A new energy station equivalent simulation method and system in a real-time simulation environment

Abstract

The application discloses a new energy station equivalent simulation method and system in a real-time simulation environment, and the new energy station equivalent simulation method comprises the following steps: according to the type of a new energy unit in a new energy station and a connected collection point bus, the new energy units in the new energy station are grouped, each new energy unit group is equivalent to a new energy station reference machine and a new energy station aggregation machine, and the new energy station reference machine and the new energy station aggregation machine are connected in parallel to the collection point bus; the new energy units in the group are clustered; the parameters of the reference machine and the aggregation machine are calculated; the new energy station aggregation equivalence is realized; the equivalent new energy station is simulated in the real-time simulation environment; and the overall equivalent simulation of the new energy station is realized, thereby providing a basis for the influence research of the grid dynamic characteristics of the large-scale new energy grid connection.

Description

TECHNICAL FIELD

[0001] The present application relates to a new energy station equivalent simulation method and system in a real-time simulation environment, and belongs to the technical field of power system real-time simulation modeling. BACKGROUND

[0002] With the increasing energy crisis and the increasing demand for energy, the development of new energy represented by wind power and photovoltaic power has been greatly promoted. In recent years, the new energy power generation industry has developed rapidly. In order to correctly evaluate the influence of large-scale new energy grid connection on the safety and stability characteristics of the power grid, it is necessary to accurately model and simulate the new energy station.

[0003] However, due to the small power of a single new energy unit, a cluster station is usually used for power generation and grid connection. Taking a photovoltaic power station as an example, a photovoltaic power station usually has dozens or even hundreds of photovoltaic power generation units. If each power generation unit is modeled separately, the complexity of the power system simulation model and the simulation calculation time will be greatly increased, and even the "dimension disaster" problem will be faced. Especially in a real-time simulation environment, the modeling method of a single photovoltaic power generation unit or a single wind turbine will seriously consume simulation resources, thereby limiting the simulation scale, so an equivalent simulation method for the whole new energy station is needed. SUMMARY

[0004] The present application provides a new energy station equivalent simulation method and system in a real-time simulation environment, which solves the problems disclosed in the background art.

[0005] In order to solve the above technical problems, the technical solution adopted by the present application is:

[0006] A new energy station equivalent simulation method in a real-time simulation environment, comprising:

[0007] According to the type of new energy unit in the new energy station and the connected collection point bus, the new energy units in the new energy station are grouped, each new energy unit group is equivalent to a new energy station reference machine and a new energy station aggregation machine connected in parallel to the collection point bus, and the new energy units in the group are clustered;

[0008] For each cluster, select any new energy unit in the cluster as the reference machine of the cluster, and equivalent all cluster reference machines to a new energy station reference machine. According to the DC voltage, output current, output active power, DC capacitor and inverter output internal potential of each cluster reference machine, the grid-connected side controlled voltage source instruction, grid-connected side output current, DC side controlled current source current instruction and equivalent DC capacitor of the new energy station reference machine are calculated;

[0009] According to the grid-connected side controlled voltage source instruction and the grid-connected side output current of the new energy station reference machine, the grid-connected filter capacitance and the grid-connected branch impedance of the new energy station reference machine are calculated;

[0010] According to the grid-connected filter capacitance and the grid-connected branch impedance of the new energy station reference machine, the grid-connected filter capacitance and the grid-connected branch impedance of the new energy station aggregation machine are calculated;

[0011] The new energy station with the calculated reference machine grid-connected filter capacitance, reference machine grid-connected branch impedance, aggregation machine grid-connected filter capacitance and aggregation machine grid-connected branch impedance is subjected to real-time simulation environment equivalent simulation of the new energy station.

[0012] According to the type of the new energy unit in the new energy station and the connected collection point bus, the new energy units in the new energy station are grouped, each new energy unit group is equivalent to a new energy station reference machine and a new energy station aggregation machine connected in parallel to the form of the collection point bus, and the new energy units in the group are clustered, including:

[0013] The new energy units in the new energy station with the same type and the same connected collection point bus are divided into the same group, and each new energy unit group is equivalent to a new energy station reference machine and a new energy station aggregation machine connected in parallel to the form of the collection point bus;

[0014] The control characteristic dynamic deviation index between the new energy units in the group is calculated;

[0015] If the control characteristic dynamic deviation index is less than a threshold value, the corresponding new energy unit is classified into the same cluster.

[0016] The control characteristic dynamic deviation index calculation formula is:

[0017]

[0018] Wherein, D(i,j') is the control characteristic dynamic deviation index between the new energy unit i and the new energy unit j', N is the number of new energy units in the group, A i (t k ) is the state vector time domain trajectory of the new energy unit i obtained by simulation or actual fault recording, A j′ (t k ) is the state vector time domain trajectory of the new energy unit j' obtained by simulation or actual fault recording, i≠j', T is the time domain trajectory duration, t k is the kth time in the 0-T time period.

