A method and device for detecting reactive current response time of new energy grid-connected equipment

Abstract

The present application provides a method and device for detecting the reactive current response time of a new energy grid-connected device. The ideal reactive current upper limit of the new energy grid-connected device is calculated based on the fundamental positive-sequence component of the voltage, the integral value of the fundamental positive-sequence component of the reactive current is determined based on the fundamental positive-sequence component of the voltage and the fundamental positive-sequence component of the reactive power, and then the reactive current response time of the new energy grid-connected device is detected based on the ideal reactive current upper limit of the new energy grid-connected device and the integral value of the fundamental positive-sequence component of the reactive current. The present application can eliminate the problem of inconsistency between the delay introduced by the starting moment and the delay introduced by the ending moment of the response time in the related art, thereby improving the detection accuracy of the response time. The present application uses the integral value of the fundamental positive-sequence component of the reactive current as the ideal reactive current upper limit of the new energy grid-connected device, thereby accurately measuring the voltage support capability of the new energy grid-connected device for the grid.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and in particular to a method and device for detecting the reactive current response time of new energy grid-connected equipment. Background Art

[0002] With the rapid development of new energy technologies, the performance evaluation of new energy grid-connected equipment has become particularly important. During this performance evaluation, when grid voltage fluctuates, new energy grid-connected equipment must rapidly adjust reactive current to actively support the grid voltage. The reactive current response time is a key indicator of the ability of new energy grid-connected equipment to support grid voltage.

[0003] In the response time detection method for new energy grid-connected equipment provided by the existing technology, the moment when the grid connection point voltage falls below 90% of the rated voltage of the new energy grid-connected equipment is usually used as the starting moment of the response time, and the moment when the inverter reactive current output value increases to 90% of the reactive current increment value is used as the ending moment of the response time. The time between the starting moment of the response time and the ending moment of the response time is the reactive current response time of the new energy grid-connected equipment. However, because the delay introduced at the starting moment of the response time is inconsistent with the delay introduced at the ending moment, the detection accuracy of the response time is low. Summary of the Invention

[0004] In order to solve the problem of low detection accuracy in the prior art, the present application provides a method and device for detecting the reactive current response time of a new energy grid-connected device.

[0005] In a first aspect, the present application provides a method for detecting the reactive current response time of a new energy grid-connected device, which may include:

[0006] The fundamental positive sequence component of voltage and the fundamental positive sequence component of reactive power are calculated based on the three-phase voltage and three-phase current of the renewable energy grid connection point.

[0007] The ideal reactive current upper limit of the new energy grid-connected equipment is calculated based on the fundamental positive sequence component of the voltage, and the integral value of the fundamental positive sequence component of the reactive current is determined based on the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power.

[0008] The reactive current response time of the renewable energy grid-connected equipment is detected according to the ideal reactive current upper limit of the renewable energy grid-connected equipment and the integral value of the fundamental positive sequence component of the reactive current.

[0009] In some possible implementations, calculating the fundamental positive sequence component of voltage and the fundamental positive sequence component of reactive power based on the three-phase voltage and three-phase current of the renewable energy grid connection point includes:

[0010] The three-phase voltage and three-phase current of the renewable energy grid connection point are subjected to full-cycle Fourier decomposition to obtain the real and imaginary parts of the three-phase voltage and the real and imaginary parts of the three-phase current.

[0011] The real and imaginary parts of the fundamental positive sequence component of the voltage are calculated based on the real and imaginary parts of the three-phase voltages, and the real and imaginary parts of the fundamental positive sequence component of the current are calculated based on the real and imaginary parts of the three-phase currents.

[0012] The fundamental positive sequence component of voltage is calculated based on the real and imaginary parts of the fundamental positive sequence component of voltage, and the fundamental positive sequence component of reactive power is calculated based on the real and imaginary parts of the fundamental positive sequence component of voltage and the real and imaginary parts of the fundamental positive sequence component of current.

[0013] In some other possible implementations, the ideal reactive current upper limit of the renewable energy grid-connected equipment is calculated based on the fundamental positive sequence component of the voltage, including:

[0014] The ideal reactive current of renewable energy grid-connected equipment is calculated based on the fundamental positive sequence component of the voltage.

[0015] The ideal reactive current upper limit of the new energy grid-connected equipment is calculated based on the ideal reactive current of the new energy grid-connected equipment.

[0016] Optionally, when the new energy grid-connected equipment is a grid-following new energy grid-connected equipment, the ideal reactive current of the new energy grid-connected equipment satisfies: .

[0017] When the new energy grid-connected equipment is a grid-building type new energy grid-connected equipment, the ideal reactive current of the new energy grid-connected equipment satisfies: .

[0018] in, Indicates the ideal reactive current of new energy grid-connected equipment, Indicates the rated current of new energy grid-connected equipment. It indicates the ratio of reactive current output by grid-connected new energy equipment to voltage change under grid voltage disturbance. Indicates the deviation of the fundamental positive sequence component of the voltage, It represents the steady-state equivalent internal impedance of the grid-connected new energy equipment. Represents the fundamental positive sequence component of voltage.

[0019] The ideal reactive current upper limit of new energy grid-connected equipment meets the following requirements: ;

[0020] in, Indicates the ideal upper limit of reactive current for new energy grid-connected equipment. Indicates the ideal reactive current of new energy grid-connected equipment, It indicates the reactive current of the new energy grid-connected equipment when the grid voltage is not disturbed. Indicates the starting moment of the voltage fundamental positive sequence component falling process, Indicates the end time of the voltage fundamental positive sequence component falling process, represents the integration variable.

