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

Abstract

The invention provides a method and a device for detecting reactive current response time of new energy grid-connected equipment. 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 a fundamental positive-sequence component integral value of the reactive current according to the fundamental positive-sequence component of the voltage and the fundamental positive-sequence component of the reactive power; and 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 fundamental wave positive sequence component integral value of the reactive current. According to the invention, the problem that the delay introduced by the starting moment of the response time is inconsistent with the delay introduced by the ending moment of the response time in the prior art can be eliminated, and the detection precision of the response time is improved. According to the invention, the fundamental positive sequence component integral value of the reactive current is used as the ideal reactive current upper limit of the new energy grid-connected equipment, so that the power grid voltage supporting capability of the new energy grid-connected equipment is accurately measured.

Description

Technical Field

[0001] This application relates to the field of new energy technologies, and specifically relates to a method and device for detecting the reactive current response time of a new energy grid-connected device. Background Art

[0002] With the rapid development of new energy technologies, the performance evaluation of new energy grid-connected devices becomes particularly important. During the performance evaluation process, when the grid voltage fluctuates, the new energy grid-connected device needs to quickly adjust the reactive current to achieve the active support of the new energy grid-connected device for the grid voltage. The response time of the reactive current is a key indicator for measuring the ability of the new energy grid-connected device to support the grid voltage.

[0003] In the existing response time detection methods for new energy grid-connected devices, the moment when the grid-connected point voltage is lower than 90% of the rated voltage of the new energy grid-connected device 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 device. However, due to the inconsistent delays introduced by the starting moment and the ending moment of the response time, the detection accuracy of the response time is relatively low. Summary of the Invention

[0004] To solve the problem of relatively low detection accuracy in the prior art, this 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, this application provides a method for detecting the reactive current response time of a new energy grid-connected device, which may include: Calculating the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power according to the three-phase phase voltages and three-phase currents of the new energy grid-connected point.

[0006] Calculating the ideal upper limit of the reactive current of the new energy grid-connected device according to the fundamental positive sequence component of the voltage, and 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.

[0007] Detecting the reactive current response time of the new energy grid-connected device according to the ideal upper limit of the reactive current of the new energy grid-connected device and the integral value of the fundamental positive sequence component of the reactive current.

[0008] In some possible implementation manners, calculating the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power according to the three-phase phase voltages and three-phase currents of the new energy grid-connected point includes: Perform full - cycle Fourier decomposition on the three - phase phase voltages and three - phase currents at the new - energy grid - connection point respectively, to obtain the real and imaginary parts of each of the three - phase phase voltages and the real and imaginary parts of each of the three - phase currents.

[0009] Calculate the real and imaginary parts of the fundamental positive - sequence component of the voltage based on the real and imaginary parts of each of the three - phase phase voltages, and calculate the real and imaginary parts of the fundamental positive - sequence component of the current based on the real and imaginary parts of each of the three - phase currents.

[0010] Calculate the fundamental positive - sequence component of the voltage based on the real and imaginary parts of the fundamental positive - sequence component of the voltage, and calculate the fundamental positive - sequence component of the reactive power based on the real and imaginary parts of the fundamental positive - sequence component of the voltage and the real and imaginary parts of the fundamental positive - sequence component of the current.

[0011] In some other possible implementation manners, calculate the upper limit of the ideal reactive current of the new - energy grid - connection device according to the fundamental positive - sequence component of the voltage, including: Calculate the ideal reactive current of the new - energy grid - connection device according to the fundamental positive - sequence component of the voltage.

[0012] Calculate the upper limit of the ideal reactive current of the new - energy grid - connection device according to the ideal reactive current of the new - energy grid - connection device.

[0013] Optionally, when the new - energy grid - connection device is a grid - following new - energy grid - connection device, the ideal reactive current of the new - energy grid - connection device satisfies: 。

[0014] When the new - energy grid - connection device is a grid - forming new - energy grid - connection device, the ideal reactive current of the new - energy grid - connection device satisfies: 。

[0015] Among them, represents the ideal reactive current of the new - energy grid - connection device, represents the rated current of the new - energy grid - connection device, represents the ratio of the reactive current output by the grid - following new - energy grid - connection device to the voltage change amount under the grid voltage disturbance, represents the deviation of the fundamental positive - sequence component of the voltage, represents the steady - state equivalent internal impedance of the grid - forming new - energy grid - connection device, represents the fundamental positive - sequence component of the voltage.

[0016] The upper limit of the ideal reactive current of the new - energy grid - connection device satisfies: ; Among them, represents the upper limit of the ideal reactive current of the new - energy grid - connection device, represents the ideal reactive current of the new - energy grid - connection device, represents the reactive current of the new - energy grid - connection device when the grid voltage has no disturbance. Indicates the starting moment of the decline process of the fundamental positive-sequence component of the voltage. Indicates the ending moment of the decline process of the fundamental positive-sequence component of the voltage. Indicates the integration variable.

