Parameter setting method and system for large-scale network access of network-forming inverter

Abstract

The invention discloses a parameter setting method and system for large-scale network access of a network-forming inverter, and belongs to the technical field of new energy grid connection. A single physical unit is used, and the access conditions of units under different control in different places are simulated by continuously changing line parameters and control parameters in sequence. A physical-digital interface is connected into a digital collection bus, parameter setting is carried out, and a digital simulation unit group is correspondingly established, so that the external performance characteristics of all units are consistent. And finally, exporting the parameters of the tested physical unit to a real grid-connected unit for grid connection. According to the parameter setting method in the method, it is ensured that the external environment of the physical unit is approximate to that of a real unit when the physical unit is connected, a high-credibility result is given when large-scale grid-connected pre-test is achieved, and the cost and threshold of physical unit test are reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy grid connection, and more specifically, relates to a parameter setting method and system for large-scale grid connection of a grid-connected inverter. Background Art

[0002] The current international energy security situation is severe, requiring the acceleration of clean and low-carbon energy transformation. For the weak power grid in the "Shagohuang" area that lacks large-scale conventional hydropower and thermal power support, networking equipment is widely praised for its ability to independently build voltage phases. Different from the current source following control of the network-following equipment, the networking equipment is a voltage source that builds voltage and frequency independently. When accessed on a large scale, it faces the problem of parallel connection of voltage sources and the need for pre-synchronization and debugging. When faced with the access and debugging of large-scale networking equipment, engineering companies often need a lot of time and power off to test the equipment, which is very time-consuming. The present invention aims to provide a low-cost and efficient debugging method and system for large-scale access of networking equipment. Summary of the invention

[0003] In order to solve the deficiencies in the prior art, the present invention provides a parameter setting method and system for large-scale grid-connected grid-connected inverters, by digitally constructing a single physical unit, and by modifying different line impedances and control parameters of each voltage loop and current loop, etc., to establish a more accurate model of the corresponding physical unit. The present invention aims to provide a platform for grid-connected testing of single or multiple physical units, ensuring that the access environment remains consistent on the digital side and the physical side when the real unit is connected to the grid, and can perform advance pre-testing and parameter correction for large-scale grid-connected inverters, improve grid-connected efficiency, and reduce the threshold and cost of physical testing.

[0004] The present invention adopts the following technical solution. A first aspect of the present invention provides a parameter setting method for large-scale grid-connected grid-connected inverters, comprising the following steps: Step 1: Establish a virtual-real fusion topology structure including digital simulation models and physical units; the digital simulation model is used to simulate the grid-connected topology structure of new energy grid-forming stations; Step 2: According to the setting order of each physical unit, the parameters of the physical unit to be pre-tested for grid connection are given to the physical unit, and the physical unit with the parameters of the physical unit is connected to the digital simulation model. After the physical unit is debugged and stabilized, the current operation control parameters of the physical unit are saved as the control parameters of the physical unit to the storage medium; Step 3: Disconnect the connection between the physical unit and the digital simulation model, and establish a digital simulation unit in the digital simulation model that is consistent with the external characteristics of the physical unit, and continue to connect the digital simulation unit to the grid in the digital simulation model to complete the grid connection pre-test of a physical unit; Step 4: Determine whether the grid-connection pre-test of all physical units has been completed. If not, return to step 2 to perform the grid-connection pre-test of the next physical unit. If completed, proceed to step 5. Step 5: Export the control parameters stored in the storage medium to the corresponding physical units.

[0005] Preferably, the virtual-real fusion topological structure comprises: a physical unit module, a physical-digital interface module and a digital simulation model, and the physical unit module is connected to the digital simulation model via the physical-digital interface module; The physical unit module includes: a physical unit measurement unit, a branch A1, and the branch A1 includes a physical unit VSG #A1, an adjustable impedance unit, and a physical unit switch unit SW connected in sequence. A1 The physical unit measurement unit is respectively connected to the adjustable impedance unit and the physical unit switch unit SW A1 The physical unit VSG #A1 includes: a first DC bus power supply interface, a first grid-connected inverter and a first inverter controller; the first DC bus power supply interface is connected to the input end of the first grid-connected inverter, and the output end of the first grid-connected inverter is connected to the physical unit switch unit SW A1 Connected to the physical-digital interface module, the first inverter controller is connected to the first grid-connected inverter; The digital simulation model comprises: a digital unit module, a busbar module and a power grid module; the digital unit module is connected to the power grid module via the busbar module, and the physical-digital interface module is connected to the busbar module.

[0006] Preferably, the digital unit module comprises: D Digital simulation unit VSG #Bi, i=1,2,···,N D Each digital simulation unit VSG #Bi passes through the digital simulation impedance unit Z Bi and digital simulation switch unit SW Bi Connected to the busbar module, forming a plurality of branches i connected to the busbar module, each branch i is provided with a digital simulation unit measurement unit i; The digital simulation unit VSG #Bi includes: a second DC bus power supply interface, a second grid-connected inverter and a second inverter controller, wherein the second DC bus power supply interface is connected to the input end of the second grid-connected inverter, and the output end of the second grid-connected inverter is connected to the digital simulation impedance unit Z Bi and digital simulation switch unit SW Bi The second inverter controller includes a delay / advance link, and the second inverter controller is connected to the second grid-connected inverter.

