Simulation method for electromagnetic transient model of wind power plant

Abstract

The invention relates to a simulation method for an electromagnetic transient model of a wind power plant, and the method comprises the steps: building a full-topology electromagnetic transient model which is 1: 1 with the scale of the wind power plant according to the actual parameters of the wind power plant and a power grid topological structure, and dividing the full-topology electromagnetic transient model into sub-models through a model segmentation method, therefore, an original large-scale wind power plant is divided into small-scale sub-models, the complexity of simulating the original large-scale wind power plant is reduced, the phenomenon that the time is too long in the simulation process is avoided, and meanwhile the utilization rate of resources is increased; and through the constructed 1: 1 full-topology electromagnetic transient model, the real wind power plant is restored as much as possible, so that the simulation platform is further improved to carry out rapid and accurate simulation.

Description

Technical Field

[0001] The invention relates to the technical field of electromagnetic transient simulation, and in particular to a simulation method for an electromagnetic transient model of a wind farm. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Nowadays, with the large-scale expansion of wind turbines, wind power generation has become an indispensable part of the power grid, and the research on wind farms and wind power collection systems has become increasingly important. In order to achieve multi-scale and multi-dimensional analysis of wind farms, it is necessary to use digital electromagnetic transient tools and combine simulation models with different simulation accuracy, simulation efficiency, and simulation focus to simulate wind farms of different sizes.

[0004] However, in the current simulation process of wind power generation systems, due to the large scale of wind farms, which usually consist of dozens of units, it is difficult to achieve equivalent modeling of wind farms; at the same time, if detailed modeling of each wind turbine unit and its control system is adopted, the complexity of the simulation will be greatly increased, resulting in problems such as long simulation calculation time and extremely low resource utilization. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a simulation method for an electromagnetic transient model of a wind farm, which can solve the problems of low accuracy and poor flexibility in the simulation process of a wind farm, and at the same time can reduce the time consumption of simulation and improve simulation efficiency.

[0006] The object of the present invention is to provide a simulation method for an electromagnetic transient model of a wind farm, comprising: According to the actual parameters of the wind farm and the topological structure of the power grid, a full topological electromagnetic transient model of the wind farm is established; The full topology electromagnetic transient model is divided into sub-models using the model partitioning method; The sub-model is connected to the power grid system, and real-time simulation is performed based on the sub-model and the system admittance matrix.

[0007] As a further technical solution, the wind farm is composed of a plurality of double-fed wind turbines.

[0008] As a further technical solution, the full topology electromagnetic transient model is constructed without performing equivalent simplification processing, so that the scale ratio between the full topology electromagnetic transient model and the actual wind farm is 1:1.

[0009] As a further technical solution, the process of constructing the full-topology electromagnetic transient model includes constructing an active power model, a reactive power model and a converter model based on the grid topology structure of the wind farm and the actual parameters of the wind farm; the converter model is used to simulate the operating state of the converter, output active power and reactive power, and is used to construct an active power model and a reactive power model.

[0010] As a further technical solution, the active power model includes a wind turbine power model, a wind turbine rotor dynamic model, a wind power model and a performance optimization model; the active power model is used to output the overall active power through the wind turbine's active power, wind speed, wind turbine rotor mechanical power and grid connection point frequency.

[0011] As a further technical solution, the reactive power model is used to output the equivalent internal potential of the wind turbine through the grid connection point voltage.

[0012] As a further technical solution, the wind turbine power model is used to output the active power of the wind turbine, the wind turbine rotor dynamic model is used to output the mechanical power of the rotor in the wind turbine, the wind power model is used to output the wind speed of the wind turbine according to the pitch angle, and the performance optimization model is used to regulate the operating status of various models in the active power model.

[0013] As a further technical solution, the construction process of the full-topology electromagnetic transient model also includes constructing a power system model and a control system model based on the power grid topology structure of the wind farm; the power system model includes a generator model, a gearbox model, a transformer model and a wind turbine model; the control system model includes a generator control system model, a gearbox control system model, a transformer control system model and a wind turbine control system model; the control system model is used to regulate the power system model.

[0014] As a further technical solution, the model segmentation method is specifically:

[0015] in, , is the equivalent power supply of the two systems, , is the equivalent impedance of the two systems, is the controlled current source current, is the current of system 2, is the controlled current source voltage, is the controlled voltage source voltage, is the delay time, is the complex frequency domain.

[0016] As a further technical solution, the sub-model is connected to the power grid system, and real-time simulation is performed according to the sub-model and the system admittance matrix as follows: Initialize the components in the sub-model and solve the admittance matrix of the sub-model; Within the preset simulation time, the Norton equivalent current of the component is obtained; Solve the node voltage of the sub-model based on the obtained Norton equivalent current and the sub-model admittance matrix; According to the node voltage of the sub-model, the internal state quantity of the component is updated and used for the simulation of the next time step until the preset end condition is met.

