Photovoltaic power station damping support reserve capacity optimization method of synchronous generator

Abstract

The invention provides a photovoltaic power station damping support reserve capacity optimization method for a synchronous generator, and belongs to the technical field of power system and new energy grid-connected control, and the method comprises the steps: 1, obtaining preset types of parameters of the synchronous generator and a photovoltaic power station, and constructing a mathematical model of a synchronous generator-photovoltaic power station combined system; 2, determining a state-space equation based on the mathematical model of the synchronous generator-photovoltaic power station combined system and a preset analysis method; 3, solving the state-space equation, and further determining a weak damped oscillation mode of the synchronous generator-photovoltaic power station combined system; 4, determining and executing a damping support control strategy of the photovoltaic power station; and 5, constructing an optimization objective function of the photovoltaic power station, determining constraint conditions, solving the optimization objective function of the photovoltaic power station based on a preset algorithm, and determining a capacity configuration scheme. And the oscillation suppression capability and the operation stability of the system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems and new energy grid-connected control, and particularly relates to a method for optimizing the damping support reserve capacity of a photovoltaic power station with a synchronous generator. Background Art

[0002] With the continuous expansion of the scale of new energy access, the proportion of photovoltaic power stations in the power system has gradually increased. However, their weak inertia and weak damping characteristics make the system more prone to oscillations when disturbances occur, threatening the safety and stability of power grid operation.

[0003] Most of the existing damping control methods are designed for a single synchronous generator or photovoltaic power station. For example, oscillation suppression is achieved by adjusting the inverter control parameters of the photovoltaic power station or the excitation control of the synchronous generator. However, these solutions do not fully consider the dynamic characteristics under the synergistic action of the photovoltaic power station and the synchronous generator, and it is difficult to achieve efficient damping support in a complex power grid environment. Based on the above existing technical solutions, there are the following defects: it is impossible to accurately identify and control the weak damping oscillation mode of the synchronous generator-photovoltaic power station combined system, and the damping support control effect is limited; the capacity configuration scheme lacks the ability of global optimization, resulting in low efficiency of the reserve capacity allocation of the photovoltaic power station.

[0004] Therefore, the present invention provides a method for optimizing the damping support reserve capacity of a photovoltaic power station with a synchronous generator. Summary of the Invention

[0005] The present invention provides a method for optimizing the damping support reserve capacity of a photovoltaic power station with a synchronous generator, which is used to optimize the damping support control strategy and reserve capacity configuration of the photovoltaic power station by constructing a mathematical model of the synchronous generator-photovoltaic power station combined system, combining the solution of the state space equation and the analysis of the weak damping oscillation mode, improving the system oscillation suppression ability and operation stability, enhancing the efficiency and accuracy of the capacity configuration of the photovoltaic power station, and being applicable to the scenario of large-scale new energy grid connection.

[0006] The present invention provides a method for optimizing the damping support reserve capacity of a photovoltaic power station with a synchronous generator, including:

[0007] Step 1: Obtain the parameters of a preset type of the synchronous generator and the photovoltaic power station, and construct a mathematical model of the synchronous generator-photovoltaic power station combined system based on the parameters of the preset type;

[0008] Step 2: Determine the state space equation based on the mathematical model of the synchronous generator-photovoltaic power station combined system and a preset analysis method;

[0009] Step 3: Solve the state space equation to further determine the weak damping oscillation mode of the synchronous generator-photovoltaic power station combined system;

[0010] Step 4: Determine the damping support control strategy for the PV power station based on the weakly damped oscillation modes of the synchronous generator-PV power station combined system and execute it;

[0011] Step 5: Construct an optimization objective function for the PV power station based on a preset type of objective function, determine the constraint conditions based on the parameters of the synchronous generator and the PV power station after executing the damping support control strategy for the PV power station, and then solve the optimization objective function of the PV power station based on a preset algorithm to determine the capacity configuration plan.

[0012] The present invention provides an optimization method for the damping support reserve capacity of a PV power station for a synchronous generator, and the weakly damped oscillation modes include: low-frequency electromechanical oscillation modes, sub-synchronous oscillation modes, and oscillation modes caused by the output power fluctuation of the PV power station.

[0013] The present invention provides an optimization method for the damping support reserve capacity of a PV power station for a synchronous generator, and obtains preset types of parameters of the synchronous generator and the PV power station, and constructs a mathematical model of the synchronous generator-PV power station combined system based on the preset types of parameters, including:

[0014] Collect the first preset type of parameters of the synchronous generator and the second preset type of parameters of the PV power station based on a preset distributed multi-source heterogeneous data acquisition system;

[0015] Perform preprocessing on the first preset type of parameters of the synchronous generator and the second preset type of parameters of the PV power station based on a preset preprocessing method;

[0016] Perform data dimensionality reduction and feature extraction on the first preset type of parameters and the second preset type of parameters of the PV power station based on a preset analysis method, and construct a mathematical model of the synchronous generator-PV power station combined system based on the extracted features.