[0019] For each cluster, select any new energy unit in the cluster as the reference machine of the cluster, and equivalent all cluster reference machines to a new energy station reference machine. According to the DC voltage, output current, output active power, DC capacitor and inverter output internal potential of each cluster reference machine, the grid-side controlled voltage source instruction of the new energy station reference machine, the grid-side output current, the DC-side controlled current source current instruction and the equivalent DC capacitor of the new energy station reference machine are calculated, including:

[0020] For each cluster, select any new energy unit in the cluster as the reference machine of the cluster, and equivalent all cluster reference machines to a new energy station reference machine. According to the DC voltage, output current, output active power, DC capacitor and inverter output internal potential of each cluster reference machine, the grid-side controlled voltage source instruction of the new energy station reference machine, the grid-side output current, the DC-side controlled current source current instruction and the equivalent DC capacitor of the new energy station reference machine are calculated, including:

[0021] For each cluster, select any new energy unit in the cluster as the reference machine of the cluster, and equivalent all cluster reference machines to a new energy station reference machine. According to the DC voltage, output current, output active power, DC capacitor and inverter output internal potential of each cluster reference machine, the grid-side controlled voltage source instruction of the new energy station reference machine, the grid-side output current, the DC-side controlled current source current instruction and the equivalent DC capacitor of the new energy station reference machine are calculated, including:

[0022] The calculation formula of the grid-side controlled voltage source instruction of each cluster reference machine is:

[0023]

[0024] Wherein, U ctl_j is the grid-side controlled voltage source instruction of the jth cluster reference machine, U dc_j is the DC voltage of the jth cluster reference machine, E j is the inverter output internal potential of the jth cluster reference machine.

[0025] The calculation formula of the grid-side controlled voltage source instruction of the new energy station reference machine is:

[0026]

[0027] Wherein, U ctl_ref is the grid-side controlled voltage source instruction of the new energy station reference machine, U ctl_j is the grid-side controlled voltage source instruction of the jth cluster reference machine, M is the number of clusters, P j is the output active power of the jth cluster reference machine, m j is the number of new energy units of the jth cluster.

[0028] The calculation formula of the grid-side output current of the new energy station reference machine is:

[0029]

[0030] wherein I ref is the grid-side output current of the new energy station reference machine, r is an equivalent coefficient set to prevent the impedance of the new energy station aggregation machine from being less than a threshold value, N is the number of new energy units in the group, E i is the effective value of the inverter output internal potential of the new energy unit i as the reference machine, is the phasor form of E i , U PCC is the effective value of the bus voltage of the collection point, is the phasor form of U PCC , Z L_i is the grid-side impedance of the new energy unit i, and Z T_i is the grid-side transformer impedance of the new energy unit i.

[0031] The DC-side controlled current source current instruction calculation formula of the new energy station reference machine is:

[0032]

[0033] wherein I dc_ref is the DC-side controlled current source current instruction of the new energy station reference machine, M is the number of clusters, i a_j , i b_j , i c_j are the instantaneous values of the three-phase currents of the inverter output of the jth cluster reference machine, e a_j , e b_j , e c_j are the instantaneous values of the three-phase voltages of the inverter output internal potential of the jth cluster reference machine, is the DC bus voltage of the new energy station reference machine, U dc_j is the DC voltage of the jth cluster reference machine.

[0034] The equivalent DC capacitance calculation formula of the new energy station reference machine is:

[0035]

[0036] wherein C ref is the equivalent DC capacitance of the new energy station reference machine, M is the number of clusters, is the DC bus voltage of the new energy station reference machine, U dc_j is the DC voltage of the jth cluster reference machine, C j is the DC capacitance of the jth cluster reference machine.

[0037] The grid-side filter capacitance calculation formula of the new energy station reference machine is:

[0038]

[0039] wherein C ft_refis the grid-connected filter capacitance of the new energy station reference machine, r is an equivalent coefficient set to prevent the impedance of the new energy station aggregation machine from being less than a threshold value, U i is the effective value of the terminal voltage of the new energy unit i, is the phasor form of U i , C i is the filter capacitance of the new energy unit i, U ctl_ref is the grid-connected side controlled voltage source instruction of the new energy station reference machine, is the phasor form of U ctl_ref , I ref is the grid-connected side output current of the new energy station reference machine, is the phasor form of I ref , Z L_ref is the internal impedance of the new energy station reference machine, and is the parallel value of the internal impedances of all cluster reference machines, and N is the number of new energy units in the group.