[0021] In some further possible implementations, determining the integral value of the fundamental positive sequence component of the reactive current according to the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power includes:

[0022] The fundamental positive sequence component of reactive current is calculated based on the fundamental positive sequence component of voltage and the fundamental positive sequence component of reactive power.

[0023] The integral value of the fundamental positive sequence component of the reactive current is calculated according to the fundamental positive sequence component of the reactive current.

[0024] Exemplarily, the fundamental positive sequence component of the reactive current satisfies: ;in, Represents the fundamental positive sequence component of reactive current, Represents the fundamental positive sequence component of the voltage, Represents the fundamental positive sequence component of reactive power.

[0025] The integral value of the fundamental positive sequence component of reactive current satisfies: ;in, Indicates the integral value of the fundamental positive sequence component of reactive current, It indicates the reactive current of the new energy grid-connected equipment when the grid voltage is not disturbed. Indicates the starting moment of the voltage fundamental positive sequence component falling process, Indicates the end time of the voltage fundamental positive sequence component falling process, Indicates the delay time, represents the integration variable.

[0026] In some further possible implementations, detecting the reactive current response time of the new energy grid-connected device based on the ideal reactive current upper limit of the new energy grid-connected device and the integral value of the fundamental positive sequence component of the reactive current includes:

[0027] When the ideal reactive current upper limit of the renewable energy grid-connected equipment is equal to the integral value of the fundamental positive sequence component of the reactive current, the delay time is taken as the response time of the reactive current.

[0028] In a second aspect, the present application provides a device for detecting reactive current response time of a new energy grid-connected device, which may include:

[0029] The calculation module is used to calculate the fundamental positive sequence component of voltage and the fundamental positive sequence component of reactive power based on the three-phase voltage and three-phase current of the new energy grid connection point.

[0030] The determination module is used to calculate the ideal reactive current upper limit of the new energy grid-connected equipment based on the fundamental positive sequence component of the voltage, and to determine the integral value of the fundamental positive sequence component of the reactive current based on the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power.

[0031] The detection module is used to detect the reactive current response time of the new energy grid-connected equipment based on the ideal reactive current upper limit of the new energy grid-connected equipment and the integral value of the fundamental positive sequence component of the reactive current.

[0032] In some possible implementations, the computing module is specifically configured to:

[0033] The three-phase voltage and three-phase current of the renewable energy grid connection point are subjected to full-cycle Fourier decomposition to obtain the real and imaginary parts of the three-phase voltage and the real and imaginary parts of the three-phase current.

[0034] The real and imaginary parts of the fundamental positive sequence component of the voltage are calculated based on the real and imaginary parts of the three-phase voltages, and the real and imaginary parts of the fundamental positive sequence component of the current are calculated based on the real and imaginary parts of the three-phase currents.

[0035] The fundamental positive sequence component of voltage is calculated based on the real and imaginary parts of the fundamental positive sequence component of voltage, and the fundamental positive sequence component of reactive power is calculated based on the real and imaginary parts of the fundamental positive sequence component of voltage and the real and imaginary parts of the fundamental positive sequence component of current.

[0036] In some other possible implementations, the determination module is specifically configured to:

[0037] The ideal reactive current of renewable energy grid-connected equipment is calculated based on the fundamental positive sequence component of the voltage.

[0038] The ideal reactive current upper limit of the new energy grid-connected equipment is calculated based on the ideal reactive current of the new energy grid-connected equipment.

[0039] For example, when the new energy grid-connected device is a grid-following new energy grid-connected device, the ideal reactive current of the new energy grid-connected device satisfies: ;

[0040] When the new energy grid-connected equipment is a grid-building type new energy grid-connected equipment, the ideal reactive current of the new energy grid-connected equipment satisfies: ;

[0041] in, Indicates the ideal reactive current of new energy grid-connected equipment, Indicates the rated current of new energy grid-connected equipment. It indicates the ratio of reactive current output by grid-connected new energy equipment to voltage change under grid voltage disturbance. Indicates the deviation of the fundamental positive sequence component of the voltage, It represents the steady-state equivalent internal impedance of the grid-connected new energy equipment. Represents the fundamental positive sequence component of voltage.

[0042] The ideal reactive current upper limit of new energy grid-connected equipment meets the following requirements: ;in, Indicates the ideal upper limit of reactive current for new energy grid-connected equipment. Indicates the ideal reactive current of new energy grid-connected equipment, It indicates the reactive current of the new energy grid-connected equipment when the grid voltage is not disturbed. Indicates the starting moment of the voltage fundamental positive sequence component falling process, Indicates the end time of the voltage fundamental positive sequence component falling process, represents the integration variable.

[0043] In some further possible implementations, the determination module is specifically configured to:

[0044] The fundamental positive sequence component of reactive current is calculated based on the fundamental positive sequence component of voltage and the fundamental positive sequence component of reactive power.

[0045] The integral value of the fundamental positive sequence component of the reactive current is calculated according to the fundamental positive sequence component of the reactive current.

[0046] Optionally, the fundamental positive sequence component of the reactive current satisfies: ;in, Represents the fundamental positive sequence component of reactive current, Represents the fundamental positive sequence component of the voltage, Represents the fundamental positive sequence component of reactive power.

[0047] The integral value of the fundamental positive sequence component of reactive current satisfies: ; Indicates the integral value of the fundamental positive sequence component of reactive current, It indicates the reactive current of the new energy grid-connected equipment when the grid voltage is not disturbed. Indicates the starting moment of the voltage fundamental positive sequence component falling process, Indicates the end time of the voltage fundamental positive sequence component falling process, Indicates the delay time, represents the integration variable.

