Vehicle-mounted distributed energy grid-connected test method and device based on modular assembly

Abstract

The invention relates to the technical field of energy grid-connected testing, in particular to a vehicle-mounted distributed energy grid-connected testing method and device based on modular assembly, and the method specifically comprises the steps: obtaining positive and negative voltage groups in voltage data based on the positive and negative conditions of voltages at adjacent moments; based on the difference between the voltage values in the positive and negative voltage groups, determining the zero moment between the voltages in the positive and negative voltage groups by combining the relative positions of the voltages in the positive and negative voltage groups in the coordinate system; the working frequency of the current moment is calculated based on the time interval between two adjacent zero point moments, and the output frequency of the vehicle-mounted distributed energy can be rapidly and accurately detected through a real-time frequency detection algorithm, so that the delay problem caused by the fact that two periodic wave bands need to be collected in traditional Fourier transform is avoided; the timeliness of a grid-connected test is improved, and reliable data support is provided for grid-connected operation.

Description

Technical Field

[0001] This application relates to the technical field of energy grid connection testing, and particularly to a vehicle-mounted distributed energy grid connection testing method and device based on modular assembly. Background Art

[0002] With the rapid development of new energy on the user side such as industrial and commercial energy storage, integrated charging and energy storage, distributed photovoltaics, and small wind turbines entering villages. Energy storage batteries can be used as carriers of vehicle-mounted distributed energy. The vehicle-mounted distributed energy is modularized. When the grid load of a certain power grid is too heavy or the power grid fails, the vehicle-mounted distributed energy module is connected to the power grid for grid connection to temporarily handle the grid fault. During the grid connection process, since the vehicle-mounted distributed energy requires a grid connection voltage, and the voltage magnitudes are different in different regions, such as 220V, 380V, 10kV, therefore, the vehicle-mounted distributed power supply needs to be tested before grid connection operation to ensure that the vehicle-mounted distributed power supply will not impact the main power grid and affect the stable operation of the main power grid after grid connection.

[0003] For the grid connection test of vehicle-mounted distributed energy, when the frequency of the vehicle-mounted distributed energy exceeds the specified range, the frequency deviation seriously affects the normal operation of relay protection equipment and safety automatic devices, and may even cause their misoperation, further expanding the accident range. Traditional technologies generally use Fourier transform to measure the frequency in the power grid. However, due to the high real-time nature of the use of vehicle-mounted distributed energy, and Fourier transform requires at least two periods of wavebands to be collected for frequency detection, which results in a delay in the detection process and cannot meet the real-time requirement. Therefore, there are certain limitations in using Fourier transform for grid connection testing of vehicle-mounted distributed power supplies. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of this application is to provide a vehicle-mounted distributed energy grid connection testing method and device based on modular assembly, and the specific technical solutions adopted are as follows: In the first aspect, an embodiment of this application provides a vehicle-mounted distributed energy grid connection testing method based on modular assembly. The method includes the following steps: Collect the voltage data of vehicle-mounted distributed energy at each moment in real time; Obtain each positive and negative voltage group in the voltage data based on the positive and negative situations of the voltage at adjacent moments. When the voltage at the current moment and the previous moment form a positive and negative voltage group, the steps to obtain the grid connection state of the vehicle-mounted distributed energy and state adjustment are as follows: Calculate the proportional correction coefficient of the positive and negative voltage group based on the difference between the voltage values in the positive and negative voltage group and the time interval between adjacent moments; Based on the relative positions of the voltages in the positive and negative voltage groups in the rectangular coordinate system, and combining with the relevant theorems of similar triangles, calculate the time interval between the voltage data in the positive and negative voltage groups and the corresponding zero point, which is denoted as the first time interval; Determine the zero point moment between the voltages in the positive and negative voltage groups based on the proportional correction coefficient and the first time interval; Calculate the operating frequency at the current moment based on the time interval between two adjacent zero point moments; Based on the operating frequency, analyze the grid connection status of the on-vehicle distributed energy and perform status adjustment.