[0040] The grid-connected branch impedance calculation formula of the new energy station reference machine is:

[0041]

[0042] wherein, Z T_ref is the grid-connected branch impedance of the new energy station reference machine, U ctl_ref is the grid-connected side controlled voltage source instruction of the new energy station reference machine, is the phasor form of U ctl_ref , I ref is the grid-connected side output current of the new energy station reference machine, is the phasor form of I ref , U PCC is the effective value of the bus voltage of the collection point, is the phasor form of U PCC .

[0043] According to the grid-connected filter capacitance and the grid-connected branch impedance of the new energy station reference machine, the grid-connected filter capacitance and the grid-connected branch impedance of the new energy station aggregation machine are calculated, including:

[0044] The grid-connected filter capacitance of the new energy station aggregation machine is r times the grid-connected filter capacitance of the new energy station reference machine, and the grid-connected branch impedance of the new energy station aggregation machine is 1 / r times the grid-connected branch impedance of the new energy station reference machine; wherein, r is an equivalent coefficient set to prevent the impedance of the new energy station aggregation machine from being less than a threshold value.

[0045] A new energy station aggregation equivalent system, comprising:

[0046] The clustering and clustering module groups the new energy units in the new energy station according to the type of the new energy units in the new energy station and the connected collection point bus, and clusters the new energy units in the new energy station, and each new energy unit group is equivalent to a new energy station reference machine and a new energy station aggregation machine connected in parallel to the form of the collection point bus, and the new energy units in the group are clustered;

[0047] The first reference machine parameter calculation module selects any new energy unit in the cluster as the reference machine of the cluster for each cluster, and calculates the grid-connected side controlled voltage source instruction, the grid-connected side output current, the direct current side controlled current source current instruction and the equivalent direct current capacitor of the new energy station reference machine according to the direct current voltage, the output current, the output active power, the direct current capacitor and the inverter output internal potential of each cluster reference machine.

[0048] The second reference machine parameter calculation module calculates the grid-connected filter capacitor and the grid-connected branch impedance of the new energy station reference machine according to the grid-connected side controlled voltage source instruction and the grid-connected side output current of the new energy station reference machine.

[0049] The aggregation machine parameter calculation module calculates the grid-connected filter capacitor and the grid-connected branch impedance of the new energy station aggregation machine according to the grid-connected filter capacitor and the grid-connected branch impedance of the new energy station reference machine.

[0050] The first reference machine parameter calculation module selects any new energy unit in the cluster as the reference machine of the cluster for each cluster, and calculates the grid-connected side controlled voltage source instruction, the grid-connected side output current, the direct current side controlled current source current instruction and the equivalent direct current capacitor of the new energy station reference machine according to the direct current voltage, the output current, the output active power, the direct current capacitor and the inverter output internal potential of each cluster reference machine.

[0051] A computer readable storage medium storing one or more programs, the one or more programs including instructions that, when executed by a computing device, cause the computing device to perform a new energy station equivalent simulation method in a real-time simulation environment.

[0052] A computing device comprising one or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, the one or more programs including instructions for performing a new energy station equivalent simulation method in a real-time simulation environment.

[0053] The present application has the following advantages: according to the type of the new energy unit in the new energy station and the connected collection point bus, the new energy units in the new energy station are grouped, each new energy unit group is equivalent to a new energy station reference machine and a new energy station aggregation machine connected in parallel to the collection point bus, the new energy units in the group are clustered, the parameters of the reference machine and the aggregation machine are calculated, the new energy station aggregation equivalence is realized, the equivalent simulation of the new energy station in the real-time simulation environment is realized, the overall equivalent simulation of the new energy station is realized, and the influence of the large-scale new energy grid connection on the dynamic characteristics of the power grid is provided. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 The flowchart of the method of the present application is shown in the figure.

[0055] Figure 2 The schematic diagram of the new energy station aggregation equivalence model is shown in the figure. DETAILED DESCRIPTION

[0056] The present application will be further described below with reference to the accompanying drawings. The following examples are only used to more clearly illustrate the technical solutions of the present application, and cannot be used to limit the protection scope of the present application.

[0057] As shown in the figure, a new energy station equivalent simulation method in a real-time simulation environment includes the following steps: Figure 1 Step 1: According to the type of the new energy unit in the new energy station and the connected collection point bus, the new energy units in the new energy station are grouped, each new energy unit group is equivalent to a new energy station reference machine and a new energy station aggregation machine connected in parallel to the collection point bus, and the new energy units in the group are clustered.

[0058] Step 2: For each cluster, select any new energy unit in the cluster as the reference machine of the cluster, and equivalent all cluster reference machines to a new energy station reference machine. According to the DC voltage, output current, output active power, DC capacitor and inverter output internal potential of each cluster reference machine, the grid-connected side controlled voltage source instruction, grid-connected side output current, DC side controlled current source current instruction and equivalent DC capacitor of the new energy station reference machine are calculated.

[0059] Step 3: According to the grid-connected side controlled voltage source instruction and the grid-connected side output current of the new energy station reference machine, the grid-connected filter capacitor and the grid-connected branch impedance of the new energy station reference machine are calculated.