[0048] In some further possible implementations, the detection module is specifically configured to:

[0049] When the ideal reactive current upper limit of the renewable energy grid-connected equipment is equal to the integral value of the fundamental positive sequence component of the reactive current, the delay time is taken as the response time of the reactive current.

[0050] On the other hand, the present application also provides a computer device, including: one or more processors.

[0051] A processor is used to execute one or more programs.

[0052] When one or more programs are executed by one or more processors, the above-mentioned detection method is implemented.

[0053] In another aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the above-mentioned detection method.

[0054] Compared with the prior art, the present invention has the following advantages:

[0055] This application provides a detection method for calculating the ideal reactive current upper limit of a new energy grid-connected device based on the fundamental positive-sequence component of voltage, determining the integral value of the fundamental positive-sequence component of reactive current based on the fundamental positive-sequence component of voltage and the fundamental positive-sequence component of reactive power, and then detecting the reactive current response time of the new energy grid-connected device based on the ideal reactive current upper limit of the new energy grid-connected device and the integral value of the fundamental positive-sequence component of reactive current. This application detects reactive current response time based on the ideal reactive current upper limit and the integral value of the fundamental positive-sequence component of reactive current, eliminating the problem of inconsistent delays introduced by the start and end times of the response time in related technologies, thereby improving the accuracy of response time detection.

[0056] The present application can accurately calculate the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power based on the three-phase voltage and three-phase current of the new energy grid-connected point, thereby realizing the accurate calculation of the ideal reactive current upper limit and the integral value of the fundamental positive sequence component of the reactive current of the new energy grid-connected equipment, further ensuring the detection accuracy of the response time.

[0057] This application calculates the ideal reactive current for each of the grid-following type new energy grid-connected equipment and the grid-building type new energy grid-connected equipment, and then realizes the detection of the reactive current response time of each of the grid-following type new energy grid-connected equipment and the grid-building type new energy grid-connected equipment.

[0058] This application uses the integral value of the fundamental positive sequence component of the reactive current as the ideal reactive current upper limit of the new energy grid-connected equipment, thereby realizing accurate detection of the reactive current response time. As a result, the new energy grid-connected equipment can support the grid voltage at the moment when the grid voltage fluctuates, thereby improving the stability of the grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0060] Figure 1 This is a schematic flow chart of a method for detecting reactive current response time of a new energy grid-connected device in an embodiment of the present application;

[0061] Figure 2 A schematic flow chart of calculating the fundamental positive sequence component of voltage and the fundamental positive sequence component of reactive power in an embodiment of the present application;

[0062] Figure 3 is a schematic waveform diagram of the fundamental positive sequence component of the voltage in the embodiment of the present application;

[0063] Figure 4 A schematic flow chart of calculating the ideal reactive current upper limit of a new energy grid-connected device in an embodiment of the present application;

[0064] Figure 5 A schematic waveform diagram of an ideal reactive current of a new energy grid-connected device in an embodiment of the present application;

[0065] Figure 6 This is a schematic flow chart of determining the integral value of the fundamental positive sequence component of reactive current in an embodiment of the present application;

[0066] Figure 7 is a schematic waveform diagram of the fundamental positive sequence component of the voltage in the embodiment of the present application;

[0067] Figure 8 is a schematic waveform diagram of the fundamental positive sequence component of the voltage in the embodiment of the present application;

[0068] Figure 9 A schematic waveform diagram of the ideal reactive current and the fundamental positive sequence component of the reactive current of the new energy grid-connected equipment in the embodiment of the present application;

[0069] Figure 10 A schematic waveform diagram of the ideal reactive current and the fundamental positive sequence component of the reactive current of the new energy grid-connected equipment in the embodiment of the present application;

[0070] Figure 11 is a schematic waveform diagram of the fundamental positive sequence component of the voltage in the embodiment of the present application;

[0071] Figure 12 is a schematic waveform diagram of the fundamental positive sequence component of the voltage in the embodiment of the present application;

[0072] Figure 13 A schematic waveform diagram of the ideal reactive current and the fundamental positive sequence component of the reactive current of the new energy grid-connected equipment in the embodiment of the present application;

[0073] Figure 14 A schematic waveform diagram of the ideal reactive current and the fundamental positive sequence component of the reactive current of the new energy grid-connected equipment in the embodiment of the present application;

[0074] Figure 15 This is a schematic structural diagram of a device for detecting reactive current response time of new energy grid-connected equipment in an embodiment of the present application. DETAILED DESCRIPTION

[0075] The technical solution in this application will be described below with reference to the accompanying drawings.

[0076] The terms "first," "second," and the like in the description, embodiments, claims, and drawings of this application are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or order. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions, such as, for example, inclusion of a series of steps or units. A method, system, product, or apparatus is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products, or apparatus.

[0077] It should be understood that in this application, "at least one (item)" means one or more, and "more" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships can exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or plural.

[0078] Example 1:

[0079] The embodiment of the present application provides a method for detecting the reactive current response time of a new energy grid-connected device. Figure 1 As shown, the detection method 100 includes the following steps:

[0080] Step S1: Calculate the fundamental positive sequence component of voltage and the fundamental positive sequence component of reactive power according to the three-phase voltage and three-phase current of the renewable energy grid connection point.

[0081] Step S2: Calculate the ideal reactive current upper limit of the new energy grid-connected equipment based on the fundamental positive sequence component of the voltage, and determine the integral value of the fundamental positive sequence component of the reactive current based on the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power.