[0005] In one of the embodiments, the process of obtaining the voltage data of each positive and negative voltage group is as follows: If the voltage at each moment is not zero, then analyze whether the positive and negative signs of the voltage at each moment and the voltage at its previous moment are the same. If they are different, then take the voltage at each moment and the voltage at its previous moment as a positive and negative voltage group.

[0006] In one of the embodiments, the process of obtaining the proportional correction coefficient of the positive and negative voltage groups is as follows: Denote the proportional correction coefficient of the positive and negative voltage group formed by the voltage at the current moment and the voltage at its previous moment as , The expression of is: , respectively represent the normalized values of the voltage data at the previous moment and the current moment of the current moment; is the arcsine function; T represents the acquisition time interval between two adjacent voltage data; represents the exponential function with the natural constant as the base.

[0007] In one of the embodiments, the process of obtaining the time interval between the voltage data in the positive and negative voltage groups and the corresponding zero point is as follows: Denote the voltage at the current moment and the voltage at its previous moment as and respectively, denote the current moment and the previous moment as and respectively, and denote the zero point between and as the first zero point; where, the voltage value of the first zero point is 0; Based on and , and , as well as the first zero point, construct triangle and triangle ; Triangle and triangle When they are similar, based on the relevant theorems of similar triangles, obtain the time interval between the previous moment of the current moment and the moment corresponding to the first zero point.

[0008] In one embodiment, the triangle and the triangle are obtained as follows: Take the coordinate point as the coordinate point , take the coordinate point as the coordinate point , take the first zero point as the coordinate point , and obtain the triangle ; take the coordinate point as the coordinate point , take the coordinate point as the coordinate point , and obtain the triangle .

[0009] In one embodiment, the process of obtaining the time interval between the previous moment of the current moment and the moment corresponding to the first zero point is as follows: When the triangle is similar to the triangle , there are: , and , where represents the time interval between the previous moment of the current moment and the moment corresponding to the first zero point; represents the time interval between the current moment and the moment corresponding to the first zero point; T represents the acquisition time interval between two adjacent voltage data; Then is expressed as: .

[0010] In one embodiment, the expression for the zero point moment between the voltages in the positive and negative voltage groups is: , in the formula, represents the current zero point moment; represents the previous moment of the current moment; represents the proportional correction coefficient of the positive and negative voltage groups formed by the voltage at the current moment and its previous moment; represents the first time interval between the previous moment of the current moment and the first zero point; where the current zero point moment is the true zero point moment between the current moment and its previous moment.

[0011] In one embodiment, the expression for the operating frequency at the current moment is: , in the formula, represents the operating frequency at the current moment; , respectively represent the current zero moment and the previous zero moment; represents a preset cycle coefficient.

[0012] In one embodiment, the method analyzes the grid connection state of the on-vehicle distributed energy and performs state adjustment, specifically as follows: If the operating frequency at the current moment is less than the preset first frequency threshold or greater than the preset second frequency threshold, the on-vehicle distributed energy is in an abnormal operating state, and the on-vehicle distributed energy is immediately terminated from power transmission to the grid line; If the operating frequency at the current moment is greater than or equal to the preset first frequency threshold and less than or equal to the preset second frequency threshold, the historical operating frequency is used as the input of the CPS1 index formula, and the output is the CPS1 value when the on-vehicle distributed energy is operating. For the CPS1 value, if it is greater than or equal to 100%, the current grid connection state is maintained; if it is less than 100%, the AGC control strategy is optimized to adjust the current grid connection state.

[0013] In a second aspect, the embodiment of the present application further provides an on-vehicle distributed energy grid connection test device based on modular assembly, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the steps of the method described in any one of the above are implemented.

