part and the imaginary part of the element in the i-th row and the j-th column of the impedance matrix, respectively, δ ij = δ i - δ j , representing the phase difference between the inverter i and the inverter j.

[0101] According to the above formula, the output power of the inverter can be written as a function of its output current, and the model of the 100% new energy power system can be written into the standard form of a nonlinear system:

[0102] In the formula, x is a vector composed of state variables, u is a vector composed of input signals, y is a vector composed of output signals, f is a vector of system functions, g is a vector of input functions, and h is a vector of output functions. The expressions of each term are as follows:

[0103] Where x i is a vector composed of state variables of the i-th unit, Δδ i represents the power angle change of the i-th inverter, Δω i represents the speed change of the i-th inverter, M pUsi and M iUsi are state variables of the d-axis outer loop controller proportional and integral elements of the inverter, M puqi and M iuqi are state variables of the q-axis outer loop controller proportional and integral elements of the inverter, f i is a vector composed of system functions of the i-th unit, ω0 is the speed reference value, H mi is the rotor inertia time constant of the i-th inverter, D i is the damping coefficient of the i-th inverter, ΔP si is the change of the output power of the inverter i, k pUsi and k puqi are the d-axis and q-axis outer loop controller proportional coefficients of the inverter i, T pUsi and T puqi are the d-axis and q-axis outer loop controller proportional element time constants of the inverter i, U si is the bus voltage amplitude of the inverter i, u sqi is the q-axis component of the bus voltage of the inverter i, g i is the input function vector of the inverter i, and U srefi is the voltage reference value of the inverter.

[0104] Since the first or second order Lie derivative of any output y i is 0, i.e.:

[0105] In the formula, L g(:,j) L f is the first order Lie derivative, and L g(:,j) L2 f is the second order Lie derivative.

[0106] Therefore, by using the input-output linearization method, the external subsystem of a 100% renewable energy power system can be obtained as follows:

[0107] in:

[0108] (2) Derive the expression of the external subsystem of a 100% new energy power system under ideal voltage control mode.

[0109] During the transient process, the voltage reference value U of each inverter is changed. sref This can effectively improve the synchronization stability of a 100% new energy power system. In other words, it achieves the effect of stabilizing the external subsystem variable ξ by designing u. Let: u=A′ξ+B′v (12)

[0110] In the formula, A' and B' are both coefficient matrices, v is the new input signal, and the expression for ξ is: ξ=[ξ1;ξ2;ξ3] (13)

[0111] The external subsystem can then be rewritten as:

[0112] The expressions for each matrix are:

[0113] (3) Based on the difference between the external subsystem expression of the actual 100% new energy power system and the ideal expression, a Lyapunov function for evaluating the transient stability of the system is constructed.

[0114] To ensure the transient stability of a 100% renewable energy power system, the control objective is set as: lim t→∞ ξ(t)-ξ0=0 (16)

[0115] In the formula, ξ0 is the initial value of the variable.

[0116] Assume there exists an ideal control scheme:

[0117] In the formula, K a and K c This is the coefficient matrix of the ideal control scheme.

[0118] Substituting the ideal control scheme into the external subsystem yields:

[0119] However, in reality, the matrix coefficients K in the ideal control scheme are unknown. a and Kc How should it be configured? Therefore, we first need to establish a feasible solution for the controller:

[0120] In the formula, and This is the coefficient matrix in the feasible solution.

[0121] Substituting the feasible solution into the external subsystem yields:

[0122] Define a Lyapunov function:

[0123] Among them, Γ a and Γ c Let ΔK be a diagonal matrix with all elements greater than 0. a and ΔK c Let t be the difference matrix between the coefficient matrix of the ideal control scheme and the coefficient matrix of the feasible solution, tr(·) represents the trace of the matrix, and the expression for e is: e=ξ(t)-ξ0 (22)

[0124] P is a positive definite matrix and satisfies the following equation:

[0125] In the formula, A ref Let Q be the ideal system matrix under the ideal control scheme, and let Q be the positive definite matrix, which is taken as the identity matrix here.

[0126] (4) Obtain the adaptive voltage control signal for the 100% new energy power system according to Lyapunov's second method.