[0082] Step S3: detecting the reactive current response time of the new energy grid-connected equipment according to the ideal reactive current upper limit of the new energy grid-connected equipment and the integral value of the fundamental positive sequence component of the reactive current.

[0083] In some possible implementations, such as Figure 2 As shown, in step S1, the fundamental positive sequence component of voltage and the fundamental positive sequence component of reactive power are calculated based on the three-phase voltage and three-phase current of the new energy grid connection point, which specifically includes the following steps:

[0084] Step S11: performing full-cycle Fourier decomposition on the three-phase voltage and three-phase current of the new energy grid-connected point to obtain the real and imaginary parts of the three-phase voltage and the real and imaginary parts of the three-phase current.

[0085] Optionally, the three-phase current at the grid connection point can be directly collected through a recording device. For a primary circuit with a neutral point, the three-phase phase voltage at the grid connection point can be directly collected through a recording device. For a primary circuit without a neutral point, the three-phase line voltage at the grid connection point can be collected. 、 、 , and then calculate the three-phase phase voltage of the grid connection point according to the three-phase line voltage:

[0086]

[0087] in, 、 、 Respectively a Mutually, b Mutually, c Phase voltage of the phase, t Indicates time.

[0088] by a Take phase as an example, a The real and imaginary parts of the phase-to-phase voltage can be expressed as:

[0089]

[0090]

[0091] in, express aThe real part of the phase-to-phase voltage, express a The imaginary part of the phase-to-phase voltage, represents the fundamental period, f represents the fundamental frequency, Indicates a time interval.

[0092] For new energy grid connection points b Phase voltage, c The phase voltages are decomposed into full-cycle Fourier transforms b Phase voltage, c The real and imaginary parts of the phase voltages can refer to the above process and will not be described in detail in this embodiment. The real and imaginary parts of the three-phase currents can be obtained by performing full-cycle Fourier decomposition on the three-phase currents. This application will not describe them in detail and you can refer to relevant literature.

[0093] Step S12: Calculate the real and imaginary parts of the fundamental positive sequence component of the voltage according to the real and imaginary parts of the three-phase voltages, and calculate the real and imaginary parts of the fundamental positive sequence component of the current according to the real and imaginary parts of the three-phase currents.

[0094] The real and imaginary parts of the fundamental positive sequence component of the voltage can satisfy:

[0095]

[0096]

[0097] in, represents the real part of the fundamental positive sequence component of the voltage, Represents the imaginary part of the fundamental positive sequence component of the voltage. 、 、 represents the real part of each of the three-phase voltages, 、 、 Indicates the imaginary part of each of the three-phase voltages.

[0098] The real and imaginary parts of the fundamental positive sequence component of the current can satisfy:

[0099]

[0100]

[0101] in, represents the real part of the fundamental positive sequence component of the current, Represents the imaginary part of the fundamental positive sequence component of the current. 、 、 represents the real part of each of the three-phase currents, 、 、 Represents the imaginary part of each of the three-phase currents.

[0102] Step S13: Calculate the fundamental positive sequence component of voltage according to the real and imaginary parts of the fundamental positive sequence component of voltage, and calculate the fundamental positive sequence component of reactive power according to the real and imaginary parts of the fundamental positive sequence component of voltage and the real and imaginary parts of the fundamental positive sequence component of current.

[0103] Fundamental positive sequence component of voltage satisfy: ; Fundamental positive sequence component of voltage The waveform diagram is as follows Figure 3 shown. Figure 3 middle, Indicates the starting moment of the voltage fundamental positive sequence component falling process, Indicates the end time of the voltage fundamental positive sequence component falling process, Indicates the deviation of the fundamental positive sequence component of the voltage.

[0104] Fundamental positive sequence value of reactive power satisfy: .

[0105] In some other possible implementations, such as Figure 4 As shown, in step S2, the ideal reactive current upper limit of the new energy grid-connected equipment is calculated based on the fundamental positive sequence component of the voltage, which may specifically include:

[0106] Step S21: Calculate the ideal reactive current of the new energy grid-connected equipment based on the fundamental positive sequence component of the voltage.

[0107] Step S22: Calculate the upper limit of the ideal reactive current of the new energy grid-connected equipment according to the ideal reactive current of the new energy grid-connected equipment.

[0108] Optionally, when the new energy grid-connected equipment is a grid-following new energy grid-connected equipment, the ideal reactive current of the new energy grid-connected equipment satisfies: .

[0109] When the new energy grid-connected equipment is a grid-building type new energy grid-connected equipment, the ideal reactive current of the new energy grid-connected equipment satisfies: .

[0110] in, Indicates the ideal reactive current of new energy grid-connected equipment, Indicates the rated current of new energy grid-connected equipment. It indicates the ratio of reactive current output by grid-connected new energy equipment to voltage change under grid voltage disturbance. Indicates the deviation of the fundamental positive sequence component of the voltage, It represents the steady-state equivalent internal impedance of the grid-connected new energy equipment. Represents the fundamental positive sequence component of voltage.

[0111] The ideal reactive current curve diagram of new energy grid-connected equipment can be referred to Figure 5 . Figure 5 middle, Indicates the ideal reactive current of new energy grid-connected equipment, Represents the fundamental positive sequence component of reactive current, Indicates the starting moment of the voltage fundamental positive sequence component falling process, Indicates the end time of the voltage fundamental positive sequence component falling process, It indicates the reactive current of new energy grid-connected equipment when the grid voltage is not disturbed.