[0060]

[0061] ​Step 4, according to the grid-connected filter capacitance and grid-connected branch impedance of the reference machine of the new energy station, the grid-connected filter capacitance and grid-connected branch impedance of the aggregation machine of the new energy station are calculated;

[0062] Step 5, for the new energy station with the calculated grid-connected filter capacitance of the reference machine, grid-connected branch impedance of the reference machine, grid-connected filter capacitance of the aggregation machine and grid-connected branch impedance of the aggregation machine, the equivalent simulation of the new energy station in the real-time simulation environment is carried out.

[0063] The above method groups the new energy units in the new energy station according to the type of the new energy units in the new energy station and the connected collection point bus, equivalently groups each new energy unit group into a new energy station reference machine and a new energy station aggregation machine connected in parallel to the collection point bus, clusters the new energy units in the group, calculates the parameters of the reference machine and the aggregation machine, realizes the aggregation equivalence of the new energy station, carries out the equivalent simulation of the new energy station in the real-time simulation environment, and realizes the equivalent simulation of the whole new energy station, thereby providing a basis for the influence of large-scale new energy grid connection on the dynamic characteristics of the power grid.

[0064] For the new energy station, the new energy units in the station need to be grouped according to their differences. The new energy units in the new energy station with the same type and connected to the same collection point bus can be divided into the same group, as follows:

[0065] In the same station, if the connected collection point buses of the new energy unit i and the new energy unit j' are different, or they are not the same type of power (doubly-fed wind turbine, direct-drive wind turbine, photovoltaic or energy storage), the two units can be directly determined to be in two groups; if the types of the new energy unit i and the new energy unit j' are the same and the connected collection point buses are the same, the two units are in the same group.

[0066] For each group, each new energy unit group is equivalently grouped into a new energy station reference machine and a new energy station aggregation machine connected in parallel to the collection point bus. The parameters of the reference machine and the aggregation machine are unknown and need to be further calculated to realize complete equivalence.

[0067] Further, the groups can be clustered based on the grouping. According to the state vector time domain trajectory of the new energy units in the same group obtained by simulation or actual fault recording, the control characteristic dynamic deviation index between the new energy units can be calculated by the following formula:

[0068]

[0069] Where D(i,j') is the control characteristic dynamic deviation index between the new energy unit i and the new energy unit j', N is the number of new energy units in the group, A i (t kA represents the time-domain trajectory of the state vector of a new energy unit i obtained from simulation or actual fault recording. j′ (t k ) represents the time-domain trajectory of the state vector of the new energy unit j′ obtained from simulation or actual fault recording, where i ≠ j′, and T is the duration of the time-domain trajectory. k Let A be the state vector of the new energy unit i at the k-th time within the time interval from 0 to T. i =(P i Q i U i V i ) T P i For the new energy unit i output active power, Q i For the new energy unit i, reactive power is output, U i V represents the effective value of the terminal voltage of the new energy unit i. i The average value of the natural characteristic quantity of new energy unit i (average wind speed for doubly fed / direct drive units, average irradiance for photovoltaic units, and average discharge rate for energy storage units).

[0070] If the dynamic deviation index of the control characteristics is less than the threshold, the corresponding new energy units are classified into the same cluster, where the threshold is the acceptable coherence deviation, which is 0.5 by default.

[0071] For each cluster, any new energy generator unit within the cluster is selected as the reference unit for that cluster. Based on the DC voltage and inverter output internal potential of each cluster's reference unit, the grid-connected controlled voltage source command for each cluster's reference unit is calculated.

[0072] Suppose that within a group of N renewable energy generating units, there are M clusters, and let m be the number of clusters in the j-th cluster. j For a given cluster of new energy generating units, any one unit can be selected as the reference unit for that cluster. The grid-connected controlled voltage source command for the reference unit can be calculated using the following formula:

[0073]

[0074] Among them, U ctl_j The command for the grid-connected controlled voltage source of the j-th cluster reference machine includes three phases a, b, and c, with the instantaneous values ​​of the three-phase voltages expressed as u. ctl.a_j u ctl.b_j u ctl.c_j U dc_j E is the DC voltage of the j-th cluster reference machine. j =(e a_j ,e b_j ,e c_j ) T For the inverter output internal potential of the j-th cluster reference machine, e a_j e b_j e c_jThe instantaneous value of the three-phase voltage of the inner potential output by the inverter of the jth cluster reference machine.

