Method and system for automatically generating detailed and equivalent simulation model of new energy and energy storage power station

Abstract

The invention discloses a method and a system for automatically generating a detailed and equivalent simulation model of a new energy and energy storage power station, and aims to solve the problem of construction of electromechanical and electromagnetic transient simulation models of the new energy and energy storage power station. And the system is developed to realize detailed and equivalent model parameter calculation, BPA electromechanical transient detailed model generation and BPA electromechanical transient equivalent model generation, and then conversion is carried out to generate a PSmodel electromagnetic transient model. The method overcomes the problems of low manual modeling efficiency and low accuracy, and realizes rapid and accurate generation of the new energy and energy storage power station simulation model.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system simulation, and in particular relates to a method and system for automatically generating detailed and equivalent simulation models of new energy and energy storage power stations. Background Art

[0002] As the installed capacity of new energy and energy storage increases, their transient characteristics have a greater impact on the power system. Constructing electromechanical transient simulation models and electromagnetic transient simulation models for new energy stations and energy storage power stations is the basis for conducting transient operation characteristics analysis of stations and stability analysis of power systems containing large-scale new energy. It is of great significance to the stable operation and risk analysis, fault reproduction, and control optimization of stations and power systems. The station simulation model can be divided into a detailed model and an equivalent model. The detailed model contains models of all units, collector lines and other components in the station, and is usually used for station stability characteristics analysis and regional power grid stability analysis with a small number of new energy stations. Since new energy stations usually contain dozens of power generation units and dozens of collector lines, the detailed model of the station needs to be modeled one by one, which has problems such as cumbersome steps, large workload, and easy errors. The equivalent model simplifies the detailed model into a small number of power generation units while retaining the characteristics of the power grid to improve calculation efficiency. It is usually used for stability analysis of provincial power systems containing large-scale new energy stations. However, the construction of the equivalent model has problems such as difficulty in calculating equivalent parameters and need to be recalculated after changing the equivalent strategy. To this end, the present invention proposes a method and system for automatically generating detailed and equivalent simulation models of new energy and energy storage power stations, which automatically generates detailed models and equivalent models based on station information collection results and equivalent strategies, effectively improving the efficiency and accuracy of station modeling. Summary of the invention

[0003] The present invention provides a method and system for automatically generating detailed and equivalent simulation models of new energy and energy storage power stations. The method automatically generates detailed station models and equivalent models for stability analysis based on the detailed information of internal components of the station and equivalent strategies, thereby effectively improving the efficiency of simulation modeling.

[0004] In order to achieve the above-mentioned purpose, the present invention provides a method and system for automatically generating detailed and equivalent simulation models of new energy and energy storage power stations, including the following steps: Step 1: Build a general structure for new energy and energy storage power stations and collect data required for site modeling; Step 2: Calculate the parameters of transformers, collectors and other components, and generate a detailed electromechanical transient model of the station based on the BPA file format; Step 3: Based on the loss consistency principle, calculate the parameters of each component after equivalent value, and generate the station electromechanical transient equivalent model based on the BPA file format; Step 4: Use the PSModel model conversion function to convert the electromechanical transient model into an electromagnetic transient model.

[0005] Compared with the traditional operation optimization method, the present invention has at least the following beneficial technical effects: Aiming at the modeling needs of wind farms, photovoltaic power stations, energy storage power stations and other types of stations, a general structure of new energy and energy storage power stations is constructed, and the station components are divided into common parts and unique parts of multiple types of stations. The common parts use the same method for capital collection, parameter calculation and model generation, and the unique parts are calculated separately according to the station type. Model generation based on this general structure enables this method to be applied to the modeling of wind farms, photovoltaic power stations and energy storage power stations at the same time.

[0006] Furthermore, a station modeling program was developed based on C# to realize functions such as modeling parameter calculation, BPA detailed model and equivalent model generation, which effectively improved the modeling efficiency and reduced the time cost and high error rate caused by manual parameter calculation and filling in BPA model parameters. At the same time, the equivalent scheme will directly affect the modeling results. When equivalent modeling is performed, it is often necessary to change the equivalent method and repeatedly carry out the work of equivalent model construction. This method can effectively shorten the time of this step and improve the efficiency of equivalent model testing and verification.

[0007] This method first constructs the general structure of new energy and energy storage power stations, collects station information based on the general structure, and then successively constructs the station electromechanical transient detailed model, electromechanical transient equivalent model, electromagnetic transient detailed model, and electromagnetic transient equivalent model to support the transient characteristics analysis and calculation needs of new energy stations. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 Constructing flow charts for simulation models of renewable energy and energy storage power plants Figure 2 This is a general structural diagram of new energy and energy storage power stations. Figure 3 Comparison results between detailed model and equivalent model of the station under typical working conditions DETAILED DESCRIPTION

[0009] In order to make the purpose and technical solution of the present invention clearer and easier to understand, the present invention is further described in detail below in conjunction with the accompanying drawings. The specific embodiments described here are only used to explain the present invention, not to limit the present invention.