[0112] The ideal reactive current upper limit of new energy grid-connected equipment meets the following requirements: ;in, Indicates the ideal upper limit of reactive current for new energy grid-connected equipment. Indicates the ideal reactive current of new energy grid-connected equipment, It indicates the reactive current of the new energy grid-connected equipment when the grid voltage is not disturbed. Indicates the starting moment of the voltage fundamental positive sequence component falling process, Indicates the end time of the voltage fundamental positive sequence component falling process, represents the integration variable.

[0113] In some other possible implementations, such as Figure 6 As shown, in step S2, determining the integral value of the fundamental positive sequence component of reactive current according to the fundamental positive sequence component of voltage and the fundamental positive sequence component of reactive power may specifically include:

[0114] Step S23: Calculate the fundamental positive sequence component of reactive current according to the fundamental positive sequence component of voltage and the fundamental positive sequence component of reactive power.

[0115] Step S24: calculating the integral value of the fundamental positive sequence component of the reactive current according to the fundamental positive sequence component of the reactive current.

[0116] Exemplarily, the fundamental positive sequence component of the reactive current satisfies: ;in, Represents the fundamental positive sequence component of reactive current, Represents the fundamental positive sequence component of the voltage, Represents the fundamental positive sequence component of reactive power.

[0117] The integral value of the fundamental positive sequence component of reactive current satisfies: ;in, Indicates the integral value of the fundamental positive sequence component of reactive current, It indicates the reactive current of the new energy grid-connected equipment when the grid voltage is not disturbed. Indicates the starting moment of the voltage fundamental positive sequence component falling process, Indicates the end time of the voltage fundamental positive sequence component falling process, Indicates the delay time, represents the integration variable.

[0118] In some further possible implementations, detecting the reactive current response time of the new energy grid-connected device according to the ideal reactive current upper limit of the new energy grid-connected device and the integral value of the fundamental positive sequence component of the reactive current in step S3 includes:

[0119] When the ideal reactive current upper limit of the renewable energy grid-connected equipment is equal to the integral value of the fundamental positive sequence component of the reactive current, the delay time is taken as the response time of the reactive current.

[0120] For grid-connected new energy grid-connected equipment, the ratio of the reactive current output by the grid-connected new energy grid-connected equipment to the voltage change under grid voltage disturbance It can be taken as 2. The fundamental positive sequence component of the voltage is obtained Waveform diagram as shown Figure 7 and Figure 8 As shown, the ideal reactive current of the new energy grid-connected equipment is obtained and the fundamental positive sequence component of reactive current like Figure 9 and Figure 10 shown. Figure 9 and Figure 10 In the figure, the dotted line represents the ideal reactive current of the new energy grid-connected equipment. , the solid line represents the fundamental positive sequence component of reactive current . Figure 7 、 Figure 8 、 Figure 9 and Figure 10 In the figure, the horizontal axis represents time. It can be 5.008s, It can be 5.027s, which is the ideal reactive current upper limit of the new energy grid-connected equipment. It can be 0.00966pu*s. The integral value of the fundamental positive sequence component of the reactive current and Delay time when equal It can be 0.008s, which means the reactive current response time is 8ms.

[0121] For grid-connected new energy grid-connected equipment, the steady-state equivalent internal impedance of grid-connected new energy grid-connected equipment You can take 0.1pu. The fundamental positive sequence component of the voltage is obtained Waveform diagram as shown Figure 11 and Figure 12 As shown, the ideal reactive current of the new energy grid-connected equipment is obtained and the fundamental positive sequence component of reactive current like Figure 13 and Figure 14 shown. Figure 13 and Figure 14 In the figure, the dotted line represents the ideal reactive current of the new energy grid-connected equipment. , the solid line represents the fundamental positive sequence component of reactive current . Figure 11 、 Figure 12 、 Figure 13 and Figure 14 In the figure, the horizontal axis represents time. can be 7.008s, It can be 7.027s, which is the ideal reactive current upper limit of the new energy grid-connected equipment. It can be 0.01357pu*s. The integral value of the fundamental positive sequence component of the reactive current and Delay time when equal It can be 0.002s, which means the reactive current response time is 2ms.

[0122] Example 2:

[0123] Based on the same inventive concept, the embodiment of the present application also provides a device for detecting the reactive current response time of a new energy grid-connected device. Figure 15 As shown, the detection device 200 may include:

[0124] The calculation module 201 is used to calculate the fundamental positive sequence component of voltage and the fundamental positive sequence component of reactive power according to the three-phase voltage and three-phase current of the new energy grid connection point.

[0125] The determination module 202 is used to calculate the ideal reactive current upper limit of the new energy grid-connected equipment according to the fundamental positive sequence component of the voltage, and determine the integral value of the fundamental positive sequence component of the reactive current according to the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power.

[0126] The detection module 203 is used to detect the reactive current response time of the new energy grid-connected equipment according to the ideal reactive current upper limit of the new energy grid-connected equipment and the integral value of the fundamental positive sequence component of the reactive current.

[0127] In some possible implementations, the calculation module 201 is specifically configured to:

[0128] The three-phase voltage and three-phase current of the renewable energy grid connection point are subjected to full-cycle Fourier decomposition to obtain the real and imaginary parts of the three-phase voltage and the real and imaginary parts of the three-phase current.

[0129] The real and imaginary parts of the fundamental positive sequence component of the voltage are calculated based on the real and imaginary parts of the three-phase voltages, and the real and imaginary parts of the fundamental positive sequence component of the current are calculated based on the real and imaginary parts of the three-phase currents.

