Synchronizer-like rapid voltage control and sub-link actual measurement method and system for networking SVG (Static Var Generator)

Abstract

The invention discloses a fast voltage control and sub-link actual measurement method and system for a similar synchronous machine of a networking SVG (Static Var Generator), and the method comprises the steps: setting the similar synchronous machine of the networking SVG to take a voltage set value as an adjustment target, and carrying out the adjustment of the voltage set value in the similar synchronous machine of the networking SVG based on a transfer function, performing analog synchronous machine voltage difference adjustment on the similar synchronous machine of the SVG by introducing an outlet voltage reference value and a reactive current compensation coefficient, and adjusting the output voltage and reactive power of the similar synchronous machine of the network-forming SVG based on a set rate; according to a sub-link principle, a monitoring point is selected based on a transfer function in a class synchronous machine of the network-forming SVG; the method comprises the following steps of: accessing a class synchronous machine of a networking SVG into a semi-physical simulation system, adding an excitation signal at a monitoring point, and recording actually measured data; establishing a control link of the transfer function based on simulation software, and generating simulation data; comparing the measured data with the simulation data, and verifying the transfer function based on a comparison result; and ring division actual measurement is carried out on the similar synchronous machine of the networking SVG.

Description

Technical Field

[0001] The present invention relates to the technical field of fast voltage control of synchronous machine-like grid-forming SVG, and more specifically, to a method and system for fast voltage control and sub-link actual measurement of synchronous machine-like grid-forming SVG. Background Art

[0002] With the large-scale access of new energy to the power system, the traditional power grid structure dominated by thermal power is gradually transforming into a structure with a high proportion of new energy and a high proportion of power electronic devices, resulting in a significant decline in the system inertia and voltage support ability. Under this background, the power grid faces problems such as dynamic stability, a sharp increase in reactive power compensation demand, and the risk of equipment start-up impact.

[0003] Therefore, the grid-forming SVG, as a new type of power electronic device, is proposed to enhance the active support ability of the power grid. Its core technologies include simulating the characteristics of synchronous generator sets, fast voltage regulation, and inertia support functions; by simulating the voltage source characteristics of synchronous machines, the grid-forming SVG has synchronous reactive power compensation ability compared with traditional SVG, can suppress the reactive power reverse adjustment caused by control delay, and realizes fast charge and discharge through super capacitors to enhance the transient stability of the system. Summary of the Invention

[0004] The technical solution of the present invention provides a method and system for fast voltage control and sub-link actual measurement of synchronous machine-like grid-forming SVG to solve the problems of how to control the synchronous machine-like grid-forming SVG and perform sub-link actual measurement.

[0005] To solve the above problems, the present invention provides a method for fast voltage control and sub-link actual measurement of synchronous machine-like grid-forming SVG, and the method includes:

[0006] Set the synchronous machine-like grid-forming SVG with the voltage set value as the adjustment target. In the synchronous machine-like grid-forming SVG, based on the transfer function, the voltage regulation of the synchronous machine of the SVG is simulated by introducing the reference value of the outlet voltage and the reactive current compensation coefficient, and the output voltage and reactive power of the synchronous machine-like grid-forming SVG are adjusted based on the set rate.

[0007] According to the sub-link principle, select monitoring points in the synchronous machine-like grid-forming SVG based on the transfer function.

[0008] Connect the synchronous machine-like grid-forming SVG to the hardware-in-the-loop simulation system, add an excitation signal at the selected monitoring points, and record the actual measured data of the monitoring point responses.

[0009] Establish the control link of the transfer function based on the simulation software to generate the simulation data of the control environment response; compare the actual measured data with the simulation data, and verify the transfer function based on the comparison result.

[0010] When the transfer function in the synchronous machine-like structure network SVG passes the verification, the loop-by-loop actual measurement of the synchronous machine-like structure network SVG is completed.

[0011] Preferably, the loop-by-loop actual measurement of the synchronous machine-like structure network SVG includes:

[0012] Set the synchronous machine-like structure network SVG to the no-load state, adjust the terminal voltage from 0% to 110% of the rated voltage at a set rate, and when the synchronous machine-like structure network SVG is stable, reduce it from 110% to 0% of the rated voltage, and record the terminal voltage during the adjustment process.

[0013] Preferably, the loop-by-loop actual measurement of the synchronous machine-like structure network SVG includes:

[0014] When the synchronous machine-like structure network SVG is stable after boosting the voltage, conduct a ±5% voltage step response test at the machine terminal, record the terminal voltage waveform, and calculate the performance index.

[0015] Preferably, the loop-by-loop actual measurement of the synchronous machine-like structure network SVG includes:

[0016] When the synchronous machine-like structure network SVG is operating under rated conditions, set the reactive current compensation coefficient to 0, keep the given value of the terminal voltage unchanged, conduct a reactive power rejection test, record the terminal voltage and reactive power before and after the load rejection, and calculate the voltage static deviation rate ε(%) according to Equation (1):

[0017] ε(%) = [(U0 - U1) / U n × 100% (1)

[0018] where U1 and U0 are the terminal voltages before and after the load rejection respectively, and U n is the rated terminal voltage.

