Power grid adaptability enhancement control method and system for network construction type energy storage converter, and computer equipment

Abstract

The invention relates to the technical field of power grids, and particularly discloses a power grid adaptability enhancement control method and system for a network-forming type energy storage converter and computer equipment. The method comprises the following steps: firstly, acquiring voltage amplitude change characteristics and voltage harmonic change characteristics at the joint of a network-forming energy storage converter and a power grid, then acquiring a voltage effective value according to the voltage amplitude change characteristics, judging whether the voltage effective value is smaller than a preset threshold, if so, judging that the power grid is in an under-voltage state, and acquiring under-voltage duration; obtaining a harmonic component effective value according to the voltage harmonic change characteristics, obtaining a harmonic distortion rate according to the harmonic component effective value and the plurality of harmonic component values, finally carrying out gradient control on the energy storage converter according to the under-voltage duration and the harmonic distortion rate, and carrying out adaptive enhanced regulation and control on the power grid based on the gradient control. Therefore, fine control of the energy storage converter is realized, and the problem of unstable power grid caused by overcurrent protection when the network-forming energy storage converter triggers the maximum current can be avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of power grids, and in particular to a method and system for enhancing the grid adaptability control of a grid-forming energy storage converter and a computer device. Background Art

[0002] With the large-scale access of new energy, the stability and reliability of the power system face new challenges. As an effective regulation means, the core device of the energy storage system, the energy storage converter, plays a key role. The grid-forming energy storage converter is a power electronic device that can independently support the grid voltage and frequency and has grid support characteristics similar to those of traditional synchronous generators. It can not only realize the bidirectional conversion of electrical energy between the energy storage system and the grid, but also provide necessary voltage and frequency support for the grid under grid faults or weak grid conditions to maintain the stable operation of the grid;

[0003] However, when the grid voltage suddenly drops, in order to keep the original power of the grid unchanged, the existing grid-forming energy storage converters need to continuously increase the output current, which will cause overcurrent protection when the maximum current is triggered. The overcurrent protection will cause the energy storage converter to be disconnected from the grid and interrupt the power regulation of the energy storage system to the grid, thus impacting the stability of the grid. Therefore, a method and system for enhancing the grid adaptability control of a grid-forming energy storage converter and a computer device are needed to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and system for enhancing the grid adaptability control of a grid-forming energy storage converter and a computer device to solve the technical problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A method for enhancing the grid adaptability control of a grid-forming energy storage converter includes:

[0007] Obtain the voltage change characteristic information at the connection between the grid-forming energy storage converter and the grid, where the voltage change characteristic information includes the voltage amplitude change characteristic and the voltage harmonic change characteristic;

[0008] Obtain the voltage values of multiple sampling points within a preset time according to the voltage amplitude change characteristic, and obtain the effective voltage value according to the voltage values of the multiple sampling points;

[0009] Judge whether the effective voltage value is less than a preset threshold;

[0010] If the effective voltage value is less than the preset threshold, it is determined that the grid is in an undervoltage state, and obtain the undervoltage duration of the undervoltage state;

[0011] Obtain a voltage waveform diagram according to the voltage harmonic variation characteristics, and obtain multiple harmonic component values according to the voltage waveform diagram;

[0012] Obtain the effective value of the harmonic component according to multiple said harmonic component values, and obtain the harmonic distortion rate according to the effective value of the harmonic component and multiple said harmonic component values;

[0013] Perform gradient control on the energy storage converter according to the undervoltage duration and the harmonic distortion rate, and perform adaptive enhancement control on the power grid based on the gradient control.

[0014] Preferably, the step of obtaining the voltage values of multiple sampling points within a preset time according to the voltage amplitude variation characteristics and obtaining the effective value of the voltage according to the voltage values of multiple sampling points includes:

[0015] Obtain a fluctuation diagram of the voltage within a preset time according to the voltage amplitude variation characteristics;

[0016] Obtain the voltage values of multiple sampling points according to the fluctuation diagram, and calculate the effective value of the voltage according to the voltage values of multiple sampling points, where the calculation formula is:

[0017]

[0018] where U(X) represents the effective value of the voltage, u(t) i represents the voltage value at the i-th sampling point, i represents the serial number of the sampling point voltage value, where i = 1, 2, 3... N.