[0017] In some other possible implementation manners, 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: 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.

[0018] 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.

[0019] Exemplarily, the fundamental positive-sequence component of the reactive current satisfies: ; where Indicates the fundamental positive-sequence component of the reactive current, Indicates the fundamental positive-sequence component of the voltage, Indicates the fundamental positive-sequence component of the reactive power.

[0020] The integral value of the fundamental positive-sequence component of the reactive current satisfies: ; where Indicates the integral value of the fundamental positive-sequence component of the reactive current, Indicates the reactive current of the new energy grid-connected device when there is no disturbance in the grid voltage, Indicates the starting moment of the decline process of the fundamental positive-sequence component of the voltage, Indicates the ending moment of the decline process of the fundamental positive-sequence component of the voltage, Indicates the delay time, Indicates the integration variable.

[0021] In some other possible implementation manners, 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 device is equal to the integral value of the fundamental positive-sequence component of the reactive current, taking the delay time as the reactive current response time.

[0022] In a second aspect, the present application provides a device for detecting the reactive current response time of a new energy grid-connected device, which may include: A calculation module, configured to calculate the fundamental positive-sequence component of the voltage and the fundamental positive-sequence component of the reactive power according to the three-phase phase voltages and three-phase currents of the new energy grid connection point.

[0023] A determination module, configured to calculate an upper limit of the ideal reactive current of a new energy grid-connected device according to a fundamental positive-sequence component of a 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.

[0024] A detection module, configured to detect a reactive current response time of the new energy grid-connected device according to the upper limit of the ideal reactive current of the new energy grid-connected device and the integral value of the fundamental positive-sequence component of the reactive current.

[0025] In some possible implementation manners, the calculation module is specifically configured to: Perform full-cycle Fourier decomposition on the three-phase phase voltages and three-phase currents of the new energy grid connection point respectively, to obtain the real and imaginary parts of each of the three-phase phase voltages and the real and imaginary parts of each of the three-phase currents.

[0026] Calculate the real and imaginary parts of the fundamental positive-sequence component of the voltage according to the real and imaginary parts of each of the three-phase 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 each of the three-phase currents.

[0027] Calculate the fundamental positive-sequence component of the voltage according to the real and imaginary parts of the fundamental positive-sequence component of the voltage, and calculate the fundamental positive-sequence component of the reactive power according to the real and imaginary parts of the fundamental positive-sequence component of the voltage and the real and imaginary parts of the fundamental positive-sequence component of the current.

[0028] In some other possible implementation manners, the determination module is specifically configured to: Calculate the ideal reactive current of the new energy grid-connected device according to the fundamental positive-sequence component of the voltage.

[0029] Calculate the upper limit of the ideal reactive current of the new energy grid-connected device according to the ideal reactive current of the new energy grid-connected device.

[0030] Exemplarily, 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: ; When the new energy grid-connected device is a grid-forming new energy grid-connected device, the ideal reactive current of the new energy grid-connected device satisfies: ; Wherein, represents the ideal reactive current of the new energy grid-connected device, represents the rated current of the new energy grid-connected device, represents the ratio of the reactive current output by the grid-following new energy grid-connected device to the voltage change amount under the grid voltage disturbance, represents the deviation of the fundamental positive-sequence component of the voltage, represents the steady-state equivalent internal impedance of the grid-forming new energy grid-connected device, represents the fundamental positive-sequence component of the voltage.

[0031] The upper limit of the ideal reactive current of the new energy grid-connected device satisfies: ; where represents the upper limit of the ideal reactive current of the new energy grid-connected device, represents the ideal reactive current of the new energy grid-connected device, represents the reactive current of the new energy grid-connected device when there is no disturbance in the grid voltage, represents the starting moment of the decline process of the fundamental positive sequence component of the voltage, represents the ending moment of the decline process of the fundamental positive sequence component of the voltage, represents the integration variable.

[0032] In some other possible implementation manners, the determining module is specifically configured to: Calculate 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.

[0033] Calculate the integral value of the fundamental positive sequence component of the reactive current according to the fundamental positive sequence component of the reactive current.

[0034] Optionally, the fundamental positive sequence component of the reactive current satisfies: ; where represents the fundamental positive sequence component of the reactive current, represents the fundamental positive sequence component of the voltage, represents the fundamental positive sequence component of the reactive power.

[0035] The integral value of the fundamental positive sequence component of the reactive current satisfies: ;[[ID=4!]] represents the integral value of the fundamental positive sequence component of the reactive current, represents the reactive current of the new energy grid-connected device when there is no disturbance in the grid voltage, represents the starting moment of the decline process of the fundamental positive sequence component of the voltage, represents the ending moment of the decline process of the fundamental positive sequence component of the voltage, represents the delay time, represents the integration variable.