[0007] Preferably, step 2 comprises: Assign serial numbers to the grid connection pre-test according to the physical unit numbers to be tested; After the parameters of the physical unit VSG #Ci are given to the physical unit VSG #A1, the physical unit switch unit SW is closed. A1 , to connect the physical unit VSG #A1 to the digital simulation model through the physical-digital interface module, i=1,2,···,N C After the physical unit VSG #A1 has been debugged and reached stable operation, the physical unit measurement unit is used to measure the electrical quantity of branch A1 to obtain the first electrical quantity of branch A1, which includes voltage, current and phase angle, and the first electrical quantity is output to the busbar module of the digital simulation model to save its waveform f A1 (t) to a storage medium; The current operation control parameters of the physical machine group VSG #A1 are saved in the storage medium as the control parameters of the replaced physical machine group VSG #Ci.

[0008] Preferably, step 3 comprises: Disconnect the physical unit VSG #A1, and model the digital simulation unit VSG #Bi in the digital simulation model according to the current operation control parameters of the physical unit VSG #A1 to obtain the digital simulation unit VSG #Bi to be connected; Close the digital simulation switch unit SW Bi , by connecting to the digital simulation unit VSG #Bi, using the digital simulation unit measurement unit i and the bus measurement unit to measure the electrical quantities on the branch i and the busbar respectively to obtain the second electrical quantities of multiple cycles, and according to the second electrical quantities of multiple cycles, the waveform f is obtained. B1 (t), the number of cycles and the waveform f A1 (t) the same; Determine whether the external characteristics of the physical unit VSG #A1 and the digital simulation unit VSG #Bi are consistent. If they are consistent, execute step 4; if they are inconsistent, adjust the control parameters of the digital simulation unit VSG #Bi until the external characteristics of the physical unit VSG #A1 and the digital simulation unit VSG #Bi are consistent, update the corresponding control parameters stored in step 2 with the adjusted control parameters of the digital simulation unit VSG #Bi, and continue to execute step 4.

[0009] Preferably, judging whether the external characteristics of the physical unit VSG #A1 and the digital simulation unit VSG #Bi are consistent includes: The waveform f A1 (t) and f B1 (t) Perform FFT processing to obtain waveform f A1 (t) and f B1 (t) The parameters of the fundamental and harmonic quantities are calculated according to the waveform fA1 (t) and f B1 (t) The parameters of the fundamental and harmonic quantities in the waveform f A1 (t) and f B1 (t)Whether there is consistency.

[0010] Preferably, according to the waveform f A1 (t) and f B1 (t) The parameters of the fundamental and harmonic quantities in the waveform f A1 (t) and f B1 (t) Whether it is consistent, including waveform f A1 (t) and f B1 (t) If the amplitude difference, frequency difference and phase difference of the fundamental wave in the waveform f are all less than the set value or ratio, then the waveform f A1 (t) and f B1 (t) The fundamental wave quantity is consistent; When the waveform f A1 (t) and f B1 If the amplitude difference, frequency difference and phase difference of the corresponding frequency harmonic quantity in (t) are less than the set value or ratio, then the waveform f A1 (t) and f B1 (t) The harmonic content is consistent; If the waveform f A1 (t) and f B1 (t) When the fundamental wave quantity and harmonic wave quantity are consistent, the external characteristics of the physical unit VSG #A1 and the digital simulation unit VSG #Bi are consistent.

[0011] Preferably, the parameters of the digital simulation unit VSG #Bi are adjusted, including: the time t of the delay / advance link d , adjust the voltage control loop proportional parameter K up , integration parameter K ui , current loop control loop proportional parameter K ip , integration parameter K ii and line impedance Z eq at least one of .

[0012] A second aspect of the present invention provides a parameter setting system for large-scale grid-connected grid-connected inverters, which is used to execute a parameter setting method for large-scale grid-connected grid-connected inverters according to the first aspect, comprising: a physical unit module, a physical-digital interface module and a digital simulation model, wherein the physical unit module is connected to the digital simulation model via the physical-digital interface module; The physical unit module includes: a physical unit VSG #A1, an adjustable impedance unit, a physical unit measurement unit and a physical unit switch unit SW A1 ; Physical unit VSG #A1, adjustable impedance unit and physical unit switch unit SWA1 They are connected in sequence to form branch A1; the physical unit measurement unit is used to measure the electrical quantity of branch A1; The digital simulation model includes: a digital unit module, a busbar module and a power grid module.

[0013] Preferably, the physical-digital interface module includes: an active four-quadrant power amplifier and a digital simulation interface; the physical unit VSG #A1 outputs an analog AC signal through a grid-connected inverter, and after passing through the active four-quadrant power amplifier, the analog quantity is converted into a digital quantity and enters the digital simulation model.

[0014] Preferably, the physical unit VSG #A1 comprises: a first DC bus power supply interface, a first grid-connected inverter and a first inverter controller; the first DC bus power supply interface is a physical device, and the power source comprises: a wind turbine plus a machine-side rectifier, a photovoltaic array and at least one of an energy storage battery; the first DC bus power supply interface is connected to the input end of the first grid-connected inverter, and the output end of the first grid-connected inverter is connected to the physical unit switch unit SW A1 Connected with the physical-digital interface module; the first inverter controller is connected with the first grid-connected inverter.