[0017] Beneficial effects of one or more of the above technical solutions: This embodiment establishes a full-topology electromagnetic transient model of the wind farm based on the actual parameters of the wind farm and the grid topology structure, and divides the full-topology electromagnetic transient model into sub-models by using a model segmentation method, thereby dividing the original large-scale wind farm into small-scale sub-models, which is conducive to the simulation platform to perform fast and accurate simulation, while reducing the complexity of simulating the original large-scale wind farm, avoiding the phenomenon that the simulation process is prone to taking too long, and improving resource utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings in the specification that constitute a part of this application are used to provide further understanding of the present application. In order to facilitate understanding, the proportions between the structures of each part are adjusted. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute a limitation on the present application.

[0019] Figure 1 The present invention is a flow chart of a simulation method for an electromagnetic transient model of a wind farm. DETAILED DESCRIPTION

[0020] The following is combined with Figure 1 , clearly and completely describe the technical solutions in the embodiments of the present invention.

[0021] Embodiment 1 Reference Figure 1 , a simulation method for an electromagnetic transient model of a wind farm, comprising: S1. Based on the actual parameters of the wind farm and the topological structure of the power grid, a full topological electromagnetic transient model of the wind farm is established.

[0022] In existing wind farms, they are usually composed of dozens or hundreds of doubly-fed wind turbines, and the area of ​​the wind farm is also over hundreds of kilometers; therefore, the simulation of the electromagnetic transient model of the wind farm is also extremely difficult.

[0023] The solution proposed in this embodiment can simulate the electromagnetic transient model of the wind farm more accurately and quickly; therefore, when constructing the full topology electromagnetic transient model of the wind farm, this embodiment does not perform equivalent simplification processing, and performs 1:1 modeling according to the scale, unit parameters and operating conditions of the actual wind farm; and through the modeling method of the same size, the operating state of the wind farm can be restored more accurately, and more realistic operating data in the wind farm can be obtained through simulation.

[0024] S101. Construct an active power model, a reactive power model and a converter model according to the grid topology of the wind farm and actual parameters of the wind farm.

[0025] The converter model is used to simulate the operating state of the converter, output active power and reactive power, and is used to construct an active power model and a reactive power model.

[0026] The active power model includes a wind turbine power model, a wind turbine rotor dynamic model, a wind power model and a performance optimization model; among them, the active power model is used to output the overall active power through the wind turbine's active power, wind speed, wind turbine rotor mechanical power and grid connection point frequency.

[0027] Specifically, the wind turbine power model is used to output the active power of the wind turbine, the wind turbine rotor dynamic model is used to output the mechanical power of the rotor in the wind turbine, the wind power model is used to output the wind speed of the wind turbine according to the pitch angle, and the performance optimization model is used to regulate the operating status of various models in the active power model.

[0028] At the same time, the reactive power model is used to output the equivalent internal potential of the wind turbine through the grid connection point voltage.

[0029] S102. Construct a power system model and a control system model based on the power grid topology of the wind farm.

[0030] Among them, the power system model includes a generator model, a gearbox model, a transformer model and a fan model; the control system model includes a generator control system model, a gearbox control system model, a transformer control system model and a fan control system model; the control system model is used to regulate the power system model.

[0031] This embodiment uses the grid topology and actual parameters of the wind farm to construct a model related to the output power in the wind farm, thereby restoring all the energy consumption and output power in the wind farm as much as possible. The power system model and the corresponding control system model of various structural devices in the wind farm are constructed through the grid topology, thereby simulating the operating state of the wind farm, and finally constructing a complete full-topology electromagnetic transient model.

[0032] S2. Use the model segmentation method to divide the full topology electromagnetic transient model into sub-models.

[0033] The full-topology electromagnetic transient model constructed today contains a large number of wind turbines. When simulating them as a whole, on the one hand, the simulation is difficult and the entire wind farm cannot be fully simulated; on the other hand, the complexity of the simulation is increased, and it will also lead to problems such as long simulation time.

[0034] To this end, this embodiment first divides the full topology electromagnetic transient model through a model segmentation method to obtain corresponding sub-models.

[0035] Among them, the calculation formula of the model segmentation method is specifically as follows: (1-1) in, , is the equivalent power supply of the two systems, , is the equivalent impedance of the two systems, is the controlled current source current, is the current of system 2, is the controlled current source voltage, is the controlled voltage source voltage, is the delay time, is the complex frequency domain.

[0036] The above formula can be used to divide the full topology electromagnetic transient model into different sub-models while ensuring the integrity of each sub-model; at the same time, the obtained sub-model needs to be tested for its stability. This process can use offline simulation to test the stability of the subsystem.

