Wind-light-water load cluster equivalent load modeling method and device

Abstract

The invention discloses a wind-light-water load cluster equivalent load modeling method and device, and the method comprises the steps: determining an equivalent comprehensive load model structure of a wind-light-water load cluster, carrying out the mathematical equivalent modeling of various loads, building a simulation model based on the equivalent comprehensive load model structure, carrying out the fitting of related parameters of the simulation model through a particle swarm algorithm, and carrying out the modeling of the equivalent load of the wind-light-water load cluster. The particle swarm optimization can identify the parameters in real time, the stability of the system is effectively improved, the accuracy of the power grid is improved, the system is not limited by the field test environment, and a large amount of data support is not needed. The technical problems that a statistical synthesis method is limited by field tests and an overall observation method needs a large amount of data support are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power system simulation, and in particular, to a method and device for modeling an equivalent load of a wind-solar-hydro-load cluster. Background Art

[0002] As the terminal of the power network, the load has a non-negligible impact on the power grid. The influence of the load model on the power system simulation results is related to the operation, planning, and decision-making of the power network. The existing two types of load modeling methods are the statistical synthesis method and the overall observation method. Due to the limitations of on-site power research tests, the overall observation method cannot be adopted by power workers at all times. The statistical observation method requires a large amount of data for experiments, resulting in a large workload. Therefore, finding a new load modeling method to solve the deficiencies of the existing statistical synthesis method and overall observation method is a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0003] The present invention provides a method and device for modeling an equivalent load of a wind-solar-hydro-load cluster, which are used to solve the technical problems that the statistical synthesis method is limited by on-site tests and the overall observation method requires a large amount of data support.

[0004] In view of this, the first aspect of the present invention provides a method for modeling an equivalent load of a wind-solar-hydro-load cluster, including:

[0005] Obtain the equivalent comprehensive load model structure of the wind-solar-hydro-load cluster, where the equivalent comprehensive load model structure includes the equivalent impedance of the distribution network load, the equivalent machine of the wind power, the equivalent machine of the hydropower, the equivalent machine of the photovoltaic power, the equivalent static load, and the equivalent induction motor;

[0006] Construct a simulation model of the wind-solar-hydro-load cluster load according to the equivalent comprehensive load model structure;

[0007] Based on the simulation model, solve the equivalent impedance of the distribution network load in the equivalent comprehensive load model structure;

[0008] Based on the simulation model and the equivalent impedance of the distribution network load, identify the impedance equivalent parameters in the equivalent induction motor and the line load impedance model structure through the particle swarm optimization algorithm.

[0009] Optionally, during the modeling process of the equivalent induction motor, the dynamic characteristics of the damping winding are ignored, and the simulation model of the motor group equipment body is equivalently described by a third-order differential model.

[0010] Optionally, the simulation model of the equivalent induction motor is:

[0011]

[0012] Wherein, is the stator open-circuit time constant of the d-axis excitation winding, is the rotor inertia time constant of the d-axis field winding, is the d-axis synchronous reactance of the equivalent induction motor, is the d-axis transient reactance of the equivalent induction motor, is the q-axis synchronous reactance of the equivalent induction motor, is the q-axis transient electromotive force, is the rotational speed, is the rotor position angle, D is the damping coefficient, is the saturation coefficient, is the center angular frequency, is the prime mover input power, is the d-axis current, is the q-axis current, is the rated frequency.

[0013] Optionally, the calculation formula for the equivalent impedance of the distribution network load is:

[0014]

[0015] where, is the equivalent impedance of the distribution network load, is the active power of the distribution network system, is the reactive power of the distribution network system, is the magnitude of the voltage at the load point.