[0017] The present invention provides an optimization method for the damping support reserve capacity of a PV power station for a synchronous generator,

[0018] The first preset type of parameters includes: mechanical parameters, electromagnetic parameters, and measured parameters of the air-gap magnetic density distribution under different working conditions;

[0019] The second preset type of parameters includes: three-dimensional surface parameters of the photoelectric conversion efficiency of the PV module with respect to light intensity, angle, and temperature, switching frequency response characteristic parameters and loss spectrum parameters of the inverter, charge and discharge rate curve parameters of the energy storage system, and capacity attenuation model parameters.

[0020] The present invention provides an optimization method for the damping support reserve capacity of a PV power station for a synchronous generator, and determines the state space equation based on the mathematical model of the synchronous generator-PV power station combined system and a preset analysis method, including:

[0021] Based on the preset analysis method, the mathematical model of the synchronous generator-photovoltaic power station combined system is dynamically decomposed to obtain the fast and slow subsystems, and then the state equations of the fast and slow subsystems are constructed respectively;

[0022] The state equations of the fast and slow subsystems are combined based on the correlation matrix to determine the state space equation.

[0023] The present invention provides a method for optimizing the reserve capacity of a damping support of a photovoltaic power station of a synchronous generator. Based on a preset analysis method, a mathematical model of a synchronous generator-photovoltaic power station combined system is dynamically decomposed to obtain fast and slow subsystems, including:

[0024] Based on the matrix of the synchronous generator-photovoltaic power station combined system, the characteristic value of the synchronous generator-photovoltaic power station combined system is determined to be λ i (∈):

[0025]

[0026] in, is the dominant eigenvalue when ∈→0;

[0027] Based on the singular perturbation principle, the time scale of fast and slow dynamics in the synchronous generator-photovoltaic power station combined system is analyzed, and then the discrimination formula of the fast and slow subsystems is determined:

[0028] and and

[0029] in, is the zero-order eigenvalue of the matrix of the synchronous generator-photovoltaic power station combined system, The first-order disturbance term of the synchronous generator-photovoltaic power station combined system, m, n, p, q are parameters adjusted according to the specific system dynamic level, is the zero-order real part of the eigenvalue of the synchronous generator-photovoltaic power station combined system, O(∈ q )express The growth or decay rate is ∈ q The rate at which the

[0030] The present invention provides a method for optimizing the reserve capacity of a damping support of a photovoltaic power station of a synchronous generator, solving a state space equation, and then determining a weakly damped oscillation mode of a synchronous generator-photovoltaic power station combined system, including:

[0031] Arrange the state-space equations into a standard form, and then solve the state-space equations based on a preset matrix eigenvalue solver and a modal participation factor analysis algorithm;

[0032] Furthermore, several eigenvalues of the synchronous generator - photovoltaic power station combined system are determined;

[0033] Based on each eigenvalue and the modal participation factor algorithm, the contribution degree of each eigenvalue to the corresponding oscillation mode is determined;

[0034] Based on all eigenvalues and the contribution degree of each eigenvalue to the corresponding oscillation mode, the weakly damped oscillation mode is determined.

[0035] The present invention provides a method for optimizing the damping support reserve capacity of a photovoltaic power station of a synchronous generator. Based on the weakly damped oscillation mode of the synchronous generator - photovoltaic power station combined system, the damping support control strategy of the photovoltaic power station is determined and executed, including:

[0036] Based on the weakly damped oscillation mode and the parameters of the second preset type, a multi - dimensional control vector is constructed;

[0037] Based on the preset model predictive control rolling optimization algorithm and the real - time state of the synchronous generator - photovoltaic power station combined system, the oscillation trend prediction data is determined;

[0038] Based on the oscillation trend prediction data, the implementation algorithm of the preset control strategy, and the preset optimization algorithm, the controller parameters are dynamically tuned, and then the damping support control strategy of the photovoltaic power station is determined and executed.