[0127] Calculating the time derivative of the Lyapunov function V yields:

[0128] Substituting the expression for e into the above equation, we get:

[0129] Furthermore, based on the properties of the matrix trace, we know that:

[0130] Substituting the above equation into the derivative of the Lyapunov function V with respect to time, and further simplifying, we get:

[0131] To ensure that the derivative of the Lyapunov function V is negative definite, the Lyapunov stability condition is obtained as follows:

[0132] Substituting the above equation into the time derivative of the Lyapunov function V, we get:

[0133] If and only if e = 0

[0134] Therefore, when the rates of change of the two coefficient matrices in the feasible solution of the controller satisfy the Lyapunov stability condition, the Lyapunov function V can be guaranteed to be positive definite, and With negative definiteness, the system is stable, and the final control law of the system is:

[0135] Wherein, the coefficient matrix and The Lyapunov stability condition must be met.

[0136] (5) Verification by Example: Verification was conducted in a modified IEEE 11-node system. In this system, the original four synchronous machines were replaced by inverters while maintaining the original output. The long tie line between the two zones was doubled. The topology of the modified IEEE 11-node system is shown in Figure 2. Before applying the adaptive voltage control method, a short-circuit fault was applied at bus 7 for 100ms, and the response curves of each inverter were obtained as shown in Figure 3. As can be seen from Figure 3, the system has experienced transient instability, manifested by a continuous increase in the relative phase angle between the two zones, which cannot return to the steady-state value. After applying the adaptive voltage control method, the same fault was applied, and the response curves of each inverter were obtained as shown in Figure 4. Comparing Figures 3 and 4, it can be seen that the adaptive voltage control method can effectively improve the transient stability of the 100% new energy power system.

[0137] To achieve the above objectives, the present invention also provides a transient stability enhancement control system suitable for new energy power systems, as shown in Figure 6. The system is applied to the aforementioned transient stability enhancement control method and includes:

[0138] The first data construction unit is used to construct and obtain an external subsystem model corresponding to the new energy power system, and based on the voltage control method, create a first matrix data corresponding to the external subsystem model; wherein, the first matrix data is the matrix expression data of the external subsystem of the new energy power system under the ideal voltage control method;

[0139] The second data construction unit is used to generate and acquire the second matrix data corresponding to the new energy power system, and combine it with the first matrix data to construct the transient stability Lyapunov function corresponding to the new energy power system in real time; wherein, the second matrix data is the matrix expression data of the external subsystem of the actual new energy power system;

[0140] The first data generation unit is used to generate and acquire first control signal data corresponding to the new energy power system based on the Lyapunov second method, and to control and improve the transient stability of the new energy power system in real time according to the first control signal data; wherein, the first control signal data is adaptive voltage control signal data of the new energy power system.

[0141] The output power data of the grid-type inverter is obtained by calculation using the following equation:

[0142] Among them, i sdi and i sqi These represent the actual output d-axis and q-axis currents of inverter i, respectively. sdi and u sqi These are the dq-axis components of the inverter i output bus voltage, R ij and X ij δ represents the real and imaginary parts of the element in the i-th row and j-th column of the impedance matrix, respectively. ij =δ i -δ j , representing the phase difference between inverter i and inverter j;

[0143] The first data construction unit further includes:

[0144] The first construction module is used to construct a grid-type inverter model corresponding to the new energy power system and create at least three control loops corresponding to the grid-type inverter; wherein, the control loop includes a virtual synchronization loop, an inner current loop, and an outer current loop;

[0145] The first data generation module is used to generate and acquire output current function data corresponding to the output power data of the grid-type inverter, and to establish a nonlinear system model corresponding to the new energy power system based on the output current function data.

[0146] And / or, the first data construction unit further includes:

[0147] The first data acquisition module is used to acquire ideal control signal data corresponding to the external subsystem of the new energy power system and under ideal voltage control mode; the ideal control signal data is obtained by calculation through the following equation:

[0148] Where: K a and K c The coefficient moments of the ideal control scheme;

[0149] And / or, the first data generation unit further includes:

[0150] A first calculation module is used to calculate and generate first control signal data; the first control signal data is obtained by calculation using the following equation:

[0151] Wherein, the coefficient matrix and Satisfies the Lyapunov stability condition;

[0152] And / or, the system further includes:

[0153] A generation and verification module is used to generate and acquire short-circuit fault data corresponding to the new energy power system, and to verify the transient stability of the new energy power system in real time based on the short-circuit fault data.