[0015] Preferably, the digital unit module comprises: D Digital simulation units, not less than the number of physical units to be connected to the network, digital simulation unit VSG #Bi represents each digital simulation unit, i=1,2,···,N D Each digital simulation unit VSG #Bi passes through the digital simulation impedance unit Z Bi and digital simulation switch unit SW Bi Connected to the busbar module, forming multiple branches i connected to the busbar module, each branch i is provided with a digital simulation unit measurement unit i for measuring the electrical quantity of the branch i; The digital simulation unit VSG #Bi includes: a second DC bus power supply interface, a second grid-connected inverter and a second inverter controller; the second DC bus power supply interface, the second grid-connected inverter and the second inverter controller of the digital simulation unit VSG #Bi are simulation models; the second inverter controller includes: a delay / advance link, which is used to adjust parameters to make the output of the physical unit VSG #A1 consistent with that of the digital simulation unit VSG #Bi.

[0016] Preferably, the busbar module comprises: a busbar and a busbar measuring unit for measuring the electrical quantity of the busbar; each digital simulation unit VSG #Bi can be connected to the busbar as a branch; The grid module includes: digital simulation grid G1 and grid impedance Z g ; Collecting busbar through grid impedance Z gConnected to the digital simulation grid G1; wherein the digital simulation grid G1 and the grid impedance Z g It is determined according to the parameters of the local power grid access.

[0017] The third aspect of the present invention provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the computer program is loaded into the processor, a parameter setting method for large-scale grid access of a grid-connected inverter according to the first aspect is implemented.

[0018] The fourth aspect of the present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements a parameter setting method for large-scale grid access of a grid-connected inverter according to the first aspect.

[0019] Compared with the prior art, the beneficial effects of the present invention include at least: 1. The present invention uses a single physical unit to simulate the access of units with different controls at different locations by continuously changing line parameters and control parameters in sequence, uses a physical-digital interface to access the digital bus, and performs parameter setting and establishes a digital simulation unit group accordingly, so that the simulation unit modeling is more in line with the actual situation, ensuring that when the physical unit is connected to the digital simulation system, its access environment is consistent with the actual unit environment, with higher credibility, and the grid-connected inverter cluster provides active and stable support for the power grid; 2. The threshold and cost of physical unit experiments have been greatly reduced, and only one physical unit is needed to complete the grid-connected pre-test. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a flow chart of a parameter setting method for large-scale grid-connection of a grid-connected inverter provided in accordance with an embodiment of the present invention; Figure 2 A schematic diagram of a virtual-real fusion topological structure including a digital simulation model and a physical unit involved in the present invention; Figure 3 It is a schematic diagram of a physical unit VSG #A1 in an embodiment of the present invention; Figure 4 It is a schematic diagram of a physical-digital interface module in an embodiment of the present invention; Figure 5 It is a schematic diagram of the digital simulation unit VSG #Bi in the embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The described embodiments are only embodiments of a part of the present invention, not all embodiments. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0022] The present invention provides a parameter setting method for large-scale grid-connected inverters, using a single physical unit to simulate the access of units with different controls at different locations by continuously changing line parameters and control parameters in sequence. The physical-digital interface is used to access the digital bus, and the parameters are set and a digital simulation unit group is established accordingly, so that the external performance characteristics of each unit are consistent. Finally, the parameters of the tested physical unit are exported to the real grid-connected unit for grid connection.

[0023] Specifically, if Figure 1 As shown, embodiment 1 of the present invention provides a parameter setting method for large-scale grid-connected grid-connected inverters, comprising the following steps: Step 1: Establish a virtual-reality fusion topology structure including digital simulation models and physical units; the digital simulation model is used to simulate the grid-connected topology structure of new energy grid-type stations; the physical units are used to gradually replace the physical units to be connected to the digital simulation model, debug and establish corresponding digital simulation units in the digital simulation model.

[0024] Preferably but not limiting, step 1 specifically comprises: Step 1.1: Construct a virtual-real fusion topology structure, including: a physical unit module, a physical-digital interface module and a digital simulation model. The physical unit module is connected to the digital simulation model through the physical-digital interface module.

[0025] Further preferably but not limiting, such as Figure 2 As shown, the physical unit module includes: physical unit VSG #A1, adjustable impedance unit, physical unit measurement unit and physical unit switch unit SW A1 ; Physical unit VSG #A1, adjustable impedance unit and physical unit switch unit SW A1 They are connected in sequence to form branch A1; the physical unit measurement unit is used to measure the electrical quantity of branch A1.

[0026] like Figure 3As shown, the physical unit VSG #A1 includes: a first DC bus power supply interface, a first grid-connected inverter and a first inverter controller; the first DC bus power supply interface is a physical device, and the power source is diverse, such as but not limited to, a wind turbine plus a machine-side rectifier, a photovoltaic array and a storage battery and other DC sources; the first DC bus power supply interface is connected to the input end of the first grid-connected inverter, and the output end of the first grid-connected inverter is connected to the physical unit switch unit SW A1 Connected with the physical-digital interface module; the first inverter controller is connected with the first grid-connected inverter.

