A method for testing adaptability of phase angle jump of a net-following type converter

Abstract

The application discloses a kind of grid-connected converter phase angle abrupt change adaptability test methods, it is related to converter test technical field, and the method includes: according to the short-circuit ratio of grid-connected converter access point, the short-circuit resistance and short-circuit reactance are calculated;The grid-connected point abrupt voltage of the grid-connected converter is calculated;Based on the short-circuit resistance, the short-circuit reactance and the grid-connected point abrupt voltage, the abrupt impedance is calculated;According to fault type, phase angle abrupt change duration is determined;According to the abrupt impedance, the abrupt change mode is selected;Based on the abrupt change mode selected, fault trigger quantity and trigger timing are determined, and phase angle abrupt change test is implemented;The method can cover single-phase, two-phase, three-phase 0~180° phase mutation test scene, meet the test demand of grid phase angle abrupt change to grid-connected converter, can all-round evaluate the phase mutation adaptability of grid-connected converter, improve the ability of grid-connected converter stable operation not off-grid during power grid fault.

Description

Technical Field

[0001] This invention relates to the field of converter testing technology, and in particular to a method for testing the phase angle change adaptability of a grid-type converter. Background Technology

[0002] With the rapid development of new energy power generation technologies, more and more new energy equipment such as wind turbines, photovoltaics, and energy storage are being connected to the power grid through grid-connected converters. The stable operation of these devices is crucial to the safety and reliability of the power grid. However, when a grid fault occurs, the phase of the grid voltage may change abruptly. Due to the limited response speed of the phase-locked loop (PLL) of the grid-connected converter, it cannot quickly follow the changes in the grid phase, which may cause the converter to disconnect from the grid, thereby affecting the stability of the entire power grid.

[0003] Current methods for testing phase angle mutations in grid-connected equipment mainly involve changing the phase of the 10kV or 35kV grid-connected power supply in actual new energy power plants. The principle is back-to-back AC-DC-AC rectification and inversion, all controlled by power electronic IGBTs. Because a large overcurrent peak is generated after a voltage phase mutation, the test can only be performed from 0° to 60° due to the overcurrent margin of the power transistors. The phase angle mutation test range is limited, the operation is complex, and it has an impact on the actual power grid.

[0004] Therefore, there is an urgent need for a new test method for the phase angle change adaptability of grid-connected converters, which can better reflect the characteristics of grid faults, meet the test requirements of grid phase angle change for grid-connected converters, and improve the ability of grid-connected converters to operate stably without disconnecting from the grid during grid faults. Summary of the Invention

[0005] The main objective of this invention is to provide a test method for the phase angle change adaptability of grid-connected converters. This method has a wider testing range and the testing conditions are more consistent with the actual grid fault characteristics. It can comprehensively evaluate the phase angle change adaptability of converters, reduce the probability of grid disconnection, and enhance grid stability.

[0006] To achieve the above objectives, the first aspect of this application provides a method for testing the phase angle change adaptability of a grid-type converter, the method comprising:

[0007] Calculate the short-circuit resistance and short-circuit reactance based on the short-circuit ratio at the connection point of the grid converter;

[0008] Calculate the grid connection point voltage change of the grid-connected converter;

[0009] Calculate the sudden impedance based on the short-circuit resistance, the short-circuit reactance, and the sudden voltage change at the grid connection point;

[0010] Determine the duration of the phase angle change based on the fault type;

[0011] Select the mutation mode based on the mutation impedance;

[0012] Based on the selected mutation method, the fault trigger quantity and trigger timing are determined, and phase angle mutation test is performed.

[0013] Optionally, the step of calculating the short-circuit resistance and short-circuit reactance based on the short-circuit ratio at the connection point of the grid converter includes:

[0014] The short-circuit resistance and short-circuit reactance are calculated based on the grid line voltage, short-circuit ratio, and rated capacity of the grid-connected converter.