[0036] In some other possible implementation manners, the detecting module is specifically configured to: When the upper limit of the ideal reactive current of the new energy grid-connected device 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.

[0037] On the other hand, the present application further provides a computer device, including: one or more processors.

[0038] The processor is configured to execute one or more programs.

[0039] When one or more programs are executed by one or more processors, the detection method as described above is implemented.

[0040] On the other hand, the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed, the detection method as described above is implemented.

[0041] Compared with the prior art, the beneficial effects of the present application are as follows: The detection method provided by the present application calculates the upper limit of the ideal reactive current of the new energy grid-connected device according to the fundamental positive-sequence component of the voltage, determines 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, and then detects the reactive current response time of the new energy grid-connected device according to the upper limit of the ideal reactive current of the new energy grid-connected device and the integral value of the fundamental positive-sequence component of the reactive current. The detection of the reactive current response time based on the upper limit of the ideal reactive current and the integral value of the fundamental positive-sequence component of the reactive current can eliminate the problem of inconsistent delays introduced at the starting moment and the ending moment of the response time in the related art, and improve the detection accuracy of the response time.

[0042] The present application can accurately calculate the fundamental positive-sequence component of the voltage and the fundamental positive-sequence component of the reactive power according to the three-phase phase voltages and three-phase currents at the new energy grid connection point, and then accurately calculate the upper limit of the ideal reactive current of the new energy grid-connected device and the integral value of the fundamental positive-sequence component of the reactive current, further ensuring the detection accuracy of the response time.

[0043] The present application calculates the respective ideal reactive currents for the grid-following new energy grid-connected device and the grid-forming new energy grid-connected device, and then detects the respective reactive current response times of the grid-following new energy grid-connected device and the grid-forming new energy grid-connected device.

[0044] The present application uses the integral value of the fundamental positive-sequence component of the reactive current as the upper limit of the ideal reactive current of the new energy grid-connected device to achieve accurate detection of the reactive current response time. Furthermore, the new energy grid-connected device can complete the support for the grid voltage at the moment when the grid voltage fluctuates, improving the stability of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0046] Figure 1It is a schematic flowchart of a method for detecting the reactive current response time of a new energy grid-connected device in an embodiment of the present application; Figure 2 It is a schematic flowchart 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; Figure 3 It is a schematic waveform diagram of the fundamental positive-sequence component of voltage in an embodiment of the present application; Figure 4 It is a schematic flowchart of calculating the upper limit of the ideal reactive current of a new energy grid-connected device in an embodiment of the present application; Figure 5 It is a schematic waveform diagram of the ideal reactive current of a new energy grid-connected device in an embodiment of the present application; Figure 6 It is a schematic flowchart of determining the integral value of the fundamental positive-sequence component of reactive current in an embodiment of the present application; Figure 7 It is a schematic waveform diagram of the fundamental positive-sequence component of voltage in an embodiment of the present application; Figure 8 It is a schematic waveform diagram of the fundamental positive-sequence component of voltage in an embodiment of the present application; Figure 9 It is a schematic waveform diagram of the ideal reactive current and the fundamental positive-sequence component of reactive current of a new energy grid-connected device in an embodiment of the present application; Figure 10 It is a schematic waveform diagram of the ideal reactive current and the fundamental positive-sequence component of reactive current of a new energy grid-connected device in an embodiment of the present application; Figure 11 It is a schematic waveform diagram of the fundamental positive-sequence component of voltage in an embodiment of the present application; Figure 12 It is a schematic waveform diagram of the fundamental positive-sequence component of voltage in an embodiment of the present application; Figure 13 It is a schematic waveform diagram of the ideal reactive current and the fundamental positive-sequence component of reactive current of a new energy grid-connected device in an embodiment of the present application; Figure 14 It is a schematic waveform diagram of the ideal reactive current and the fundamental positive-sequence component of reactive current of a new energy grid-connected device in an embodiment of the present application; Figure 15 It is a schematic structural diagram of a device for detecting the reactive current response time of a new energy grid-connected device in an embodiment of the present application. Specific embodiments

[0047] Next, the technical solutions in the present application will be described with reference to the accompanying drawings.

[0048] In the embodiments of the specification, claims, and drawings of the present application, terms such as "first" and "second" are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying an order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a method, system, product, or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0049] It should be understood that in the present application, "at least one (item)" means one or more, and "a plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" may mean: only A exists, only B exists, and both A and B exist simultaneously. Here, A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one (one)" or similar expressions thereof refer to any combination of these items, including any combination of single items (ones) or plural items (ones). For example, at least one (one) of a, b, or c may 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 multiple.