[0039] Compared with the prior art, the beneficial effects of the present application are as follows:

[0040] By constructing a mathematical model of the synchronous generator - photovoltaic power station combined system, combining the solution of the state - space equation and the analysis of the weakly damped oscillation mode, the damping support control strategy and the reserve capacity configuration of the photovoltaic power station are optimized, the system oscillation suppression ability and operation stability are improved, the efficiency and accuracy of the photovoltaic power station capacity configuration are enhanced, and it is applicable to the scenario of large - scale grid connection of new energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0042] Figure 1 It is a schematic flow chart of a method for optimizing the damping support reserve capacity of a photovoltaic power station of a synchronous generator provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Apparently, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0044] Embodiment 1:

[0045] The embodiment of the present invention provides an optimization method for the damping support reserve capacity of a photovoltaic power station of a synchronous generator, as Figure 1 shown, including:

[0046] Step 1: Obtain the parameters of the preset type of the synchronous generator and the photovoltaic power station, and construct a mathematical model of the synchronous generator-photovoltaic power station combined system based on the parameters of the preset type;

[0047] Step 2: Determine the state space equation based on the mathematical model of the synchronous generator-photovoltaic power station combined system and the preset analysis method;

[0048] Step 3: Solve the state space equation, and then determine the weak damping oscillation mode of the synchronous generator-photovoltaic power station combined system;

[0049] Step 4: Determine the damping support control strategy of the photovoltaic power station based on the weak damping oscillation mode of the synchronous generator-photovoltaic power station combined system and execute it;

[0050] Step 5: Construct an optimization objective function of the photovoltaic power station based on the objective function of the preset type, determine the constraint conditions based on the parameters of the synchronous generator and the photovoltaic power station after executing the damping support control strategy of the photovoltaic power station, and then solve the optimization objective function of the photovoltaic power station based on the preset algorithm and determine the capacity configuration plan.

[0051] In this embodiment, the mathematical model of the synchronous generator-photovoltaic power station combined system is realized through parameter acquisition, feature extraction, and dynamic modeling based on the physical and electrical characteristics of both. This model includes the following content: Synchronous generator part: Mechanical part: Moment of inertia equation, used to describe the dynamic characteristics of the generator rotor. Electromagnetic part: Based on the excitation and armature voltage equations of the synchronous generator, describe the dynamic relationship between magnetic field changes and current. Photovoltaic power station part: Photovoltaic module: A model that describes the change of photovoltaic conversion efficiency with light intensity, angle, and temperature. Inverter dynamic model: Use small-signal modeling to describe the dynamic behavior of the inverter, including output voltage and current control characteristics. Combined system model. For example, assume a system composed of a 100MW synchronous generator and a 50MW photovoltaic power station: Synchronous generator: J = 5J = 5kg·m 2, T′ = 0.2T′ = 0.2 s, Xd = 1.2Xd = 1.2 pu, and the initial mechanical power Tm = 0.8Tm = 0.8 pu. Photovoltaic power station: module efficiency η = 0.18η = 0.18, module area A = 104A = 104 m 2 , the initial light intensity G = 800G = 800 W / m 2 , the combined mathematical model of the system will combine the dynamic characteristics of both for subsequent state - space modeling and optimal control.

[0052] In this embodiment, the damping support control strategy of the photovoltaic power station effectively suppresses system oscillations by dynamically adjusting its output power and voltage. It specifically includes the following:

[0053] Construction of the multi - dimensional control vector: Construct control variables, namely active power, reactive power, and voltage reference values. Based on the weakly damped oscillation mode, adjust parameters in real - time to counter oscillations. Oscillation trend prediction: Use model predictive control (MPC) to predict the system oscillation trend through a rolling optimization algorithm, and perform real - time analysis on the oscillation frequency and amplitude to dynamically adjust the control variables. Implementation of the control algorithm: Frequency support control: When the system frequency decreases, the photovoltaic power station increases its active power output, simulating the characteristics of a generator through virtual inertia. Damping control: Use inverter control to reduce the voltage fluctuation amplitude and improve the grid stability by adjusting the reactive power support.

[0054] The beneficial effects of the above - mentioned technical solution are as follows: By constructing the combined mathematical model of the synchronous generator - photovoltaic power station, combining the solution of the state - space equation and the analysis of the weakly damped oscillation mode, optimizing the damping support control strategy and reserve capacity configuration of the photovoltaic power station, the system oscillation suppression ability and operation stability are improved, the efficiency and accuracy of the photovoltaic power station capacity configuration are enhanced, and it is applicable to the scenario of large - scale grid connection of new energy.

[0055] Embodiment 2:

[0056] The embodiment of the present invention provides an optimization method for the damping support reserve capacity of a photovoltaic power station of a synchronous generator, with weakly damped oscillation modes, including: low - frequency electromechanical oscillation modes, subsynchronous oscillation modes, and oscillation modes caused by the output power fluctuation of the photovoltaic power station.