[0014] The embodiment of the present application has at least the following beneficial effects: The present application collects the voltage data of the on-vehicle distributed energy at each moment in real time; obtains each positive and negative voltage group in the voltage data based on the positive and negative situations of the voltage at adjacent moments; calculates the proportional correction coefficient of the positive and negative voltage groups based on the difference between the voltage values in the positive and negative voltage groups and the time interval between adjacent moments; calculates the time interval between the voltage data in the positive and negative voltage groups and the corresponding zero moment based on the relative position of the voltage in the positive and negative voltage groups in the rectangular coordinate system and in combination with the relevant theorem of similar triangles, denoted as the first time interval; determines the zero moment between the voltages in the positive and negative voltage groups based on the proportional correction coefficient and the first time interval; calculates the operating frequency at the current moment based on the time interval between two adjacent zero moments. Through the real-time frequency detection algorithm, it can quickly and accurately detect the output frequency of the on-vehicle distributed energy, avoid the delay problem caused by the need to collect two cycle bands in the traditional Fourier transform, improve the timeliness of the grid connection test, and provide reliable data support for the grid connection operation; it can effectively prevent the misoperation of relay protection equipment and safety automatic devices caused by excessive frequency deviation, help reduce the occurrence of power grid faults, improve the stability and safety of the power grid, and thus ensure the reliable operation of the power grid; it helps to optimize the operation strategy of the on-vehicle distributed energy and improve its support ability for the power grid. Brief Description of the Drawings

[0015] To more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 It is a flowchart of the steps of a vehicle-mounted distributed energy grid-connected test method based on modular assembly provided by an embodiment of the present application; Figure 2 It is a schematic diagram of voltage data; Figure 3 It is a schematic diagram of triangle similarity; Figure 4 It is a partial zero-point diagram of the schematic diagram of triangle similarity. Detailed Embodiments

[0017] In order to further elaborate on the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following will, in conjunction with the drawings and preferred embodiments, detail the specific embodiments, structures, features and effects of the vehicle-mounted distributed energy grid-connected test method and device based on modular assembly proposed according to the present application. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs.

[0019] The following will specifically describe the specific solutions of the vehicle-mounted distributed energy grid-connected test method and device based on modular assembly provided by the present application with reference to the drawings.

[0020] Please refer to Figure 1 , which shows a flowchart of the steps of a vehicle-mounted distributed energy grid-connected test method based on modular assembly provided by an embodiment of the present application. The method includes the following steps: Step S1, collect the voltage data of the vehicle-mounted distributed energy at each moment in real time.

[0021] For the modular assembled vehicle-mounted distributed energy, it includes a distribution energy storage mobile detection vehicle module, a workstation module, a sensor module, a power grid simulation power supply module, and a switch module. Among them, the energy storage mobile detection vehicle module is used for grid connection testing; the workstation is used to collect and transmit the data collected by the sensors; the sensor module is used to collect data; the power grid simulation power supply module is used to simulate the power supply; the switch module is used for switching of each function.

[0022] An intelligent electricity meter is installed at the output of the vehicle-mounted distributed energy to collect the voltage data of the vehicle-mounted distributed energy in real time. For the collection of voltage data, preferably, in the embodiments of the present application, the data collection frequency is set to 10 kHz. As other embodiments of the present application, the implementer can set the data collection frequency according to the actual situation. All the voltage data collected before the current moment are arranged in ascending order of the collection time, and the formed sequence is denoted as the frequency-identified voltage sequence. The frequency-identified voltage sequence is denoised by the SG filtering algorithm (Savitzky-Golay). Among them, the SG filtering algorithm is a well-known technology, and the specific process will not be elaborated. In other embodiments of the present application, the implementer can also use other denoising algorithms to denoise the frequency-identified voltage sequence.

[0023] Step S2, obtain each positive and negative voltage group in the voltage data based on the positive and negative conditions of the voltage at adjacent moments.

[0024] When detecting the frequency of the vehicle-mounted distributed energy by Fourier transform, at least two cycles of discrete data are required, resulting in poor real-time performance. When quickly detecting the voltage frequency of the vehicle-mounted distributed energy, generally, the time difference between the zero-crossing points of the voltage data is detected, and the frequency of the voltage is calculated. For the detection of the zero-crossing point, only less data is required to calculate the zero position, so as to improve the detection efficiency and enhance the real-time performance of the detection. For the output voltage of electric energy, the voltage waveform of alternating current is a sine function. Since the collected data is discrete data, not continuous data. When the collected data coincides with the waveform period of alternating current, there are zero points for both discrete data and continuous data, as shown in Figure 2 a and b. However, when collecting data, if it fails to synchronize with the waveform period of alternating current, there are still zero points for continuous data, but the collected discrete data may not have 0 elements, as shown in Figure 2 c and d.