[0019] Preferably, the loop-by-loop actual measurement of the synchronous machine-like structure network SVG includes:

[0020] When the synchronous machine-like structure network SVG is operating under rated conditions, keep the given value of the terminal voltage unchanged, conduct disconnection at different reactive current compensation coefficients respectively, record the terminal voltage and reactive power before and after the reactive power rejection, and calculate the regulation rate D according to Equation (2):

[0021]

[0022] where U1 and U0 are the terminal voltages before and after the load rejection respectively, and U n is the rated terminal voltage, S N is the apparent power, and Q is the reactive power.

[0023] Based on another aspect of the present invention, the present invention provides a quasi-synchronous machine fast voltage control and sub-link actual measurement system for a grid-forming SVG, and the system includes:

[0024] A setting unit for setting the quasi-synchronous machine of the grid-forming SVG to use the voltage set value as the adjustment target. In the quasi-synchronous machine of the grid-forming SVG, based on the transfer function, the voltage droop of the quasi-synchronous machine of the SVG is simulated by introducing the outlet voltage reference value and the reactive current compensation coefficient, and the output voltage and reactive power of the quasi-synchronous machine of the grid-forming SVG are adjusted based on the set rate;

[0025] A selection unit for selecting monitoring points based on the transfer function in the quasi-synchronous machine of the grid-forming SVG according to the sub-link principle;

[0026] A first recording unit for connecting the quasi-synchronous machine of the grid-forming SVG to the hardware-in-the-loop simulation system, adding an excitation signal at the selected monitoring points, and recording the actual measured data of the monitoring point responses;

[0027] A second recording unit for establishing a control link of the transfer function based on simulation software and generating simulation data of the control environment response;

[0028] A verification unit for comparing the actual measured data with the simulation data and verifying the transfer function based on the comparison result;

[0029] A result unit for performing sub-link actual measurement on the quasi-synchronous machine of the grid-forming SVG when the transfer function in the quasi-synchronous machine of the grid-forming SVG passes the verification.

[0030] Preferably, the result unit for performing sub-link actual measurement on the quasi-synchronous machine of the grid-forming SVG is further configured to:

[0031] Set the quasi-synchronous machine of the grid-forming SVG to the no-load state, adjust the terminal voltage from 0% to 110% of the rated voltage at the set rate, and when the quasi-synchronous machine of the grid-forming SVG is stable, reduce it from 110% to 0% of the rated voltage, and record the terminal voltage during the adjustment process.

[0032] Preferably, the result unit for performing sub-link actual measurement on the quasi-synchronous machine of the grid-forming SVG is further configured to:

[0033] When the quasi-synchronous machine of the grid-forming SVG is stable after voltage boost, perform a ±5% voltage step response test at the machine terminal, record the terminal voltage waveform, and calculate the performance index.

[0034] Preferably, the result unit for performing sub-link actual measurement on the quasi-synchronous machine of the grid-forming SVG is further configured to:

[0035] When the synchronous machine-like grid-forming SVG operates under rated conditions, set the reactive current compensation coefficient to 0, keep the given value of the terminal voltage unchanged, conduct a reactive power rejection test, record the terminal voltage and reactive power before and after the load rejection, and calculate the voltage static deviation rate ε(%) according to Equation (1):

[0036] ε(%) = [(U0 - U1) / U n ×100% (1)

[0037] where U1 and U0 are the terminal voltages before and after the load rejection respectively, and U n is the rated terminal voltage.

[0038] Preferably, the result unit is used to conduct a loop-by-loop actual measurement on the synchronous machine-like grid-forming SVG, and is also used for:

[0039] When the synchronous machine-like grid-forming SVG operates under rated conditions, keep the given value of the terminal voltage unchanged, conduct a disconnection at different reactive current compensation coefficients respectively, record the terminal voltage and reactive power before and after the reactive power rejection, and calculate the regulation rate D according to Equation (2):

[0040]

[0041] where U1 and U0 are the terminal voltages before and after the load rejection respectively, and U n is the rated terminal voltage, S N is the apparent power, and Q is the reactive power.