[0027] Further preferably but not limiting, such as Figure 4 As shown, the physical-digital interface module includes: an active four-quadrant power amplifier and a digital simulation interface; the physical unit VSG #A1 outputs an analog AC signal through the first grid-connected inverter, and after passing through the active four-quadrant power amplifier, the analog quantity is converted into a digital quantity and enters the digital simulation model.

[0028] Further preferably but not limiting, such as Figure 2 As shown, the digital simulation model includes: a digital unit module, a busbar module and a power grid module; the digital unit module is connected to the power grid module via the busbar module, and the physical-digital interface module is connected to the busbar module.

[0029] Digital unit module includes: N D digital simulation units, not less than the number of physical units to be connected to the network; for example but not limited to, digital simulation unit VSG #Bi represents each digital simulation unit, i=1,2,···,N D Each digital simulation unit VSG#Bi passes through the digital simulation impedance unit Z Bi and digital simulation switch unit SW Bi It is connected to the busbar module to form multiple branches i connected to the busbar module. Each branch i is provided with a digital simulation unit measurement unit i for measuring the electrical quantity of the branch i.

[0030] like Figure 5 As shown, the digital simulation unit VSG #Bi is similar in structure to the physical unit VSG #A1, and also includes: a second DC bus power supply interface, a second grid-connected inverter and a second inverter controller; it can be understood that the second DC bus power supply interface, the second grid-connected inverter and the second inverter controller of the digital simulation unit VSG #Bi are simulation models; it is worth noting that compared with the physical unit VSG #A1, the digital simulation unit VSG #Bi has an additional delay / advance link at the second inverter controller, which is used to adjust parameters to make the output of the physical unit VSG #A1 consistent with that of the digital simulation unit VSG #Bi.

[0031] The busbar module includes: a busbar and a busbar measuring unit for measuring the electrical quantities of the busbar; each digital simulation unit VSG #Bi can be connected to the busbar as a branch.

[0032] The grid module includes: digital simulation grid G1 and grid impedance Z g ; Collecting busbar through grid impedance Z g Connected to the digital simulation grid G1; wherein the digital simulation grid G1 and the grid impedance Z g It is determined according to the parameters of the local power grid access.

[0033] Step 1.2: Get N C Parameters of the physical units to be connected to the network, for example but not limited to, the physical unit VSG #Ci represents each physical unit to be connected to the network, i=1,2,···,N C The physical unit VSG #Ci parameters include: voltage and current loop / active and reactive loop control parameters, impedance size and other related parameters.

[0034] Step 2: According to the set order, the parameters of a physical unit to be pre-tested for grid connection are given to the physical unit, and the physical unit is connected to the digital simulation model. After the physical unit VSG #A1 is debugged and stabilized, the current operating control parameters of the physical unit are saved to the storage medium as the control parameters of the replaced physical unit.

[0035] Preferably but not limiting, step 2 specifically comprises: Step 2.1: Assign a serial number to the grid pre-test according to the number of the physical unit to be tested. For example, if the physical unit of the current grid pre-test is numbered VSG #C1, then set i=1 to subsequently establish the corresponding digital simulation unit VSG#B1.

[0036] Step 2.2: Give the physical unit VSG #Ci parameters to the physical unit VSG #A1, and close the physical unit switch unit SW A1 , connect the physical unit VSG #A1 to the digital simulation model through the physical-digital interface module; after the physical unit VSG #A1 is debugged and reaches stable operation, the physical unit measurement unit is used to measure the electrical quantity of branch A1 to obtain the first electrical quantity of branch A1, the first electrical quantity includes: voltage, current and phase angle, and the first electrical quantity is output to the collection bus of the digital simulation model to save its waveform f A1 (t) to a storage medium, for example but not limited to, taking 10 periodic quantities; measuring the electrical quantities of the busbar module with a busbar measurement unit to obtain the voltage, current and phase angle of the busbar.

[0037] For example but not limited to, when i=1, the parameters of the physical unit VSG #C1 are given to the physical unit VSG #A1, and the physical unit VSG #A1 replaces the physical unit VSG #C1 to access the digital simulation model, and the electrical quantity data is obtained by the physical unit measurement unit.

[0038] The real-time feedback data of the electrical quantity of branch A1 and the collection bus include: frequency ω g , voltage amplitude U g , Active power P g and reactive power Q g The equivalent internal potential phase θ and amplitude E of the busbar are generated through the active control loop and the reactive control loop. m .

[0039] Step 2.3: Save the current operating control parameters of the physical unit VSG #A1 as the replaced control parameters of the physical unit VSG #Ci to the storage medium.

[0040] Step 3: Disconnect the physical unit, and establish a digital simulation unit in the digital simulation model that is consistent with the external characteristics of the physical unit. The digital simulation unit is connected to the grid in the digital simulation model, thus completing the grid-connection pre-test of a physical unit.

[0041] Preferably but not limiting, step 3 specifically comprises: Step 3.1: Disconnect the physical unit VSG #A1, and model the digital simulation unit VSG #Bi in the digital simulation model according to the current parameters of the physical unit VSG #A1 to obtain the digital simulation unit VSG #Bi to be connected. For example, but not limited to, when i=1, the digital simulation unit VSG #B1 is obtained by modeling according to the current parameters of the physical unit VSG #A1.