[0025] Since during the process of collecting data, the position where the data is collected is not the initial point or the half-period point of the sine function. Then it is very likely that the collected discrete data does not have a zero point, and the accuracy of the frequency obtained by the time difference between two non-zero points is relatively low. When determining the zero point moment of the voltage data, since the discrete data may not have a zero point, and the position of the zero point is between two voltage data with adjacent data collection times but different positive and negative signs.

[0026] Therefore, taking the current moment as an example, first determine whether the voltage at the current moment is zero. If it is zero, use the voltage data at the current moment as a zero point of the voltage frequency and continue data acquisition. If it is not zero, determine whether the positive and negative signs of the voltage at the current moment and the voltage at the previous moment are the same, that is, whether the voltages at the current moment and the previous moment are both positive voltages or both negative voltages. If the positive and negative signs of the voltage are the same, continue data acquisition. If the positive and negative signs of the voltage are different, use the voltages at the current moment and the previous moment as a positive and negative voltage group to determine the zero point position between the current moment and the previous moment and continue data acquisition. Among them, if the voltage data at the previous moment of the current moment has been determined to be a zero point, only perform a zero point judgment on the current moment and do not perform relevant judgments on the subsequent positive and negative voltage groups. Denote the positive and negative voltage group at the current moment as the first positive and negative voltage group.

[0027] Step S3: Calculate the proportional correction coefficient of the positive and negative voltage group based on the difference between the voltage values in the positive and negative voltage group and the time interval between adjacent moments.

[0028] For the on-vehicle distributed energy after being converted into alternating current by an inverter, the waveform of the continuous current is a sine function, and the sine function is rotationally symmetric at the periodic point and the half-period point, that is, the intersection point of the sine function and the x-axis. Therefore, the positive and negative voltage group data can be regarded as data composed of two similar triangles. As Figure 3 shown. Figure 3 In it represents the voltage data point at the previous moment with the corresponding voltage value of ; the coordinate point represents the point on the horizontal axis where the moment is located; the coordinate point represents the voltage data point at the current moment with the corresponding voltage value of ; the coordinate point represents the point on the horizontal axis where the moment is located; the coordinate point represents the zero point between the moment and the moment, and denote this zero point as the first zero point.

[0029] Figure 3 In triangle is similar to triangle Figure 4 as shown in , ), so the moment of the zero point can be calculated through the similarity ratio between the positive and negative voltage groups ( triangle It is only approximate and not similar. Therefore, before calculating through the similarity ratio, it is necessary to calculate the ratio correction coefficient. The expressions for the ratio correction coefficients of the positive and negative voltage groups are as follows: In the formula, represents the ratio correction coefficient of the first positive and negative voltage group; and respectively represent the normalized values of the voltage data at the previous moment and the current moment of the current moment; is the arcsine function; T represents the acquisition time interval between two adjacent voltage data. In the embodiments of the present application ; represents the exponential function with the natural constant as the base; represents the absolute value symbol. Among them, and are calculated as and respectively. In the formula, is the maximum value among the absolute values of the historical voltage data.

[0030] Step S4: Based on the relative positions of the voltages in the positive and negative voltage groups in the rectangular coordinate system, combined with the relevant theorems of similar triangles, calculate the time interval between the voltage data in the positive and negative voltage groups and the corresponding zero point, denoted as the first time interval.

[0031] Since triangle and triangle are only approximate and not similar to each other, there is a certain positional difference between the result of the zero point position and the true zero point position after the calculation process through the similarity theorem. Therefore, correction is performed through the angle ratio of the elements in the positive and negative voltage groups. At the same time, during the calculation process, the larger the sampling frequency, the smaller the time interval between two adjacent sampling data, and the higher the similarity degree between the triangles formed by the positive and negative voltage groups and the zero point. Therefore, the ratio correction coefficient is corrected through the time interval.