[0016] Optionally, the objective function for identifying the equivalent parameters of the wind-solar-hydro-load cluster load in the equivalent integrated load model structure by the particle swarm algorithm is:

[0017]

[0018]

[0019]

[0020] where U is the actual voltage, is the base voltage, P is the active power absorbed by the load, Q is the reactive power absorbed by the load, is the active power absorbed by the load when the terminal voltage is 0, is the reactive power absorbed by the load when the terminal voltage is 0, , , , , and are the proportionality coefficients of the load respectively, V is the power supply voltage, is the terminal voltage, is the electromagnetic torque, is the maximum electromagnetic torque, S is the slip, is the critical slip, is the impedance of the induction motor, is the stator resistance, is the equivalent excitation resistance, is the rotor resistance, is the stator reactance, is the equivalent excitation reactance, is the rotor reactance, is the equivalent induction motor resistance, is the equivalent induction motor reactance, and j is the imaginary symbol.

[0021] Optionally, the linear problem representation model of the objective function is:

[0022]

[0023]

[0024] where, is the active power of the motor, is the reactive power of the motor, is the motor parameter matrix, is the power factor angle, and J is the parameter identification function symbol, is the active power of the system, is the reactive power of the system, t is the time variable, and N is the total time.

[0025] The second aspect of the present invention provides a modeling device for the equivalent load of a wind-solar-hydro-load cluster, including:

[0026] An acquisition module, configured to acquire the equivalent comprehensive load model structure of the wind-solar-hydro-load cluster, and the equivalent comprehensive load model structure includes the equivalent impedance of the distribution network load, the equivalent machine of wind power, the equivalent machine of hydropower, the equivalent machine of photovoltaic power, the equivalent static load, and the equivalent induction motor;

[0027] A simulation modeling module, configured to construct a simulation model of the load of the wind-solar-hydro-load cluster according to the equivalent comprehensive load model structure;

[0028] An equivalent impedance solving module, configured to solve the equivalent impedance of the distribution network load in the equivalent comprehensive load model structure based on the simulation model;

[0029] An equivalent parameter solving module, configured to identify the impedance equivalent parameters in the equivalent induction motor and the line load impedance model structure based on the simulation model and the equivalent impedance of the distribution network load through a particle swarm algorithm.

[0030] Optionally, the dynamic characteristics of the damping winding are ignored during the modeling of the equivalent induction motor, and the simulation model of the motor group equipment body is equivalently described by a third-order differential model.

[0031] Optionally, the simulation model of the equivalent induction motor is as follows:

[0032]

[0033] Wherein, is the stator open - circuit time constant of the d - axis field winding, is the rotor inertia time constant of the d - axis field winding, is the d - axis synchronous reactance of the equivalent induction motor, is the d - axis transient reactance of the equivalent induction motor, is the q - axis synchronous reactance of the equivalent induction motor, is the q - axis transient electromotive force, is the rotational speed, is the rotor position angle, D is the damping coefficient, is the saturation coefficient, is the central angular frequency, is the prime - mover input power, is the d - axis current, is the q - axis current, is the rated frequency.

[0034] Optionally, the calculation formula for the equivalent impedance of the distribution network load is:

[0035]

[0036] Wherein, is the equivalent impedance of the distribution network load, which is composed of the equivalent combination of the induction motor impedance and the line impedance, is the active power of the distribution network system, is the reactive power of the distribution network system, is the magnitude of the voltage at the load point.

[0037] Optionally, the objective function for identifying the equivalent parameters of the wind - solar - hydro - load cluster load in the equivalent integrated load model structure by the particle swarm algorithm is:

[0038]

[0039]

[0040]

[0041] Wherein, U is the actual voltage, is the base voltage, P is the active power absorbed by the load, Q is the reactive power absorbed by the load, is the active power absorbed by the load when the terminal voltage is 0, is the reactive power absorbed by the load when the terminal voltage is 0, , , , , and are the proportionality coefficients of the load respectively, V is the power supply voltage, is the terminal voltage of the machine, is the electromagnetic torque, is the maximum electromagnetic torque, S is the slip, is the critical slip, is the impedance of the induction motor, is the stator resistance, is the equivalent excitation resistance, is the rotor resistance, is the stator reactance, is the equivalent excitation reactance, is the rotor reactance, is the equivalent induction motor resistance, is the equivalent induction motor reactance, j is the imaginary symbol.