[0042] Step 3.2: Close the digital simulation switch unit SW Bi , connect to the digital simulation unit VSG #Bi, use the digital simulation unit measurement unit i and the bus measurement unit to measure the electrical quantities on the branch i and the bus respectively, and obtain the second electrical quantities of multiple cycles. According to the second electrical quantities of multiple cycles, the waveform f is obtained. B1 (t), the number of cycles and the waveform f A1 (t) is the same, for example but not limited to, taking 10 cycles.

[0043] Step 3.3: After the measurement is completed, compare the waveforms of the electrical quantity output by the physical unit VSG #A1 and the electrical quantity output by the digital simulation unit VSG #Bi. A1 (t) and f B1(t) Perform a comparison at the same time starting point. If the external characteristics of the physical unit VSG #A1 and the digital simulation unit VSG #Bi are consistent, the control parameters of the digital simulation unit VSG #Bi do not need to be adjusted, and continue to execute step 4; if the external characteristics of the physical unit VSG #A1 and the digital simulation unit VSG #Bi are inconsistent, the control parameters of the digital simulation unit VSG #Bi need to be adjusted, and execute step 3.4; preferably, but not limited to, waveform f A1 (t) and f B1 (t) Take 10 cycles to determine whether the external characteristics of the physical unit VSG #A1 and the digital simulation unit VSG #Bi are consistent, and adjust the control parameters.

[0044] Further preferably but not limiting, judging whether the external characteristics of the physical unit VSG #A1 and the digital simulation unit VSG #Bi are consistent includes: Step a: Transform waveform f A1 (t) and f B1 (t) are subjected to FFT respectively, which is expressed as follows:

[0045]

[0046] Where: V 1 and V 1 ' Respectively represent the waveform f A1 (t) and f B1 (t) is the amplitude of the fundamental wave, ω 1 and ω 1 ' Respectively represent the waveform f A1 (t) and f B1 (t) is the frequency of the fundamental wave quantity, V j and V j ' Respectively represent the waveform f A1 (t) and f B1 The amplitude of the jth harmonic of (t), ω j and ω j ' Respectively represent the waveform f A1 (t) and f B1 The frequency of the jth harmonic of (t), where j = 2, 3, ..., N; N represents the number of sampling points; Indicates waveform f A1 (t) and f B1 (t) Phase difference.

[0047] Step b: Determine the waveform f based on the fundamental wave and harmonic wave similarity. A1 (t) and f B1 (t)Whether there is consistency.

[0048] Fundamental wave similarity judgment includes: waveform f A1 (t) and f B1 If the amplitude difference, frequency difference and phase difference of the FFT fundamental wave of (t) are all less than the set value or ratio, the fundamental wave has consistency, preferably but not limited to, the amplitude difference ΔV≤1%; the frequency difference Δf≤0.1%; the phase difference ≤0.5°, expressed as follows:

[0049] The harmonic similarity judgment includes: the FFT harmonic amount of each waveform should be basically proportional, and the number of harmonics to be taken depends on the actual situation. The similarity judgment standard of the second and above harmonics is that the amplitude or frequency deviation of the corresponding frequency harmonic is less than the set value or ratio, preferably but not limited to, the deviation ratio is less than 5%, which is expressed by the following formula:

[0050] Where: A i Indicates waveform f A1 (t) harmonic amplitude or frequency, A i ' represents the waveform f B1 The harmonic amplitude or frequency of (t) can be substituted into the FFT formula in step a to obtain the waveform f A1 (t) and f B1 (t) harmonic amplitude V j and V j 'To judge the harmonic similarity, you can also substitute the waveform f A1 (t) and f B1 (t) Harmonic frequency ω j and ω j 'Perform harmonic similarity judgment.

[0051] If the fundamental wave and harmonic wave similarity judgments are consistent, then the waveform f A1 (t) and f B1 (t) Whether they are consistent, that is, whether the external characteristics of the physical unit VSG #A1 and the digital simulation unit VSG #Bi are consistent.

[0052] Step 3.4: Adjust the digital simulation unit VSG #Bi parameters, including: delay / advance link time t d , voltage loop control parameters, such as but not limited to, voltage control loop proportional parameter K up , integration parameter Kui , current loop control loop proportional parameter K ip , integration parameter K ii and line impedance Z eq At least one of them, and use the adjusted digital simulation unit VSG #Bi control parameter to update the corresponding control parameter stored in step 2, and return to step 3.2.

[0053] It can be understood that by adjusting these parameters and cyclically executing steps 3.2 to 3.4, the effect of making the digital simulation unit VSG #B1 equivalent to the physical unit VSG #A1 can be achieved, that is, the two have almost the same external characteristics.

[0054] It is worth noting that the digital simulation unit that has completed the grid connection prediction trial of a physical unit remains connected to the grid in the digital simulation model, and the physical unit VSG #A1 replaces the physical unit one by one, establishes the corresponding digital simulation unit and remains connected to the grid, thus realizing the grid connection pre-test of the physical unit group, that is, the present invention provides a more practical digital simulation unit group modeling method. As one of the outstanding substantive features of the present invention, the digital simulation unit is modeled with high precision through the physical unit, and the grid connection test of each unit is carried out under the condition of multiple units in parallel, so as to quickly complete the task of large-scale inverter grid connection pre-test.

[0055] Step 4: Determine whether the grid-connection pre-test of all physical units has been completed. If not, return to step 2 and perform the grid-connection pre-test of the next physical unit. If completed, proceed to step 5.