[0057] In this embodiment, the low-frequency electromechanical oscillation mode results from the interaction between the electromechanical oscillation characteristics of the synchronous generator rotor and the system. For example, when the system is subjected to small disturbances, the generator rotor starts to perform periodic oscillations around the synchronous speed due to inertia. In terms of electrical quantities, this is reflected as low-frequency oscillations in the terminal voltage, current, and output power of the generator. Its oscillation frequency is generally between 0.1 Hz and 2 Hz, which is relatively common in some large power systems. For example, in a certain regional power grid connected to multiple large-capacity synchronous generators and a large-scale photovoltaic power station, when the load suddenly changes, some generator rotors are subjected to torque shocks, triggering low-frequency electromechanical oscillations around 0.5 Hz. This is manifested as the active power of the generator fluctuating up and down within a certain range near the rated value, and at the same time, the terminal voltage of the generator also shows corresponding low-frequency fluctuations. If not effectively suppressed, it may lead to system instability and affect the continuity of power supply;

[0058] In this embodiment, the subsynchronous oscillation mode is related to devices such as series capacitor compensation and high-voltage direct current transmission (HVDC) in the power system, especially when interacting with synchronous generators, it is prone to be triggered. When the operating conditions of the system change, such as the rapid adjustment of the power of the HVDC system or the change of the series capacitor compensation degree, it will excite electrical oscillations in the subsynchronous frequency range. Its frequency is usually lower than the synchronous frequency (50 Hz or 60 Hz) but higher than the low-frequency electromechanical oscillation frequency, generally in the range of 10 Hz - 50 Hz. Taking a transmission line with series capacitor compensation to improve transmission capacity as an example, when the compensation degree is set improperly and is close to coupling with the torsional vibration frequency of the shafting of the connected synchronous generator, subsynchronous oscillations may be triggered. At this time, the generator shafting will bear alternating stress, and in severe cases, even shafting fatigue damage may occur. At the same time, in terms of electrical quantities, it is manifested as large oscillations in the line current and bus voltage at subsynchronous frequencies, threatening the safe operation of the system;

[0059] In this embodiment, the oscillation mode caused by the output power fluctuation of the photovoltaic power station is because the power generation characteristics of the photovoltaic power station highly depend on natural factors such as light intensity and temperature. The rapid changes of these factors will lead to unstable output power of the photovoltaic power station. When this instability interacts with the inherent frequency characteristics of the power grid or synchronous generator, oscillations may be triggered. For example, when clouds quickly pass over the photovoltaic power station, the light intensity changes sharply in a short time, and the output power of the photovoltaic power station fluctuates greatly accordingly. If the equivalent impedance characteristics of the power grid and the excitation regulation system of the synchronous generator cannot adapt to this change in time, oscillations with a frequency between 0.5 Hz and 5 Hz may be induced. Specifically, it is manifested as increased voltage fluctuations at the power grid connection point and frequent reactive power regulation of the synchronous generator to try to maintain the stability of the terminal voltage. The entire system is at the edge of unstable oscillation and requires timely damping support control to quell the oscillations.

[0060] The beneficial effects of the above technical solution are as follows: By analyzing the oscillation modes caused by low-frequency electromechanical oscillations, subsynchronous oscillations, and the output fluctuations of photovoltaic power plants, accurately identifying the weak damping oscillation characteristics of the system, proposing targeted damping support control strategies, effectively suppressing system oscillations, enhancing the stability and dynamic response ability of the power grid, optimizing the reserve capacity configuration of photovoltaic power plants, improving the utilization efficiency of new energy, and being applicable to stable operation in complex power grid environments.

[0061] Embodiment 3:

[0062] The embodiment of the present invention provides a method for optimizing the damping support reserve capacity of a photovoltaic power plant of a synchronous generator, obtaining parameters of a preset type of the synchronous generator and the photovoltaic power plant, and constructing a mathematical model of a synchronous generator-photovoltaic power plant combined system based on the parameters of the preset type, including:

[0063] Based on a preset distributed multi-source heterogeneous data acquisition system, acquiring the first preset type of parameters of the synchronous generator and the second preset type of parameters of the photovoltaic power plant;

[0064] Based on a preset preprocessing method, preprocessing the first preset type of parameters of the synchronous generator and the second preset type of parameters of the photovoltaic power plant;

[0065] Based on a preset analysis method, performing data dimensionality reduction and feature extraction on the first preset type of parameters and the second preset type of parameters of the photovoltaic power plant, and constructing a mathematical model of the synchronous generator-photovoltaic power plant combined system based on the extracted features.