[0042] Optionally, the linear problem representation model of the objective function is:

[0043]

[0044]

[0045] where, is the active power of the motor, is the reactive power of the motor, is the motor parameter matrix, is the power factor angle, J is the parameter identification function symbol, is the active power of the system, is the reactive power of the system, t is the time variable, N is the total time.

[0046] It can be seen from the above technical solutions that the method for modeling the equivalent load of the wind-solar-hydro-load cluster provided by the present invention has the following advantages:

[0047] The method for modeling the equivalent load of the wind-solar-hydro-load cluster provided by the present invention determines the structure of the equivalent comprehensive load model of the wind-solar-hydro-load cluster, performs mathematical equivalent modeling on various types of loads, then constructs a simulation model based on the structure of the equivalent comprehensive load model, and uses the particle swarm algorithm to fit the relevant parameters of the simulation model to obtain the corresponding parameters in the equivalent comprehensive load model. The particle swarm algorithm can identify the parameters in real time, effectively improve the stability of the system, improve the accuracy of the power grid, is not limited by the on-site test environment, and does not require a large amount of data support, solving the technical problems that the statistical synthesis method is limited by on-site tests and the overall observation method requires a large amount of data support. Brief Description of the Drawings

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0049] Figure 1 It is a schematic flowchart of a method for modeling the equivalent load of a wind-solar-hydro-load cluster provided in an embodiment of the present invention;

[0050] Figure 2 It is a schematic diagram for obtaining the equivalent parameters of the nth harmonic model of the equivalent load of a wind-solar-hydro-load cluster provided in an embodiment of the present invention;

[0051] Figure 3 It is a waveform diagram of the active power during operation under the condition of the equivalent load of a wind-solar-hydro-load cluster provided in an embodiment of the present invention;

[0052] Figure 4 It is a waveform diagram of the load change during operation under the condition of the equivalent load of a wind-solar-hydro-load cluster provided in an embodiment of the present invention;

[0053] Figure 5 It is a transient load equivalent diagram during operation under the condition of the equivalent load of a wind-solar-hydro-load cluster provided in an embodiment of the present invention;

[0054] Figure 6 It is a power error and its density diagram during operation under the condition of the equivalent load of a wind-solar-hydro-load cluster in different years provided in an embodiment of the present invention;

[0055] Figure 7 It is a schematic structural diagram of a device for modeling the equivalent load of a wind-solar-hydro-load cluster provided in an embodiment of the present invention. Detailed implementation manners

[0056] In order to enable those skilled in the art to better understand the solutions of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0057] For easy understanding, please refer to Figure 1 , the present invention provides an embodiment of a method for modeling the equivalent load of a wind-solar-hydro-load cluster, including:

[0058] Step 101: Obtain the equivalent comprehensive load model structure of the wind-solar-hydro-load cluster. The equivalent comprehensive load model structure includes the equivalent impedance of the distribution network load, the equivalent machine of wind power, the equivalent machine of hydropower, the equivalent machine of photovoltaic power, the equivalent static load, and the equivalent induction motor.

[0059] It should be noted that in the embodiments of the present invention, first, the equivalent comprehensive load model structure of the wind-solar-hydro-load cluster is determined, including the equivalent impedance of the distribution network load, the equivalent machine of wind power, the equivalent machine of hydropower, the equivalent machine of photovoltaic power, the equivalent static load, and the equivalent induction motor.

[0060] Step 102: Construct a simulation model of the wind-solar-hydro-load cluster load according to the equivalent comprehensive load model structure.

[0061] It should be noted that mathematical equivalent modeling is carried out for various types of loads, modular design is adopted, and an overall model of the wind-solar-hydro-load cluster load is established. The modules interact through a control system to coordinate the power generation and load management of the three energy sources of wind, light, and water. Based on the above equivalent model, a simulation model is constructed, and each module is integrated into the simulation model.