[0075] The reference machines of all clusters can be further equivalent to a new energy station reference machine. According to the grid-connected side controlled voltage source instruction of each cluster reference machine and the output active power, the grid-connected side controlled voltage source instruction of the new energy station reference machine is calculated according to the following formula:

[0076]

[0077] wherein, U ctl_ref =(u ctl.a_ref ,u ctl.b_ref ,u ctl.c_ref ) T is the grid-connected side controlled voltage source instruction of the new energy station reference machine, containing abc three-phase, and the instantaneous values of the three-phase voltages are respectively represented by u ctl.a_ref ,u ctl.b_ref ,u ctl.c_ref , and P j is the output active power of the jth cluster reference machine.

[0078] The grid-connected side output current of the new energy station reference machine can be further calculated according to the inner potential output by the inverter of each cluster reference machine according to the following formula:

[0079]

[0080] wherein, I ref is the grid-connected side output current of the new energy station reference machine, r is an equivalent coefficient set to prevent the impedance of the new energy station aggregation machine from being less than a threshold (i.e., the impedance is too small), 1 < r < N, E i is the effective value of the inner potential output by the inverter of the new energy unit i as the reference machine, is the phasor form of E i , U PCC is the effective value of the bus voltage of the collection point, is the phasor form of U PCC , Z L_i is the grid-connected impedance of the new energy unit i, and Z T_i is the grid-connected transformer impedance of the new energy unit i.

[0081] The DC side controlled current source current instruction of the new energy station reference machine can be further calculated according to the output current and the DC voltage of each cluster reference machine, and the equivalent DC capacitor of the new energy station reference machine can be calculated according to the DC capacitor and the DC voltage of each cluster reference machine.

[0082] Compared with the equivalent front new energy unit, the primary circuit model of the station reference machine does not contain the grid-connected side three-phase IGBT switching bridge arm, and the grid-connected side three-phase IGBT switching bridge arm is replaced by a controlled current source in parallel with an equivalent DC capacitor, so the formula for calculating the DC side controlled current source current command and the equivalent DC capacitor is as follows:

[0083]

[0084]

[0085] wherein, I dc_ref is the DC side controlled current source current command of the new energy station reference machine, M is the number of clusters, i a_j , i b_j , i c_j is the instantaneous value of the inverter output three-phase current of the jth cluster reference machine, is the DC bus voltage of the new energy station reference machine, U dc_j is the DC voltage of the jth cluster reference machine, C ref is the equivalent DC capacitor of the new energy station reference machine, M is the number of clusters, C j is the DC capacitor of the jth cluster reference machine.

[0086] According to the grid-connected side controlled voltage source command and the grid-connected side output current of the new energy station reference machine, the grid-connected filter capacitor and the grid-connected branch impedance of the new energy station reference machine can be calculated by the following formula:

[0087]

[0088]

[0089] wherein, C ft_ref is the grid-connected filter capacitor of the new energy station reference machine, is the phasor form of U i , C i is the filter capacitor of the new energy unit i, is the phasor form of U ctl_ref , is the phasor form of I ref , Z L_ref is the internal impedance of the new energy station reference machine, and the parallel value of the internal impedance of all cluster reference machines is taken, Z T_ref is the grid-connected branch impedance of the new energy station reference machine.

[0090] Since the grid-connected filter capacitance of the new energy station aggregation machine is r times the grid-connected filter capacitance of the new energy station reference machine, and the grid-connected branch impedance of the new energy station aggregation machine is 1 / r times the grid-connected branch impedance of the new energy station reference machine, the grid-connected filter capacitance and the grid-connected branch impedance of the new energy station aggregation machine can be calculated according to the grid-connected filter capacitance and the grid-connected branch impedance of the new energy station reference machine.

[0091] After obtaining the parameters of the reference machine and the aggregation machine of each group, the new energy station aggregation equivalence is realized by combining the equivalent form of each group.

[0092] Based on the above method, the new energy station aggregation equivalence of a certain new energy station is obtained, as shown in Figure 2 From the Figure 2 It can be seen that the new energy equivalent machine proposed by the above method includes a station reference machine and a station aggregation machine, which are connected in parallel, the primary side parameters of the station reference machine of the equivalent machine set are only related to the operating condition, and the controller can be directly taken from the actual machine set in the station, the station aggregation machine parameter has no controller part, and the primary side parameter is only related to the equivalent coefficient, so it is not necessary to use the capacity weighting method to perform parameter conversion; meanwhile, the output currents of the station reference machine and the station aggregation machine are strictly synchronized, and are superimposed through the parallel connection, so that the oscillation problem caused by the asynchronization of signal sampling and signal amplification in some scenarios caused by the multiplication method can be effectively solved.

[0093] The new energy station whose reference machine grid-connected filter capacitance, reference machine grid-connected branch impedance, aggregation machine grid-connected filter capacitance and aggregation machine grid-connected branch impedance are calculated, i.e., the equivalent new energy station, is subjected to new energy station equivalent simulation in a real-time simulation environment.