[0015] Optionally, calculating the grid connection point voltage change of the grid-connected converter includes:

[0016] Collect the grid connection point voltage of the grid-connected converter when it is operating at its rated capacity;

[0017] Based on the grid connection point voltage, combined with the voltage drop coefficient and phase change, the grid connection point change voltage is calculated.

[0018] Optionally, the fault types include single-phase mutation, two-phase mutation, and three-phase mutation;

[0019] Determining the duration of phase angle change based on the fault type includes:

[0020] If the fault type is the single-phase mutation or the two-phase mutation, the duration of the phase angle mutation is the first time.

[0021] If the fault type is the three-phase sudden change, the duration of the phase angle sudden change is calculated based on the voltage drop coefficient.

[0022] Optionally, the selection of the mutation mode is based on the real and imaginary characteristics of the mutation impedance, specifically including:

[0023] If both the real and imaginary parts of the transient impedance are greater than or equal to zero, then the impedance transient mode is selected.

[0024] Otherwise, choose the voltage source sudden change method.

[0025] Optionally, determining the fault trigger quantity and trigger timing based on the selected mutation method includes:

[0026] If the impedance change method is selected, the fault triggering quantity is the change impedance, and the phase angle change is achieved by switching the impedance;

[0027] If the voltage source sudden change method is selected, the fault triggering quantity is the change in the three-phase voltage of the power grid, and the phase angle sudden change is achieved by changing the voltage source.

[0028] Optionally, the phase angle mutation test is performed on the RTlab / RTDS real-time simulation platform and in conjunction with the hardware-in-the-loop controller of the grid converter.

[0029] A second aspect of this application provides a test device for the phase angle change adaptability of a grid converter, comprising:

[0030] The first calculation module is used to calculate the short-circuit resistance and short-circuit reactance based on the short-circuit ratio at the connection point of the grid-type converter.

[0031] The second calculation module is used to calculate the grid connection point voltage change of the grid-connected converter.

[0032] The third calculation module is used to calculate the sudden impedance based on the short-circuit resistance, the short-circuit reactance, and the sudden voltage at the grid connection point;

[0033] The determination module is used to determine the duration of the phase angle change based on the fault type;

[0034] The selection module is used to select the mutation mode based on the mutation impedance.

[0035] The testing module is used to determine the fault trigger quantity and trigger timing based on the selected mutation method, and to perform phase angle mutation tests.

[0036] A third aspect of this application provides an electronic device including a memory and a processor, the memory storing a computer program that, when executed by the processor, causes the processor to perform steps as described in the first aspect and any possible implementation thereof.

[0037] A fourth aspect of this application provides a computer-readable storage medium, wherein when a computer program is executed by a processor, the processor performs the steps of the first aspect and any possible implementation thereof.

[0038] This application provides a method for testing the phase angle change adaptability of a grid-connected converter. The method involves calculating the short-circuit resistance and short-circuit reactance based on the short-circuit ratio at the grid-connected converter's connection point; calculating the grid connection point change voltage of the grid-connected converter; calculating the change impedance based on the short-circuit resistance, short-circuit reactance, and grid connection point change voltage; determining the duration of the phase angle change based on the fault type; selecting the change mode based on the change impedance; determining the fault trigger quantity and triggering sequence based on the selected change mode; and performing the phase angle change test. This method can cover single-phase, two-phase, and three-phase 0°~180° phase change test scenarios, meeting the testing requirements of grid phase angle changes for grid-connected converters. It can comprehensively evaluate the phase change adaptability of grid-connected converters and improve their ability to operate stably without disconnecting from the grid during grid faults. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] in:

[0041] Figure 1 A schematic flowchart illustrating a phase angle change adaptability test method for a grid converter provided in an embodiment of this application;

[0042] Figure 2 This is a schematic diagram of a fault scenario simulation process provided in an embodiment of this application;

[0043] Figure 3 This is a schematic diagram of a simulation result verification and calibration process provided in an embodiment of this application;

[0044] Figure 4 A schematic diagram of a phase angle change adaptability testing device for a grid-type converter provided in an embodiment of this application;

[0045] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0046] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0047] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0048] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0049] The embodiments of this application mentioned below are described in conjunction with the accompanying drawings.