[0032] During the process of calculating the zero point moment, when estimating using the similar triangle theorem, if triangle is similar to triangle , then there is: In the formula, and respectively represent the voltage at the previous moment and the current moment of the current moment; represents the time interval between the previous moment of the current moment and the corresponding moment of the first zero point; represents the time interval between the current moment and the moment corresponding to the first zero point; T represents the acquisition time interval between two adjacent voltage data; Furthermore, through the above formula, it can be obtained that The expression for is:

[0033] In actual situations, due to and are very likely not to be equal. Therefore, and are not equal. So, triangle and triangle are not similar but only approximate. Therefore, the calculation result of the expression for obtaining does not necessarily equal the time interval between the previous moment of the current moment and the true zero point moment in actual situations. Thus, needs to be corrected before the moment of the true zero point can be determined.

[0034] Step S5: Determine the zero point moment between the voltages in the positive and negative voltage groups based on the proportional correction coefficient and the first time interval.

[0035] Using the proportional correction coefficient of the positive and negative voltage groups and combining the distance between the zero point moment and the moments of the voltage data in the positive and negative voltage groups, calculate the true zero point moment. Among them, the true zero point moment between the current moment and its previous moment is denoted as the current zero point moment. Taking the current zero point moment as an example, its expression is: In the formula, represents the current zero point moment; represents the previous moment of the current moment; represents the proportional correction coefficient of the first positive and negative voltage group; represents the time interval between the previous moment and the moment corresponding to the first zero point calculated through the first expression, denoted as the first time interval. It should be noted that the calculation of the above expression is carried out on the premise that there is a zero point moment between the current moment and its previous moment.

[0036] When the time interval between the zero point moment and the moments of the two elements in the positive and negative voltage groups is closer, the triangle and the triangle are more similar, and the proportional correction coefficient of the positive and negative voltage groups is closer to 1, and the influence degree on is smaller. The more accurate the true zero point moment corrected by the proportional correction coefficient is, the more accurate the calculation of the output frequency of the on-vehicle distributed energy is.

[0037] Further, based on each positive and negative voltage group, using the same acquisition method as the current zero-crossing moment, each zero-crossing moment is obtained.

[0038] Step S6, calculate the working frequency at the current moment based on the time interval between two adjacent zero-crossing moments.

[0039] For the real-time frequency of in-vehicle distributed energy, since the voltage waveform of in-vehicle distributed energy is a sine function, it can be measured through the time interval between adjacent zero-crossings. Based on the above analysis, calculate the working frequency at the current moment of in-vehicle distributed energy, and the expression is: In the formula, represents the working frequency at the current moment; and represent the current zero-crossing moment and the previous zero-crossing moment respectively; represents the period coefficient. Since is the time length of half a cycle of the voltage sine wave, therefore, the value of a is 2.

[0040] When the difference between the time interval between two adjacent zero-crossings and the specified time interval is smaller, the working frequency at the current moment is closer to the frequency specified by the state, and the operating state of the in-vehicle distributed energy is better. Among them, V represents the voltage frequency specified by the national grid. Since the voltage frequency specified by the national grid is 50, then V = 50 in this application; since the time interval between two zero-crossings is half a cycle, therefore, V×2 is required.

[0041] Thus, through the above steps, the zero-crossing moment of the voltage data can be calculated through two adjacent discrete data, and the working frequency of the voltage data can be calculated using two adjacent zero-crossing moments. Compared with the Fourier transform, the data used in this application is less, and the calculation amount is less than that of the Fourier transform, which can enhance the real-time performance of the in-vehicle distributed energy during the grid connection test.

[0042] Step S7, analyze the grid connection state of the in-vehicle distributed energy based on the working frequency and perform state adjustment.

[0043] For the working frequency at the current moment, according to the standard in the national standard "GB / T 33593-2017", if the working frequency at the current moment satisfies the condition or , then the in-vehicle distributed energy is in an abnormal operating state and it is necessary to immediately terminate the power supply of the in-vehicle distributed energy to the grid line. Among them, is used as the first frequency threshold, and is used as the second frequency threshold.