[0066] In this embodiment, preprocessing the first preset type of parameters of the synchronous generator and the second preset type of parameters of the photovoltaic power plant based on a preset preprocessing method uses big data cleaning technology, double-checking based on physical rules and statistical laws, removing abnormal data caused by sensor failures and communication interferences, and then filling in key missing data through the radial basis function neural network interpolation method.

[0067] The beneficial effects of the above technical solution are as follows: By obtaining the key parameters of the synchronous generator and the photovoltaic power plant through a distributed multi-source heterogeneous data acquisition system, extracting features by combining the preprocessing method and data dimensionality reduction technology, constructing an accurate mathematical model of the combined system, improving the accuracy and efficiency of system modeling, providing a reliable basis for subsequent oscillation analysis and optimization, and helping to enhance the stability of power grid operation and the utilization rate of new energy.

[0068] Embodiment 4:

[0069] The embodiment of the present invention provides a method for optimizing the damping support reserve capacity of a photovoltaic power plant of a synchronous generator,

[0070] Parameters of the first preset type, including: mechanical parameters, electromagnetic parameters, and measured parameters of air-gap magnetic density distribution under different working conditions;

[0071] Parameters of the second preset type, including: three-dimensional surface parameters of the photovoltaic conversion efficiency of photovoltaic modules with respect to light intensity, angle, and temperature, switching frequency response characteristic parameters and loss spectrum parameters of inverters, charge-discharge rate curve parameters of energy storage systems, and capacity attenuation model parameters.

[0072] In this embodiment, parameters of the first preset type (for synchronous generators): Mechanical parameters: Describe the mechanical properties of the generator rotor, such as moment of inertia, damping coefficient, mechanical power input, etc. Electromagnetic parameters: Include electrical characteristics such as stator reactance, field reactance, leakage reactance, etc., which are used to describe electromagnetic dynamics. Measured parameters of air-gap magnetic density distribution: Reflect the distribution of the air-gap magnetic field intensity of the generator under different working conditions (such as load changes), which affects the stability and efficiency of the motor.

[0073] In this embodiment, parameters of the second preset type (for photovoltaic power plants): Three-dimensional surface parameters of the photovoltaic conversion efficiency of photovoltaic modules: Describe the relationship between efficiency and light intensity, light angle, and temperature. For example, the higher the light intensity and the closer the angle is to vertical, the higher the efficiency. Inverter parameters: Switching frequency response characteristic parameters: Describe the dynamic performance of the inverter, such as response time. Loss spectrum parameters: Reflect the energy losses of the inverter under different load conditions. Energy storage system parameters: Charge-discharge rate curve: Represents the power output capacity of the energy storage system at different rates. Capacity attenuation model parameters: Reflect the capacity degradation trend of energy storage devices over time and charge-discharge cycles.

[0074] The beneficial effects of the above technical solutions are: By introducing the mechanical, electromagnetic, and measured air-gap magnetic density parameters of synchronous generators, as well as the multi-dimensional dynamic characteristic parameters of photovoltaic modules, inverters, and energy storage systems, a more accurate combined system mathematical model is constructed, improving the ability to describe the dynamic characteristics of the system under complex working conditions, optimizing the damping support effect and capacity configuration scheme of photovoltaic power plants, and effectively enhancing the stability of power grid operation and the utilization efficiency of new energy.

[0075] Embodiment 5:

[0076] An embodiment of the present invention provides a method for optimizing the damping support reserve capacity of a photovoltaic power plant of a synchronous generator, which determines the state-space equation based on the mathematical model of the synchronous generator-photovoltaic power plant combined system and a preset analysis method, including:

[0077] Based on the preset analysis method, the mathematical model of the synchronous generator-photovoltaic power plant combined system is dynamically decomposed to obtain fast and slow subsystems, and then the state equations of the fast and slow subsystems are respectively constructed;

[0078] The state equations of the fast and slow subsystems are combined based on the correlation matrix to determine the state space equation.

[0079] In this embodiment, the preset analysis method includes: singular perturbation method: by identifying the time scale difference of variables in the joint system (such as the dynamic behavior of fast variables and slow variables), the system model is decomposed: fast variables: such as the output current and voltage dynamics of the photovoltaic inverter. Slow variables: such as the speed of the synchronous generator and the dynamics of the electromagnetic torque. Assuming that the fast dynamics reach a quasi-steady state (x˙fast=0x˙fast=0), the fast subsystem and the slow subsystem are decoupled and modeled separately. Modal analysis method: by calculating the eigenvalues ​​of the Jacobian matrix of the joint system, the fast and slow modes of the system are identified: fast mode: the mode with a larger absolute value of the real part of the corresponding eigenvalue and a higher frequency. Slow mode: the mode with a smaller absolute value of the real part of the corresponding eigenvalue and a lower frequency. Based on the modal decomposition results, the system is divided into fast dynamic and slow dynamic subsystems. Eigenvalue decomposition method: based on the state matrix of the joint system, the dynamic behavior of the system is linearized. Through eigenvalue decomposition, the state equations of fast and slow dynamics are constructed into two subsystems, and the correlation matrix is ​​used to connect the two.