[0010] In response to the difficulty in constructing electromechanical and electromagnetic transient simulation models of new energy and energy storage power stations, the present invention proposes a method and system for automatically generating detailed and equivalent simulation models of new energy and energy storage power stations. The proposed method takes into account various modeling requirements such as detailed electromechanical models, equivalent electromechanical models, detailed electromagnetic models, equivalent electromagnetic models, etc. of multiple types of stations such as wind power, photovoltaic, and storage, and develops a model automatic generation program based on C#, which effectively improves the efficiency and accuracy of station modeling.

[0011] Reference Figure 1 , a method and system for automatically generating detailed and equivalent simulation models of new energy and energy storage power stations, the specific implementation steps are as follows: Step 1: Build a general structure for new energy and energy storage power stations, and collect data required for site modeling.

[0012] The structures of wind farms, photovoltaic power stations, and energy storage power stations are similar. Based on this, a general structure of new energy stations is proposed: Figure 2 As shown. The internal components of the new energy station mainly include 220 / 110kV busbar, step-up transformer, 35kV busbar, SVG, capacitor reactance, and power generation unit. Except for the power generation unit, other components are common to wind, light, and storage stations, and the same funding template and modeling method can be used. The power generation units of photovoltaic and energy storage are similar, consisting of a section of collector line, box transformer, and power generation node; the wind power generation unit consists of multiple sections of collector lines, multiple box transformers and wind turbines, which need to be funded and modeled separately.

[0013] Based on the general structure of the above-mentioned station model, the data required for modeling is collected, including station information and modeling solutions, including: 1) Station modeling control parameters, including station name, benchmark capacity, grid connection point name, station type, short-circuit ratio, etc.; 2) Boost transformer parameters, including model, rated capacity, rated voltage, operating voltage, node name, boost transformer type, reference voltage, load loss, short-circuit impedance, wiring method, etc.; 3) Wind power collector line parameters, including collector line model, unit length resistance, reactance, capacitance, zero-sequence resistance, zero-sequence reactance, zero-sequence capacitance, etc.; 4) Wind power collector line topology, including the starting point, end point, length, collector line group, connected wind turbine model, etc. of each collector line; 5) Wind power and box transformer parameters, including wind turbine model, rated power, box transformer rated voltage, rated capacity, load loss, short-circuit impedance, operating voltage, wind turbine transient model, etc.; 6) SVG parameters, including model, connection node name, capacity, control node name, control voltage reference, SVG transient model, etc.; 7) Capacitor reactance parameters, including type, capacity, connection node name, etc.; 8) Parameters of photovoltaic and energy storage collector lines, including model, connection node name, length, etc.; 9) Parameters of photovoltaic power generation units, including the number of inverters, power generation, rated voltage of the box transformer, rated capacity, load loss, short-circuit impedance, operating voltage, transient model of photovoltaic units, etc.; 10) Energy storage power generation unit parameters, including PCS quantity, power generation power, box transformer rated voltage, rated capacity, load loss, short-circuit impedance, operating voltage, energy storage unit transient model, etc.; 11) Equal value strategy, equal value is performed according to the collector group, including the equal previous collector group corresponding to each equal value power generation unit.

[0014] Step 2: Calculate the parameters of components such as transformers and collectors, and generate a detailed electromechanical transient model of the station based on the BPA file format.

[0015] Based on the collected data, the parameters of each component of the station are calculated. Among them, the main parameters of the transformer are calculated as follows: (1) (2) (3) in, , , are the transformer resistance, reactance and susceptance respectively. is the transformer rated voltage, is the rated capacity of the transformer, , , They are transformer load loss, short-circuit voltage percentage, and no-load current percentage respectively.

[0016] The parameters of the collector line are calculated as follows: (4) (5) (6) in, , , are the resistance, reactance and susceptance of the collector circuit respectively. , , They are the resistance per unit length, reactance per unit length, and capacitance per unit length of the collector line, is the rated frequency (50Hz), is the line length.

[0017] After the parameter calculation is completed, the dat file and swi file required for BPA electromechanical transient calculation are generated according to the BPA model format requirements, including busbars, step-up transformers, box transformers, collectors, fans, SVGs, capacitors and reactances, photovoltaic units, energy storage units and other components.