[0050] Figure 1 This is a flowchart illustrating a phase angle change adaptability test method for a grid-type converter provided in an embodiment of this application, as shown below. Figure 1 As shown, the method includes:

[0051] 101. Calculate the short-circuit resistance and short-circuit reactance based on the short-circuit ratio at the connection point of the grid-type converter.

[0052] The execution subject of the method in this application embodiment can be a grid converter phase angle change adaptability test device, which can be implemented on an electronic device in practical applications.

[0053] The Short-Circuit Ratio (SCR) mentioned in the embodiments of this application is an important parameter in power systems, used to describe the strength of the power grid. It is defined as the ratio of the short-circuit capacity of the power grid to the rated capacity of the converter.

[0054] Specifically, in one optional implementation, step 101 includes:

[0055] The above-mentioned short-circuit resistance and short-circuit reactance are calculated based on the grid line voltage, short-circuit ratio, and rated capacity of the grid-connected converter.

[0056] Optionally, the specific calculation formulas for short-circuit resistance and short-circuit reactance can be as follows:

[0057]

[0058]

[0059] in, U This represents the power grid line voltage, in kV. S In The rated capacity of the grid-connected converter is expressed in MW or MVA. R SCR and X SCR These are the aforementioned short-circuit resistance and the aforementioned short-circuit reactance, respectively; K SCRThis is the short-circuit ratio.

[0060] Alternatively, for the two types of grid-connected converters, wind turbine converters and photovoltaic inverters, K SCR The value should be no less than 10 for both energy storage converters and dynamic reactive power compensation devices, which are grid-connected converters. K SCR The value should be no less than 20.

[0061] 102. Calculate the sudden voltage change at the grid connection point of the above-mentioned grid-connected converter.

[0062] The point of common coupling (PCC) is the common connection point between the converter and the power grid, typically located between the converter's output and the grid connection point. It is the physical interface through which the converter interacts with the grid, and also the point where grid faults and disturbances directly affect the converter.

[0063] The grid connection point sudden voltage mentioned in this application refers to the phenomenon where the voltage amplitude and phase of the grid connection point of the grid-connected converter suddenly change under grid fault or other disturbance conditions. This sudden voltage is an important parameter for evaluating the converter's adaptability to phase angle sudden changes.

[0064] In one optional implementation, step 102 includes:

[0065] Collect the grid connection point voltage of the above-mentioned grid-connected converter when it is operating at its rated capacity;

[0066] Based on the grid connection point voltage mentioned above, combined with the voltage drop factor and phase change, the grid connection point change voltage is calculated.

[0067] Specifically, it can collect t At time 0, the grid-connected voltage is compared with that of the grid-connected converter when it is operating at rated capacity. Considering the characteristics of voltage amplitude drop and phase change after a grid fault, this is taken into account. t The sudden voltage change at the grid connection point of the grid-connected converter at time 1 is:

[0068]

[0069] in, k T This is the voltage drop factor, typically ranging from 0.2 to 0.5. U 0 and θ 0 represents t At time 0, the grid connection point voltage and phase of the grid-connected converter are compared. U 1 and θ 1 are respectively t 1. The instantaneous voltage and phase at the grid connection point of the grid-connected converter are constant, i.e., the above formula uses phasor representation of amplitude and phase; Δ θ The angle of change can be 0° to 180°.

[0070] 103. Based on the above short-circuit resistance, the above short-circuit reactance and the above grid connection point sudden voltage, calculate the sudden impedance.

[0071] The transient impedance involved in this application refers to the equivalent impedance calculated when the voltage and current at the grid connection point of the grid-connected converter change under grid fault or other disturbance conditions. It is an important parameter for evaluating the dynamic behavior of the converter during grid faults.