[0019] Preferably, the step of obtaining the undervoltage duration of the undervoltage state includes:

[0020] Obtain multiple first effective voltage values of the undervoltage state within a preset sampling period;

[0021] Sequentially judge whether multiple said first effective voltage values are less than a preset threshold interval based on the time series until there is a first effective voltage value less than the preset threshold interval, and take the occurrence moment of the first effective voltage value corresponding to less than the preset threshold interval in the preset time series as the first starting moment;

[0022] Sequentially judge whether the remaining multiple said first effective voltage values are less than the preset threshold interval until there is a first effective voltage value greater than or equal to the preset threshold interval, and take the occurrence moment of the first effective voltage value corresponding to greater than or equal to the preset threshold interval in the preset time series as the first ending moment;

[0023] Calculate the undervoltage duration according to the first ending moment and the first starting moment.

[0024] Preferably, the steps of obtaining a voltage waveform diagram according to the voltage harmonic change characteristics and obtaining a plurality of harmonic component values according to the voltage waveform diagram include:

[0025] Obtaining a plurality of voltage harmonic electrical signals according to the voltage harmonic change characteristics;

[0026] Converting the plurality of voltage harmonic electrical signals into a plurality of voltage harmonic frequency domains based on Fourier transform, and obtaining a plurality of harmonic amplitudes and a plurality of harmonic phases according to the plurality of voltage harmonic frequency domains;

[0027] Drawing a voltage waveform diagram by plotting the plurality of harmonic amplitudes and the plurality of harmonic phases according to a preset voltage harmonic electrical signal acquisition period;

[0028] Obtaining a fundamental frequency according to the voltage waveform diagram;

[0029] Obtaining a plurality of harmonic frequencies according to the plurality of harmonic amplitudes and the plurality of harmonic phases, and obtaining a plurality of harmonic component values according to the plurality of harmonic frequencies and the fundamental frequency.

[0030] Preferably, the steps of obtaining a harmonic component effective value according to the plurality of harmonic component values and obtaining a harmonic distortion rate according to the harmonic component effective value and the plurality of harmonic component values include:

[0031] Obtaining a harmonic component effective value according to the plurality of harmonic component values, where the calculation formula:

[0032]

[0033] where V(X) represents the harmonic component effective value, A(Z) h represents the value of the h-th harmonic component, h represents the order of the harmonic component value, where h = 1, 2, 3... H;

[0034] Obtaining a harmonic reference value;

[0035] Obtaining a harmonic distortion rate according to the harmonic component effective value and the plurality of harmonic component values, where the calculation formula:

[0036]

[0037] where THD represents the harmonic distortion rate, V(X) represents the harmonic component effective value, j(z) represents the harmonic reference value, A(Z) o represents the value of the o-th harmonic component, o represents the order of the harmonic component value, where o = 1, 2, 3... k.

[0038] Preferably, the step of gradient - controlling the energy - storage converter according to the undervoltage duration and the harmonic distortion rate and adaptively enhancing the regulation of the power grid based on the gradient control includes:

[0039] Obtain the reference power factor of the grid - forming energy - storage converter;

[0040] Map the undervoltage duration and the harmonic distortion rate into a two - dimensional coordinate system to obtain an undervoltage duration - harmonic distortion rate two - dimensional coordinate system. Among them, the undervoltage duration - harmonic distortion rate two - dimensional coordinate system includes an undervoltage duration interval with the undervoltage duration as the x - axis coordinate and a harmonic distortion rate interval with the harmonic distortion rate as the y - axis coordinate;

[0041] Divide the undervoltage duration - harmonic distortion rate two - dimensional coordinate system into three gradient intervals according to the undervoltage duration and the harmonic distortion rate. Among them, the three gradient intervals include a reminder interval, a warning interval, and a danger interval;

[0042] When in the reminder interval, obtain the first harmonic distortion rate interval value corresponding to the reminder interval, obtain the corresponding first apparent power according to the first harmonic distortion rate interval value, calculate the first power factor according to the first apparent power and the preset active power, adjust the reference power factor based on the first power factor, and take the process of adjusting the reference power factor with the first power factor as the first strategy;

[0043] When in the warning interval, obtain the corresponding first reactive power according to the undervoltage duration, then obtain the corresponding second reactive power based on the harmonic distortion rate, and calculate the third reactive power according to the first reactive power and the second reactive power;

[0044] Obtain the first active power corresponding to the warning interval, calculate the second apparent power according to the first active power and the third reactive power, calculate the second power factor according to the second apparent power and the preset active power, adjust the reference power factor based on the second power factor, and take the process of adjusting the reference power factor with the second power factor as the second strategy;

[0045] When in the danger interval, issue a danger start command according to the danger interval, perform off - grid protection control on the energy - storage converter according to the danger start command, and take the process of performing off - grid protection control on the energy - storage converter with the danger start command as the third strategy;

[0046] Generate a gradient control strategy table according to the first strategy, the second strategy, and the third strategy, and perform adaptive enhancement regulation on the power grid according to the gradient control strategy table.