[0130] The fundamental positive sequence component of voltage is calculated based on the real and imaginary parts of the fundamental positive sequence component of voltage, and the fundamental positive sequence component of reactive power is calculated based on the real and imaginary parts of the fundamental positive sequence component of voltage and the real and imaginary parts of the fundamental positive sequence component of current.

[0131] Specifically, the three-phase current of the grid connection point can be directly collected through the recording equipment. For the primary circuit with a neutral point, the three-phase phase voltage of the grid connection point can be directly collected through the recording equipment. For the primary circuit without a neutral point, the three-phase line voltage of the grid connection point can be collected. 、 、 The calculation module 201 calculates the three-phase phase voltage of the grid connection point according to the following formula based on the three-phase line voltage:

[0132]

[0133] in, 、 、 Respectively a Mutually, b Mutually, c Phase voltage of the phase, t Indicates time.

[0134] by a Take phase as an example, a The real and imaginary parts of the phase-to-phase voltage can be expressed as:

[0135]

[0136]

[0137] in, express a The real part of the phase-to-phase voltage, express a The imaginary part of the phase-to-phase voltage, represents the fundamental period, f represents the fundamental frequency, Indicates a time interval.

[0138] For new energy grid connection points b Phase voltage, cThe phase voltages are decomposed into full-cycle Fourier transforms b Phase voltage, c The real and imaginary parts of the phase voltages can refer to the above process and will not be described in detail in this embodiment. The real and imaginary parts of the three-phase currents can be obtained by performing full-cycle Fourier decomposition on the three-phase currents. This application will not describe them in detail and you can refer to relevant literature.

[0139] Optionally, the calculation module 201 calculates the real part and the imaginary part of the fundamental positive sequence component of the voltage according to the following formula:

[0140]

[0141]

[0142] in, represents the real part of the fundamental positive sequence component of the voltage, Represents the imaginary part of the fundamental positive sequence component of the voltage. 、 、 represents the real part of each of the three-phase voltages, 、 、 Indicates the imaginary part of each of the three-phase voltages.

[0143] The calculation module 201 calculates the real part and the imaginary part of the fundamental positive sequence component of the current according to the following formula:

[0144]

[0145]

[0146] in, represents the real part of the fundamental positive sequence component of the current, Represents the imaginary part of the fundamental positive sequence component of the current. 、 、 represents the real part of each of the three-phase currents, 、 、 Represents the imaginary part of each of the three-phase currents.

[0147] The calculation module 201 calculates the fundamental positive sequence component of the voltage according to the formula: :

[0148]

[0149] The calculation module 201 calculates the fundamental positive sequence value of reactive power according to the following formula: :

[0150]

[0151] In some other possible implementations, the determining module 202 is specifically configured to:

[0152] Calculate the ideal reactive current of renewable energy grid-connected equipment based on the fundamental positive sequence component of the voltage. Calculate the upper limit of the ideal reactive current of renewable energy grid-connected equipment based on the ideal reactive current of renewable energy grid-connected equipment.

[0153] For example, when the new energy grid-connected device is a grid-following new energy grid-connected device, the ideal reactive current of the new energy grid-connected device satisfies: .

[0154] When the new energy grid-connected equipment is a grid-building type new energy grid-connected equipment, the ideal reactive current of the new energy grid-connected equipment satisfies: .

[0155] in, Indicates the ideal reactive current of new energy grid-connected equipment, Indicates the rated current of new energy grid-connected equipment. It indicates the ratio of reactive current output by grid-connected new energy equipment to voltage change under grid voltage disturbance. Indicates the deviation of the fundamental positive sequence component of the voltage, It represents the steady-state equivalent internal impedance of the grid-connected new energy equipment. Represents the fundamental positive sequence component of voltage.

[0156] The ideal reactive current upper limit of new energy grid-connected equipment meets the following requirements: .in, Indicates the ideal upper limit of reactive current for new energy grid-connected equipment. Indicates the ideal reactive current of new energy grid-connected equipment, It indicates the reactive current of the new energy grid-connected equipment when the grid voltage is not disturbed. Indicates the starting moment of the voltage fundamental positive sequence component falling process, Indicates the end time of the voltage fundamental positive sequence component falling process, represents the integration variable.

[0157] In some further possible implementations, the determining module 202 is specifically configured to:

[0158] The fundamental positive sequence component of the reactive current is calculated based on the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power. The integral value of the fundamental positive sequence component of the reactive current is calculated based on the fundamental positive sequence component of the reactive current.

[0159] Optionally, the fundamental positive sequence component of the reactive current satisfies: ;in, Represents the fundamental positive sequence component of reactive current, Represents the fundamental positive sequence component of the voltage, Represents the fundamental positive sequence component of reactive power.

[0160] The integral value of the fundamental positive sequence component of reactive current satisfies: ; Indicates the integral value of the fundamental positive sequence component of reactive current, It indicates the reactive current of the new energy grid-connected equipment when the grid voltage is not disturbed. Indicates the starting moment of the voltage fundamental positive sequence component falling process, Indicates the end time of the voltage fundamental positive sequence component falling process, Indicates the delay time, represents the integration variable.

[0161] In some other possible implementations, the detection module 203 is specifically configured to: when the ideal reactive current upper limit of the new energy grid-connected equipment is equal to the integral value of the fundamental positive sequence component of the reactive current, use the delay time as the response time of the reactive current.