[0072] Specifically, the sudden change impedance can be calculated using the following formula. Z T :

[0073]

[0074] in j It is an imaginary number.

[0075] 104. Determine the duration of phase angle change based on the fault type.

[0076] The phase angle abrupt change involved in the embodiments of this application refers to the phenomenon of a rapid change in the phase of the power grid voltage within a short period of time, which usually occurs under power grid faults (such as short circuits, voltage dips, etc.) or other disturbance conditions. This abrupt change has a significant impact on the stable operation of grid-connected power equipment (such as converters).

[0077] In one alternative implementation, the aforementioned fault types include single-phase abrupt change, two-phase abrupt change, and three-phase abrupt change;

[0078] Step 103 above includes:

[0079] If the above fault type is the above single-phase sudden change or the above two-phase sudden change, the duration of the above phase angle sudden change is the first time.

[0080] If the above fault type is the above three-phase sudden change, the duration of the above phase angle sudden change is calculated based on the above voltage drop coefficient.

[0081] Specifically, the above-mentioned fault types can be divided into single-phase sudden change (sudden change in the voltage of any one of the three phases A, B, and C), two-phase sudden change (sudden change in the voltage of any two of the three phases A, B, and C), and three-phase sudden change (sudden change in the voltage of all three phases A, B, and C simultaneously); in one implementation:

[0082] (1) If the fault type is a single-phase sudden change or a two-phase sudden change, the duration of the phase angle sudden change is T O12 =0.05s.

[0083] (2) If the fault type is a three-phase sudden change, the duration of the phase angle sudden change is... T OT3 for:

[0084]

[0085] in, k T This is the voltage drop factor, which is typically taken as 0.2 to 0.5.

[0086] The embodiments of this application can be set and adjusted as needed. T O12 The values ​​of , voltage drop coefficients and related parameters in the formula are not limited in this application embodiment.

[0087] 105. Select the mutation method based on the above mutation impedance.

[0088] In this embodiment, the mutation mode (impedance mutation mode) can be selected according to different mutation impedances, and the corresponding relationship between mutation impedance and mutation mode can be set as needed for selection and judgment.

[0089] In one optional implementation, the selection of the above-mentioned mutation mode is based on the real and imaginary characteristics of the above-mentioned mutation impedance, specifically including:

[0090] If both the real and imaginary parts of the above-mentioned transient impedance are greater than or equal to zero, then the impedance transient method is selected.

[0091] Otherwise, choose the voltage source sudden change method.

[0092] To give a specific example:

[0093] (1) If Re( Z T )≥0 and Im( Z T If )≥0, then the impedance mutation type method is selected.

[0094] (2) If Re( Z T )<0 and Im( Z T )≥0、Re( Z T )≥0 and Im( Z T )<0、Re( Z T )<0 and Im( Z T If ) < 0, then the voltage source mutation mode is selected.

[0095] Where Re is the complex number calculated with the real part taken, and Im is the complex number calculated with the imaginary part taken.

[0096] 106. Based on the selected mutation method, determine the fault trigger quantity and trigger timing, and implement phase angle mutation test.

[0097] The phase angle change test mentioned in this application embodiment is a test method for evaluating the adaptability and stability of power equipment (such as converters, energy storage systems, etc.) when the grid voltage phase changes abruptly.

[0098] The fault triggering quantity and fault triggering sequence of phases A, B, and C are determined by the impedance change method. Based on the triggering sequence, phase angle change tests of single-phase change, two-phase change, or three-phase change of grid-connected converters can be carried out.

[0099] In one optional implementation, the determination of the fault trigger quantity and trigger timing based on the selected mutation method includes:

[0100] If the above impedance change method is selected, the above fault triggering quantity is the above change impedance, and the phase angle change is achieved by switching the impedance.

[0101] If the above voltage source sudden change method is selected, the above fault triggering quantity is the change in the three-phase voltage of the power grid, and the phase angle sudden change is achieved by changing the voltage source.