[0042] The technical solution of the present invention provides a method and system for fast voltage control and sub-link measurement of a synchronous machine-like grid-forming SVG. The method includes: setting the synchronous machine-like grid-forming SVG with the voltage set value as the adjustment target, and based on the transfer function in the synchronous machine-like grid-forming SVG, simulating the voltage regulation of the synchronous machine by introducing the reference value of the output voltage and the reactive current compensation coefficient, and adjusting the output voltage and reactive power of the synchronous machine-like grid-forming SVG based on the set rate; according to the principle of sub-links, selecting monitoring points in the synchronous machine-like grid-forming SVG based on the transfer function; connecting the synchronous machine-like grid-forming SVG to the hardware-in-the-loop simulation system, adding an excitation signal at the selected monitoring points, and recording the measured data of the response of the monitoring points; establishing the control link of the transfer function based on the simulation software to generate the simulation data of the control environment response; comparing the measured data with the simulation data, and verifying the transfer function based on the comparison result; when the transfer function in the synchronous machine-like grid-forming SVG passes the verification, performing sub-link measurement on the synchronous machine-like grid-forming SVG. The technical solution of the present invention realizes the adjustment target with the voltage set value through the fast voltage control of the synchronous machine-like grid-forming SVG, simulates the characteristics of the synchronous generator set to achieve fast voltage adjustment, introduces the reactive current compensation coefficient to realize the voltage regulation of the simulated synchronous machine, and adjusts the output voltage and reactive power of the grid-forming SVG according to the rate. The method for fast voltage control and sub-link measurement of the synchronous machine-like grid-forming SVG provided by the technical solution of the present invention is simple and clear, highly feasible, and the test results are highly accurate. It verifies the authenticity of voltage control under static and dynamic conditions respectively, and verifies the voltage regulation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The exemplary embodiments of the present invention can be more fully understood by referring to the following drawings:

[0044] Figure 1 FIG. is a flowchart of a method for fast voltage control and sub-link measurement of a synchronous machine-like grid-forming SVG according to a preferred embodiment of the present invention;

[0045] Figure 2 FIG. is a schematic diagram of the transfer function of the fast voltage control of the synchronous machine-like grid-forming SVG according to a preferred embodiment of the present invention;

[0046] Figure 3 FIG. is a schematic diagram of the numbers in the red circles in the figure being the selected monitoring points according to a preferred embodiment of the present invention;

[0047] Figure 4 FIG. is a flowchart of the sub-link test method according to a preferred embodiment of the present invention;

[0048] Figure 5 FIG. is a schematic diagram of the response curves of recording monitoring points 1 and 2 when Xc = 0.1 according to a preferred embodiment of the present invention;

[0049] Figure 6 Schematic diagram of the response curves of recording monitoring points 1 and 2 at Xc = 0.05 according to the preferred embodiment of the present invention;

[0050] Figure 7 For recording monitoring points 2 and 3 according to the preferred embodiment of the present invention at K V = 2; schematic diagram of the response curves

[0051] Figure 8 For recording monitoring points 2 and 3 according to the preferred embodiment of the present invention at K V = 4; schematic diagram of the response curves

[0052] Figure 9 For recording monitoring points 3 and 4 according to the preferred embodiment of the present invention at PI (K = 0.01, K I = 0.01); schematic diagram of the response curves

[0053] Figure 10 For recording monitoring points 3 and 4 according to the preferred embodiment of the present invention at PI (K = 0.01, K I = 0.03); schematic diagram of the response curves

[0054] Figure 11 For recording monitoring points 3 and 4 according to the preferred embodiment of the present invention at PI (K = 0.03, K I = 0.03); schematic diagram of the response curves

[0055] Figure 12 Schematic diagram of the comparison between the measured and simulated results of recording monitoring point 2 at Xc = 0.1 according to the preferred embodiment of the present invention;

[0056] Figure 13 Schematic diagram of the comparison between the measured and simulated results of recording monitoring point 2 at Xc = 0.05 according to the preferred embodiment of the present invention;

[0057] Figure 14 For recording monitoring point 3 according to the preferred embodiment of the present invention at K V = 2; schematic diagram of the comparison between the measured and simulated results

[0058] Figure 15 For recording monitoring point 3 according to the preferred embodiment of the present invention at K V = 4; schematic diagram of the comparison between the measured and simulated results

[0059] Figure 16 For recording monitoring point 4 according to the preferred embodiment of the present invention at PI (K = 0.01, K I = 0.01); schematic diagram of the comparison between the measured and simulated results

[0060] Figure 17 Schematic diagram of the comparison between the measured and simulated results of the recording monitoring point 4 at PI (K = 0.01, K I = 0.03) according to the preferred embodiment of the present invention;

[0061] Figure 18 Schematic diagram of the comparison between the measured and simulated results of the recording monitoring point 4 at PI (K = 0.03, K I = 0.03) according to the preferred embodiment of the present invention;

[0062] Figure 19 Schematic diagram of the 0 - 110% voltage test according to the preferred embodiment of the present invention;

[0063] Figure 20 Schematic diagram of the 110% - 0 voltage test according to the preferred embodiment of the present invention;

[0064] Figure 21 Schematic diagram of the no - load voltage step - test data according to the preferred embodiment of the present invention;

[0065] Figure 22 Schematic diagram of the static - error rate reactive - power rejection test data according to the preferred embodiment of the present invention;

[0066] Figure 23 Schematic diagram of the +5% regulation test according to the preferred embodiment of the present invention;

[0067] Figure 24 Schematic diagram of the - 5% regulation test according to the preferred embodiment of the present invention; and

[0068] Figure 25 Structural diagram of the fast voltage control and sub - link measured system of the grid - forming SVG's quasi - synchronous machine according to the preferred embodiment of the present invention. Detailed implementation manners

[0069] Now, exemplary embodiments of the present invention will be introduced with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms in the exemplary embodiments shown in the drawings are not limitations on the present invention. In the drawings, the same units / components are denoted by the same reference numerals.