[0018] Based on the above method, C# was used to develop an automatic generation system for station electromechanical transient detailed models suitable for BPA to realize parameter calculation and model file generation.

[0019] Step 3: Based on the loss consistency principle, calculate the parameters of each component after equivalent value, and generate the station electromechanical transient equivalent model based on the BPA file format.

[0020] The components that need to be equivalent include: three-winding step-up transformer, collector line, box transformer, wind turbine / photovoltaic inverter / PCS and other power generation equipment. Among them, wind turbine / photovoltaic inverter / PCS and other power generation equipment use the multiplication function of BPA, and modify the capacity and number of units based on the single-machine model.

[0021] The three-winding step-up transformer in the new energy station is usually a split transformer, which can be equivalent to a two-winding transformer. The transformer impedance after equivalent is calculated as follows: (7) in, is the impedance of the high voltage side winding of the split transformer, is the impedance of a single low-voltage side winding of the split transformer, and They are the wind turbine power connected to the two low-voltage side windings respectively.

[0022] The multiple groups of collector lines and their box-type transformers are equivalent to one section of collector line and one box-type transformer. The impedance of the collector line after the equivalent is calculated as follows: (8) in, is the number of collector lines in the detailed model corresponding to the equivalent collector line, The equivalent unit includes the total capacity of wind turbines / photovoltaic / energy storage, which is For the The impedance of the segment collector, For the flow through The power of the segment collector is calculated based on the topological structure of the collector.

[0023] The collector impedance is calculated as follows: (9) in, For the The electrical susceptance of the segment collector.

[0024] The impedance of the box transformer after equalization is calculated as follows: (10) in, , Respectively The impedance of the transformer and the power of the connected wind turbine / photovoltaic inverter / energy storage PCS, is the number of box-type transformers before being equalized.

[0025] After completing the equivalent parameter calculation, generate the dat file and swi file required for BPA electromechanical transient calculation according to the BPA model format requirements, including busbar, step-up transformer / equivalent step-up transformer, equivalent box transformer, equivalent collector line, fan, SVG, capacitor reactance, photovoltaic unit, energy storage unit and other components.

[0026] Based on the above method, an automatic generation system of electromechanical transient equivalent model for BPA was developed using C# to realize parameter calculation and model file generation.

[0027] Step 4: Use the PSModel model conversion function to convert the electromechanical transient model into an electromagnetic transient model.

[0028] Based on the generated BPA electromechanical transient station detailed model and station equivalent model, the PSModel automatic conversion tool is used to generate the station electromagnetic transient detailed model and equivalent model suitable for PSModel.

[0029] To further illustrate the effect of this method, a wind farm is taken as an example to generate a detailed model and an equivalent model of the station electromechanical transient state using this method. The comparison of the grid connection point voltage of the two models under typical fault conditions is shown in the figure below. Figure 3 As shown in the figure, the grid connection point voltages of the two models before, during and after the fault are relatively close, indicating that the model generated by this method is highly accurate.

[0030] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method and system for automatically generating detailed and equivalent simulation models of new energy and energy storage power stations, characterized in that: The following steps are involved: Step 1: Build a general structure for new energy and energy storage power stations and collect data required for site modeling; Step 2: Calculate the parameters of components such as transformers and collectors, and generate a detailed electromechanical transient model of the station based on the BPA file format; Step 3: Based on the loss consistency principle, calculate the parameters of each component after equivalent value, and generate the station electromechanical transient equivalent model based on the BPA file format; Step 4: Use the PSModel model conversion function to convert the electromechanical transient model into an electromagnetic transient model.

2. A method and system for automatically generating detailed and equivalent simulation models of new energy and energy storage power stations according to claim 1, characterized in that Step 1 constructs the general structure of new energy and energy storage power stations, and divides the components contained in the power station into common parts and unique parts for wind, solar, storage and other types of stations. The common parts adopt a unified funding and modeling scheme, so that this method can simultaneously complete the modeling work of multiple types of wind, solar, and storage stations.

3. A method and system for automatically generating detailed and equivalent simulation models of new energy and energy storage power stations according to claim 1, characterized in that The detailed model parameter calculation and file generation in step 2 and the equivalent model parameter calculation and file generation in step 3 are both implemented based on C# programs, avoiding the problems of low efficiency and low accuracy caused by manual generation.

4. A method and system for automatically generating detailed and equivalent simulation models of new energy and energy storage power stations according to claim 1, characterized in that Step 3 performs equivalent calculations on the internal components of the station, such as the split step-up transformer, the collector line, and the box transformer, based on the loss consistency principle, ensuring that the active and reactive losses inside the wind farm remain unchanged before and after the equivalent calculations, thereby improving the accuracy of the equivalent model.

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