[0062] During the modeling process of the equivalent induction motor, the dynamic characteristics of the damper winding are ignored, and the simulation model of the motor group equipment body is equivalently described by a third-order differential model:

[0063]

[0064] Among them, is the stator open-circuit time constant of the d-axis excitation winding, is the rotor inertia time constant of the d-axis excitation winding, is the d-axis synchronous reactance of the equivalent induction motor, is the d-axis transient reactance of the equivalent induction motor, is the q-axis synchronous reactance of the equivalent induction motor, is the q-axis transient electromotive force, is the rotational speed, is the rotor position angle, D is the damping coefficient, is the saturation coefficient, is the central angular frequency, is the input power of the prime mover, is the d-axis current, is the q-axis current, is the rated frequency.

[0065] The third-order induction motor load means that on the basis of considering the mechanical transient process, the electromagnetic transient process is also considered, that is, the influence of the transient electromotive force of the induction motor on the load power is taken into account. In power system calculations, the real and imaginary parts of the transient electromotive force of the induction motor are usually calculated separately. Together with the slip variable, the induction motor model will then contain three state variables, that is, the model content will include three differential equations, so it is called the third-order induction motor model.

[0066] Step 103: Based on the simulation model, solve the equivalent impedance of the distribution network load in the equivalent comprehensive load model structure.

[0067] It should be noted that the nth harmonic equivalent model of the equivalent load of the wind-solar-hydro-load cluster is as Figure 2 shown, and the output variables include the equivalent impedance of the distribution network load (constant impedance), non-linear static load, first-order induction motor load, and third-order induction motor load.

[0068] Set all distributed new energies in the power supply area of the substation where the load is modeled to not output power, and then calculate the equivalent impedance of the distribution network load in the equivalent comprehensive load model structure according to the equality of the power consumed by the impedance of the distribution network system and the sum of the powers consumed by each transformer and each distribution line in the distribution network. The calculation formula for the equivalent impedance of the distribution network load is:

[0069]

[0070] where is the equivalent impedance of the distribution network load, is the active power of the distribution network system, is the reactive power of the distribution network system, is the magnitude of the voltage at the load point.

[0071] Step 104: Based on the simulation model and the equivalent impedance of the distribution network load, identify the equivalent impedance parameters in the equivalent induction motor and line load impedance model structure through the particle swarm optimization algorithm.

[0072] It should be noted that according to the sensitivity of the dynamic trajectory of the system output variables to the change of the equivalent load parameters, the ratio of the change amount of the trajectory of the state variable or output variable to the change amount of the parameters in the system is obtained. The derivative is calculated by the median method according to the output of the equivalent load, and the trajectory is calculated twice to obtain higher calculation accuracy, and the relative value of the trajectory sensitivity is obtained. According to the relative value of the trajectory sensitivity, the trajectory sensitivity analysis curve is obtained. Through the sensitivity analysis curve, the amplitude of the trajectory sensitivity corresponding to the equivalent load parameters is obtained. According to the magnitude of the trajectory sensitivity amplitude, the key parameters in the equivalent load parameters are identified. The particle swarm optimization algorithm is used to optimize the identified key parameters. Specifically, first, for the dynamic response of the key parameters to the system, based on the root mean square error of the change of the bus voltage curve, the fitness function is determined:

[0073]

[0074] Among them, Fitness is the fitness function, RMSE is the root mean square error, and N is the number of sampling points. is the bus voltage of the i-th point obtained by prediction after equivalence. is the bus voltage of the i-th point obtained by simulation before equivalence.