[0047] This application also provides a grid adaptability enhancement control system for a grid - forming energy - storage converter, including:

[0048] A first acquisition module, configured to acquire voltage change characteristic information at the connection between a network-forming energy storage converter and a power grid, where the voltage change characteristic information includes voltage amplitude change characteristics and voltage harmonic change characteristics;

[0049] A second acquisition module, configured to acquire multiple sampled point voltage values within a preset time according to the voltage amplitude change characteristics, and acquire a voltage effective value according to the multiple sampled point voltage values;

[0050] A first judgment module, configured to judge whether the voltage effective value is less than a preset threshold;

[0051] If the voltage effective value is less than the preset threshold, it is determined that the power grid is in an undervoltage state, and the undervoltage duration of the undervoltage state is acquired;

[0052] A third acquisition module, configured to acquire a voltage waveform diagram according to the voltage harmonic change characteristics, and acquire multiple harmonic component values according to the voltage waveform diagram;

[0053] A fourth acquisition module, configured to acquire a harmonic component effective value according to the multiple harmonic component values, and acquire a harmonic distortion rate according to the harmonic component effective value and the multiple harmonic component values;

[0054] A first control module, configured to perform gradient control on the energy storage converter according to the undervoltage duration and the harmonic distortion rate, and perform adaptive enhancement regulation on the power grid based on the gradient control.

[0055] Preferably, the second acquisition module includes:

[0056] A first acquisition unit, configured to acquire a voltage fluctuation diagram within a preset time according to the voltage amplitude change characteristics;

[0057] A second acquisition unit, configured to acquire multiple sampled point voltage values according to the fluctuation diagram, and calculate a voltage effective value according to the multiple sampled point voltage values, where the calculation formula is:

[0058]

[0059] where U(X) represents the voltage effective value, u(t) i represents the voltage value at the i-th sampled point, and i represents the sequence number of the sampled point voltage value, where i = 1, 2, 3... N.

[0060] This application also provides a computer device, including a memory and a processor, where the memory stores a computer program, and when the processor executes the computer program, the steps of the above method are implemented.

[0061] The present application also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above method are implemented.

[0062] The beneficial effects of the present application are as follows: the present invention first obtains the voltage amplitude change characteristics and the voltage harmonic change characteristics at the connection point between the grid-type energy storage converter and the power grid, and then obtains the voltage effective value within a preset time according to the voltage amplitude change characteristics, and at the same time determines whether the voltage effective value is less than a preset threshold value. If the voltage effective value is less than the preset threshold value, it is determined that the power grid is in an undervoltage state, and the undervoltage duration of the undervoltage state is obtained, and then multiple harmonic component values ​​are obtained according to the voltage harmonic change characteristics, and then the harmonic component effective values ​​are obtained according to the multiple harmonic component values, and the harmonic component effective values ​​and the multiple harmonic component effective values ​​are obtained according to the harmonic component effective values ​​and the multiple harmonic component effective values. The harmonic distortion rate is obtained by obtaining the harmonic component value, and finally, the energy storage inverter is gradient controlled according to the undervoltage duration and the harmonic distortion rate, and the power grid is adaptively enhanced and regulated based on the gradient control, thereby realizing refined control of the energy storage inverter, taking different measures according to the different abnormality levels of the power grid, and improving the stability and reliability of the power grid. At the same time, it can also avoid the problem that the existing grid-forming energy storage inverter needs to continuously increase the output current in order to keep the original power of the power grid unchanged, which causes the grid-forming energy storage inverter to perform overcurrent protection when the maximum current is triggered, and is disconnected from the power grid, resulting in grid instability. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 The figure is a schematic diagram of a method flow of an embodiment of the present application.

[0064] Figure 2 A schematic diagram of the system structure of an embodiment of the present application.

[0065] Figure 3 A schematic diagram of the internal structure of a computer device according to an embodiment of the present application.

[0066] Figure 4 Schematic diagram of the structure of the undervoltage duration-harmonic distortion rate two-dimensional coordinate system according to an embodiment of the present application.

