A method and system for automatically generating a detailed and equivalent simulation model of a new energy and energy storage power station

Abstract

The application discloses a new energy and energy storage power station detailed and equivalent simulation model automatic generation method and system, the method aims at the electromechanical and electromagnetic transient simulation model construction problem of the new energy and energy storage power station, constructs a general structure of the station, and develops a system to realize parameter calculation of the detailed and equivalent models, generation of a BPA electromechanical transient detailed model, generation of a BPA electromechanical transient equivalent model, and further conversion to generate a PSmodel electromagnetic transient model. The method overcomes the problems of low efficiency and low accuracy of artificial modeling, and realizes fast and accurate generation of the simulation model of the new energy and energy storage power station.

Description

Technical Field

[0001] This invention belongs to the field of power system simulation technology, specifically relating to a method and system for automatically generating detailed and equivalent simulation models of new energy and energy storage power stations. Background Technology

[0002] With the increasing installed capacity of new energy and energy storage, their transient characteristics have a greater impact on the power system. Constructing electromechanical and electromagnetic transient simulation models for new energy power plants and energy storage power stations is fundamental for analyzing the transient operating characteristics of these plants and the stability of power systems containing large-scale new energy sources. It is crucial for the stable operation and risk analysis, fault reproduction, and control optimization of power plants and power systems. Power plant simulation models can be divided into detailed models and equivalent models. Detailed models include models of all units and collector lines within the power plant and are typically used for power plant stability characteristic analysis and regional power grid stability analysis with a small number of new energy power plants. Since new energy power plants usually contain dozens of generating units and dozens of collector lines, detailed models require modeling each one individually, which is cumbersome, labor-intensive, and prone to errors. Equivalent models, on the other hand, simplify the detailed model to a small number of generating units while retaining the grid's key features, thus improving computational efficiency. They are typically used for the stability analysis of provincial power systems containing large-scale new energy power plants. However, constructing equivalent models presents challenges such as difficulties in calculating equivalent parameters and the need for recalculation after changing the equivalent strategy. To address this, the present invention proposes an automatic generation method and system for detailed and equivalent simulation models of new energy and energy storage power stations. Based on the data collection results and equivalent strategies of the power station, the method automatically generates detailed and equivalent models, effectively improving the efficiency and accuracy of power station modeling. Summary of the Invention

[0003] This invention provides a method and system for automatically generating detailed and equivalent simulation models of new energy and energy storage power plants. Based on detailed information of internal components and equivalent strategies, the method automatically generates detailed and equivalent models of the power plant for stability analysis, effectively improving the efficiency of simulation modeling.

[0004] To achieve the above objectives, the present invention provides a method and system for automatically generating detailed and equivalent simulation models of new energy and energy storage power stations, comprising the following steps:

[0005] Step 1: Construct a general structure for new energy and energy storage power stations, and collect the data required for site modeling;

[0006] Step 2: Calculate the parameters of components such as transformers and collector wires, and generate a detailed electromechanical transient model of the station based on the BPA file format;

[0007] Step 3: Based on the principle of consistent loss, calculate the equivalent parameters of each component and generate the equivalent electromechanical transient model of the station based on the BPA file format;

[0008] Step 4: Use the PSModel conversion function to convert the electromechanical transient model into an electromagnetic transient model.

[0009] Compared with traditional operation optimization methods, the present invention has at least the following beneficial technical effects:

[0010] To address the modeling needs of various power plant types, including wind farms, photovoltaic power plants, and energy storage power plants, a general structure for new energy and energy storage power plants is constructed. Power plant components are divided into common parts and unique parts across different power plant types. Common parts are processed using the same method for data collection, parameter calculation, and model generation, while unique parts are calculated separately for each power plant type. Model generation is based on this general structure, enabling this method to be applied simultaneously to the modeling of wind farms, photovoltaic power plants, and energy storage power plants.