[0070] Unless otherwise specified, the terms (including scientific and technical terms) used herein have the ordinary meaning understood by those skilled in the art. Additionally, it can be understood that the terms defined in the commonly used dictionary should be understood to have a meaning consistent with the context of their related fields and should not be understood in an idealized or overly formal sense.

[0071] Figure 1 Flow chart of the fast voltage control and sub - link measurement method of the synchronous - machine - like SVG for network formation according to the preferred embodiment of the present invention.

[0072] The present invention proposes a fast voltage control logic for the synchronous - machine - like SVG for network formation and a sub - link measurement method for this control system. The present invention performs closed - loop control on the terminal voltage of the network - forming SVG, simulates the characteristics of the synchronous generator set to achieve fast voltage regulation; the sub - link measurement method verifies the accuracy of the control logic and model of the network - forming SVG, and can provide a detection basis for the accuracy of equipment research and development and power grid simulation.

[0073] As Figure 1 shown, the present invention provides a fast voltage control and sub - link measurement method for the synchronous - machine - like SVG for network formation. The method includes:

[0074] Step 101: Set the synchronous - machine - like SVG for network formation with the voltage set value as the adjustment target. Based on the transfer function in the synchronous - machine - like SVG for network formation, simulate the voltage regulation of the synchronous machine by introducing the reference value of the outlet voltage and the reactive current compensation coefficient, and regulate the output voltage and reactive power of the synchronous - machine - like SVG for network formation based on the set rate.

[0075] To meet the need of applying the network - forming SVG to achieve active voltage support by simulating the characteristics of the synchronous - machine voltage source, the present invention provides a control device for the network - forming SVG with the target of controlling the outlet voltage Vm of the power generation unit, which can set the reference value V * ref of the outlet voltage of the power generation unit, introduce the reactive current compensation coefficient Xc, and can control the issuing speed of the V * m command at the rate ramp. The main control loop uses PI for the control device of the network - forming SVG, such as the control branch in the blue box part in the following figure; and for the above - mentioned system, a sub - link measurement method is formulated.

[0076] The fast voltage control transfer function of the synchronous - machine - like SVG for network formation of the present invention is as Figure 2 shown. Figure 2 The meanings of the symbols in it are as follows: f is the power grid frequency; g(f) is the frequency - DC voltage mapping function; u * c is the DC total voltage command; u c is the DC total voltage; k P is the DC total voltage regulation coefficient; ω n is the synchronous angular velocity of the power grid; J is the moment of inertia of the virtual synchronous condenser; D is the damping coefficient; θ is the angle of the virtual synchronous condenser; Q * is the reactive power command; Q is the reactive power; U is the internal potential of the virtual synchronous condenser; X C is the voltage regulation coefficient; V* ref , V * m is the PCC point voltage command; V m is the PCC point voltage; k v is the voltage regulation coefficient; E0 is the rated value of the PCC point voltage.

[0077] Step 102: According to the principle of separate links, select monitoring points based on the transfer function in the virtual synchronous machine of the grid-forming SVG;

[0078] In the fast voltage control separate-link actual measurement method for the virtual synchronous machine of the grid-forming SVG provided by the present invention, according to the principle of separate links, monitoring points are selected for the transfer function, and the specific measurement points are as Figure 3 shown.

[0079] Step 103: Connect the virtual synchronous machine of the grid-forming SVG to the hardware-in-the-loop simulation system, add an excitation signal at the selected monitoring points, and record the actual measured data of the responses of the monitoring points;

[0080] Step 104: Establish the control links of the transfer function based on the simulation software to generate the simulation data of the control environment response; Compare the actual measured data with the simulation data, and verify the transfer function based on the comparison results;

[0081] Step 105: When the transfer function in the virtual synchronous machine of the grid-forming SVG passes the verification, complete the separate-link actual measurement of the virtual synchronous machine of the grid-forming SVG.

[0082] The present invention implements this transfer function control logic in the SVG control device, connects it to the hardware-in-the-loop simulation system, adds an excitation signal at the monitoring points, and records the response curves of other monitoring points;

[0083] The present invention uses the simulation software to establish the transfer function or individual control links, compares the simulation result data with the actual measured data of the monitoring points in the control links in the previous step, and verifies the authenticity and accuracy of each link function in the transfer function.

[0084] Preferably, the separate-link actual measurement of the virtual synchronous machine of the grid-forming SVG includes:

[0085] Set the virtual synchronous machine of the grid-forming SVG to the no-load state, adjust the terminal voltage from 0% to 110% of the rated voltage at the set rate, and when the virtual synchronous machine of the grid-forming SVG is stable, reduce it from 110% to 0% of the rated voltage, and record the terminal voltage during the adjustment process.