[0154] The specific relational formula of the external subsystem model is as follows:

[0155] Where: ξ is the external subsystem variable of the new energy power system, A, B and C are coefficient matrices, and v is the auxiliary control signal of each inverter in the system.

[0156] In the system solution embodiment of the present invention, the specific details of the method steps involved in the transient stability control applicable to new energy power systems have been described above. That is to say, the functional modules in the system are used to implement the steps or sub-steps in the above method embodiment, which will not be repeated here.

[0157] This invention constructs and obtains an external subsystem model corresponding to a new energy power system through a method, and creates first matrix data corresponding to the external subsystem model based on a voltage control method; wherein, the first matrix data is the matrix expression data of the external subsystem of the new energy power system under an ideal voltage control method; generates and obtains second matrix data corresponding to the new energy power system, and combines the first matrix data to construct a transient stability Lyapunov function corresponding to the new energy power system in real time; wherein, the second matrix data is the matrix expression data of the actual external subsystem of the new energy power system; generates and obtains first control signal data corresponding to the new energy power system based on a second Lyapunov method, and improves the transient stability of the new energy power system in real time according to the first control signal data; wherein, the first control signal data is the adaptive voltage control signal data of the new energy power system; and a system corresponding to the method, which improves the transient stability of the system by modifying the voltage command value of the inverter.

[0158] In other words, the present invention constructs an external subsystem for a 100% new energy power system and derives an analytical expression for the inverter voltage control signal based on Lyapunov theory, thereby improving the transient stability of the system by modifying the inverter's voltage command value.

[0159] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for improving transient stability control applicable to new energy power systems, characterized in that, The method includes the following steps: An external subsystem model corresponding to the new energy power system is constructed and obtained, and a first matrix data corresponding to the external subsystem model is created based on the voltage control method; wherein, the first matrix data is the matrix expression data of the external subsystem of the new energy power system under the ideal voltage control method; Generate and acquire second matrix data corresponding to the new energy power system, and combine it with the first matrix data to construct a transient stability Lyapunov function corresponding to the new energy power system in real time; wherein, the second matrix data is the matrix representation data of the external subsystem of the actual new energy power system; Based on Lyapunov's second method, a first control signal data corresponding to the new energy power system is generated and acquired, and the transient stability of the new energy power system is improved in real time according to the first control signal data; wherein, the first control signal data is the adaptive voltage control signal data of the new energy power system.

2. The method for improving transient stability control applicable to new energy power systems according to claim 1, characterized in that, The process of constructing and obtaining an external subsystem model corresponding to the new energy power system, and creating first matrix data corresponding to the external subsystem model based on the voltage control method, further includes: Construct a grid-type inverter model corresponding to the new energy power system, and create at least three control loops corresponding to the grid-type inverter; wherein, the control loop includes a virtual synchronization loop, an inner current loop, and an outer current loop; The system generates and acquires output current function data corresponding to the output power data of the grid-connected inverter, and establishes a nonlinear system model corresponding to the new energy power system based on the output current function data.

3. The method for improving transient stability control applicable to new energy power systems according to claim 2, characterized in that, The output power data of the grid-type inverter is obtained by calculation using the following equation: Among them, i sdi and i sqi These represent the actual output d-axis and q-axis currents of inverter i, respectively. sdi and u sqi These are the dq-axis components of the inverter i output bus voltage, R ij and X ij δ represents the real and imaginary parts of the element in the i-th row and j-th column of the impedance matrix, respectively. ij =δ i -δ j , representing the phase difference between inverter i and inverter j.

4. A method for improving transient stability control applicable to new energy power systems according to claim 1 or 2, characterized in that, The process of constructing and obtaining an external subsystem model corresponding to the new energy power system, and creating first matrix data corresponding to the external subsystem model based on the voltage control method, further includes: Obtain ideal control signal data corresponding to the external subsystem of the new energy power system under ideal voltage control mode; the ideal control signal data is obtained by calculation using the following equation: Where: K a and K c The coefficient moments are for the ideal control scheme.