[0011] Furthermore, a site modeling program was developed based on C#, enabling functions such as calculating modeling parameters, generating detailed BPA models and equivalent models. This effectively improves modeling efficiency and reduces the high time cost and error rate associated with manual parameter calculation and BPA model parameter input. Simultaneously, the equivalent modeling scheme directly impacts the modeling results. Equivalent modeling often requires changing the equivalent method and repeatedly constructing the equivalent model; this method effectively shortens this step and improves the efficiency of equivalent model testing and verification.

[0012] This method first constructs a general structure for new energy and energy storage power stations, collects station information based on the general structure, and then constructs detailed electromechanical transient models, equivalent electromechanical transient models, detailed electromagnetic transient models, and equivalent electromagnetic transient models in sequence to support the transient characteristic analysis and calculation needs of new energy power stations. Attached Figure Description

[0013] Figure 1 Flowchart for building simulation models of new energy and energy storage power plants

[0014] Figure 2 A schematic diagram of a general structure for new energy and energy storage power stations.

[0015] Figure 3 Comparison results between detailed and equivalent models of the power station under typical operating conditions Detailed Implementation

[0016] To make the objectives and technical solutions of this invention clearer and easier to understand, the invention will be further described in detail below with reference to the accompanying drawings. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0017] This invention addresses the challenge of constructing electromechanical and electromagnetic transient simulation models for new energy and energy storage power plants. It proposes an automatic generation method and system for detailed and equivalent simulation models of new energy and energy storage power plants. The proposed method considers the modeling needs of various types of power plants, such as wind power, photovoltaic, and energy storage, including detailed electromechanical models, equivalent electromechanical models, detailed electromagnetic models, and equivalent electromagnetic models. Furthermore, an automatic model generation program was developed based on C#, which effectively improves the efficiency and accuracy of power plant modeling.

[0018] Reference Figure 1 A method and system for automatically generating detailed and equivalent simulation models of new energy and energy storage power stations are described below:

[0019] Step 1: Construct a general structure for new energy and energy storage power stations and collect the data required for station modeling.

[0020] Wind farms, photovoltaic power stations, and energy storage power stations share similar structures. Based on this, a general structure for new energy power stations is proposed, such as... Figure 2 As shown. The main internal components of a new energy power station include 220 / 110kV busbars, step-up transformers, 35kV busbars, SVG, capacitors and reactors, and generation units. Except for the generation units, the other components are common to wind, solar, and energy storage power stations and can use the same data acquisition templates and modeling methods. The generation units for photovoltaic and energy storage are similar, consisting of a collector line, a transformer substation, and generation nodes; the generation units for wind power consist of multiple collector lines, multiple transformer substations, and wind turbines, requiring separate data acquisition and modeling.

[0021] Based on the general structure of the above-mentioned site model, the data collection required for modeling, including site information and modeling scheme, is carried out, specifically including:

[0022] 1) Control parameters for station modeling, including station name, baseline capacity, grid connection point name, station type, short-circuit ratio, etc.;

[0023] 2) Parameters of the step-up transformer, including model, rated capacity, rated voltage, operating voltage, node name, step-up transformer type, reference voltage, load loss, short-circuit impedance, wiring method, etc.

[0024] 3) Parameters of wind power collector wires, including collector wire type, resistance per unit length, reactance, capacitance, zero-sequence resistance, zero-sequence reactance, zero-sequence capacitance, etc.

[0025] 4) Wind power collector topology, including the start point, end point, length, collector group to which each collector segment belongs, and the model of the wind turbine connected to it;

[0026] 5) Wind power and transformer parameters, including wind turbine model, rated power, transformer rated voltage, rated capacity, load loss, short-circuit impedance, operating voltage, wind turbine transient model, etc.

[0027] 6) SVG parameters, including model, connection node name, capacity, control node name, control voltage reference, SVG transient model, etc.

[0028] 7) Capacitor reactance parameters, including type, capacity, connection node name, etc.;

[0029] 8) Parameters of photovoltaic and energy storage current collectors, including model, connection node name, length, etc.;

[0030] 9) Photovoltaic power generation unit parameters, including the number of inverters, power generation, rated voltage and rated capacity of the transformer substation, load loss, short-circuit impedance, operating voltage, and transient model of the photovoltaic unit, etc.