[0162] Example 3:

[0163] Based on the same inventive concept, an embodiment of the present application further provides a computer device, the computer device including a processor and a memory, the memory being used to store a computer program, the computer program including program instructions, and the processor being used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc., which are the computing core and control core of the terminal, and are suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in a computer storage medium to implement corresponding method flows or corresponding functions, so as to implement the steps of the detection method provided in the above embodiment.

[0164] Example 4:

[0165] Based on the same inventive concept, embodiments of the present application also provide a computer-readable storage medium, specifically a computer-readable storage medium (Memory). The computer-readable storage medium is a memory device in a computer device, used to store programs and data. It is understood that the computer-readable storage medium herein may include both built-in storage media in the computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides storage space, which stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for being loaded and executed by a processor. These instructions may be one or more computer programs (including program code). It should be noted that the computer-readable storage medium herein may be high-speed RAM memory or non-volatile memory, such as at least one disk storage device. The processor may load and execute the one or more instructions stored in the computer-readable storage medium to implement the steps of the detection method provided in the above embodiments.

[0166] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0167] The application is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the application. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0168] These computer program instructions may 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 produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1The function specified in one or more boxes.

[0169] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0170] The above are merely embodiments of the application and are not intended to limit the application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the application are included in the scope of the claims of the pending application.

Claims

1. A method for detecting reactive current response time of a new energy grid-connected device, characterized in that: include: Calculate the fundamental positive sequence component of voltage and the fundamental positive sequence component of reactive power based on the three-phase voltage and three-phase current at the renewable energy grid connection point; Calculating an ideal reactive current upper limit of the new energy grid-connected equipment according to the fundamental positive sequence component of the voltage, and determining an integral value of the fundamental positive sequence component of the reactive current according to the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power; Detecting the reactive current response time of the new energy grid-connected equipment according to the ideal reactive current upper limit of the new energy grid-connected equipment and the integral value of the fundamental positive sequence component of the reactive current; The determining of the integral value of the fundamental positive sequence component of the reactive current according to the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power comprises: Calculating the fundamental positive sequence component of the reactive current according to the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power; Calculating an integral value of a fundamental positive sequence component of the reactive current according to the fundamental positive sequence component of the reactive current; The fundamental positive sequence component of the reactive current satisfies: I Q1 =Q1 / 3U1; where I Q1 represents the fundamental positive sequence component of the reactive current, U1 represents the fundamental positive sequence component of the voltage, and Q1 represents the fundamental positive sequence component of the reactive power; The integral value of the fundamental positive sequence component of the reactive current satisfies: Among them, I Q1_X represents the integral value of the fundamental positive sequence component of the reactive current, I0 represents the reactive current of the new energy grid-connected equipment when the grid voltage is not disturbed, t Ut1 Indicates the starting time of the voltage fundamental positive sequence component falling process, t Ut2 Indicates the end time of the voltage fundamental positive sequence component falling process, t delay represents the delay time, dt represents the integral variable; The detecting the reactive current response time of the new energy grid-connected device according to the ideal reactive current upper limit of the new energy grid-connected device and the integral value of the fundamental positive sequence component of the reactive current includes: When the ideal reactive current upper limit of the new energy grid-connected equipment is equal to the integral value of the fundamental positive sequence component of the reactive current, the delay time is used as the response time of the reactive current.

2. The detection method according to claim 1, characterized in that The method of calculating the fundamental positive sequence component of voltage and the fundamental positive sequence component of reactive power based on the three-phase voltage and three-phase current of the new energy grid connection point includes: Performing full-cycle Fourier decomposition on the three-phase voltage and three-phase current of the new energy grid-connected point to obtain the real part and imaginary part of each of the three-phase voltage and the real part and imaginary part of each of the three-phase current; Calculating the real part and imaginary part of the fundamental positive sequence component of the voltage according to the real part and imaginary part of each of the three-phase voltages, and calculating the real part and imaginary part of the fundamental positive sequence component of the current according to the real part and imaginary part of each of the three-phase currents; The fundamental positive sequence component of the voltage is calculated according to the real part and the imaginary part of the fundamental positive sequence component of the voltage, and the fundamental positive sequence component of the reactive power is calculated according to the real part and the imaginary part of the fundamental positive sequence component of the voltage and the real part and the imaginary part of the fundamental positive sequence component of the current.

3. The detection method according to claim 1, wherein Calculating the ideal reactive current upper limit of the new energy grid-connected equipment based on the fundamental positive sequence component of the voltage includes: Calculating the ideal reactive current of the new energy grid-connected equipment based on the fundamental positive sequence component of the voltage; The ideal reactive current upper limit of the new energy grid-connected equipment is calculated according to the ideal reactive current of the new energy grid-connected equipment.

4. The detection method according to claim 3, characterized in that When the new energy grid-connected equipment is a grid-following new energy grid-connected equipment, the ideal reactive current of the new energy grid-connected equipment satisfies: I Q1_ideal =I N ×k IQ ×(0.9-U1); When the new energy grid-connected equipment is a grid-building type new energy grid-connected equipment, the ideal reactive current of the new energy grid-connected equipment satisfies: I Q1_ideal =I N ×ΔU1 / Z W_EQ ; Among them, I Q1_ideal It represents the ideal reactive current of the new energy grid-connected equipment, I N Indicates the rated current of the new energy grid-connected equipment, k IQ It represents the ratio of reactive current output by the grid-connected new energy equipment to the voltage change under grid voltage disturbance, ΔU1 represents the deviation of the fundamental positive sequence component of the voltage, Z W_EQ It represents the steady-state equivalent internal impedance of the grid-connected new energy equipment, and U1 represents the fundamental positive sequence component of the voltage.