[0056] Specifically, if the current i <N C , then it is not completed, return to step 2, if i=N C , the grid-connection pre-test of the last physical unit has been completed, and step 5 is performed.

[0057] Step 5: Export the control parameters saved in the storage medium to the corresponding physical units for grid connection.

[0058] Specifically, the control parameters corresponding to each physical unit stored in the storage medium are exported to the units that are actually to be connected to the power grid for formal grid connection. For example, the parameters of unit 2 imported during modeling are saved to the storage medium after fine-tuning, and the parameter settings numbered 2 are returned to the actual unit 2 to be connected to the power grid. The same applies to the remaining units, which can be matched one by one in sequence. Finally, the parameters of the physical units stored in the storage medium are exported to the units that are actually connected to the power grid for grid connection.

[0059] As one of the outstanding essential features of the present invention, the parameter setting method in this method not only ensures that the external environment of the physical unit is similar to that of the real unit when it is connected, and gives highly reliable results when implementing large-scale grid-connected pre-tests, but also reduces the cost and threshold of physical unit testing. It is equivalent to providing a platform for grid-connected testing of single or multiple physical units, ensuring that the access environment is consistent on the digital side and the physical side when the real unit is connected to the grid, and can pre-test and correct parameters for large-scale grid-connected inverters in advance, improve grid-connected efficiency, and reduce the threshold and cost of physical testing.

[0060] Furthermore, this method can be used not only in the scenario of large-scale grid-connected grid-type inverters, but the typical grid-type scenario is used in the present invention to illustrate the feasibility. In fact, similar effects can be achieved in hybrid grid-connected and grid-connected inverters.

[0061] Embodiment 2 of the present invention provides a parameter setting system for large-scale access of a grid-type inverter to the grid, and runs a parameter setting method for large-scale access of a grid-type inverter to the grid as described in embodiment 1, comprising: a physical unit module, a physical-digital interface module and a digital simulation model, wherein the physical unit module is connected to the digital simulation model via the physical-digital interface module; The physical unit module includes: a physical unit VSG #A1, an adjustable impedance unit, a physical unit measurement unit and a physical unit switch unit SW A1 ; Physical unit VSG #A1, adjustable impedance unit and physical unit switch unit SW A1 They are connected in sequence to form branch A1; the physical unit measurement unit is used to measure the electrical quantity of branch A1.

[0062] Preferably but not restrictively, the physical unit VSG #A1 includes: a first DC bus power supply interface, a first grid-connected inverter and a first inverter controller; the first DC bus power supply interface is a physical device, and the power source includes: a wind turbine plus a machine-side rectifier, a photovoltaic array and at least one of an energy storage battery; the first DC bus power supply interface is connected to the input end of the first grid-connected inverter, and the output end of the first grid-connected inverter is connected to the physical unit switch unit SW A1 Connected with the physical-digital interface module; the inverter controller is connected with the first grid-connected inverter.

[0063] The digital simulation model comprises: a digital unit module, a busbar module and a power grid module; the digital unit module is connected to the power grid module via the busbar module, and the physical-digital interface module is connected to the busbar module.

[0064] Preferably but not restrictively, the digital unit module includes: N digital simulation units, not less than the number of physical units to be connected to the network, each digital simulation unit is represented by a digital simulation unit VSG #Bi, i=1,2,···,N; each digital simulation unit VSG #Bi is connected to the digital simulation impedance unit Z Bi and digital simulation switch unit SW Bi Connected to the busbar module, forming multiple branches i connected to the busbar module, each branch i is provided with a digital simulation unit measurement unit i for measuring the electrical quantity of the branch i; The digital simulation unit VSG #Bi includes: a second DC bus power supply interface, a second grid-connected inverter and a second inverter controller; the second DC bus power supply interface, the second grid-connected inverter and the second inverter controller of the digital simulation unit VSG #Bi are simulation models; the second inverter controller includes: a delay / advance link, which is used to adjust parameters to make the output of the physical unit VSG #A1 consistent with that of the digital simulation unit VSG #Bi.

[0065] The busbar module includes: a busbar and a busbar measurement unit for measuring the electrical quantity of the busbar; each digital simulation unit VSG #Bi can be connected to the busbar as a branch; The grid module includes: digital simulation grid G1 and grid impedance Z g ; Collecting busbar through grid impedance Z g Connected to the digital simulation grid G1; wherein the digital simulation grid G1 and the grid impedance Z g It is determined according to the parameters of the local power grid access.

[0066] The physical-digital interface module includes: an active four-quadrant power amplifier and a digital simulation interface; the physical unit VSG#A1 outputs an analog AC signal through the first grid-connected inverter, and after passing through the active four-quadrant power amplifier, the analog quantity is converted into a digital quantity and enters the digital simulation model.

[0067] Embodiment 3 of the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the computer program is loaded into the processor, a parameter setting method for large-scale grid access of a grid-connected inverter according to Embodiment 1 is implemented.

[0068] Embodiment 4 of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the parameter setting method for large-scale grid access of a grid-connected inverter according to embodiment 1 is implemented.