[0050] Embodiment 1: The embodiment of the present application provides a method for detecting the reactive current response time of a new energy grid-connected device. As Figure 1 shown, the detection method 100 includes the following steps: Step S1: Calculate the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power according to the three-phase phase voltages and three-phase currents of the new energy grid connection point.

[0051] Step S2: Calculate the ideal upper limit of the reactive current of the new energy grid-connected device 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.

[0052] Step S3: Detect the reactive current response time of the new energy grid-connected device according to the ideal upper limit of the reactive current of the new energy grid-connected device and the integral value of the fundamental positive sequence component of the reactive current.

[0053] In some possible implementation manners, as Figure 2 shown, in step S1, calculating the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power according to the three-phase phase voltages and three-phase currents of the new energy grid connection point specifically includes the following steps: Step S11: Perform full-cycle Fourier decomposition on the three-phase phase voltages and three-phase currents at the new energy grid connection point to obtain the real and imaginary parts of each of the three-phase phase voltages and the real and imaginary parts of each of the three-phase currents.

[0054] Optionally, the three-phase currents at the grid connection point can be directly collected by a waveform recording device. For a primary circuit with a neutral point, the three-phase phase voltages at the grid connection point can be directly collected by a waveform recording device. For a primary circuit without a neutral point, the three-phase line voltages at the grid connection point can be collected, and then the three-phase phase voltages at the grid connection point can be calculated from the three-phase line voltages according to the following formula: 、 、 , and then the three-phase phase voltages at the grid connection point are calculated from the three-phase line voltages according to the following formula:

[0055] where 、 、 represent the phase voltages of phase a phase, b phase, c phase respectively, and t represents time.

[0056] Taking a phase as an example, the real and imaginary parts of the a phase phase voltage can be expressed as:

[0057]

[0058] where represents the real part of the a phase phase voltage, represents the imaginary part of the a phase phase voltage, represents the fundamental period, f represents the fundamental frequency, and represents the time interval.

[0059] For the b phase phase voltage and c phase phase voltage at the new energy grid connection point, after performing full-cycle Fourier decomposition respectively, the real and imaginary parts of the b phase phase voltage and c phase phase voltage can refer to the above process, which will not be introduced in this embodiment of the present application. The full-cycle Fourier decomposition of the three-phase currents to obtain the real and imaginary parts of each of the three-phase currents will not be detailed in this application either, and relevant literature can be referred to.

[0060] Step S12: Calculate the real part and the imaginary part of the fundamental positive-sequence component of the voltage according to the real part and the imaginary part of each of the three-phase phase voltages, and calculate the real part and the imaginary part of the fundamental positive-sequence component of the current according to the real part and the imaginary part of each of the three-phase currents.

[0061] The real part and the imaginary part of the fundamental positive-sequence component of the voltage can satisfy:

[0062]

[0063] Wherein, 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. , , represent the real parts of each of the three-phase phase voltages, , , represent the imaginary parts of each of the three-phase phase voltages.

[0064] The real part and the imaginary part of the fundamental positive-sequence component of the current can satisfy:

[0065]

[0066] Wherein, 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. , , represent the real parts of each of the three-phase currents, , , represent the imaginary parts of each of the three-phase currents.

[0067] Step S13: Calculate the fundamental positive-sequence component of the voltage according to the real part and the imaginary part of the fundamental positive-sequence component of the voltage, and calculate the fundamental positive-sequence component of the reactive power 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.

[0068] The fundamental positive-sequence component of the voltage satisfies: ; The waveform of the fundamental positive-sequence component of the voltage is as shown in Figure 3 . Figure 3 In represents the starting moment of the descending process of the fundamental positive-sequence component of the voltage, represents the ending moment of the descending process of the fundamental positive-sequence component of the voltage, Indicates the deviation of the fundamental positive-sequence component of the voltage.

[0069] The fundamental positive-sequence value of the reactive power Satisfies: .

[0070] In some other possible implementation manners, such as Figure 4 shown, in step S2, calculating the upper limit of the ideal reactive current of the new energy grid-connected device according to the fundamental positive-sequence component of the voltage may specifically include: Step S21: Calculating the ideal reactive current of the new energy grid-connected device according to the fundamental positive-sequence component of the voltage.

[0071] Step S22: Calculating the upper limit of the ideal reactive current of the new energy grid-connected device according to the ideal reactive current of the new energy grid-connected device.

[0072] Optionally, 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: .

[0073] When the new energy grid-connected device is a grid-forming new energy grid-connected device, the ideal reactive current of the new energy grid-connected device satisfies: .