[0037] S3. Connect the sub-model to the power grid system and perform real-time simulation based on the sub-model and the system admittance matrix.

[0038] The specific steps are as follows: S301, initializing the elements in the sub-model and solving to obtain the admittance matrix of the sub-model; S302, solving and obtaining the Norton equivalent current of the component within a preset simulation time; S303, solving the node voltage of the sub-model according to the obtained Norton equivalent current and the sub-model admittance matrix; S304, updating the internal state quantity of the component according to the node voltage of the sub-model, and using the internal state quantity for the simulation of the next time step until the preset end condition is met.

[0039] At the same time, the number of sub-models can be adjusted accordingly; for example, the sub-model obtained by the first division can be divided twice to obtain a new sub-model. Moreover, during the simulation process, two sub-models can be simulated simultaneously; and the selected sub-model can be selected according to the corresponding attention level.

[0040] For example, when one is interested in the total power of a wind turbine, one can select the sub-models including the wind turbine power model, the wind turbine rotor dynamic model and the wind power model for simulation, thereby obtaining the total power of the wind turbine.

[0041] By dividing the full topology electromagnetic transient model into different sub-models and simulating each sub-model separately, the time spent on the simulation process is greatly reduced, and the complexity of simulating the original large-scale wind farm is reduced.

[0042] After being combined, each sub-model can be of the same scale as the original wind farm, ensuring the accuracy of the simulation while improving the utilization of resources.

[0043] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A simulation method for electromagnetic transient model of wind farm, It is characterized in that include: According to the actual parameters of the wind farm and the topological structure of the power grid, a full topological electromagnetic transient model of the wind farm is established; The full topology electromagnetic transient model is divided into sub-models using the model partitioning method; The sub-model is connected to the power grid system, and real-time simulation is performed based on the sub-model and the system admittance matrix.

2. A simulation method for an electromagnetic transient model of a wind farm as claimed in claim 1, It is characterized in that The wind farm is composed of a plurality of double-fed wind turbine generator sets.

3. A simulation method for a wind farm electromagnetic transient model according to claim 1, It is characterized in that The full topology electromagnetic transient model is constructed without equivalent simplification, so that the scale ratio between the full topology electromagnetic transient model and the actual wind farm is 1:

1.

4. A simulation method for a wind farm electromagnetic transient model according to claim 1, It is characterized in that The construction process of the full-topology electromagnetic transient model includes constructing an active power model, a reactive power model and a converter model based on the grid topology structure of the wind farm and the actual parameters of the wind farm; the converter model is used to simulate the operating state of the converter, output active power and reactive power, and is used to construct the active power model and the reactive power model.

5. A simulation method for an electromagnetic transient model of a wind farm as claimed in claim 4, It is characterized in that The active power model includes a fan power model, a fan rotor dynamic model, a wind power model and a performance optimization model; the active power model is used to output the overall active power through the fan's active power, wind speed, fan rotor mechanical power and grid connection point frequency.

6. A simulation method for a wind farm electromagnetic transient model as claimed in claim 4, It is characterized in that The reactive power model is used to output the equivalent internal potential of the wind turbine through the grid connection point voltage.

7. A simulation method for a wind farm electromagnetic transient model as claimed in claim 4, It is characterized in that The fan power model is used to output the active power of the fan, the fan rotor dynamic model is used to output the mechanical power of the rotor in the fan, the wind power model is used to output the wind speed of the fan according to the pitch angle, and the performance optimization model is used to regulate the operating status of various models in the active power model.

8. A simulation method for a wind farm electromagnetic transient model according to claim 1, It is characterized in that The construction process of the full-topology electromagnetic transient model also includes constructing a power system model and a control system model based on the power grid topology structure of the wind farm; the power system model includes a generator model, a gearbox model, a transformer model and a wind turbine model; the control system model includes a generator control system model, a gearbox control system model, a transformer control system model and a wind turbine control system model; the control system model is used to regulate the power system model.

9. A simulation method for a wind farm electromagnetic transient model according to claim 1, It is characterized in that The model segmentation method is specifically as follows: in, , is the equivalent power supply of the two systems, , is the equivalent impedance of the two systems, is the controlled current source current, is the current of system 2, is the controlled current source voltage, is the controlled voltage source voltage, is the delay time, is the complex frequency domain.

10. A simulation method for a wind farm electromagnetic transient model according to claim 1, It is characterized in that The sub-model is connected to the power grid system, and real-time simulation is performed according to the sub-model and the system admittance matrix as follows: Initialize the components in the sub-model and solve the admittance matrix of the sub-model; Within the preset simulation time, the Norton equivalent current of the component is obtained; Solve the node voltage of the sub-model based on the obtained Norton equivalent current and the sub-model admittance matrix; According to the node voltage of the sub-model, the internal state quantity of the component is updated and used for the simulation of the next time step until the preset end condition is met.

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