[0080] The beneficial effect of the above technical solution is: the joint system is divided into fast and slow subsystems through dynamic decomposition method, the state equations are constructed respectively, and the complete state space equations are formed by combining the correlation matrix. This method reduces the difficulty of complex system modeling, improves the efficiency and accuracy of solution, provides a reliable foundation for subsequent oscillation mode analysis and capacity optimization, and significantly enhances the stability and dynamic response capability of the power grid.

[0081] Embodiment 6:

[0082] The embodiment of the present invention provides a method for optimizing the reserve capacity of a damping support of a photovoltaic power station of a synchronous generator, which dynamically decomposes a mathematical model of a synchronous generator-photovoltaic power station combined system based on a preset analysis method to obtain fast and slow subsystems, including:

[0083] Based on the matrix of the synchronous generator-photovoltaic power station combined system, the characteristic value of the synchronous generator-photovoltaic power station combined system is determined to be λ i (∈):

[0084]

[0085] in, is the dominant eigenvalue when ∈→0;

[0086] Based on the singular perturbation principle, the time scale of fast and slow dynamics in the synchronous generator-photovoltaic power station combined system is analyzed, and then the discrimination formula of the fast and slow subsystems is determined:

[0087] and and

[0088] wherein is the zero - order eigenvalue of the matrix of the synchronous generator - photovoltaic power station combined system, is the first - order perturbation term of the synchronous generator - photovoltaic power station combined system, and m, n, p, q are parameters adjusted according to the specific system dynamic level respectively, is the zero - order real part of the eigenvalue of the synchronous generator - photovoltaic power station combined system, and O(∈ q ) represents the growth or decay rate of q changes at the rate of ∈

[0089] In this embodiment, the dominant eigenvalue represents the preliminary division of the fast and slow dynamic levels of the system;

[0090] In this embodiment, the first - order perturbation term reflects the influence of high - order perturbations on the system dynamics;

[0091] In this embodiment, for m, n, p, q, m>1 represents the significant influence of fast dynamics, n>1 represents the significant influence of slow dynamics, and p, q further reflect the high - order influence of the perturbation term on the system decomposition.

[0092] The beneficial effects of the above - mentioned technical solution are as follows: By matrix analysis, the eigenvalues of the synchronous generator - photovoltaic power station combined system are determined, and based on the singular perturbation principle, the time scales of the fast and slow dynamics of the system are analyzed. Then, the discrimination formula for the fast and slow subsystems is proposed to accurately identify the dynamic levels of the system. The zero - order eigenvalue and the perturbation term are used to optimize the oscillation characteristics of the system, improve the system stability and response ability, and provide theoretical support for the capacity optimization and stable control of the power grid.

[0093] Embodiment 7:

[0094] The embodiment of the present invention provides a method for optimizing the damping support reserve capacity of a photovoltaic power station of a synchronous generator, which solves the state - space equation and then determines the weakly damped oscillation mode of the synchronous generator - photovoltaic power station combined system, including:

[0095] The state - space equation is arranged into a standard form, and then the state - space equation is solved based on a preset matrix eigenvalue solver and a modal participation factor analysis algorithm;

[0096] Then, several eigenvalues of the synchronous generator - photovoltaic power station combined system are determined;

[0097] Based on each eigenvalue and the modal participation factor algorithm, the contribution degree of each eigenvalue to the corresponding oscillation mode is determined;

[0098] Determine the weakly damped oscillation mode based on all eigenvalues and the contribution degree of each eigenvalue to the corresponding oscillation mode.

[0099] In this embodiment, the modal participation factor algorithm is an algorithm for analyzing and evaluating the contribution degree of each mode in the system to the overall oscillation mode. By analyzing the eigenvalues (usually representing the natural frequencies of the system) and the corresponding modal shapes, the relative importance of each mode in the oscillation can be determined. The basic idea of this algorithm is that the response of the system is not determined by a single eigenvalue, but by multiple eigenvalues and their corresponding modes. Therefore, the modal participation factor helps to identify which eigenvalues have a greater impact on the weakly damped oscillation mode of the system, so as to optimize.