[0086] The voltage regulation range test method of the present invention: The grid-forming SVG control device is in the no-load state, adjust the terminal voltage from 0% to 110% of the rated voltage at the set rate, and when it is stable, reduce it from 110% to 0% of the rated voltage, and record the terminal voltage during the adjustment process.

[0087] Preferably, conduct loop-by-loop actual measurement on the synchronous machine-like device of the network-forming SVG, including:

[0088] After the voltage of the synchronous machine-like device of the network-forming SVG is stabilized during boosting, conduct a ±5% voltage step response test at the machine terminal, record the waveform of the machine-terminal voltage, and calculate the performance indicators.

[0089] The no-load voltage step response test method of the present invention: After the boosting of the network-forming SVG control device is stable, conduct a ±5% voltage step response test at the machine terminal, record the waveform of the machine-terminal voltage, and calculate the performance indicators.

[0090] Preferably, conduct loop-by-loop actual measurement on the synchronous machine-like device of the network-forming SVG, including:

[0091] When the synchronous machine-like device of the network-forming SVG operates under the rated condition, set the reactive current compensation coefficient to 0, keep the given value of the machine-terminal voltage unchanged, conduct a reactive power shedding test, record the machine-terminal voltage and reactive power before and after shedding the load, and calculate the voltage regulation rate ε(%) according to formula (1):

[0092] ε(%) = [(U0 - U1) / U n × 100% (1)

[0093] wherein, U1 and U0 are the machine-terminal voltages before and after shedding the load respectively, and U n is the rated machine-terminal voltage.

[0094] For the regulation rate test of the present invention, when the network-forming SVG control device operates under the rated condition, set the reactive current compensation coefficient to 0, keep the given value of the machine-terminal voltage unchanged, conduct a reactive power shedding test, record the machine-terminal voltage and reactive power before and after shedding the load, and calculate the voltage regulation rate according to formula (1):

[0095] ε(%) = [(U0 - U1) / U n × 100% (1)

[0096] In the formula: U1 and U0 are the machine-terminal voltages before and after shedding the load, kV / p.u.; U n is the rated machine-terminal voltage, kV / p.u.

[0097] Preferably, conduct loop-by-loop actual measurement on the synchronous machine-like device of the network-forming SVG, including:

[0098] When the synchronous machine-like device of the network-forming SVG operates under the rated condition, keep the given value of the machine-terminal voltage unchanged, conduct disconnection at different reactive current compensation coefficients respectively, record the machine-terminal voltage and reactive power before and after shedding the reactive power, and calculate the regulation rate D according to formula (2):

[0099]

[0100] Among them, U1 and U0 are the terminal voltages before and after load rejection respectively, and U n is the rated terminal voltage, and S N is the apparent power, and Q is the reactive power.

[0101] For the reactive current compensation coefficient test of the present invention, the grid-forming SVG control device operates under rated conditions, keeps the given value of the terminal voltage unchanged, and performs disconnection at different reactive current compensation coefficients respectively, records the terminal voltage and reactive power before and after reactive power rejection, and calculates the regulation rate according to Equation (2):

[0102]

[0103] In the formula: U1 and U0 are the terminal voltages before and after load rejection, kV / p.u.; U n is the rated terminal voltage, kV / p.u.; S N is the apparent power; Q is the reactive power.

[0104] The method for fast voltage control of the grid-forming SVG provided by the present invention in the form of a synchronous machine has the following excellent effects:

[0105] (1) The fast voltage control of the grid-forming SVG in the form of a synchronous machine can achieve the same fast voltage regulation characteristics as a synchronous generator;

[0106] (2) The fast voltage control structure of the grid-forming SVG in the form of a synchronous machine is simple, takes the voltage set value (PCC point voltage command) as the regulation target, and realizes fast charge and discharge through a super capacitor to enhance the transient stability of the system;

[0107] (3) Introducing the reactive current compensation coefficient can achieve the same function of voltage regulation as that of a synchronous generator;

[0108] (4) The output voltage (PCC point voltage) and reactive power of the grid-forming SVG can be regulated at a certain rate;

[0109] The sub-link measurement method for fast voltage control of the grid-forming SVG provided by the present invention in the form of a synchronous machine has the following excellent effects:

[0110] The test method is simple and clear, and has high feasibility;

[0111] The test results have high accuracy;

[0112] The authenticity of voltage control is verified respectively under static and dynamic conditions;

[0113] The voltage regulation performance is verified.

[0114] The following further describes in detail the specific implementation manners of the present invention with reference to the drawings and embodiments.

[0115] AsFigure 4 As shown in the figure, the present invention takes the test verification of a 50 Mvar grid-connected SVG as an example to further elaborate on the present invention in detail, but the embodiments of the present invention are not limited thereto.