[0075] The objective function for identifying the impedance equivalent parameters in the equivalent induction motor and line load impedance model structure by the particle swarm algorithm is:

[0076]

[0077]

[0078]

[0079] Among them, U is the actual voltage. is the reference voltage, P is the active power absorbed by the load, Q is the reactive power absorbed by the load. is the active power absorbed by the load when the terminal voltage is 0. is the reactive power absorbed by the load when the terminal voltage is 0. and and and and and are the proportionality coefficients of the load respectively. + + = 1. + + = 1, V is the power supply voltage. is the terminal voltage of the machine. is the electromagnetic torque (in per-unit value). is the maximum electromagnetic torque (in per-unit value), S is the slip. is the critical slip. is the impedance of the induction motor. is the stator resistance. is the equivalent excitation resistance. is the rotor resistance. is the stator reactance. is the equivalent excitation reactance. is the rotor reactance. is the resistance of the equivalent induction motor. is the reactance of the equivalent induction motor, and j is the imaginary symbol. and and , , and are static in the load composition and are also not easily statistically or computationally obtained. They are the parameters to be identified in this non-linear model. In the statistical synthesis method, different types of loads are weighted and summed, but the determination of the weights has no reliable theoretical basis, which will introduce uncontrollable biases in the statistics. Therefore, weight adjustment is still required, and this process will be rather cumbersome, increasing the workload. Usually, the change in the system frequency is very small. Therefore, the polynomial model adopted in the present invention will ignore the influence of frequency changes on the load power. In the dynamic simulation calculation of the power system in the present invention, the system frequency is defaulted to a constant 50 Hz.

[0080] , is the first-order equivalent model of the induction motor.

[0081] Identify the key parameters and obtain the corresponding values of the key parameters. The optimization of parameter identification can be transformed into a linear problem. Therefore, the linear problem representation model of the above objective function is:

[0082]

[0083]

[0084] where, is the active power of the motor, is the reactive power of the motor, is the motor parameter matrix, is the power factor angle, J is the symbol of the parameter identification function, is the active power of the system, is the reactive power of the system, t is the time variable, and N is the total time.

[0085] Transform the non-linear problem in load modeling into a linear problem, and represent the comprehensive load model by combining dynamic and static components, so as to achieve the goal of simplifying the power network.

[0086] Through the above first-order induction motor formula, and then solve the corresponding parameter values from each state component, and can also be deduced through the corresponding formula.

[0087]

[0088]

[0089] where, is the active power of the induction motor, is the reactive power of the induction motor, is the electromotive force on the x-axis component, is the electromotive force on the y-axis component, is the x-axis component of the terminal voltage of the machine, is the y-axis component of the terminal voltage of the machine, is the equivalent reactance of the motor.

[0090] In the first-order induction motor formula, the electromagnetic torque of the induction motor is related to the slip, the maximum electromagnetic torque, and the terminal voltage:

[0091]

[0092] Among them, is the x-axis current of the motor, is the y-axis current of the motor, is the x-axis electromotive force, is the y-axis electromotive force.

[0093] During the operation of the power system, the relationships between various variables within the network can have transient processes, and the corresponding relationships are described through differential equations or algebraic simulations:

[0094]

[0095] Among them, x is the operating variable of various components of the power system itself, and y is the operating variable of the power network. In the algebraic equation, the parameters can change abruptly during dynamic operation, but they cannot change abruptly in the differential equation, and the state variable slip s will not change abruptly.

[0096] Each particle in the equivalent voltage curve is optimized and iteratively searched by its position and velocity, and the velocity and position update formulas are:

[0097]

[0098] Among them, is the velocity vector of the k-th particle in the current generation, is the velocity vector of the k-th particle in the next generation, is the position vector of the k-th particle in the current generation, is the position vector of the k-th particle in the next generation, w is the inertia weight factor, and w takes a certain constant in the range of 0.5 to 0.8, and are the learning factors, is the optimal solution found by the k-th particle itself, rand is a random number between 0 and 1, is the optimal solution found by the entire population so far. The population size is 10 to 60.

[0099] The updated velocity and position are determined as the optimal values of the key parameters.