[0100] The beneficial effects of the above technical solution are as follows: By solving the eigenvalues of the state space equation and analyzing the modal participation factors, the weakly damped oscillation modes in the synchronous generator - photovoltaic power station combined system are accurately identified, the contributions of various eigenvalues to the oscillation modes are quantified, the understanding of the dynamic characteristics and oscillation mechanism of the system is improved, a scientific basis is provided for optimizing the damping support and enhancing the power grid stability, and the reliability and efficiency of the system operation are significantly improved.

[0101] Embodiment 8:

[0102] The embodiment of the present invention provides a method for optimizing the damping support reserve capacity of a photovoltaic power station of a synchronous generator, which determines and executes the damping support control strategy of the photovoltaic power station based on the weakly damped oscillation mode of the synchronous generator - photovoltaic power station combined system, including:

[0103] Construct a multi - dimensional control vector based on the weakly damped oscillation mode and the parameters of the second preset type;

[0104] Determine the oscillation trend prediction data based on the preset model predictive control rolling optimization algorithm and the real - time state of the synchronous generator - photovoltaic power station combined system;

[0105] Dynamically tune the controller parameters based on the oscillation trend prediction data, the implementation algorithm of the preset control strategy, and the preset optimization algorithm, and then determine and execute the damping support control strategy of the photovoltaic power station.

[0106] In this embodiment, the predictive model predictive control rolling optimization algorithm is an advanced control strategy. Based on the mathematical model of the system, it predicts the dynamic behavior of the system over a period of time in the future, and real-time rolls and optimizes the control variables to achieve the optimal control of the system. The principle is as follows: Prediction model: Use the mathematical model of the system to predict the state evolution over a period of time in the future (such as the dynamic behavior of the synchronous generator - photovoltaic power station combined system). Rolling optimization: In each control cycle, calculate the optimal control input over a period of time in the future based on the current system state, with the goal of minimizing a cost function (such as the system oscillation amplitude, energy loss). Execution and update: Only execute the first calculated control input, then update the system state, and repeat the above steps again. Dynamic adjustment: Continuously roll and update the control input and prediction to adapt to the changes in the system state in real time. The model predictive control rolling optimization algorithm combines real-time state data, predicts the trend of weakly damped oscillations, and dynamically tunes the controller parameters, finally determining the damping support strategy of the photovoltaic power station and optimizing the grid stability.

[0107] In this embodiment, the oscillation trend prediction data refers to predicting the future oscillation trend of the system by collecting the system state (such as voltage, frequency, rotational speed) in real time and combining with a mathematical model. These data reflect the changes in the system oscillation mode, including: Oscillation amplitude change: Whether the oscillation of voltage or frequency increases or decreases. Oscillation frequency: Whether the frequency of the dominant oscillation mode changes. Damping characteristics: Whether the damping ratio of the system becomes stronger or weaker. These prediction data are used to judge the potential risks and trends of system oscillation, thus providing a reference for optimizing the controller parameters.

[0108] The beneficial effects of the above technical solution are as follows: By constructing a multi-dimensional control vector and combining the model predictive control rolling optimization algorithm, real-time obtain the oscillation trend prediction data, dynamically tune the controller parameters, optimize the damping support control strategy of the photovoltaic power station, achieve precise suppression of weakly damped oscillations, enhance the dynamic response ability of the system and the grid stability, and effectively improve the cooperative operation efficiency of the photovoltaic power station and the synchronous generator.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for optimizing the reserve capacity of damping support of a photovoltaic power station with a synchronous generator, characterized in that: include: Step 1: Obtaining parameters of preset types of synchronous generators and photovoltaic power plants, and constructing a mathematical model of a synchronous generator-photovoltaic power plant combined system based on the parameters of the preset types; Step 2: Determine the state space equation based on the mathematical model of the synchronous generator-photovoltaic power station combined system and the preset analysis method; Step 3: Solve the state space equations to determine the weakly damped oscillation mode of the synchronous generator-photovoltaic power station combined system; Step 4: Determine and execute the damping support control strategy of the photovoltaic power station based on the weakly damped oscillation mode of the synchronous generator-photovoltaic power station combined system; Step 5: Construct the optimization objective function of the photovoltaic power station based on the preset type of objective function, determine the constraint conditions based on the parameters of the synchronous generator and the photovoltaic power station after executing the damping support control strategy of the photovoltaic power station, and then solve the optimization objective function of the photovoltaic power station based on the preset algorithm and determine the capacity configuration plan.

2. The method for optimizing the reserve capacity of damping support of a photovoltaic power station with a synchronous generator according to claim 1, characterized in that: Weakly damped oscillation modes include: low-frequency electromechanical oscillation mode, subsynchronous oscillation mode, and oscillation mode caused by output fluctuations of photovoltaic power stations.