[0031] 10) Energy storage and power generation unit parameters, including the number of PCS, power generation, rated voltage and rated capacity of the transformer substation, load loss, short-circuit impedance, operating voltage, and transient model of the energy storage unit, etc.

[0032] 11) Equivalent strategy, equivalent to the collector line group, including the collector line group corresponding to each equivalent power generation unit.

[0033] 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.

[0034] Based on the data collection results, the parameters of each component in the substation are calculated. Among them, the main parameters of the transformer are calculated using the following formula:

[0035] (1)

[0036] (2)

[0037] (3)

[0038] in, , , These are the transformer resistance, reactance, and susceptance, respectively. This is the transformer's rated voltage. The rated capacity of the transformer. , , These are the transformer load loss, short-circuit voltage percentage, and no-load current percentage, respectively.

[0039] The parameters of the collector line are calculated using the following formula:

[0040] (4)

[0041] (5)

[0042] (6)

[0043] in, , , These are the resistance, reactance, and susceptance of the collector circuit, respectively. , , These are the resistance per unit length, reactance per unit length, and capacitance per unit length of the collector line, respectively. The rated frequency is 50Hz. This represents the line length.

[0044] After the parameter calculation is completed, the .dat and .swi files required for BPA electromechanical transient calculation are generated according to the BPA model format requirements. These files include components such as busbars, step-up transformers, box-type transformers, collector lines, wind turbines, SVG, capacitors and reactors, photovoltaic units, and energy storage units.

[0045] Based on the above method, an automatic generation system for detailed transient electromechanical models of stations suitable for BPA was developed using C#, realizing parameter calculation and model file generation.

[0046] Step 3: Based on the principle of consistent loss, calculate the equivalent parameters of each component and generate the equivalent electromechanical model of the station based on the BPA file format.

[0047] The components that need to be equivalent include: three-winding step-up transformers, collector lines, box-type substations, wind turbines / photovoltaic inverters / PCS and other power generation equipment. Among them, the wind turbines / photovoltaic inverters / PCS and other power generation equipment can be multiplied using the built-in multiplication function of BPA, and the capacity and number of units can be modified based on the single-unit model.

[0048] In renewable energy power plants, three-winding step-up transformers are typically split transformers, which can be equivalent to two-winding transformers. The impedance of the equivalent transformer is calculated using the following formula:

[0049] (7)

[0050] in, The impedance of the high-voltage winding of the split transformer. The impedance of a single low-voltage winding of a split transformer. and These represent the power outputs of the wind turbines connected to the two low-voltage side windings, respectively.

[0051] Multiple sets of collector cables and their transformer substations are equivalent to one section of collector cable and one transformer substation. The impedance of the equivalent collector cable is calculated using the following formula:

[0052] (8)

[0053] in, This represents the number of feed lines in the detailed model corresponding to this equivalent feed line. This equivalent unit includes the total capacity of wind turbines / photovoltaics / energy storage. For the first The impedance of the segmented cable, For the flow through the first The power of the collector wire is calculated based on the topology of the collector wire.

[0054] The collector wire susceptance is calculated using the following formula:

[0055] (9)

[0056] in, For the first The susceptance of the segmented wire.

[0057] The equivalent impedance of the transformer box is calculated using the following formula:

[0058] (10)

[0059] in, , The first The impedance of the transformer substation and the power of the connected wind turbine / photovoltaic inverter / energy storage PCS. This represents the number of transformer substations before the equivalent value was calculated.

[0060] After completing the equivalent parameter calculation, the .dat and .swi files required for BPA electromechanical transient calculation are generated according to the BPA model format requirements. These files include components such as busbars, step-up transformers / equivalent step-up transformers, equivalent box-type transformers, equivalent collector lines, wind turbines, SVG, capacitors and reactors, photovoltaic units, and energy storage units.

[0061] Based on the above method, an automatic generation system for equivalent electromechanical transient models of stations suitable for BPA was developed using C#, realizing parameter calculation and model file generation.