[0067] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0068] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0069] like Figures 1-4 As shown, the present application provides a grid adaptability enhancement control method for a grid-connected energy storage converter, comprising:

[0070] S1. Obtain the voltage change characteristic information at the connection between the grid-forming energy storage converter and the power grid, where the voltage change characteristic information includes the voltage amplitude change characteristic and the voltage harmonic change characteristic;

[0071] S2. Obtain the voltage values of multiple sampling points within a preset time according to the voltage amplitude change characteristic, and obtain the effective voltage value according to the voltage values of the multiple sampling points;

[0072] S3. Determine whether the effective voltage value is less than a preset threshold;

[0073] If the effective voltage value is less than the preset threshold, it is determined that the power grid is in an undervoltage state, and the undervoltage duration of the undervoltage state is obtained;

[0074] S4. Obtain the voltage waveform diagram according to the voltage harmonic change characteristic, and obtain multiple harmonic component values according to the voltage waveform diagram;

[0075] S5. Obtain the effective value of the harmonic components according to the multiple harmonic component values, and obtain the harmonic distortion rate according to the effective value of the harmonic components and the multiple harmonic component values;

[0076] S6. Perform gradient control on the energy storage converter according to the undervoltage duration and the harmonic distortion rate, and perform adaptive enhancement control on the power grid based on the gradient control.

[0077] As described in the above steps S1 - S6, when there is a sudden drop in the grid voltage, in order to keep the original power of the grid unchanged, the existing grid-forming energy storage converter needs to continuously increase the output current, which in turn causes the grid-forming energy storage converter to perform overcurrent protection when the maximum current is triggered. The overcurrent protection will cause the energy storage converter to disconnect from the grid and interrupt the power regulation of the energy storage system to the grid, thus impacting the stability of the grid. Therefore, the present invention first obtains the voltage change characteristic information at the connection between the grid-forming energy storage converter and the grid. Among them, the voltage change characteristic information includes the voltage amplitude change characteristic and the voltage harmonic change characteristic. At the same time, since the voltage amplitude change characteristic and the voltage harmonic change characteristic will affect the change of the grid, the voltage amplitude change characteristic and the voltage harmonic change characteristic at the connection between the grid-forming energy storage converter and the grid are comprehensively collected to provide the original data basis for subsequent analysis of the grid state. By mastering this information, it is possible to understand the fluctuation of the grid voltage and the presence and impact of harmonics. Since the effective voltage value is an important indicator for judging whether the grid voltage is normal. In the actual operation of the grid, the operating characteristics and lifespan of equipment are closely related to the effective voltage value. By calculating the effective voltage value, it can provide a quantitative basis for judging whether the grid is in an undervoltage state and key data for formulating subsequent control strategies. Therefore, according to the voltage amplitude change characteristic, the voltage values of multiple sampling points within a preset time are obtained, and the effective voltage value is obtained based on the voltage values of the multiple sampling points. In this way, the voltage values of multiple sampling points within a preset time are obtained according to the voltage amplitude change characteristic, and the effective voltage value is calculated. The effective voltage value can reflect the comprehensive level of the voltage over a period of time. Compared with the instantaneous voltage value, it can more accurately measure the impact of the voltage on the energy storage converter and grid equipment. Since undervoltage will damage the equipment in the grid and affect its normal operation. Accurately judging the undervoltage state and obtaining the undervoltage duration helps to take targeted measures, such as adopting a mild compensation strategy when the undervoltage duration is short, and more radical regulation means when the undervoltage duration is long, to protect the energy storage converter and grid equipment. Therefore, it is judged whether the effective voltage value is less than a preset threshold. If the effective voltage value is less than the preset threshold, it is determined that the grid is in an undervoltage state, and the undervoltage duration of the undervoltage state is obtained. In this way, by comparing the effective voltage value with the preset threshold, it is judged whether the grid is in an undervoltage state and the undervoltage duration is accurately obtained.The under-voltage duration can reflect the duration of the under-voltage state of the power grid, which is crucial for evaluating the severity of power grid faults and formulating corresponding control strategies. Since harmonics can cause problems such as increased power loss in the power grid, equipment heating, and affecting the normal operation of relay protection devices, obtaining the harmonic component values can clarify the specific situation of harmonics. Then, based on the voltage harmonic change characteristics, a voltage waveform diagram can be obtained, and based on the voltage waveform diagram, multiple harmonic component values can be obtained. Thus, a voltage waveform diagram can be obtained according to the voltage harmonic change characteristics, and then multiple harmonic component values can be obtained. Then, the harmonic component values can clearly show the situation of each harmonic in the power grid, helping to analyze the degree and nature of the impact of harmonics on the power grid. Since the harmonic distortion rate can comprehensively reflect the overall impact of harmonics in the power grid. By obtaining the harmonic distortion rate, it can be judged whether the power quality of the power grid meets the standards. Then, based on multiple harmonic component values, the effective value of the harmonic components can be obtained, and based on the effective value of the harmonic components and multiple harmonic component values, the harmonic distortion rate can be obtained. In this way, the effective value of the harmonic components and the harmonic distortion rate are calculated from the harmonic component values. The harmonic distortion rate is an important indicator for measuring the power quality of the power grid, reflecting the ratio of the harmonic content to the fundamental wave, and can intuitively indicate the degree of harmonic pollution in the power grid. Finally, gradient control is performed on the energy storage converter according to the under-voltage duration and the harmonic distortion rate, and adaptive enhancement regulation is performed on the power grid based on the gradient control. In this way, gradient control is performed on the energy storage converter based on the under-voltage duration and the harmonic distortion rate, different control strategies are formulated, and a gradient control strategy table is generated according to these strategies to perform adaptive enhancement regulation on the power grid, realizing refined control of the energy storage converter, taking different measures according to different abnormal degrees of the power grid, improving the stability and reliability of the power grid, and at the same time being able to avoid the problem of grid instability caused by the existing grid-forming energy storage converter continuously increasing the output current in order to keep the original power of the power grid unchanged and resulting in over-current protection when the grid-forming energy storage converter triggers the maximum current and disconnecting from the grid.