[0094] Based on the same technical solution, the application further discloses a software system of the above method, and a new energy station equivalent simulation system in a real-time simulation environment, which comprises:

[0095] The group and cluster dividing module divides the new energy machine groups in the new energy station according to the types of the new energy machine groups and the connected collection point bus, equivalently connects each new energy machine group into a new energy station reference machine and a new energy station aggregation machine connected in parallel to the collection point bus, and divides the new energy machine groups into clusters.

[0096] The first reference machine parameter calculation module selects any new energy unit within each cluster as the reference machine for that cluster. Based on the DC voltage and inverter output internal potential of each cluster's reference machine, it calculates the grid-connected controlled voltage source command for each cluster's reference machine. It then equates all clusters' reference machines to a single new energy power station reference machine. Based on the grid-connected controlled voltage source command and active power output of each cluster's reference machine, it calculates the grid-connected controlled voltage source command for the new energy power station reference machine. Based on the inverter output internal potential of each cluster's reference machine, it calculates the grid-connected output current of the new energy power station reference machine. Based on the output current and DC voltage of each cluster's reference machine, it calculates the DC-side controlled current source current command for the new energy power station reference machine. Finally, based on the DC capacitance and DC voltage of each cluster's reference machine, it calculates the equivalent DC capacitance of the new energy power station reference machine.

[0097] The second reference unit parameter calculation module calculates the grid-connected filter capacitor and grid-connected branch impedance of the new energy power station reference unit based on the grid-connected side controlled voltage source command and grid-connected side output current.

[0098] The aggregator parameter calculation module calculates the grid-connected filter capacitor and grid-connected branch impedance of the aggregator in the new energy power station based on the grid-connected filter capacitor and grid-connected branch impedance of the reference unit.

[0099] The equivalent simulation module performs a real-time equivalent simulation of a new energy power station under a given simulation environment, based on the calculated reference generator grid-connected filter capacitor, reference generator grid-connected branch impedance, aggregater grid-connected filter capacitor, and aggregater grid-connected branch impedance.

[0100] In the above system, the data processing flow of each module is the same as that of the above method, so it will not be described again here.

[0101] Based on the same technical solution, the present invention also discloses a computer-readable storage medium storing one or more programs, wherein the one or more programs include instructions that, when executed by a computing device, cause the computing device to perform an equivalent simulation method for new energy power stations in a real-time simulation environment.

[0102] Based on the same technical solution, the present invention also discloses a computing device, including one or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, and the one or more programs include instructions for executing an equivalent simulation method for new energy power plants in a real-time simulation environment.

[0103] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0104] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0105] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0106] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0107] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. A method for equivalent simulation of new energy power stations in a real-time simulation environment, characterized in that, include: New energy units in new energy power stations of the same type and connected to the same aggregation point bus are divided into the same group. Each new energy unit group is equivalent to a new energy power station reference machine and a new energy power station aggregator machine connected in parallel to the aggregation point bus. The dynamic deviation index of control characteristics between new energy units in the group is calculated. If the dynamic deviation index of control characteristics is less than the threshold, the corresponding new energy units are classified into the same cluster. For each cluster, any new energy unit within the cluster is selected as the reference unit for that cluster. All reference units in all clusters are equivalent to one new energy power station reference unit. Based on the DC voltage, output current, output active power, DC capacitance, and inverter output internal potential of each cluster reference unit, the grid-connected side controlled voltage source command, grid-connected side output current, DC side controlled current source current command, and equivalent DC capacitance of the new energy power station reference unit are calculated. Based on the grid-connected controlled voltage source command and grid-connected output current of the new energy power station reference unit, calculate the grid-connected filter capacitor and grid-connected branch impedance of the new energy power station reference unit; Based on the grid-connected filter capacitor and grid-connected branch impedance of the reference unit of the new energy power station, calculate the grid-connected filter capacitor and grid-connected branch impedance of the aggregator of the new energy power station. For new energy power plants with calculated reference generator grid-connected filter capacitor, reference generator grid-connected branch impedance, aggregator grid-connected filter capacitor, and aggregator grid-connected branch impedance, perform equivalent simulation of the new energy power plant in a real-time simulation environment; The formula for calculating the dynamic deviation index of the above control characteristics is as follows: Where D(i,j′) is the dynamic deviation index of the control characteristics between new energy unit i and new energy unit j′, N is the number of new energy units in the group, and A i (t k A represents the time-domain trajectory of the state vector of a new energy unit i obtained from simulation or actual fault recording. j′ (t k ) represents the time-domain trajectory of the state vector of the new energy unit j′ obtained from simulation or actual fault recording, where i ≠ j′, and T is the duration of the time-domain trajectory. k It represents the k-th moment within the time interval from 0 to T.