5. The method for improving transient stability control applicable to new energy power systems according to claim 4, characterized in that, The specific relational formula of the external subsystem model is as follows: Where: ξ is the external subsystem variable of the new energy power system, A, B and C are coefficient matrices, and v is the auxiliary control signal of each inverter in the system.

6. The method for improving transient stability control applicable to new energy power systems according to claim 1, characterized in that, The method based on Lyapunov's second method, which generates and acquires first control signal data corresponding to the new energy power system, and improves the transient stability of the new energy power system in real time based on the first control signal data, further includes: The first control signal data is calculated and obtained by the following equation: Wherein, the coefficient matrix and It satisfies the Lyapunov stability condition.

7. A method for improving transient stability control applicable to new energy power systems according to claim 1 or 6, characterized in that, After generating and acquiring first control signal data corresponding to the new energy power system based on the Lyapunov second method, and improving the transient stability of the new energy power system in real time according to the first control signal data, the method further includes: Generate and acquire short-circuit fault data corresponding to the new energy power system, and based on the short-circuit fault data, perform real-time... Verify the transient stability of the new energy power system.

8. A transient stability improvement control system suitable for new energy power systems, characterized in that, The system is applied to the transient stability improvement control method as described in any one of claims 1-7, and the system comprises: The first data construction unit is used to construct and obtain an external subsystem model corresponding to the new energy power system, and based on the voltage control method, create a first matrix data corresponding to the external subsystem model; wherein, the first matrix data is the matrix expression data of the external subsystem of the new energy power system under the ideal voltage control method; The second data construction unit is used to generate and acquire the second matrix data corresponding to the new energy power system, and combine it with the first matrix data to construct the transient stability Lyapunov function corresponding to the new energy power system in real time; wherein, the second matrix data is the matrix expression data of the external subsystem of the actual new energy power system; The first data generation unit is used to generate and acquire first control signal data corresponding to the new energy power system based on the Lyapunov second method, and to control and improve the transient stability of the new energy power system in real time according to the first control signal data; wherein, the first control signal data is adaptive voltage control signal data of the new energy power system.

9. A transient stability improvement control system for new energy power systems according to claim 8, characterized in that, The output power data of the grid-type inverter is obtained by calculation using the following equation: Among them, i sdi and i sqi These represent the actual output d-axis and q-axis currents of inverter i, respectively. sdi and u sqi These are the dq-axis components of the inverter i output bus voltage, R ij and X ij δ represents the real and imaginary parts of the element in the i-th row and j-th column of the impedance matrix, respectively. ij =δ i -δ j , representing the phase difference between inverter i and inverter j; The first data construction unit further includes: The first construction module is used to construct a grid-type inverter model corresponding to the new energy power system and create at least three control loops corresponding to the grid-type inverter; wherein, the control loop includes a virtual synchronization loop, an inner current loop, and an outer current loop; The first data generation module is used to generate and acquire output current function data corresponding to the output power data of the grid-type inverter, and to establish a nonlinear system model corresponding to the new energy power system based on the output current function data. And / or, the first data construction unit further includes: The first data acquisition module is used to acquire ideal control signal data corresponding to the external subsystem of the new energy power system and under ideal voltage control mode; the ideal control signal data is obtained by calculation through the following equation: Where: K a and K c The coefficient moments of the ideal control scheme; And / or, the first data generation unit further includes: A first calculation module is used to calculate and generate first control signal data; the first control signal data is obtained by calculation using the following equation: Wherein, the coefficient matrix and Satisfies the Lyapunov stability condition; And / or, the system further includes: A generation and verification module is used to generate and acquire short-circuit fault data corresponding to the new energy power system, and to verify the transient stability of the new energy power system in real time based on the short-circuit fault data.

10. A transient stability enhancement control system for new energy power systems according to claim 8 or 9, characterized in that, The specific relational formula of the external subsystem model is as follows: Where: ξ is the external subsystem variable of the new energy power system, A, B and C are coefficient matrices, and v is the auxiliary control signal of each inverter in the system.

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