[0078] In one embodiment, the step S2 of obtaining multiple sampling point voltage values within a preset time according to the voltage amplitude change characteristics and obtaining the voltage effective value according to the multiple sampling point voltage values includes:

[0079] S201. Obtain the fluctuation diagram of the voltage within a preset time according to the voltage amplitude change characteristics;

[0080] S202. Obtain multiple sampling point voltage values according to the fluctuation diagram, and calculate the voltage effective value according to the multiple sampling point voltage values, where the calculation formula is:

[0081]

[0082] where U(X) represents the voltage effective value, and u(t) iIt represents the voltage value at the i-th sampling point, where i represents the serial number of the sampling point voltage value, and i = 1, 2, 3... N.

[0083] As described in the above steps S201 - S202, since in actual power grid operation, the voltage is not constant and its fluctuation conditions are complex and diverse. Drawing a voltage fluctuation graph can present these complex changes in a visual form. The present invention first obtains the voltage fluctuation graph within a preset time according to the voltage amplitude change characteristics. By analyzing the voltage amplitude change characteristics to draw the voltage fluctuation graph within the preset time, it can intuitively show the change trend of the voltage over time. This helps to quickly understand the dynamic change situation of the voltage, including information such as the voltage fluctuation amplitude, frequency, and whether there are abnormal mutations. It is of great significance for monitoring the stability of the power grid, and potential problems such as voltage sags, swells, or overly frequent fluctuations can be detected in a timely manner. Then, based on the fluctuation graph, multiple sampling point voltage values are obtained, and the effective voltage value is calculated according to the multiple sampling point voltage values. That is, multiple sampling point voltage values are obtained based on the voltage fluctuation graph, and then the effective voltage value is calculated according to a specific formula. The effective voltage value is an important indicator for measuring the actual effect of the voltage on electrical equipment over a period of time. It comprehensively considers the voltage fluctuation situation and can more accurately reflect the energy equivalent value of the voltage. By calculating the effective voltage value, the voltage values at different times can be converted into a representative value, which is convenient for comparison with a preset threshold to determine whether the power grid is in a normal operating state.

[0084] In one embodiment, step S3 of obtaining the undervoltage duration of the undervoltage state includes:

[0085] S301. Obtain multiple first effective voltage values of the undervoltage state within a preset sampling period;

[0086] S302. Based on the time series, sequentially determine whether multiple first effective voltage values are less than a preset threshold interval until there is a first effective voltage value less than the preset threshold interval, and take the occurrence moment of the first effective voltage value corresponding to less than the preset threshold interval on the preset time series as the first starting moment;

[0087] S303. Sequentially determine whether the remaining multiple first effective voltage values are less than the preset threshold interval until there is a first effective voltage value greater than or equal to the preset threshold interval, and take the occurrence moment of the first effective voltage value corresponding to greater than or equal to the preset threshold interval on the preset time series as the first ending moment;

[0088] S304. Calculate the undervoltage duration according to the first ending moment and the first starting moment.