2. The method for equivalent simulation of new energy power stations in a real-time simulation environment according to claim 1, characterized in that, For each cluster, any new energy unit within the cluster is selected as the reference unit for that cluster. All reference units across all clusters are treated as a single new energy power station reference unit. Based on the DC voltage, output current, output active power, DC capacitance, and inverter output internal potential of each cluster's reference unit, the grid-connected controlled voltage source command, grid-connected output current, DC-connected controlled current source command, and equivalent DC capacitance of the new energy power station reference unit are calculated, including: For each cluster, select any new energy unit within the cluster as the reference unit for that cluster. Based on the DC voltage and inverter output internal potential of each cluster's reference unit, calculate the grid-connected controlled voltage source command for each cluster's reference unit. The reference units of all clusters are treated as a single reference unit for the new energy power station. Based on the grid-connected controlled voltage source command and active power output of each cluster reference unit, the grid-connected controlled voltage source command of the new energy power station reference unit is calculated. Based on the inverter output internal potential of each cluster reference unit, the grid-connected output current of the new energy power station reference unit is calculated. Based on the output current and DC voltage of each cluster reference unit, the DC-side controlled current source command of the new energy power station reference unit is calculated. Based on the DC capacitance and DC voltage of each cluster reference unit, the equivalent DC capacitance of the new energy power station reference unit is calculated.

3. The method for equivalent simulation of new energy power stations in a real-time simulation environment according to claim 2, characterized in that, The calculation formula for the grid-connected controlled voltage source command of each cluster reference machine is as follows: Among them, U ctl_j For the grid-connected controlled voltage source command of the j-th cluster reference machine, U dc_j E is the DC voltage of the j-th cluster reference machine. j The inverter output internal potential is the reference machine of the j-th cluster.

4. The method for equivalent simulation of new energy power stations in a real-time simulation environment according to claim 2, characterized in that, The formula for calculating the grid-connected controlled voltage source command of the reference unit in a new energy power station is as follows: Among them, U ctl_ref For the grid-connected controlled voltage source command of the reference unit of the new energy power station, U ctl_j The command is the grid-connected controlled voltage source command for the j-th cluster reference machine, where M is the number of clusters, and P is the value of the reference machine. j For the active power output of the j-th cluster reference machine, m j Let be the number of new energy generating units in the j-th cluster.

5. The method for equivalent simulation of new energy power stations in a real-time simulation environment according to claim 2, characterized in that, The formula for calculating the grid-connected output current of the reference unit in a new energy power station is as follows: Among them, I ref E represents the grid-connected output current of the reference unit in the renewable energy power station, r is the equivalent coefficient set to prevent the impedance of the polymer generator in the renewable energy power station from falling below a threshold, and E is the reference output current on the grid-connected side. i The effective value of the inverter output internal electromotive force when the new energy unit i is used as the reference unit. For E i phasor form, U PCC This represents the effective value of the bus voltage at the collection point. For U PCC The phasor form of Z L_i Z is the grid-connected internal impedance of the new energy unit i. T_i Let be the impedance of the grid-connected transformer for new energy unit i.

6. The method for equivalent simulation of new energy power stations in a real-time simulation environment according to claim 2, characterized in that, The formula for calculating the DC-side controlled current source current command of the reference unit in a new energy power station is as follows: Among them, I dc_ref For the DC-side controlled current source current command of the reference unit of the new energy power station, M is the number of clusters, i a_j i b_j i c_j e represents the instantaneous value of the three-phase current output by the inverter of the j-th cluster reference machine. a_j e b_j e c_j Let be the instantaneous values ​​of the three-phase voltage and internal electromotive force of the inverter output of the j-th cluster reference machine. U is the DC bus voltage of the reference unit for the new energy power station. dc_j Let be the DC voltage of the j-th cluster reference machine.

7. The method for equivalent simulation of new energy power stations in a real-time simulation environment according to claim 2, characterized in that, The formula for calculating the equivalent DC capacitance of the reference unit in a new energy power station is as follows: Among them, C ref Here, M represents the equivalent DC capacitance of the reference unit at the renewable energy power station, and M is the number of clusters. U is the DC bus voltage of the reference unit for the new energy power station. dc_j C is the DC voltage of the j-th cluster reference machine. j Let be the DC capacitor of the j-th cluster reference machine.

8. The method for equivalent simulation of new energy power stations in a real-time simulation environment according to claim 1, characterized in that, The formula for calculating the grid-connected filter capacitor of the reference unit in a new energy power station is: Among them, C ft_ref U is the grid-connected filter capacitor for the reference unit of the new energy power station; r is the equivalent coefficient set to prevent the impedance of the aggregation unit of the new energy power station from falling below the threshold; U i Let be the effective value of the terminal voltage of the new energy unit i. It's U i phasor form, C i For the filter capacitor of the new energy unit i, U ctl_ref This is a command for the grid-connected controlled voltage source of the reference unit in a new energy power station. For U ctl_ref phasor form, I ref The grid-connected output current of the reference unit in the new energy power station. For I ref The phasor form of Z L_ref The internal impedance of the reference unit in the new energy power station is taken as the parallel value of the internal impedances of all cluster reference units.