[0100] Substitute the optimal values of the key parameters into the simulation model of the integrated wind-solar-hydro-load cluster, conduct fault simulations, and fit the parameter values output from the fault simulation calculations with the actual parameter values output by the system faults to obtain optimized equivalent parameter values for the integrated wind-solar-hydro-load cluster. The technical effects achieved by the equivalent load modeling method for the integrated wind-solar-hydro-load cluster provided in the present invention are as follows Figures 3 - 6 shown. It can be Figure 3 intuitively seen that the output fluctuations of photovoltaic power generation are relatively large, while the others are relatively small. From Figure 4 it can be seen that the load changes during the operation of the integrated wind-solar-hydro-load cluster under equivalent load conditions are fluctuating, and the induction motor has a greater impact on it. From Figure 5 the transient load equivalent diagram during the operation of the integrated wind-solar-hydro-load cluster under equivalent load conditions in it, it can be seen that the operation results of its equivalent parameters are close to the actual effects, and their change trends are consistent. From Figure 6 the power error and its density diagram during the operation of the integrated wind-solar-hydro-load cluster under equivalent load conditions in different years in it, it can be seen that under different power levels, the equivalent load error is small, meeting the expected effects.

[0101] For the equivalent load modeling method of the integrated wind-solar-hydro-load cluster provided in the present invention, determine the equivalent integrated load model structure of the integrated wind-solar-hydro-load cluster, conduct mathematical equivalent modeling for various types of loads, then construct a simulation model based on the equivalent integrated load model structure, use the particle swarm optimization algorithm to fit the relevant parameters of the simulation model, and obtain the corresponding parameters in the equivalent integrated load model. The particle swarm optimization algorithm can identify parameters in real time, effectively improve the stability of the system, improve the accuracy of the power grid, is not restricted by the on-site test environment, and does not require a large amount of data support, solving the technical problems that the statistical synthesis method is restricted by on-site tests and the overall observation method requires a large amount of data support.

[0102] For ease of understanding, please refer to Figure 7 , and an embodiment of an equivalent load modeling device for the integrated wind-solar-hydro-load cluster provided in the present invention is provided, including:

[0103] An acquisition module for acquiring the equivalent integrated load model structure of the integrated wind-solar-hydro-load cluster, where the equivalent integrated load model structure includes the equivalent impedance of the distribution network load, the equivalent wind power generator, the equivalent hydro power generator, the equivalent photovoltaic power generator, the equivalent static load, and the equivalent induction motor;

[0104] A simulation modeling module for constructing a simulation model of the integrated wind-solar-hydro-load cluster according to the equivalent integrated load model structure;

[0105] An equivalent impedance solving module for solving the equivalent impedance of the distribution network load in the equivalent integrated load model structure based on the simulation model;

[0106] The equivalent parameter solving module is used to identify the impedance equivalent parameters in the equivalent induction motor and line load impedance models based on the simulation model and the equivalent impedance of the distribution network load through the particle swarm optimization algorithm.

[0107] In one embodiment, during the modeling process of the equivalent induction motor, the dynamic characteristics of the damping winding are ignored, and the simulation model of the motor group equipment body is equivalently described by a third-order differential model.

[0108] In one embodiment, the simulation model of the equivalent induction motor is:

[0109]

[0110] Where, is the stator open-circuit time constant of the d-axis field winding, is the rotor inertia time constant of the d-axis field winding, is the d-axis synchronous reactance of the equivalent induction motor, is the d-axis transient reactance of the equivalent induction motor, is the q-axis synchronous reactance of the equivalent induction motor, is the q-axis transient electromotive force, is the rotational speed, is the rotor position angle, D is the damping coefficient, is the saturation coefficient, is the central angular frequency, is the prime mover input power, is the d-axis current, is the q-axis current, is the rated frequency.

[0111] In one embodiment, the calculation formula for the equivalent impedance of the distribution network load is:

[0112]

[0113] Where, is the equivalent impedance of the distribution network load, is the active power of the distribution network system, is the reactive power of the distribution network system, is the magnitude of the voltage at the load point.