[0074] Wherein, represents the ideal reactive current of the new energy grid-connected device, represents the rated current of the new energy grid-connected device, represents the ratio of the reactive current output by the grid-following new energy grid-connected device under the grid voltage disturbance to the voltage change amount, represents the deviation of the fundamental positive-sequence component of the voltage, represents the steady-state equivalent internal impedance of the grid-forming new energy grid-connected device, represents the fundamental positive-sequence component of the voltage.

[0075] The curve schematic diagram of the ideal reactive current of the new energy grid-connected device can refer to Figure 5 . Figure 5 In represents the ideal reactive current of the new energy grid-connected device, represents the fundamental positive-sequence component of the reactive current, represents the starting moment of the decline process of the fundamental positive-sequence component of the voltage, represents the ending moment of the decline process of the fundamental positive-sequence component of the voltage, represents the reactive current of the new energy grid-connected device when the grid voltage is not disturbed.

[0076] The upper limit of the ideal reactive current of the new energy grid-connected device satisfies: ; wherein, Represents the upper limit of the ideal reactive current of the new energy grid-connected equipment, Represents the ideal reactive current of the new energy grid-connected equipment, Represents the reactive current of the new energy grid-connected equipment under the condition that the grid voltage does not fluctuate, Represents the starting moment of the decline process of the fundamental positive sequence component of the voltage, Represents the ending moment of the decline process of the fundamental positive sequence component of the voltage, Represents the integration variable.

[0077] In some other possible implementation manners, such as Figure 6 shown, in step S2, 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 may specifically include: Step S23: Calculate 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.

[0078] Step S24: Calculate the integral value of the fundamental positive sequence component of the reactive current according to the fundamental positive sequence component of the reactive current.

[0079] Exemplarily, the fundamental positive sequence component of the reactive current satisfies: ; where represents the fundamental positive sequence component of the reactive current, represents the fundamental positive sequence component of the voltage, represents the fundamental positive sequence component of the reactive power.

[0080] The integral value of the fundamental positive sequence component of the reactive current satisfies: ; where represents the integral value of the fundamental positive sequence component of the reactive current, represents the reactive current of the new energy grid-connected equipment under the condition that the grid voltage does not fluctuate, represents the starting moment of the decline process of the fundamental positive sequence component of the voltage, represents the ending moment of the decline process of the fundamental positive sequence component of the voltage, represents the delay time, represents the integration variable.

[0081] In some other possible implementation manners, in step S3, detecting the reactive current response time of the new energy grid-connected equipment according to the upper limit of the ideal reactive current of the new energy grid-connected equipment and the integral value of the fundamental positive sequence component of the reactive current includes: When the upper limit of the ideal reactive current of the new energy grid-connected equipment is equal to the integral value of the fundamental positive sequence component of the reactive current, taking the delay time as the reactive current response time.

[0082] For grid-following new energy grid-connected equipment, the ratio of the reactive current output by the grid-following new energy grid-connected equipment to the voltage change under grid voltage disturbance can be taken as 2. The fundamental positive sequence component of the obtained voltage The waveform schematic diagram is as Figure 7 and Figure 8 shown. The ideal reactive current of the obtained new energy grid-connected equipment and the fundamental positive sequence component of the reactive current are as Figure 9 and Figure 10 shown. Figure 9 and Figure 10 In, the dashed line represents the ideal reactive current of the new energy grid-connected equipment , and the solid line represents the fundamental positive sequence component of the reactive current . Figure 7 , Figure 8 , Figure 9 and Figure 10 In, the abscissa represents time, can be 5.008 s, can be 5.027 s. The upper limit of the ideal reactive current of the calculated new energy grid-connected equipment can be 0.00966 p.u.*s. The integral value of the fundamental positive sequence component of the reactive current is equal to The delay time can be 0.008 s, and the reactive current response time of 8 ms can be obtained.

[0083] For grid-forming new energy grid-connected equipment, the steady-state equivalent internal impedance of the grid-forming new energy grid-connected equipment can be taken as 0.1 p.u. The fundamental positive sequence component of the obtained voltage The waveform schematic diagram is as Figure 11 and Figure 12 shown. The ideal reactive current of the obtained new energy grid-connected equipment and the fundamental positive sequence component of the reactive current are as Figure 13 and Figure 14 shown. Figure 13 and Figure 14 In, the dashed line represents the ideal reactive current of the new energy grid-connected equipment , and the solid line represents the fundamental positive sequence component of the reactive current . Figure 11 , Figure 12 , Figure 13 and Figure 14 In, the abscissa represents time, can be 7.008 s, It can be 7.027 s, and the calculated upper limit of the ideal reactive current of the new energy grid-connected equipment It can be 0.01357 p.u.*s. The integral value of the fundamental positive sequence component of the reactive current and the delay time when they are equal It can be 0.002 s, and the reactive current response time can be obtained as 2 ms.