[0062] Step 4: Use the PSModel conversion function to convert the electromechanical transient model into an electromagnetic transient model.

[0063] Based on the generated BPA electromechanical transient station detailed model and station equivalent model, the PSModel automatic conversion tool is used to generate a station electromagnetic transient detailed model and equivalent model suitable for PSModel.

[0064] To further illustrate the effectiveness of this method, a wind farm is used as an example to generate a detailed transient electromechanical model and an equivalent model of the wind farm. The comparison of the grid connection point voltages of the two models under typical fault conditions is shown below. Figure 3As shown, the grid connection point voltages of the two models before, during, and after the fault are quite similar, indicating that the model generated by this method has high accuracy.

[0065] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for automatically generating detailed and equivalent simulation models of new energy and energy storage power stations, characterized in that, Includes the following steps: Step 1: Construct a general structure for new energy and energy storage power stations, and collect the data required for site modeling; Step 2: Calculate the parameters of the transformer and collector wire components, and generate a detailed electromechanical transient model of the station based on the BPA file format; Based on the data collection results, the parameters of each component in the substation are calculated. Among them, the main parameters of the transformer are calculated using the following formula: （1） （2） （3） in, , , These are the transformer resistance, reactance, and susceptance, respectively. This is the rated voltage of the transformer. This refers to the rated capacity of the transformer. , , These are the transformer load loss, short-circuit voltage percentage, and no-load current percentage, respectively. The parameters of the collector line are calculated using the following formula: （4） （5） （6） in, , , These are the resistance, reactance, and susceptance of the collector circuit, respectively. , , These represent the resistance per unit length, reactance per unit length, and capacitance per unit length of the collector line, respectively. For the rated frequency, This refers to the line length; After the parameter calculation is completed, the .dat and .swi files required for BPA electromechanical transient calculation are generated according to the BPA model format requirements. Step 3: Based on the principle of consistent loss, calculate the equivalent parameters of each component and generate the equivalent electromechanical transient model of the station based on the BPA file format; In new energy power plants, the three-winding step-up transformer is converted into a split transformer, which is equivalent to a two-winding transformer. The impedance of the equivalent transformer is calculated using the following formula: （7） in, The impedance of the high-voltage winding of the split transformer. The impedance of a single low-voltage winding of a split transformer. and These represent the power outputs of the wind turbines connected to the two low-voltage side windings, respectively. Multiple sets of collector cables and their transformer substations are equivalent to one section of collector cable and one transformer substation. The impedance of the equivalent collector cable is calculated using the following formula: （8） in, This represents the number of feeders in the detailed model corresponding to the equivalent feeder. This includes the total capacity of wind turbines, solar power, and energy storage. For the first The impedance of the segmented cable, For the flow through the first The power of the collector cable is calculated based on the topology of the collector cable. The collector wire susceptance is calculated using the following formula: （9） in, For the first The susceptance of the segmented wire; The equivalent impedance of the transformer box is calculated using the following formula: （10） in, , The first The impedance of the transformer substation and the power of the connected wind turbine / photovoltaic inverter / energy storage PCS. This represents the number of transformer substations before the equivalent value was calculated. After completing the equivalent parameter calculation, generate the .dat and .swi files required for BPA electromechanical transient calculation according to the BPA model format requirements; Step 4: Use the PSModel conversion function to convert the electromechanical transient model into an electromagnetic transient model.

2. The method 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 a general structure for new energy and energy storage power stations, dividing the components included in the power station into common parts and unique parts for wind, solar and energy storage types of stations. The common parts adopt a unified data collection and modeling scheme, enabling this method to complete the modeling work of multiple types of wind, solar and energy storage stations at the same time.

3. The method 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 using a C# program.

4. The method 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 uses the principle of consistent loss to perform equivalent transformation on the internal components of the split step-up transformer, collector lines, and box-type substation, ensuring that the active and reactive power losses inside the wind farm remain unchanged before and after the equivalent transformation, thus improving the accuracy of the equivalent model.

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