[0114] In one embodiment, the objective function for identifying the equivalent parameters of the wind-solar-hydro-load cluster load in the equivalent integrated load model structure through the particle swarm optimization algorithm is:

[0115]

[0116]

[0117]

[0118] Among them, U is the actual voltage, is the reference voltage, P is the active power absorbed by the load, Q is the reactive power absorbed by the load, is the active power absorbed by the load when the terminal voltage is 0, is the reactive power absorbed by the load when the terminal voltage is 0, 、 、 、 、 and are respectively the proportionality coefficients of the load, V is the power supply voltage, is the terminal voltage of the machine, is the electromagnetic torque, is the maximum electromagnetic torque, S is the slip, is the critical slip, is the impedance of the induction motor, is the stator resistance, is the equivalent excitation resistance, is the rotor resistance, is the stator reactance, is the equivalent excitation reactance, is the rotor reactance, is the equivalent induction motor resistance, is the equivalent induction motor reactance, j is the imaginary symbol.

[0119] In one embodiment, the linear problem representation model of the objective function is:

[0120]

[0121]

[0122] Among them, is the active power of the motor, is the reactive power of the motor, is the motor parameter matrix, is the power factor angle, J is the parameter identification function symbol, is the active power of the system, is the reactive power of the system, t is the time variable, N is the total time.

[0123] The device for modeling the equivalent load of the wind-solar-hydro-load cluster provided in the present invention is used to execute the method for modeling the equivalent load of the wind-solar-hydro-load cluster provided in the present invention. Its principle and the achieved technical effects are the same as those of the method for modeling the equivalent load of the wind-solar-hydro-load cluster provided in the present invention, and will not be elaborated here.

[0124] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0125] In several embodiments provided by the present invention, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections between each other can be through some interfaces, and the indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0126] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0127] In addition, each functional unit in various embodiments of the present invention can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0128] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: USB flash drives, mobile hard disks, read-only memories (English full name: Read-Only Memory, English abbreviation: ROM), random access memories (English full name: Random Access Memory, English abbreviation: RAM), magnetic disks, or optical disks, etc., which can store program codes.

[0129] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it; 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 described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A modeling method for equivalent load of a wind-solar-hydro-pumped storage cluster, characterized in that, Including: Obtain the equivalent comprehensive load model structure of the wind-solar-hydro-load cluster. The equivalent comprehensive load model structure includes the equivalent impedance of the distribution network load, wind power equivalent machine, hydro power equivalent machine, photovoltaic power equivalent machine, equivalent static load, and equivalent induction motor; Construct a simulation model of the wind-solar-hydro-load cluster load according to the equivalent comprehensive load model structure; Based on the simulation model, solve the equivalent impedance of the distribution network load in the equivalent comprehensive load model structure; Based on the simulation model and the equivalent impedance of the distribution network load, identify the equivalent comprehensive load parameters of the equivalent induction motor and the line load impedance model structure through the particle swarm optimization algorithm.

2. The method for modeling equivalent load of a wind-solar-hydro-pumped storage cluster according to claim 1, wherein, During the modeling process of the equivalent induction motor, the dynamic characteristics of the damper winding are ignored, and the simulation model of the motor unit body is equivalently described by a third-order differential model.

3. The method for modeling the equivalent load of a wind-solar-hydro-pumped storage cluster according to claim 2, wherein, The simulation model of the equivalent induction motor is: Among them, is the stator open-circuit time constant of the d-axis field winding, is the rotor inertia time constant of the d-axis field winding, is the d-axis synchronous reactance of the equivalent induction motor, is the d-axis transient reactance of the equivalent induction motor, is the q-axis synchronous reactance of the equivalent induction motor, is the q-axis transient electromotive force, is the rotational speed, is the rotor position angle, D is the damping coefficient, is the saturation coefficient, is the central angular frequency, is the prime mover input power, is the d-axis current, is the q-axis current, is the rated frequency.