[0084] Embodiment 2: Based on the same inventive concept, an embodiment of the present application further provides a detection device for the reactive current response time of a new energy grid-connected equipment. As Figure 15 shown, the detection device 200 may include: A calculation module 201, configured to calculate the fundamental positive sequence component of the voltage and the fundamental positive sequence component of the reactive power according to the three-phase phase voltages and three-phase currents at the new energy grid connection point.

[0085] A determination module 202, configured to calculate the upper limit of the ideal reactive current 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.

[0086] A detection module 203, configured to detect the reactive current response time of the new energy grid-connected equipment according to the upper limit of the ideal reactive current of the new energy grid-connected equipment and the integral value of the fundamental positive sequence component of the reactive current.

[0087] In some possible implementation manners, the calculation module 201 is specifically configured to: Perform full-cycle Fourier decomposition on the three-phase phase voltages and three-phase currents at the new energy grid connection point respectively, to obtain the real part and imaginary part of each of the three-phase phase voltages and the real part and imaginary part of each of the three-phase currents.

[0088] Calculate 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 phase voltages, and calculate 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.

[0089] Calculate the fundamental positive sequence component of the voltage according to the real part and imaginary part of the fundamental positive sequence component of the voltage, and calculate the fundamental positive sequence component of the reactive power according to the real part and imaginary part of the fundamental positive sequence component of the voltage and the real part and imaginary part of the fundamental positive sequence component of the current.

[0090] Specifically, the three-phase currents at the grid connection point can be directly collected by a recording device. For a primary circuit with a neutral point, the three-phase phase voltages at the grid connection point can be directly collected by a recording device. For a primary circuit without a neutral point, the three-phase line voltages at the grid connection point can be collected 、 、 , the calculation module 201 calculates the three-phase phase voltages at the grid connection point according to the three-phase line voltages as follows:

[0091] Among them, 、 、 respectively represent a phase, b phase, c the phase voltages of the phase, t represents time.

[0092] Taking a phase as an example, a the real and imaginary parts of the phase-phase voltage can be expressed as:

[0093]

[0094] Among them, represents a the real part of the phase-phase voltage, represents a the imaginary part of the phase-phase voltage, represents the fundamental period, f represents the fundamental frequency, represents the time interval.

[0095] For the b phase-phase voltage and c phase-phase voltage of the new energy grid connection point, respectively perform full-cycle Fourier decomposition to obtain b phase-phase voltage and c the real and imaginary parts of the phase-phase voltage of each phase can refer to the above process, which will not be introduced in this embodiment of the present application. The full-cycle Fourier decomposition of the three-phase currents to obtain the real and imaginary parts of the three-phase currents respectively will not be described in detail in this application either, and relevant literature can be referred to.

[0096] Optionally, the calculation module 201 calculates the real and imaginary parts of the fundamental positive-sequence component of the voltage according to the following formula:

[0097]

[0098] Among them, 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. 、 、 represent the real parts of the three-phase phase voltages respectively, 、 、 Represents the imaginary part of each of the three-phase phase voltages.

[0099] 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:

[0100]

[0101] Wherein, 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] The calculation module 201 calculates the fundamental positive-sequence component of the voltage according to the following formula :

[0103] The calculation module 201 calculates the fundamental positive-sequence value of the reactive power according to the following formula :

[0104] In some other possible implementation manners, the determination module 202 is specifically configured to: Calculate the ideal reactive current of the new energy grid-connected device according to the fundamental positive-sequence component of the voltage. Calculate the upper limit of the ideal reactive current of the new energy grid-connected device according to the ideal reactive current of the new energy grid-connected device.

[0105] Exemplarily, 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: .

[0106] When the new energy grid-connected device is a grid-forming new energy grid-connected device, the ideal reactive current of the new energy grid-connected device satisfies: .

[0107] Wherein, Represents the ideal reactive current of the new energy grid-connected device, Represents the rated current of the new energy grid-connected device, Represents the ratio of the reactive current output by the grid-following new energy grid-connected device to the voltage change amount under the grid voltage disturbance, Represents the deviation of the fundamental positive-sequence component of the voltage, Represents the steady-state equivalent internal impedance of the grid-forming new energy grid-connected device, Represents the fundamental positive sequence component of voltage.

[0108] The upper limit of the ideal reactive current of the new energy grid-connected device satisfies: . Wherein, Represents the upper limit of the ideal reactive current of the new energy grid-connected device, Represents the ideal reactive current of the new energy grid-connected device, Represents the reactive current of the new energy grid-connected device when the grid voltage is not disturbed, Represents the starting moment of the decline process of the fundamental positive sequence component of voltage, Represents the ending moment of the decline process of the fundamental positive sequence component of voltage, Represents the integration variable.

[0109] In some other possible implementation manners, the determining module 202 is specifically configured to: Calculate 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. Calculate the integral value of the fundamental positive sequence component of the reactive current according to the fundamental positive sequence component of the reactive current.