[0102] Figure 2 This is a schematic diagram illustrating the principle of voltage source mutation and impedance mutation phase angle mutation, provided for embodiments of this application.

[0103] like Figure 2 As shown, the left side is a grid-connected converter; the voltage includes three-phase voltages A, B, and C; the switches (such as...) S A , S B , S C The switch is used to control the triggering of mutations. The state of the switch (closed or open) determines the manner and duration of the mutation. Figure 2 The text demonstrates two mutation methods:

[0104] Voltage source abrupt change type: This method simulates a phase angle abrupt change by altering the voltage amplitude and phase on the grid side. It is suitable for a large range of phase angle abrupt changes (e.g., 0°~180°).

[0105] Impedance-induced sudden change type: This method simulates a sudden change in phase angle by introducing a sudden change in impedance at the grid connection point. This approach takes into account the non-periodic DC attenuation component during grid faults, and is more consistent with the characteristics of actual grid faults.

[0106] The triggering sequence of the switch differs for single-phase, two-phase, and three-phase abrupt changes. The specific timing sequence will be explained in conjunction with the table later.

[0107] Specifically:

[0108] (1) If it is an impedance mutation type, the fault triggering quantity is the sudden impedance. Z T ,switch S A , S B , S C The initial state of all three phases of the power grid is open. U A , U B , U C It remains unchanged, specifically:

[0109]

[0110] Let the mutation time be... t 1. Based on Figure 2 The structure and triggering timing can be referenced in Table 1, which shows the correspondence between different impedance change modes and triggering timings for a single impedance change type.

[0111]

[0112] Table 1

[0113] (2) If it is a voltage source sudden change type, the fault triggering quantity is the three-phase voltage of the power grid. U AT , U BT , U CT Specifically:

[0114]

[0115] Let the mutation time be... t 1. Switch S A , S B , S C The voltage source is always in the off state. The trigger timing can be referred to Table 2, which shows the correspondence between different voltage source mutation modes and trigger timing.

[0116]

[0117] Table 2

[0118] Based on the above triggering sequence, phase angle change tests can be carried out for single-phase change, two-phase change, or three-phase change of grid-connected converters.

[0119] In one alternative implementation, the phase angle mutation test is performed on the RTlab / RTDS real-time simulation platform and in conjunction with the hardware-in-the-loop controller of the grid converter.

[0120] Specifically, the method in this application embodiment can be mainly applied to the small signal low voltage RTlab / RTDS real-time simulation platform. It only needs to be implemented in conjunction with the semi-physical controller of the grid converter. It is simple to operate, safe and efficient, and avoids the risk of high voltage electric shock or machine explosion caused by actual 10kV or 35kV grid-connected power supply operation.

[0121] Furthermore, the method in this application comprehensively considers the impact of the short-circuit ratio on the peak value of the phase angle sudden change overcurrent. The higher the short-circuit ratio, the larger the peak value of the overcurrent. This method proposes that the phase angle sudden change adaptability test of the grid-type converter should be carried out under the condition of a strong grid with a high short-circuit ratio, which is consistent with the actual grid situation. Moreover, it cleverly combines impedance sudden change and voltage source sudden change. The impedance sudden change considers the non-periodic DC component, which is consistent with the characteristics of grid faults and meets the requirements for phase angle sudden change test from 0° to 180°.

[0122] Figure 3 This is a schematic flowchart of another phase angle change adaptability test method for grid-type converters provided in this application embodiment. Figure 3 As shown, the specific steps are as follows:

[0123] 1. Calculate the short-circuit resistance and short-circuit reactance at the connection point of the grid-connected converter.

[0124] 2. Collection t Voltage at grid connection point of the grid-connected converter at time 0

[0125] 3. Calculate the sudden voltage change at the grid connection point of the grid-connected converter.

[0126] 4. Calculate the impedance of sudden change based on the sudden change voltage.

[0127] 5. Calculate the duration of the phase angle change.

[0128] 6. Select the mutation mode based on mutation impedance.