[0089] As described in the above steps S301 - S304, since the grid voltage varies dynamically during actual operation, relying solely on the voltage value at a single moment cannot accurately determine whether it is truly in an undervoltage state. Therefore, the present invention first obtains multiple first effective voltage values of the undervoltage state within a preset sampling period. By collecting multiple effective voltage values within a certain time range in this way, the reliability and accuracy of the judgment can be increased. Under different grid operating conditions, the voltage may experience short - term fluctuations, but this does not necessarily mean entering the undervoltage state. The collection of multiple data points can effectively filter out these interference factors, ensuring the scientific nature of subsequent judgments. At the same time, obtaining multiple first effective voltage values within the preset sampling period can comprehensively judge the change trend of the grid voltage from the voltage data at multiple time points. These data points form a discrete sampling observation of the grid voltage state, which helps to more comprehensively understand whether there are abnormal fluctuations in the voltage within a period of time and whether it is close to or lower than the normal operating threshold, providing a rich data basis for accurately judging the undervoltage state subsequently, and avoiding misjudging the grid state due to voltage measurement errors or accidental fluctuations at a single point. Then, based on the time series, it is sequentially judged whether multiple of the first effective voltage values are less than a preset threshold range until there is a first effective voltage value less than the preset threshold range, and the occurrence time of the first effective voltage value corresponding to less than the preset threshold range on the preset time series is used as the first starting time. By marking the moment when the first of the multiple first effective voltage values is first less than the preset threshold range as the first starting time, the time point when the grid voltage starts to enter a possible undervoltage state is clarified. This is crucial for subsequent calculation of the undervoltage duration and analysis of the starting stage of the grid fault, can accurately define the starting time of the problem, provide key information about the fault occurrence time for grid operation and maintenance personnel, help to take timely measures to deal with grid anomalies, and also provide a time reference basis for subsequent control strategy adjustment. Immediately afterwards, it is sequentially judged whether the remaining multiple first effective voltage values are less than the preset threshold range until there is a first effective voltage value greater than or equal to the preset threshold range, and the occurrence time of the first effective voltage value corresponding to greater than or equal to the preset threshold range on the preset time series is used as the first ending time. By sequentially judging the subsequent first effective voltage values until the judgment ends when it is greater than or equal to the preset threshold range, and taking this moment as the first ending time. This step precisely defines the time point when the grid voltage recovers from the undervoltage state to the normal range, thereby determining the complete undervoltage time period.By clarifying the start and end times of undervoltage, the undervoltage duration can be accurately calculated, providing a crucial time parameter for evaluating the severity and impact scope of power grid faults, and also providing necessary data support for subsequent implementation of corresponding control strategies based on the undervoltage duration. Finally, the undervoltage duration is calculated according to the first end time and the first start time. In this way, calculating the undervoltage duration based on the first end time and the first start time obtains a quantified time index, which intuitively reflects the duration of the power grid in the undervoltage state. This time index is one of the important bases for subsequent implementation of the gradient control strategy. Different undervoltage durations will correspond to different control strategy adjustments, so as to achieve precise control of the energy storage converter, enabling it to better adapt to abnormal situations of the power grid and maintain the stable operation of the power grid. At the same time, it also helps power grid operation and maintenance personnel quickly evaluate and make decisions on the severity of power grid faults.

[0090] In one embodiment, step S4 of obtaining a voltage waveform diagram according to the voltage harmonic change characteristics and obtaining multiple harmonic component values according to the voltage waveform diagram includes:

[0091] S401. Obtain multiple voltage harmonic electrical signals according to the voltage harmonic change characteristics;

[0092] S402. Based on Fourier transform, convert the multiple voltage harmonic electrical signals into multiple voltage harmonic frequency domains, and obtain multiple harmonic amplitudes and multiple harmonic phases according to the multiple voltage harmonic frequency domains;

[0093] S403. Draw a voltage waveform diagram by plotting the multiple harmonic amplitudes and the multiple harmonic phases according to a preset voltage harmonic electrical signal acquisition period;

[0094] S404. Obtain the fundamental frequency according to the voltage waveform diagram;

[0095] S405. Obtain multiple harmonic frequencies according to the multiple harmonic amplitudes and the multiple harmonic phases, and obtain multiple harmonic component values according to the multiple harmonic frequencies and the fundamental frequency.