5. The detection method according to claim 3, characterized in that The ideal reactive current upper limit of the new energy grid-connected equipment meets the following requirements: Among them, I Q1_sum It represents the ideal reactive current upper limit of the new energy grid-connected equipment, I Q1_ideal represents the ideal reactive current of the new energy grid-connected equipment, I0 represents the reactive current of the new energy grid-connected equipment when the grid voltage is not disturbed, and t Ut1 Indicates the starting time of the voltage fundamental positive sequence component falling process, t Ut2 represents the end time of the decrease process of the fundamental positive sequence component of the voltage, and dt represents the integral variable.

6. A device for detecting reactive current response time of new energy grid-connected equipment, characterized in that: include: A calculation module, used to calculate the fundamental positive sequence component of voltage and the fundamental positive sequence component of reactive power based on the three-phase voltage and three-phase current of the renewable energy grid connection point; a determination module, configured to calculate an ideal reactive current upper limit of the new energy grid-connected equipment according to the fundamental positive sequence component of the voltage, and determine an integral value of the fundamental positive sequence component of the reactive current according to the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power; a detection module, configured to detect a reactive current response time of the new energy grid-connected device according to an ideal reactive current upper limit of the new energy grid-connected device and an integral value of a fundamental positive sequence component of the reactive current; The determining module is specifically configured to: Calculating the fundamental positive sequence component of the reactive current according to the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power; Calculating an integral value of a fundamental positive sequence component of the reactive current according to the fundamental positive sequence component of the reactive current; The fundamental positive sequence component of the reactive current satisfies: I Q1 =Q1 / 3U1; where I Q1 represents the fundamental positive sequence component of the reactive current, U1 represents the fundamental positive sequence component of the voltage, and Q1 represents the fundamental positive sequence component of the reactive power; The integral value of the fundamental positive sequence component of the reactive current satisfies: Among them, I Q1_X represents the integral value of the fundamental positive sequence component of the reactive current, I0 represents the reactive current of the new energy grid-connected equipment when the grid voltage is not disturbed, t Ut1 Indicates the starting time of the voltage fundamental positive sequence component falling process, t Ut2 Indicates the end time of the voltage fundamental positive sequence component falling process, t delay represents the delay time, dt represents the integral variable; The detection module is specifically used for: When the ideal reactive current upper limit of the new energy grid-connected equipment is equal to the integral value of the fundamental positive sequence component of the reactive current, the delay time is used as the response time of the reactive current.

7. The detection device according to claim 6, characterized in that The calculation module is specifically used for: Performing full-cycle Fourier decomposition on the three-phase voltage and three-phase current of the new energy grid-connected point to obtain the real part and imaginary part of each of the three-phase voltage and the real part and imaginary part of each of the three-phase current; Calculating the real part and imaginary part of the fundamental positive sequence component of the voltage according to the real part and imaginary part of each of the three-phase voltages, and calculating the real part and imaginary part of the fundamental positive sequence component of the current according to the real part and imaginary part of each of the three-phase currents; The fundamental positive sequence component of the voltage is calculated according to the real part and the imaginary part of the fundamental positive sequence component of the voltage, and the fundamental positive sequence component of the reactive power is calculated according to the real part and the imaginary part of the fundamental positive sequence component of the voltage and the real part and the imaginary part of the fundamental positive sequence component of the current.

8. The detection device according to claim 6, characterized in that The determining module is specifically configured to: Calculating the ideal reactive current of the new energy grid-connected equipment based on the fundamental positive sequence component of the voltage; The ideal reactive current upper limit of the new energy grid-connected equipment is calculated according to the ideal reactive current of the new energy grid-connected equipment.

9. The detection device according to claim 8, characterized in that When the new energy grid-connected equipment is a grid-following new energy grid-connected equipment, the ideal reactive current of the new energy grid-connected equipment satisfies: I Q1_ideal =I N ×k IQ ×(0.9-U1); When the new energy grid-connected equipment is a grid-building type new energy grid-connected equipment, the ideal reactive current of the new energy grid-connected equipment satisfies: I Q1_ideal =I N ×ΔU1 / Z W_EQ ; Among them, I Q1_ideal It represents the ideal reactive current of the new energy grid-connected equipment, I N Indicates the rated current of the new energy grid-connected equipment, k IQ It represents the ratio of reactive current output by the grid-connected new energy equipment to the voltage change under grid voltage disturbance, ΔU1 represents the deviation of the fundamental positive sequence component of the voltage, Z W_EQ It represents the steady-state equivalent internal impedance of the grid-connected new energy equipment, and U1 represents the fundamental positive sequence component of the voltage.

10. The detection device according to claim 8, characterized in that: The ideal reactive current upper limit of the new energy grid-connected equipment meets the following requirements: Among them, I Q1_sum It represents the ideal reactive current upper limit of the new energy grid-connected equipment, I Q1_ideal represents the ideal reactive current of the new energy grid-connected equipment, I0 represents the reactive current of the new energy grid-connected equipment when the grid voltage is not disturbed, and t Ut1 Indicates the starting time of the voltage fundamental positive sequence component falling process, t Ut2 represents the end time of the decrease process of the fundamental positive sequence component of the voltage, and dt represents the integral variable.

11. A computer device, characterized in that: include: one or more processors; The processor is configured to store one or more programs; When the one or more programs are executed by the one or more processors, the detection method according to any one of claims 1 to 5 is implemented.

12. A computer-readable storage medium, characterized in that A computer program is stored thereon, and when the computer program is executed, the detection method according to any one of claims 1 to 5 is implemented.

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