9. The method for equivalent simulation of new energy power stations in a real-time simulation environment according to claim 1, characterized in that, The formula for calculating the grid connection branch impedance of the reference unit in a new energy power station is: Among them, Z T_ref U is the grid connection branch impedance of the reference unit for the new energy power station. ctl_ref This is a command for the grid-connected controlled voltage source of the reference unit in a new energy power station. For U ctl_ref phasor form, I ref The grid-connected output current of the reference unit in the new energy power station. For I ref phasor form, U PCC This represents the effective value of the bus voltage at the collection point. For U PCC The phasor form.

10. The method for equivalent simulation of new energy power stations in a real-time simulation environment according to claim 1, characterized in that, Based on the grid-connected filter capacitor and grid-connected branch impedance of the reference unit in the new energy power station, calculate the grid-connected filter capacitor and grid-connected branch impedance of the aggregator in the new energy power station, including: The grid-connected filter capacitor of the new energy power station aggregator is r times the grid-connected filter capacitor of the new energy power station reference unit, and the grid-connected branch impedance of the new energy power station aggregator is 1 / r of the grid-connected branch impedance of the new energy power station reference unit; where r is an equivalent coefficient set to prevent the impedance of the new energy power station aggregator from being less than the threshold.

11. A real-time simulation system for equivalent simulation of new energy power stations, characterized in that, include: The grouping and clustering module divides new energy units in new energy power stations of the same type and connected to the same aggregation point bus into the same group. Each new energy unit group is equivalent to a new energy power station reference machine and a new energy power station aggregator machine connected in parallel to the aggregation point bus. The module calculates the dynamic deviation index of control characteristics between new energy units in the group. If the dynamic deviation index of control characteristics is less than the threshold, the corresponding new energy units are classified into the same cluster. The formula for calculating the dynamic deviation index of control characteristics is: Where D(i,j′) is the dynamic deviation index of the control characteristics between new energy unit i and new energy unit j′, N is the number of new energy units in the group, and A i (t k A represents the time-domain trajectory of the state vector of a new energy unit i obtained from simulation or actual fault recording. j′ (t k ) represents the time-domain trajectory of the state vector of the new energy unit j′ obtained from simulation or actual fault recording, where i ≠ j′, and T is the duration of the time-domain trajectory. k It represents the k-th moment within the time interval from 0 to T; The first reference machine parameter calculation module selects any new energy unit within each cluster as the reference machine for that cluster, and equates all the reference machines in all clusters to a single new energy power station reference machine. Based on the DC voltage, output current, output active power, DC capacitance, and inverter output internal potential of each cluster's reference machine, it calculates the grid-connected side controlled voltage source command, grid-connected side output current, DC side controlled current source current command, and equivalent DC capacitance of the new energy power station reference machine. The second reference machine parameter calculation module calculates the grid-connected filter capacitor and grid-connected branch impedance of the new energy power station reference machine based on the grid-connected side controlled voltage source command and grid-connected side output current of the new energy power station reference machine. The aggregator parameter calculation module calculates the grid-connected filter capacitor and grid-connected branch impedance of the aggregator in the new energy power station based on the grid-connected filter capacitor and grid-connected branch impedance of the reference unit. The equivalent simulation module performs a real-time equivalent simulation of a new energy power station under a given simulation environment, based on the calculated reference generator grid-connected filter capacitor, reference generator grid-connected branch impedance, aggregater grid-connected filter capacitor, and aggregater grid-connected branch impedance.

12. The equivalent simulation system for new energy power stations in a real-time simulation environment according to claim 11, characterized in that, The first reference machine parameter calculation module selects any new energy unit within each cluster as the reference machine for that cluster. Based on the DC voltage and inverter output internal potential of each cluster's reference machine, it calculates the grid-connected controlled voltage source command for each cluster's reference machine. It then equates all clusters' reference machines to a single new energy power station reference machine. Based on the grid-connected controlled voltage source command and active power output of each cluster's reference machine, it calculates the grid-connected controlled voltage source command for the new energy power station reference machine. Based on the inverter output internal potential of each cluster's reference machine, it calculates the grid-connected output current of the new energy power station reference machine. Based on the output current and DC voltage of each cluster's reference machine, it calculates the DC-side controlled current source current command for the new energy power station reference machine. Finally, based on the DC capacitance and DC voltage of each cluster's reference machine, it calculates the equivalent DC capacitance of the new energy power station reference machine.

13. A computer-readable storage medium for storing one or more programs, characterized in that, The one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any of the methods according to claims 1 to 10.

14. A computing device, characterized in that, include: One or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, the one or more programs including instructions for performing any of the methods according to claims 1 to 10.

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