[0129] Specifically, it determines whether it conforms to Re( Z T )≥0 and Im( Z T )≥0;

[0130] If so, choose the impedance mutation type; otherwise, choose the voltage source mutation type.

[0131] 7. Determine the fault trigger quantity

[0132] The fault trigger quantity is determined based on the selected mutation method, where:

[0133] Impedance abrupt change type, trigger quantity is abrupt impedance change Z T ;

[0134] Voltage source sudden change type, the trigger quantity is the change in three-phase voltage of the power grid. U AT , U BT , U CT .

[0135] 8. Determine the fault triggering sequence based on the fault type.

[0136] Determine the switch based on the fault type (single-phase, two-phase, or three-phase sudden change). S A , S B , S C The on / off timing.

[0137] 9. Phase angle mutation tests can be performed based on the triggering sequence.

[0138] Existing methods for testing phase angle mutations in grid-connected equipment mainly involve altering the phase of the 10kV or 35kV grid-connected power supply in actual new energy power plants. The principle is back-to-back AC-DC-AC rectification and inversion, all controlled by power electronic IGBTs. Due to the large overcurrent peak generated after a voltage phase mutation, the test can only achieve phase angle mutations from 0° to 60°, limited by the overcurrent margin of the power transistors. Furthermore, the test does not consider the impact of non-periodic DC attenuation components and the grid-connected short-circuit ratio on phase angle mutations during grid faults. The test range for phase angle mutations is limited, the operation is complex, and it has an impact on the actual power grid.

[0139] In view of the above problems, this application proposes a phase angle sudden change adaptability test method for grid-connected converters, wherein: considering the influence of the short-circuit ratio on the peak value of the phase angle sudden change overcurrent, the test is required to be carried out under strong grid and high short-circuit ratio conditions. The larger the peak value of the overcurrent, the better the phase angle sudden change tolerance capability of the grid-connected converter can be tested, and the short-circuit resistance and short-circuit reactance are finally obtained; the sudden change voltage at the grid connection point of the grid-connected converter, i.e., the target value of the phase angle sudden change, is calculated, which can be determined according to the actual test requirements, including amplitude drop and phase change; based on the results of the above steps, the sudden change impedance at the grid connection point of the grid-connected converter is calculated, and the phase angle sudden change will be realized by switching the impedance; then the duration of the phase angle sudden change is calculated, fully covering the single Phase abrupt changes, two-phase abrupt changes, and three-phase abrupt changes are identified. The abrupt change method will be selected based on the aforementioned impedance. Impedance abrupt changes take into account the influence of non-periodic DC attenuation components during grid faults, making them more consistent with grid characteristics. This method is generally used for 0°~90° phase abrupt change testing. The complementary voltage source abrupt change method can broaden the phase abrupt change testing range, allowing the impedance and voltage source abrupt changes to work together to meet the 0°~180° phase abrupt change testing requirements. Finally, the phase angle abrupt change fault trigger quantity and fault trigger sequence will be set based on the selected abrupt change method. Subsequently, RTDS or RTlab simulation platforms can be used to complete single-phase, two-phase, and three-phase 0°~180° phase abrupt change tests according to the fault sequence.

[0140] As can be seen, the method in this application embodiment considers the impact of short-circuit ratio and aperiodic DC attenuation components on phase angle mutations, covering single-phase, two-phase, and three-phase 0°~180° phase mutation test scenarios, which is more in line with the characteristics of power grid faults, fully meets the test requirements of grid phase angle mutations for grid-connected converters, can comprehensively evaluate the phase mutation adaptability of grid-connected converters, and improve the ability of grid-connected converters to operate stably without disconnecting from the grid during power grid faults.

[0141] Based on the description of the foregoing method embodiments, this application also provides a test device for the phase angle change adaptability of a grid converter.