[0110] Optionally, the fundamental positive sequence component of the reactive current satisfies: ; wherein, Represents the fundamental positive sequence component of the reactive current, Represents the fundamental positive sequence component of the voltage, Represents the fundamental positive sequence component of the reactive power.

[0111] The integral value of the fundamental positive sequence component of the reactive current satisfies: ; Represents the integral value of the fundamental positive sequence component of the reactive current, Represents the reactive current of the new energy grid-connected device when the grid voltage is not disturbed, Represents the starting moment of the decline process of the fundamental positive sequence component of voltage, Represents the ending moment of the decline process of the fundamental positive sequence component of voltage, Represents the delay time, Represents the integration variable.

[0112] In some other possible implementation manners, the detecting module 203 is specifically configured to: when the upper limit of the ideal reactive current of the new energy grid-connected device 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.

[0113] Embodiment 3: Based on the same inventive concept, an embodiment of the present application further provides a computer device, which includes a processor and a memory. The memory is used to store a computer program, and the computer program includes program instructions. The processor is used to execute the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function, so as to implement the steps of the detection method provided in the above embodiment.

[0114] Embodiment 4: Based on the same inventive concept, an embodiment of the present application further provides a computer-readable storage medium, specifically a computer-readable storage medium (Memory). The computer-readable storage medium is a memory device in the computer device and is used to store programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and, of course, the extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, and the operating system of the terminal is stored in this storage space. And, one or more instructions suitable for being loaded and executed by the processor are also stored in this storage space. These instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The one or more instructions stored in the computer-readable storage medium can be loaded and executed by the processor to implement the steps of the detection method provided in the above embodiment.

[0115] Those skilled in the art should understand that the embodiments of the application can be provided as a method, a system, or a computer program product. Therefore, the application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0116] The application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the application. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0117] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0118] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0119] The above are only embodiments of the application and are not used to limit the application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the application are included in the scope of the claims of the application pending for invention.

Claims

1. A detection method for the reactive current response time of a new energy grid-connected device, characterized in that Including: Calculating the fundamental positive-sequence component of voltage and the fundamental positive-sequence component of reactive power according to the three-phase phase voltages and three-phase currents at the new energy grid connection point; Calculating the upper limit of the ideal reactive current of the new energy grid-connected device according to the fundamental positive-sequence component of the voltage, and 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; Detecting the reactive current response time of the new energy grid-connected device according to the upper limit of the ideal reactive current of the new energy grid-connected device and the integral value of the fundamental positive-sequence component of the reactive current.

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

3. The detection method according to claim 1, characterized in that, The calculating the upper limit of the ideal reactive current of the new energy grid-connected device according to the fundamental positive-sequence component of the voltage includes: Calculating the ideal reactive current of the new energy grid-connected device according to the fundamental positive-sequence component of the voltage; Calculating the upper limit of the ideal reactive current of the new energy grid-connected device according to the ideal reactive current of the new energy grid-connected device.

4. The detection method according to claim 3, wherein When the new energy grid-connected device is a follow-the-grid new energy grid-connected device, the ideal reactive current of the new energy grid-connected device satisfies: ; When the new energy grid-connected device is a network-forming new energy grid-connected device, the ideal reactive current of the new energy grid-connected device satisfies: ; Among them, represents the ideal reactive current of the new energy grid-connected device, represents the rated current of the new energy grid-connected device, represents the ratio of the reactive current output by the grid-following new energy grid-connected device to the voltage change under the grid voltage disturbance, represents the deviation of the fundamental positive sequence component of the voltage, represents the steady-state equivalent internal impedance of the grid-forming new energy grid-connected device, represents the fundamental positive sequence component of the voltage.

5. The detection method according to claim 3, wherein The upper limit of the ideal reactive current of the new energy grid-connected device satisfies: ; where, represents the upper limit of the ideal reactive current of the new energy grid-connected device, represents the ideal reactive current of the new energy grid-connected device, represents the reactive current of the new energy grid-connected device when there is no disturbance in the grid voltage, represents the starting moment of the decline process of the fundamental positive sequence component of the voltage, represents the ending moment of the decline process of the fundamental positive sequence component of the voltage, represents the integration variable.

6. The detection method according to claim 1, wherein The 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: 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 the integral value of the fundamental positive-sequence component of the reactive current according to the fundamental positive-sequence component of the reactive current.

7. The detection method according to claim 6, wherein The fundamental positive sequence component of the reactive current satisfies: ; where represents the fundamental positive sequence component of the reactive current, represents the fundamental positive sequence component of the voltage, represents the fundamental positive sequence component of the reactive power; The integral value of the fundamental positive sequence component of the reactive current satisfies: ; where represents the integral value of the fundamental positive sequence component of the reactive current, represents the reactive current of the new energy grid-connected device when there is no disturbance in the grid voltage, represents the starting moment of the decline process of the fundamental positive sequence component of the voltage, represents the ending moment of the decline process of the fundamental positive sequence component of the voltage, represents the delay time, represents the integration variable.