[0116] The step-by-step actual measurement using the method provided by the present invention is as follows:

[0117] Step 1: Select monitoring points for the Figure 3 transfer function. The numbers in the red circles in the figure are the measuring point numbers;

[0118] Step 2: Implement the control logic of this transfer function in the SVG control device, connect it to the hardware-in-the-loop simulation system, add step excitation signals at monitoring points ①, ②, and ③ respectively, and record the response curves of each monitoring point, as Figures 5 to 11 shown;

[0119] Step 3: Use simulation software to establish a single control link, and compare the simulation result data with the measured data of the monitoring points in the control link in Step 2, as Figures 12 to 18 shown;

[0120] After signal comparison and analysis, the set parameters are basically consistent with the measured and calculated parameters, and each link of the transfer function conforms to the measured results as shown in Table 1.

[0121] Table 1 Transfer Function Test Record Table

[0122]

[0123] Step 4: The grid-connected SVG control device is in the no-load state. Adjust the terminal voltage at a set rate from 0% to 110% of the rated voltage, and after stabilization, reduce it from 110% to 0% of the rated voltage, and record the terminal voltage during the adjustment process as Figure 19 and 20 shown:

[0124] Step 5: After the grid-connected SVG control device has a stable boost, conduct a ±5% voltage step response test on the terminal voltage, and record the terminal voltage as Figure 21 shown, and calculate the performance indicators as shown in Table 2;

[0125] Table 2 Electrical Quantity Quality Parameters

[0126] Index Name <![CDATA[Static synchronous compensator terminal voltage U t > <![CDATA[Initial value U t0 > 0.953 <![CDATA[Steady-state value U t > 1.003 <![CDATA[Maximum value U tmax > 1.003 <![CDATA[Overshoot (%) M p > 0 <![CDATA[Time T of the maximum value p > 0.625 <![CDATA[90% step quantity time T up > 0.211 <![CDATA[Adjustment time T s > 0.27 Number of Oscillations 0

[0127] Step 6: The grid-connected SVG control device operates under rated conditions. Set the reactive current compensation coefficient to 0, keep the terminal voltage set value unchanged, conduct a reactive power shedding test, and record the reactive power and terminal voltage before and after load shedding as Figure 22 shown, and calculate the voltage static droop rate according to Equation (1) as shown in Table 3;

[0128] Table 3 Record of Measured Data for Static Droop Rate

[0129]

[0130] Step 7: The grid-forming SVG control device operates under rated conditions, keeping the given value of the terminal voltage unchanged. Unloading is carried out at different reactive current compensation coefficients, and the reactive power and terminal voltage before and after reactive power shedding are recorded as Figure 23 、 Figure 24 , and the regulation rate is calculated according to Equation (2) as shown in Table 4.

[0131] Table 4 Comparison of calculation results of reactive current compensation coefficients

[0132] Serial Number <![CDATA[Throw forward U t (p.u.)]]> <![CDATA[Trailing U t (p.u.)]]> Set Value of Reactive Current Compensation Coefficient Measured Value of Voltage Regulation 1 1.0844 1.1343 +5％ -4.99％ 2 1.0844 1.0345 -5％ +4.99％

[0133] It can be seen from the test results that the quasi-synchronous machine fast voltage control of this grid-forming SVG realizes the voltage setting value as the regulation target, simulates the characteristics of the synchronous unit to realize the fast voltage regulation, introduces the reactive current compensation coefficient to realize the voltage regulation of the quasi-synchronous machine, and regulates the output voltage and reactive power of the grid-forming SVG according to the rate; through the test method and test results, the effectiveness of the method provided by the present invention in actual system analysis is verified.

[0134] Figure 25 It is a structural diagram of the quasi-synchronous machine fast voltage control and sub-link actual measurement system of a grid-forming SVG according to a preferred embodiment of the present invention.

[0135] As Figure 25 shown, the present invention provides a quasi-synchronous machine fast voltage control and sub-link actual measurement system for a grid-forming SVG. The system includes:

[0136] A setting unit 201, configured to set the quasi-synchronous machine of the grid-forming SVG with the voltage setting value as the regulation target. In the quasi-synchronous machine of the grid-forming SVG, based on the transfer function, the voltage regulation of the quasi-synchronous machine is carried out by introducing the outlet voltage reference value and the reactive current compensation coefficient, and the output voltage and reactive power of the quasi-synchronous machine of the grid-forming SVG are regulated based on the set rate;

[0137] A selection unit 202, configured to select monitoring points based on the transfer function in the quasi-synchronous machine of the grid-forming SVG according to the sub-link principle;

[0138] A first recording unit 203, configured to connect the quasi-synchronous machine of the grid-forming SVG to the hardware-in-the-loop simulation system, add an excitation signal at the selected monitoring points, and record the measured data of the monitoring point responses;

[0139] A second recording unit 204, configured to establish a control link of the transfer function based on simulation software and generate simulation data of the control environment response;

[0140] The verification unit 205 is used to compare the measured data with the simulation data and verify the transfer function based on the comparison result;

[0141] The result unit 205 is used to perform a loop-by-loop measurement of the synchronous machine-like structure network SVG when the transfer function in the synchronous machine-like structure network SVG passes the verification.