[0044] When Since the on-vehicle distributed energy is used as the temporarily-supplied energy, during the grid connection process, the operating frequency of the on-vehicle distributed energy is affected by the grid load, and the stability of the operating frequency will change. Therefore, the historical operating frequency is used as the input of the CPS1 (Control Performance Standard 1) index formula, and the output is the CPS1 value when the on-vehicle distributed energy is operating. If CPS1 ≥ 100%, it means that the dynamic regulation ability of the grid meets the requirements, the frequency recovery ability is good, and there is no need to adjust the current grid connection state. If CPS1 < 100%, it means that the dynamic regulation ability of the grid is insufficient, and it is necessary to further optimize the AGC control strategy and adjust the current grid connection state. Among them, the calculation of CPS1 and the process of optimizing the AGC control strategy therein are well-known technologies, and the specific process will not be elaborated here.

[0045] Based on the same inventive concept as the above method, the embodiment of the present application also provides an on-vehicle distributed energy grid connection test device based on modular assembly, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any one of the above methods of the on-vehicle distributed energy grid connection test method based on modular assembly.

[0046] In summary, the embodiment of the present application provides an on-vehicle distributed energy grid connection test method based on modular assembly. By collecting the voltage data of the on-vehicle distributed energy at each moment in real time; obtaining each positive and negative voltage group in the voltage data based on the positive and negative conditions of the voltage at adjacent moments; calculating the proportional correction coefficient of the positive and negative voltage groups based on the difference between the voltage values in the positive and negative voltage groups and the time interval between adjacent moments; based on the relative positions of the voltages in the positive and negative voltage groups in the rectangular coordinate system, combining the relevant theorems of similar triangles, calculating the time interval between the voltage data in the positive and negative voltage groups and the corresponding zero point moment, denoted as the first time interval; determining the zero point moment between the voltages in the positive and negative voltage groups based on the proportional correction coefficient and the first time interval; calculating the operating frequency at the current moment based on the time interval between adjacent two zero point moments. Through the real-time frequency detection algorithm, it can quickly and accurately detect the output frequency of the on-vehicle distributed energy, avoiding the delay problem caused by the need to collect two cycle bands in the traditional Fourier transform, improving the timeliness of the grid connection test, providing reliable data support for the grid connection operation; it can effectively prevent the misoperation of relay protection devices and safety automatic devices caused by excessive frequency deviation, help reduce the occurrence of grid faults, improve the stability and safety of the grid, and thus ensure the reliable operation of the grid; it helps to optimize the operation strategy of the on-vehicle distributed energy and improve its supporting ability for the grid.

[0047] It should be noted that: the above sequence of embodiments of the present application is only for description and does not represent the superiority or inferiority of the embodiments. And the specific embodiments of the present application have been described above. Additionally, the processes depicted in the drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0048] Each embodiment in the present application is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other, and the key point of each embodiment is to illustrate the differences from other embodiments.

[0049] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the principle of the present application shall be included within the protection scope of the present application.

Claims

1. A vehicle-mounted distributed energy grid-connected testing method based on modular assembly, characterized in that: The method comprises the following steps: Real-time collection of voltage data of on-board distributed energy at all times; Based on the positive and negative voltage conditions at adjacent moments, each positive and negative voltage group in the voltage data is obtained; when the voltage at the current moment and the voltage at the previous moment form a positive and negative voltage group, the steps for obtaining the grid connection status and status adjustment of the on-board distributed energy are as follows: Calculating a proportional correction coefficient for the positive and negative voltage groups based on a difference between voltage values ​​in the positive and negative voltage groups and a time interval between adjacent moments; Based on the relative positions of the voltages in the positive and negative voltage groups in the rectangular coordinate system and in combination with the related theorem of similar triangles, the time interval between the voltage data in the positive and negative voltage groups and the corresponding zero point is calculated, which is recorded as the first time interval; Determine a zero point time between voltages in the positive and negative voltage groups based on the proportional correction coefficient and the first time interval; Calculate the working frequency at the current moment based on the time interval between two adjacent zero moments; Based on the working frequency, the grid-connected status of the on-board distributed energy is analyzed and the status is adjusted.