3. The method for optimizing the reserve capacity of damping support of a photovoltaic power station with a synchronous generator according to claim 1, characterized in that: Obtaining parameters of preset types of synchronous generators and photovoltaic power plants, and constructing a mathematical model of a synchronous generator-photovoltaic power plant combined system based on the parameters of the preset types, including: Based on a preset distributed multi-source heterogeneous data acquisition system, parameters of a first preset type of synchronous generator and parameters of a second preset type of photovoltaic power station are collected; Preprocessing the parameters of the first preset type of the synchronous generator and the parameters of the second preset type of the photovoltaic power station based on a preset preprocessing method; Based on a preset analysis method, data dimension reduction and feature extraction are performed on parameters of a first preset type and parameters of a second preset type of a photovoltaic power station, and a mathematical model of a synchronous generator-photovoltaic power station combined system is constructed based on the extracted features.

4. The method for optimizing the reserve capacity of damping support of a photovoltaic power station with a synchronous generator according to claim 3 is characterized in that: The first preset type of parameters includes: mechanical parameters, electromagnetic parameters, and measured parameters of air gap magnetic flux distribution under different working conditions; The parameters of the second preset type include: three-dimensional surface parameters of the photovoltaic module's photoelectric conversion efficiency with light intensity, angle, and temperature, switching frequency response characteristic parameters and loss spectrum parameters of the inverter, charge and discharge rate curve parameters of the energy storage system, and capacity attenuation model parameters.

5. The method for optimizing the reserve capacity of damping support of a photovoltaic power station with a synchronous generator according to claim 1, characterized in that: The state space equations are determined based on the mathematical model of the synchronous generator-photovoltaic power station combined system and the preset analysis method, including: Based on the preset analysis method, the mathematical model of the synchronous generator-photovoltaic power station combined system is dynamically decomposed to obtain the fast and slow subsystems, and then the state equations of the fast and slow subsystems are constructed respectively; The state equations of the fast and slow subsystems are combined based on the correlation matrix to determine the state space equation.

6. The method for optimizing the reserve capacity of damping support of a photovoltaic power station with a synchronous generator according to claim 5, characterized in that: Based on the preset analysis method, the mathematical model of the synchronous generator-photovoltaic power station combined system is dynamically decomposed to obtain the fast and slow subsystems, including: Based on the matrix of the synchronous generator-photovoltaic power station combined system, the characteristic value of the synchronous generator-photovoltaic power station combined system is determined to be λ i (∈): in, is the dominant eigenvalue when ∈→0; Based on the singular perturbation principle, the time scale of fast and slow dynamics in the synchronous generator-photovoltaic power station combined system is analyzed, and then the discrimination formula of the fast and slow subsystems is determined: and Fast dynamic subsystem and Slow dynamic subsystem in, is the zero-order eigenvalue of the matrix of the synchronous generator-photovoltaic power station combined system, The first-order disturbance term of the synchronous generator-photovoltaic power station combined system, m, n, p, q are parameters adjusted according to the specific system dynamic level, is the zero-order real part of the eigenvalue of the synchronous generator-photovoltaic power station combined system, O(∈ q )express The growth or decay rate is ∈ q The rate at which the 7. The method for optimizing the reserve capacity of damping support of a photovoltaic power station with a synchronous generator according to claim 1, characterized in that: Solve the state space equations to determine the weakly damped oscillation mode of the synchronous generator-photovoltaic power station combined system, including: Arrange the state-space equations into a standard form, and then solve the state-space equations based on a preset matrix eigenvalue solver and a modal participation factor analysis algorithm; Then, several characteristic values ​​of the synchronous generator-photovoltaic power station combined system are determined; Determine the contribution of each eigenvalue to the corresponding oscillation mode based on each eigenvalue and the modal participation factor algorithm; The weakly damped oscillation mode is determined based on all eigenvalues ​​and the contribution degree of each eigenvalue to the corresponding oscillation mode.

8. The method for optimizing the reserve capacity of damping support of a photovoltaic power station with a synchronous generator according to claim 3, characterized in that: Based on the weakly damped oscillation mode of the synchronous generator-photovoltaic power station combined system, the damping support control strategy of the photovoltaic power station is determined and executed, including: constructing a multidimensional control vector based on the weakly damped oscillation mode and the parameters of the second preset type; Determine the oscillation trend prediction data based on the preset model predictive control rolling optimization algorithm and the real-time status of the synchronous generator-photovoltaic power station combined system; The controller parameters are dynamically adjusted based on the oscillation trend prediction data, the preset control strategy implementation algorithm and the preset optimization algorithm, and then the damping support control strategy of the photovoltaic power station is determined and executed.

Images