[0142] Preferably, the result unit 205 is used to perform a loop-by-loop measurement of the synchronous machine-like structure network SVG and is also used for:

[0143] Set the synchronous machine-like structure network SVG to the no-load state, adjust the terminal voltage from 0% to 110% of the rated voltage at a set rate, and when the synchronous machine-like structure network SVG is stable, reduce it from 110% to 0% of the rated voltage, and record the terminal voltage during the adjustment process.

[0144] Preferably, the result unit 205 is used to perform a loop-by-loop measurement of the synchronous machine-like structure network SVG and is also used for:

[0145] When the synchronous machine-like structure network SVG is stable after voltage boost, perform a ±5% voltage step response test at the terminal, record the terminal voltage waveform, and calculate the performance index.

[0146] Preferably, the result unit 205 is used to perform a loop-by-loop measurement of the synchronous machine-like structure network SVG and is also used for:

[0147] When the synchronous machine-like structure network SVG is operating under rated conditions, set the reactive current compensation coefficient to 0, keep the terminal voltage set value unchanged, perform a reactive power shedding test, record the terminal voltage and reactive power before and after shedding the load, and calculate the voltage static deviation rate ε(%) according to Equation (1):

[0148]

[0149] where U1 and U0 are the terminal voltages before and after shedding the load, respectively, and U n is the rated terminal voltage.

[0150] Preferably, the result unit 205 is used to perform a loop-by-loop measurement of the synchronous machine-like structure network SVG and is also used for:

[0151] When the synchronous machine-like structure network SVG is operating under rated conditions, keep the terminal voltage set value unchanged, perform disconnection at different reactive current compensation coefficients respectively, record the terminal voltage and reactive power before and after shedding the reactive power, and calculate the regulation rate D according to Equation (2):

[0152]

[0153] where U1 and U0 are the terminal voltages before and after shedding the load, respectively, and U n is the rated terminal voltage, and SN where \(S\) is the apparent power and \(Q\) is the reactive power.

[0154] The fast voltage control and sub - link measurement system of the grid - forming SVG's virtual synchronous machine in a preferred embodiment of the present invention corresponds to the fast voltage control and sub - link measurement method of the grid - forming SVG's virtual synchronous machine in another preferred embodiment of the present invention, and will not be elaborated here.

[0155] Those skilled in the art should understand that the embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer - usable storage media (including but not limited to disk memory, CD - ROM, optical memory, etc.) containing computer - usable program code. The solutions in the embodiments of the present invention can be implemented in various computer languages. For example, object - oriented programming languages such as Java and interpreted scripting languages such as JavaScript.

[0156] The present invention is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of flows and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general - purpose computer, a special - purpose computer, an embedded processor, or other programmable data - processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data - processing devices generate means for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0157] These computer program instructions can also be stored in a computer - readable memory that can direct a computer or other programmable data - processing device to work in a specific manner, so that the instructions stored in the computer - readable memory generate a manufactured article including instruction means, and the instruction means implement the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0158] These computer program instructions can also be loaded onto a computer or other programmable data - processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer - implemented process. Thus, the instructions executed on the computer or other programmable device provide means for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1Steps of the functions specified in one or more boxes.

[0159] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concepts. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0160] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

[0161] The present invention has been described by reference to a few embodiments. However, as is well known to those skilled in the art, other embodiments equivalent to those disclosed above of the present invention equally fall within the scope of the present invention as defined by the appended patent claims.

[0162] Generally, all terms used in the claims are construed according to their ordinary meanings in the technical field, unless otherwise clearly defined therein. All references to "a / the [device, component, etc.]" are to be construed broadly as at least one instance of the device, component, etc., unless otherwise explicitly stated. The steps of any method disclosed herein need not be performed in the exact order disclosed, unless explicitly stated.

Claims

1. A method for rapid voltage control and sub - link measurement of a synchronous - machine - like grid - forming SVG, the method comprising: Setting the synchronous - machine - like grid - forming SVG with a voltage set value as the adjustment target. In the synchronous - machine - like grid - forming SVG, based on the transfer function, by introducing the outlet voltage reference value and the reactive current compensation coefficient, the voltage regulation of the synchronous - machine - like SVG is simulated, and the output voltage and reactive power of the synchronous - machine - like grid - forming SVG are adjusted based on the set rate; According to the principle of sub - links, selecting monitoring points in the synchronous - machine - like grid - forming SVG based on the transfer function; Connecting the synchronous - machine - like grid - forming SVG to a hardware - in - the - loop simulation system, adding an excitation signal at the selected monitoring points, and recording the measured data of the monitoring point responses; Establishing the control link of the transfer function based on simulation software to generate simulation data of the control environment response; comparing the measured data with the simulation data, and verifying the transfer function based on the comparison result; When the transfer function in the synchronous - machine - like grid - forming SVG passes the verification, the sub - link measurement of the synchronous - machine - like grid - forming SVG is completed.