[0096] As described in the above steps S401 - S405, in a complex power grid environment, the sources of harmonic generation are diverse, such as the connection of non - linear loads, etc. In order to comprehensively understand the harmonic condition of the power grid, it is first necessary to obtain electrical signals that can accurately represent harmonics. Only by obtaining these signals can subsequent analysis methods and technologies be used to conduct in - depth research on harmonics. At the same time, the voltage harmonic electrical signal is the starting point of the entire harmonic analysis work and plays a key supporting role in the development of subsequent steps. Therefore, the present invention first obtains multiple voltage harmonic electrical signals according to the voltage harmonic change characteristics. In this way, through in - depth analysis of the voltage harmonic change characteristics, multiple voltage harmonic electrical signals are obtained. These signals carry rich information such as the frequency and amplitude of harmonics in the power grid and are the basic data sources for subsequent harmonic analysis. They can intuitively reflect the existence form and distribution of harmonics in the power grid and provide accurate basis for quickly identifying whether there is harmonic pollution in the power grid and the approximate degree of pollution. Then, based on the Fourier transform, the multiple voltage harmonic electrical signals are transformed into multiple voltage harmonic frequency domains, and multiple harmonic amplitudes and multiple harmonic phases are obtained according to the multiple voltage harmonic frequency domains. In this way, by using the Fourier transform to convert the voltage harmonic electrical signal from the time domain to the frequency domain, different frequency harmonic components can be clearly separated, thereby obtaining multiple harmonic amplitudes and multiple harmonic phases. This step enables the originally complex and mixed signals in the time domain to be clearly presented in the frequency domain, and the specific parameters of each harmonic can be intuitively seen, providing key data for accurately evaluating the impact of harmonics on the power grid, helping to judge the harm degree and potential risks of harmonics. Then, the multiple harmonic amplitudes and the multiple harmonic phases are used to draw a voltage waveform diagram according to a preset voltage harmonic electrical signal acquisition period. By drawing the voltage waveform diagram according to the obtained harmonic amplitudes and phases according to the preset voltage harmonic electrical signal acquisition period, the overall waveform of the power grid voltage can be intuitively displayed in a graphical manner, including the superposition effect of the fundamental wave and each harmonic. By observing the waveform diagram, the staff can more vividly understand the distortion of the power grid voltage and quickly discover abnormal changes in the voltage waveform, such as problems such as the distortion degree and symmetry caused by harmonics, so as to make a preliminary qualitative judgment on the power quality of the power grid. Then, the fundamental wave frequency is obtained according to the voltage waveform diagram. And accurately obtaining the fundamental wave frequency from the drawn voltage waveform diagram is one of the key parameters for the operation of the power grid. The stability of the fundamental wave frequency is the basis for the normal operation of the power grid. By determining the fundamental wave frequency, a benchmark can be provided for subsequent judgment of the relationship between the harmonic frequency and the fundamental wave frequency. Then, multiple harmonic frequencies are obtained according to the multiple harmonic amplitudes and the multiple harmonic phases, and multiple harmonic component values are obtained according to the multiple harmonic frequencies and the fundamental wave frequency. In this way, according to the obtained harmonic amplitudes, phases and the fundamental wave frequency, multiple harmonic frequencies are further calculated, and multiple harmonic component values are determined in combination with the fundamental wave frequency.Meanwhile, the harmonic component values accurately quantify the content and influence degree of each harmonic in the power grid, providing detailed data support for comprehensively evaluating the harmonic condition of the power grid, and are the key basis for subsequent calculation of the harmonic distortion rate and formulation of harmonic suppression strategies.

[0097] In one embodiment, step S5 of obtaining the effective value of the harmonic component according to the multiple harmonic component values and obtaining the harmonic distortion rate according to the effective value of the harmonic component and the multiple harmonic component values includes:

[0098] S501. Obtain the effective value of the harmonic component according to the multiple harmonic component values, where the calculation formula:

[0099]

[0100] where V(X) represents the effective value of the harmonic component, and A(Z) h represents the value of the h-th harmonic component, h represents the order of the harmonic component value, where h = 1, 2, 3... H;

[0101] S502. Obtain the harmonic reference value;

[0102] S503. Obtain the harmonic distortion rate according to the effective value of the harmonic component and the multiple harmonic component values, where the calculation formula:

[0103]

[0104] where THD represents the harmonic distortion rate, V(X) represents the effective value of the harmonic component, j(z) represents the harmonic reference value, and A(Z) o represents the value of the o-th harmonic component, o represents the order of the harmonic component value, where o = 1, 2, 3... k.