[0142] Figure 4 This is a schematic diagram of a phase angle change adaptability testing device for a grid-type converter, provided as an embodiment of this application. Figure 4 As shown, the phase angle change adaptability test device 400 for grid-type converters includes:

[0143] The first calculation module 410 is used to calculate the short-circuit resistance and short-circuit reactance based on the short-circuit ratio of the grid-connected converter connection point;

[0144] The second calculation module 420 is used to calculate the sudden voltage change at the grid connection point of the above-mentioned grid-connected converter.

[0145] The third calculation module 430 is used to calculate the sudden impedance based on the short-circuit resistance, the short-circuit reactance and the sudden voltage at the grid connection point.

[0146] Module 440 is used to determine the duration of the phase angle change based on the fault type;

[0147] Selection module 450 is used to select the mutation mode based on the above-mentioned mutation impedance;

[0148] Test module 460 is used to determine the fault trigger quantity and trigger timing based on the selected mutation method, and to perform phase angle mutation test.

[0149] Optionally, the first calculation module 410 described above is specifically used for:

[0150] The above-mentioned short-circuit resistance and short-circuit reactance are calculated based on the grid line voltage, short-circuit ratio, and rated capacity of the grid-connected converter.

[0151] Optionally, the second calculation module 420 mentioned above is specifically used for:

[0152] Collect the grid connection point voltage of the above-mentioned grid-connected converter when it is operating at its rated capacity;

[0153] Based on the grid connection point voltage mentioned above, combined with the voltage drop factor and phase change, the grid connection point change voltage is calculated.

[0154] Optionally, the above-mentioned fault types include single-phase mutation, two-phase mutation, and three-phase mutation;

[0155] The aforementioned determining module 440 is specifically used for:

[0156] If the above fault type is the above single-phase sudden change or the above two-phase sudden change, the duration of the above phase angle sudden change is the first time.

[0157] If the above fault type is the above three-phase sudden change, the duration of the above phase angle sudden change is calculated based on the above voltage drop coefficient.

[0158] Optionally, the selection of the above-mentioned mutation mode is based on the real and imaginary characteristics of the above-mentioned mutation impedance; the selection module 450 is specifically used for:

[0159] If both the real and imaginary parts of the above-mentioned transient impedance are greater than or equal to zero, then the impedance transient method is selected.

[0160] Otherwise, choose the voltage source sudden change method.

[0161] Optionally, the aforementioned test module 460 is specifically used for:

[0162] If the above impedance change method is selected, the above fault triggering quantity is the above change impedance, and the phase angle change is achieved by switching the impedance.

[0163] If the above voltage source sudden change method is selected, the above fault triggering quantity is the change in the three-phase voltage of the power grid, and the phase angle sudden change is achieved by changing the voltage source.

[0164] Optionally, the phase angle mutation test described above is performed on the RTlab / RTDS real-time simulation platform and is used in conjunction with the hardware-in-the-loop controller of the grid converter described above.

[0165] Understandably, this involves Figure 4 The relevant content of each module in the above method embodiments has been described in detail, and you can refer to the content of the method embodiments for details; that is... Figure 4 The provided grid converter phase angle change adaptability test device 400 can perform, for example, Figure 1 or Figure 3 Any steps in the illustrated embodiments will not be described in detail here.

[0166] In one embodiment of this application, an electronic device is also provided. See also... Figure 5 , Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 5 As shown, the electronic device 500 includes a processor 501 and a memory 502. The memory 502 stores a computer program, which, when executed by the processor 501, will perform actions such as... Figure 1 or Figure 3 Any step in the method embodiment shown. The electronic device 500 may also include input / output devices, etc. In a specific embodiment, the electronic device may be a terminal device, etc.

[0167] In one embodiment, a computer-readable storage medium is also provided, which stores a computer program that, when executed by a processor 501, causes the processor 501 to perform any of the steps in the above method embodiments.