4. The equivalent load modeling method for the wind-solar-hydro-pumped storage cluster according to claim 1, characterized in that The calculation formula for the equivalent impedance of the distribution network load is: Among them, is the equivalent impedance of the distribution network load, is the active power of the distribution network system, is the reactive power of the distribution network system, is the magnitude of the voltage at the load point.

5. The method for modeling equivalent load of a wind-solar-hydro-pumped storage cluster according to claim 1, wherein The objective function for identifying the equivalent load parameters of the wind-solar-hydro-load cluster in the equivalent comprehensive load model structure through the particle swarm optimization algorithm is: Among them, U is the actual voltage, is the reference voltage, P is the active power absorbed by the load, Q is the reactive power absorbed by the load, is the active power absorbed by the load when the terminal voltage is 0, is the reactive power absorbed by the load when the terminal voltage is 0, , , , , and are the proportionality coefficients of the load respectively, V is the source voltage, is the terminal voltage, is the electromagnetic torque, is the maximum electromagnetic torque, S is the slip, is the critical slip, is the impedance of the induction motor, is the stator resistance, is the equivalent excitation resistance, is the rotor resistance, is the stator reactance, is the equivalent excitation reactance, is the rotor reactance, is the equivalent induction motor resistance, is the equivalent induction motor reactance, j is the imaginary symbol.

6. The equivalent load modeling method for the wind-solar-hydro-pumped storage cluster according to claim 5, characterized in that, The linear problem representation model of the objective function is: Among them, is the active power of the motor, is the reactive power of the motor, is the motor parameter matrix, is the power factor angle, J is the symbol of the parameter identification function, is the active power of the system, is the reactive power of the system, t is the time variable, and N is the total time.

7. A modeling device for equivalent load of a cluster of wind, light, water and load, characterized in that Including: An acquisition module for obtaining the equivalent comprehensive load model structure of the wind-solar-hydro-load cluster. The equivalent comprehensive load model structure includes the equivalent impedance of the distribution network load, wind power equivalent machine, hydro power equivalent machine, photovoltaic power equivalent machine, equivalent static load, and equivalent induction motor; A simulation modeling module for constructing a simulation model of the wind-solar-hydro-load cluster load according to the equivalent comprehensive load model structure; An equivalent impedance solving module for solving the equivalent impedance of the distribution network load in the equivalent comprehensive load model structure based on the simulation model; An equivalent parameter solving module for identifying the impedance equivalent parameters in the equivalent induction motor and the line load impedance model structure through the particle swarm optimization algorithm based on the simulation model and the equivalent impedance of the distribution network load.

8. The equivalent load modeling device for the wind-solar-hydro-pumped storage cluster according to claim 7, characterized in that During the modeling process of the equivalent induction motor, the dynamic characteristics of the damper winding are ignored, and the simulation model of the motor unit body is equivalently described by a third-order differential model.

9. The equivalent load modeling device for a wind-solar-hydro-pumped storage cluster according to claim 8, characterized in that, The simulation model of the equivalent induction motor is: Among them, is the stator open-circuit time constant of the d-axis field winding, is the rotor inertia time constant of the d-axis field winding, is the d-axis synchronous reactance of the equivalent induction motor, is the d-axis transient reactance of the equivalent induction motor, is the q-axis synchronous reactance of the equivalent induction motor, is the q-axis transient electromotive force, is the rotational speed, is the rotor position angle, D is the damping coefficient, is the saturation coefficient, is the central angular frequency, is the prime mover input power, is the d-axis current, is the q-axis current, is the rated frequency.

10. The modeling device for equivalent load of wind-solar-hydro-pumped storage cluster according to claim 7, characterized in that The calculation formula for the equivalent impedance of the distribution network load is: Among them, is the equivalent impedance of the distribution network load, is the active power of the distribution network system, is the reactive power of the distribution network system, is the magnitude of the voltage at the load point.

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