8. The detection method according to claim 7, wherein The detecting the reactive current response time of the new energy grid-connected device according to the upper limit of the ideal reactive current of the new energy grid-connected device and the integral value of the fundamental positive-sequence component of the reactive current includes: When the upper limit of the ideal reactive current of the new energy grid-connected device is equal to the integral value of the fundamental positive-sequence component of the reactive current, taking the delay time as the response time of the reactive current.

9. A detection device for the reactive current response time of a new energy grid-connected device, characterized in that, Including: A calculation module for calculating the fundamental positive-sequence component of voltage and the fundamental positive-sequence component of reactive power according to the three-phase phase voltages and three-phase currents at the new energy grid connection point; A determination module for calculating the upper limit of the ideal reactive current of the new energy grid-connected device according to the fundamental positive-sequence component of the voltage, and 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; A detection module, configured to detect the reactive current response time of the new energy grid-connected device according to the upper limit of the ideal reactive current of the new energy grid-connected device and the integral value of the fundamental positive sequence component of the reactive current.

10. The detection device according to claim 9, characterized in that, Specifically, the calculation module is configured to: Perform full-cycle Fourier decomposition on the three-phase phase voltages and three-phase currents of the new energy grid connection point respectively, to obtain the real part and imaginary part of each of the three-phase phase voltages and the real part and imaginary part of each of the three-phase currents; Calculate 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 phase voltages, and calculate 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; Calculate the fundamental positive sequence component of the voltage according to the real part and imaginary part of the fundamental positive sequence component of the voltage, and calculate the fundamental positive sequence component of the reactive power according to the real part and imaginary part of the fundamental positive sequence component of the voltage and the real part and imaginary part of the fundamental positive sequence component of the current.

11. The detection device according to claim 9, characterized in that, Specifically, the determination module is configured to: Calculate the ideal reactive current of the new energy grid-connected device according to the fundamental positive sequence component of the voltage; Calculate the upper limit of the ideal reactive current of the new energy grid-connected device according to the ideal reactive current of the new energy grid-connected device.

12. The detection device according to claim 11, wherein 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: ; When the new energy grid-connected device is a network-forming new energy grid-connected device, the ideal reactive current of the new energy grid-connected device satisfies: ; Among them, represents the ideal reactive current of the new energy grid-connected device, represents the rated current of the new energy grid-connected device, represents the ratio of the reactive current output by the grid-following new energy grid-connected device to the voltage change under grid voltage disturbance, represents the deviation of the fundamental positive sequence component of the voltage, represents the steady-state equivalent internal impedance of the grid-forming new energy grid-connected device, represents the fundamental positive sequence component of the voltage.

13. The detection device according to claim 11, wherein The upper limit of the ideal reactive current of the new energy grid-connected device satisfies: ; where represents the upper limit of the ideal reactive current of the new energy grid-connected device, represents the ideal reactive current of the new energy grid-connected device, represents the reactive current of the new energy grid-connected device when there is no disturbance in the grid voltage, represents the starting moment of the decline process of the fundamental positive sequence component of the voltage, represents the ending moment of the decline process of the fundamental positive sequence component of the voltage, represents the integration variable.

14. The detection device according to claim 9, characterized in that, Specifically, the determination module is configured to: Calculate 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; Calculate the integral value of the fundamental positive sequence component of the reactive current according to the fundamental positive sequence component of the reactive current.

15. The detection device according to claim 14, wherein The fundamental positive sequence component of the reactive current satisfies: ; where represents the fundamental positive sequence component of the reactive current, represents the fundamental positive sequence component of the voltage, represents the fundamental positive sequence component of the reactive power; The integral value of the fundamental positive-sequence component of the reactive current satisfies: ; where represents the integral value of the fundamental positive-sequence component of the reactive current, represents the reactive current of the new energy grid-connected device when there is no disturbance in the grid voltage, represents the starting moment of the decline process of the fundamental positive-sequence component of the voltage, represents the ending moment of the decline process of the fundamental positive-sequence component of the voltage, represents the delay time, represents the integration variable.

16. The detection device according to claim 15, characterized in that, Specifically, the detection module is configured to: When the upper limit of the ideal reactive current of the new energy grid-connected device 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.

17. A computer device, characterized in that, Comprising: 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, implement the detection method according to any one of claims 1 to 8.

18. A computer-readable storage medium, characterized in that, There is a computer program stored thereon, and when the computer program is executed, implement the detection method according to any one of claims 1 to 8.

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