2. The method according to claim 1, wherein the sub - link measurement of the synchronous - machine - like grid - forming SVG comprises: Setting the synchronous - machine - like grid - forming SVG to the no - load state, adjusting the terminal voltage from 0% to 110% of the rated voltage at the set rate, and when the synchronous - machine - like grid - forming SVG is stable, reducing it from 110% to 0% of the rated voltage, and recording the terminal voltage during the adjustment process.

3. The method according to claim 1, wherein the sub - link measurement of the synchronous - machine - like grid - forming SVG comprises: When the synchronous - machine - like grid - forming SVG is stable after voltage boosting, performing a ± 5% voltage step - response test at the machine terminal, recording the terminal voltage waveform, and calculating the performance index.

4. The method according to claim 1, wherein the sub - link measurement of the synchronous - machine - like grid - forming SVG comprises: When the synchronous - machine - like grid - forming SVG is operating under the rated condition, setting the reactive current compensation coefficient to 0, keeping the terminal voltage given value unchanged, performing a reactive power shedding test, recording the terminal voltage and reactive power before and after the load shedding, and calculating the voltage static regulation rate ε(%) according to formula (1): ε(%) = [(U0 - U1) / U n × 100% (1) Among them, U1 and U0 are the terminal voltages before and after load rejection respectively, and U n is the rated terminal voltage.

5. The method according to claim 1, wherein the sub - link measurement of the synchronous - machine - like grid - forming SVG comprises: When the synchronous - machine - like grid - forming SVG is operating under the rated condition, keeping the terminal voltage given value unchanged, performing disconnection at different reactive current compensation coefficients respectively, recording the terminal voltage and reactive power before and after the reactive power shedding, and calculating the regulation rate D according to formula (2): Among them, U1 and U0 are the terminal voltages before and after load rejection respectively, U n is the rated terminal voltage, S N is the apparent power, and Q is the reactive power.

6. A system for rapid voltage control and sub - link measurement of a synchronous - machine - like grid - forming SVG, the system comprising: A setting unit for setting the synchronous - machine - like grid - forming SVG with a voltage set value as the adjustment target. In the synchronous - machine - like grid - forming SVG, based on the transfer function, by introducing the outlet voltage reference value and the reactive current compensation coefficient, the voltage regulation of the synchronous - machine - like SVG is simulated, and the output voltage and reactive power of the synchronous - machine - like grid - forming SVG are adjusted based on the set rate; A selection unit, configured to select monitoring points based on a transfer function in a synchronous machine-like grid-forming SVG according to the principle of sub-link; A first recording unit, configured to connect the synchronous machine-like grid-forming SVG to a hardware-in-the-loop simulation system, add an excitation signal at the selected monitoring points, and record the measured data of the responses of the monitoring points; A second recording unit, configured to establish a control link of the transfer function based on simulation software and generate simulation data of the responses of the control environment; A verification unit, configured to compare the measured data with the simulation data and verify the transfer function based on the comparison result; A result unit, configured to perform sub-link measurement on the synchronous machine-like grid-forming SVG when the transfer function in the synchronous machine-like grid-forming SVG passes the verification; 7. The system according to claim 6, wherein the result unit, for performing sub-link measurement on the synchronous machine-like grid-forming SVG, is further configured to: Set the synchronous machine-like grid-forming SVG to an unloaded state, adjust the terminal voltage from 0% to 110% of the rated voltage at a set rate, and when the synchronous machine-like grid-forming SVG is stable, reduce it from 110% to 0% of the rated voltage, and record the terminal voltage during the adjustment process; 8. The system according to claim 6, wherein the result unit, for performing sub-link measurement on the synchronous machine-like grid-forming SVG, is further configured to: When the synchronous machine-like grid-forming SVG is stable after voltage boost, perform a ±5% voltage step response test at the terminal, record the terminal voltage waveform, and calculate the performance index; 9. The system according to claim 6, wherein the result unit, for performing sub-link measurement on the synchronous machine-like grid-forming SVG, is further configured to: When the synchronous machine-like grid-forming SVG is operating under rated conditions, set the reactive current compensation coefficient to 0, keep the terminal voltage set value unchanged, perform a reactive power shedding test, record the terminal voltage and reactive power before and after load shedding, and calculate the voltage static deviation rate ε(%) according to Equation (1); ε(%) = [(U0 - U1) / U n × 100% (1) Among them, U1 and U0 are the terminal voltages before and after load rejection respectively, and U n is the rated terminal voltage.

10. The system according to claim 6, wherein the result unit, for performing sub-link measurement on the synchronous machine-like grid-forming SVG, is further configured to: When the synchronous machine-like grid-forming SVG is operating under rated conditions, keep the terminal voltage set value unchanged, perform disconnection at different reactive current compensation coefficients respectively, record the terminal voltage and reactive power before and after reactive power shedding, and calculate the regulation rate D according to Equation (2); Among them, U1 and U0 are the terminal voltages before and after load rejection respectively, and U n is the rated terminal voltage, and S N is the apparent power, and Q is the reactive power.

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