[0069] The present disclosure may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A parameter setting method for large-scale grid-connected grid-connected inverters, characterized in that: The following steps are involved: Step 1: Establish a virtual-real fusion topology structure including digital simulation models and physical units; the digital simulation model is used to simulate the grid-connected topology structure of new energy grid-forming stations; Step 2: According to the setting order of each physical unit, the parameters of the physical unit to be pre-tested for grid connection are given to the physical unit, and the physical unit with the parameters of the physical unit is connected to the digital simulation model. After the physical unit is debugged and stabilized, the current operation control parameters of the physical unit are saved as the control parameters of the physical unit to the storage medium; Step 3: Disconnect the connection between the physical unit and the digital simulation model, and establish a digital simulation unit in the digital simulation model that is consistent with the external characteristics of the physical unit, and continue to connect the digital simulation unit to the grid in the digital simulation model to complete the grid connection pre-test of a physical unit; Step 4: Determine whether the grid-connection pre-test of all physical units has been completed. If not, return to step 2 to perform the grid-connection pre-test of the next physical unit. If completed, proceed to step 5. Step 5: Export the control parameters stored in the storage medium to the corresponding physical units.

2. According to claim 1, a parameter setting method for large-scale grid-connected grid-connected inverters is characterized by: The virtual-real fusion topology structure includes: a physical unit module, a physical-digital interface module and a digital simulation model. The physical unit module is connected to the digital simulation model through the physical-digital interface module. The physical unit module includes: a physical unit measurement unit, a branch A1, and the branch A1 includes a physical unit VSG #A1, an adjustable impedance unit, and a physical unit switch unit SW connected in sequence. A1 The physical unit measurement unit is respectively connected to the adjustable impedance unit and the physical unit switch unit SW A1 The physical unit VSG #A1 includes: a first DC bus power supply interface, a first grid-connected inverter and a first inverter controller; the first DC bus power supply interface is connected to the input end of the first grid-connected inverter, and the output end of the first grid-connected inverter is connected to the physical unit switch unit SW A1 Connected to the physical-digital interface module, the first inverter controller is connected to the first grid-connected inverter; The digital simulation model comprises: a digital unit module, a busbar module and a power grid module; the digital unit module is connected to the power grid module via the busbar module, and the physical-digital interface module is connected to the busbar module.

3. The parameter setting method for large-scale grid-connected grid-connected inverters according to claim 2 is characterized in that: Digital unit module includes: N D Digital simulation unit VSG #Bi, i=1,2,···,N D Each digital simulation unit VSG#Bi passes through the digital simulation impedance unit Z Bi and digital simulation switch unit SW Bi Connected to the busbar module to form a plurality of branches i connected to the busbar module, each branch i is provided with a digital simulation unit measurement unit i; The digital simulation unit VSG #Bi includes: a second DC bus power supply interface, a second grid-connected inverter and a second inverter controller, wherein the second DC bus power supply interface is connected to the input end of the second grid-connected inverter, and the output end of the second grid-connected inverter is connected to the digital simulation impedance unit Z Bi and digital simulation switch unit SW Bi The second inverter controller includes a delay / advance link, and the second inverter controller is connected to the second grid-connected inverter.

4. The parameter setting method for large-scale grid-connected grid-connected inverters according to claim 3 is characterized in that: Step 2 includes: Assign serial numbers to the grid connection pre-test according to the physical unit numbers to be tested; After the parameters of the physical unit VSG #Ci are given to the physical unit VSG #A1, the physical unit switch unit SW is closed. A1 , to connect the physical unit VSG #A1 to the digital simulation model through the physical-digital interface module, i=1,2,···,N C After the physical unit VSG #A1 has been debugged and reached stable operation, the physical unit measurement unit is used to measure the electrical quantity of branch A1 to obtain the first electrical quantity of branch A1, which includes voltage, current and phase angle, and the first electrical quantity is output to the busbar module of the digital simulation model to save its waveform f A1 (t) to a storage medium; The current operation control parameters of the physical machine group VSG #A1 are saved in the storage medium as the control parameters of the replaced physical machine group VSG #Ci.

5. The parameter setting method for large-scale grid-connected grid-connected inverters according to claim 4 is characterized in that: Step 3 includes: Disconnect the physical unit VSG #A1, and model the digital simulation unit VSG #Bi in the digital simulation model according to the current operation control parameters of the physical unit VSG #A1 to obtain the digital simulation unit VSG #Bi to be connected; Close the digital simulation switch unit SW Bi , by connecting to the digital simulation unit VSG #Bi, using the digital simulation unit measurement unit i and the bus measurement unit to measure the electrical quantities on the branch i and the busbar respectively to obtain the second electrical quantities of multiple cycles, and according to the second electrical quantities of multiple cycles, the waveform f is obtained. B1 (t), the number of cycles and the waveform f A1 (t) the same; Determine whether the external characteristics of the physical unit VSG #A1 and the digital simulation unit VSG #Bi are consistent. If they are consistent, execute step 4; if they are inconsistent, adjust the control parameters of the digital simulation unit VSG #Bi until the external characteristics of the physical unit VSG #A1 and the digital simulation unit VSG #Bi are consistent, update the corresponding control parameters stored in step 2 with the adjusted control parameters of the digital simulation unit VSG #Bi, and continue to execute step 4.