[0168] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0169] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0170] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for testing the adaptability of a grid-type converter to sudden phase angle changes, characterized in that, include: Calculate the short-circuit resistance and short-circuit reactance based on the short-circuit ratio at the connection point of the grid converter; Calculate the grid connection point voltage change of the grid-connected converter; Calculate the sudden impedance based on the short-circuit resistance, the short-circuit reactance, and the sudden voltage change at the grid connection point; Determine the duration of the phase angle change based on the fault type; Select the mutation mode based on the mutation impedance; Based on the selected mutation method, the fault trigger quantity and trigger timing are determined, and phase angle mutation test is performed; The calculation of the grid connection point voltage change of the grid-connected converter includes: The grid-connected voltage of the grid-connected converter at its rated capacity is collected. Based on this grid-connected voltage, and combined with the voltage sag coefficient and phase change, the grid-connected voltage change is calculated. Specifically, this includes: collecting... t At time 0, the grid-connected converter operates at its rated capacity with the grid connection point voltage. Considering the characteristics of voltage amplitude drop and phase change after an actual grid fault, t The sudden voltage change at the grid connection point of the grid-connected converter at time 1 is: in, k T The voltage drop factor is defined as 0.2 to 0.

5. U 0 and θ 0 represents t The grid connection point voltage and phase of the grid-connected converter at time 0 are described. U 1 and θ 1 are respectively t The sudden change in voltage and phase at the grid connection point of the grid-connected converter at time 1; Δ θ The angle of abrupt change ranges from 0° to 180°. The fault types include single-phase sudden change, two-phase sudden change, and three-phase sudden change; determining the phase angle sudden change duration based on the fault type includes: if the fault type is a single-phase sudden change or a two-phase sudden change, the phase angle sudden change duration is a first time; if the fault type is a three-phase sudden change, the phase angle sudden change duration is calculated based on the voltage drop coefficient, and the phase angle sudden change duration is... T OT3 for: ； The selection of the mutation mode is based on the real and imaginary characteristics of the mutation impedance, specifically including: If both the real and imaginary parts of the transient impedance are greater than or equal to zero, then the impedance transient method is selected; otherwise, the voltage source transient method is selected. The determination of the fault triggering quantity and triggering sequence based on the selected mutation method includes: If the impedance mutation method is selected, the fault triggering quantity is the mutation impedance, and the phase angle mutation is achieved by switching the impedance; if the voltage source mutation method is selected, the fault triggering quantity is the change in the three-phase voltage of the power grid, and the phase angle mutation is achieved by changing the voltage source.

2. The method for testing the phase angle change adaptability of a grid-connected converter according to claim 1, characterized in that, The calculation of short-circuit resistance and short-circuit reactance based on the short-circuit ratio at the connection point of the grid converter includes: The short-circuit resistance and short-circuit reactance are calculated based on the grid line voltage, short-circuit ratio, and rated capacity of the grid-connected converter.

3. The method for testing the phase angle change adaptability of a grid-connected converter according to claim 1, characterized in that, The phase angle mutation test was performed on the RTlab / RTDS real-time simulation platform and was conducted in conjunction with the hardware-in-the-loop controller of the grid converter.

4. A phase angle change adaptability testing device for a grid-type converter, characterized in that, Steps for performing the method as described in any one of claims 1-3; comprising: The first calculation module is used to calculate the short-circuit resistance and short-circuit reactance based on the short-circuit ratio at the connection point of the grid-type converter. The second calculation module is used to calculate the grid connection point voltage change of the grid-connected converter. The third calculation module is used to calculate the sudden impedance based on the short-circuit resistance, the short-circuit reactance, and the sudden voltage at the grid connection point; The determination module is used to determine the duration of the phase angle change based on the fault type; The selection module is used to select the mutation mode based on the mutation impedance. The testing module is used to determine the fault trigger quantity and trigger timing based on the selected mutation method, and to perform phase angle mutation tests.

5. An electronic device, characterized in that, It includes a memory and a processor, the memory storing a computer program that, when executed by the processor, causes the processor to perform the steps of the method as described in any one of claims 1-3.

6. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, the processor performs the steps of the method as described in any one of claims 1-3.

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