2. The vehicle-mounted distributed energy grid-connected testing method based on modular assembly as claimed in claim 1, characterized in that: The process of obtaining each positive and negative voltage group in the voltage data is as follows: If the voltage at each moment is not zero, then analyze whether the positive and negative signs of the voltage at each moment are the same as those at the previous moment. If they are different, then treat the voltage at each moment and the previous moment as a positive and negative voltage group.

3. The vehicle-mounted distributed energy grid-connected testing method based on modular assembly as claimed in claim 1, characterized in that: The process of obtaining the proportional correction coefficient of the positive and negative voltage groups is as follows: The proportional correction coefficient of the positive and negative voltage group formed by the voltage at the current moment and the voltage at the previous moment is recorded as , The expression is: , where; , Respectively represent the normalized values ​​of the voltage data at the moment before the current moment and the current moment; is an inverse sine function; T represents the acquisition time interval between two adjacent voltage data; Represents an exponential function with a natural constant as its base.

4. The vehicle-mounted distributed energy grid-connected testing method based on modular assembly as claimed in claim 1, characterized in that: The process of obtaining the time interval between the voltage data in the positive and negative voltage groups and the corresponding zero point is as follows: The voltage at the current moment and the previous moment are respectively recorded as and , and the current moment and the previous moment are respectively recorded as and ,Will and The zero point between the moments is recorded as the first zero point; wherein the voltage value of the first zero point is 0; based on and , and , and the first zero point, construct the triangle and triangle ; triangle and triangle When similar, based on the related theorem of similar triangles, the time interval between the previous moment of the current moment and the moment corresponding to the first zero point is obtained.

5. The vehicle-mounted distributed energy grid-connected testing method based on modular assembly as claimed in claim 4, characterized in that: The triangle and triangle The acquisition process is: The coordinate point As coordinate point , the coordinate point As coordinate point , take the first zero point as the coordinate point , we get the triangle ; Set the coordinate point As coordinate point , the coordinate point As coordinate point , we get the triangle .

6. The vehicle-mounted distributed energy grid-connected testing method based on modular assembly as claimed in claim 4, characterized in that: The process of obtaining the time interval between the moment before the current moment and the moment corresponding to the first zero point is: triangle With triangle When similar, there is: ,as well as ,in, Indicates the time interval between the moment before the current moment and the moment corresponding to the first zero point; represents the time interval between the current moment and the moment corresponding to the first zero point; T represents the acquisition time interval between two adjacent voltage data; but The expression is: .

7. The vehicle-mounted distributed energy grid-connected testing method based on modular assembly as claimed in claim 1, characterized in that: The expression of the zero point moment between the voltages in the positive and negative voltage groups is: , where Indicates the current zero time; Indicates the moment before the current moment; Indicates the proportional correction coefficient of the positive and negative voltage group formed by the voltage at the current moment and the voltage at the previous moment; Represents the first time interval between the moment before the current moment and the first zero point; wherein the current zero point moment is the real zero point moment between the current moment and the moment before it.

8. The vehicle-mounted distributed energy grid-connected testing method based on modular assembly as claimed in claim 7, characterized in that: The expression of the working frequency at the current moment is: , where Indicates the working frequency at the current moment; , Respectively represent the current zero time and the previous zero time; Indicates the preset period coefficient.

9. The vehicle-mounted distributed energy grid-connected testing method based on modular assembly as claimed in claim 1, characterized in that: The analysis of the grid-connected state of the vehicle-mounted distributed energy and the adjustment of the state are specifically as follows: If the current operating frequency is less than the preset first frequency threshold or greater than the preset second frequency threshold, the on-board distributed energy is in an abnormal operating state, and the on-board distributed energy is immediately stopped from transmitting power to the grid line; If the current operating frequency is greater than or equal to the preset first frequency threshold and less than or equal to the preset second frequency threshold, the historical operating frequency is used as the input of the CPS1 indicator formula, and the output is the CPS1 value when the on-board distributed energy is working. For the CPS1 value, if it is greater than or equal to 100%, the current grid-connected state is maintained; if it is less than 100%, the AGC control strategy is optimized and the current grid-connected state is adjusted.

10. A vehicle-mounted distributed energy grid-connected test device based on modular assembly, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 9 are implemented.

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