6. A parameter setting method for large-scale grid-connected grid-connected inverters according to claim 5, characterized in that: Determining whether the external characteristics of the physical unit VSG #A1 and the digital simulation unit VSG #Bi are consistent includes: The waveform f A1 (t) and f B1 (t) Perform FFT processing to obtain waveform f A1 (t) and f B1 (t) The parameters of the fundamental and harmonic quantities are calculated according to the waveform f A1 (t) and f B1 (t) The parameters of the fundamental and harmonic quantities in the waveform f A1 (t) and f B1 (t)Whether there is consistency.

7. A parameter setting method for large-scale grid-connected grid-connected inverters according to claim 6, characterized in that: According to the waveform f A1 (t) and f B1 (t) The parameters of the fundamental and harmonic quantities in the waveform f A1 (t) and f B1 (t) Whether it is consistent, including waveform f A1 (t) and f B1 (t) If the amplitude difference, frequency difference and phase difference of the fundamental wave in the waveform f are all less than the set value or ratio, then the waveform f A1 (t) and f B1 (t) The fundamental wave quantity is consistent; When the waveform f A1 (t) and f B1 If the amplitude difference, frequency difference and phase difference of the corresponding frequency harmonic quantity in (t) are less than the set value or ratio, then the waveform f A1 (t) and f B1 (t) The harmonic content is consistent; If the waveform f A1 (t) and f B1 (t) When the fundamental wave quantity and harmonic wave quantity are consistent, the external characteristics of the physical unit VSG #A1 and the digital simulation unit VSG #Bi are consistent.

8. A parameter setting method for large-scale grid-connected grid-connected inverters according to claim 6 or 7, characterized in that: Adjust the digital simulation unit VSG #Bi parameters, including: delay / advance link time t d , adjust the voltage control loop proportional parameter K up , integration parameter K ui , current loop control loop proportional parameter K ip , integration parameter K ii and line impedance Z eq at least one of .

9. A parameter setting system for large-scale grid-connected inverters, used to execute a parameter setting method for large-scale grid-connected inverters according to any one of claims 1 to 8, characterized in that: include: A physical unit module, a physical-digital interface module and a digital simulation model, wherein the physical unit module is connected to the digital simulation model via the physical-digital interface module; The physical unit module includes: a physical unit VSG #A1, an adjustable impedance unit, a physical unit measurement unit and a physical unit switch unit SW A1 ; Physical unit VSG #A1, adjustable impedance unit and physical unit switch unit SW A1 They are connected in sequence to form branch A1; the physical unit measurement unit is used to measure the electrical quantity of branch A1; The digital simulation model includes: a digital unit module, a busbar module and a power grid module.

10. A parameter setting system for large-scale grid-connected grid-connected inverters according to claim 9, characterized in that: The physical-digital interface module includes: an active four-quadrant power amplifier and a digital simulation interface; the physical unit VSG #A1 outputs an analog AC signal through a grid-connected inverter, and after passing through the active four-quadrant power amplifier, the analog quantity is converted into a digital quantity and enters the digital simulation model.

11. A parameter setting system for large-scale grid-connected grid-connected inverters according to claim 9, characterized in that: The physical unit VSG #A1 includes: a first DC bus power supply interface, a first grid-connected inverter and a first inverter controller; the first DC bus power supply interface is a physical device, and the power source includes: a wind turbine plus a machine-side rectifier, a photovoltaic array and at least one of an energy storage battery; the first DC bus power supply interface is connected to the input end of the first grid-connected inverter, and the output end of the first grid-connected inverter is connected to the physical unit switch unit SW A1 Connected with the physical-digital interface module; the first inverter controller is connected with the first grid-connected inverter.

12. A parameter setting system for large-scale grid-connected grid-connected inverters according to claim 9, characterized in that: Digital unit module includes: N D Digital simulation units, not less than the number of physical units to be connected to the network, digital simulation unit VSG #Bi represents each digital simulation unit, i=1,2,···,N D Each digital simulation unit VSG #Bi passes through the digital simulation impedance unit Z Bi and digital simulation switch unit SW Bi Connected to the busbar module, forming multiple branches i connected to the busbar module, each branch i is provided with a digital simulation unit measurement unit i for measuring the electrical quantity of the branch i; The digital simulation unit VSG #Bi includes: a second DC bus power supply interface, a second grid-connected inverter and a second inverter controller; the second DC bus power supply interface, the second grid-connected inverter and the second inverter controller of the digital simulation unit VSG #Bi are simulation models; the second inverter controller includes: a delay / advance link, which is used to adjust parameters to make the output of the physical unit VSG #A1 consistent with that of the digital simulation unit VSG #Bi.

13. A parameter setting system for large-scale grid-connected grid-connected inverters according to claim 12, characterized in that: The busbar module includes: a busbar and a busbar measurement unit for measuring the electrical quantity of the busbar; each digital simulation unit VSG #Bi can be connected to the busbar as a branch; The grid module includes: digital simulation grid G1 and grid impedance Z g ; Collecting busbar through grid impedance Z g Connected to the digital simulation grid G1; wherein the digital simulation grid G1 and the grid impedance Z g It is determined according to the parameters of the local power grid access.

14. An electronic device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the computer program is loaded into the processor, a parameter setting method for large-scale grid access of a grid-connected inverter is implemented according to any one of claims 1 to 8.

15. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, a parameter setting method for large-scale grid-connected grid-connected inverters according to any one of claims 1 to 8 is implemented.

Images