[0105] As described in the above steps S501 - S503, the present invention first obtains the effective value of the harmonic component according to the multiple harmonic component values, and then obtains the harmonic reference value. Since the harmonic distortion rate is an important indicator for measuring the power quality of the power grid, it intuitively reflects the proportion of harmonics in the power grid and the degree of distortion of the sinusoidal waveform of the power grid. Therefore, obtaining the harmonic distortion rate according to the effective value of the harmonic component and the multiple harmonic component values can clearly understand the harmonic pollution condition of the power grid, and provides a key decision-making basis for judging whether the power grid needs harmonic governance and what governance measures to take.

[0106] In one embodiment, step S6 of performing gradient control on the energy storage converter according to the undervoltage duration and the harmonic distortion rate and performing adaptive enhancement regulation on the power grid based on the gradient control includes:

[0107] S601. Obtain the reference power factor of the grid-forming energy storage converter;

[0108] S602. Map the undervoltage duration and the harmonic distortion rate into a two-dimensional coordinate system to obtain an undervoltage duration - harmonic distortion rate two-dimensional coordinate system, where the undervoltage duration - harmonic distortion rate two-dimensional coordinate system includes an undervoltage duration interval with the undervoltage duration as the x-axis coordinate and a harmonic distortion rate interval with the harmonic distortion rate as the y-axis coordinate;

[0109] S603. Divide the undervoltage duration - harmonic distortion rate two-dimensional coordinate system into three gradient intervals according to the undervoltage duration and the harmonic distortion rate, where the three gradient intervals include a reminder interval, a warning interval, and a danger interval;

[0110] S604. When in the reminder interval, obtain the first harmonic distortion rate interval value corresponding to the reminder interval, obtain the corresponding first apparent power according to the first harmonic distortion rate interval value, calculate the first power factor according to the first apparent power and the preset active power, adjust the reference power factor based on the first power factor, and take the process of adjusting the reference power factor with the first power factor as the first strategy;

[0111] S605. When in the warning interval, obtain the corresponding first reactive power according to the undervoltage duration, then obtain the corresponding second reactive power based on the harmonic distortion rate, and calculate the third reactive power according to the first reactive power and the second reactive power;

[0112] S606. Obtain the first active power corresponding to the warning interval, calculate the second apparent power according to the first active power and the third reactive power, calculate the second power factor according to the second apparent power and the preset active power, adjust the reference power factor based on the second power factor, and take the process of adjusting the reference power factor with the second power factor as the second strategy;

[0113] S607. When in the danger interval, issue a danger start command according to the danger interval, perform off-grid protection control on the energy storage converter according to the danger start command, and take the process of performing off-grid protection control on the energy storage converter with the danger start command as the third strategy;

[0114] S608. Generate a gradient control strategy table according to the first strategy, the second strategy, and the third strategy, and perform adaptive enhancement regulation on the power grid according to the gradient control strategy table.

[0115] As described in the above steps S601 - S608, the present invention first obtains the reference power factor of the grid - forming energy storage converter. Obtaining the reference power factor of the grid - forming energy storage converter provides an initial reference value for subsequent adjustment of the power factor according to the grid state. The power factor is an important indicator measuring the proportional relationship between the active power and the apparent power in the power system, and its magnitude affects the power transmission efficiency of the grid and the operating state of the equipment. The reference power factor can reflect the power factor level of the energy storage converter under normal conditions. When the grid experiences abnormalities, adjusting based on this can help optimize the power distribution and transmission of the grid, reduce the reactive power loss, and improve the overall operating efficiency of the grid. Then, the undervoltage duration and the harmonic distortion rate are mapped into a two - dimensional coordinate system to obtain the undervoltage duration - harmonic distortion rate two - dimensional coordinate system. Among them, the undervoltage duration - harmonic distortion rate two - dimensional coordinate system includes an undervoltage duration interval with the undervoltage duration as the x - axis coordinate and a harmonic distortion rate interval with the harmonic distortion rate as the y - axis coordinate. Mapping the undervoltage duration and the harmonic distortion rate into a two - dimensional coordinate system creates the undervoltage duration - harmonic distortion rate two - dimensional coordinate system. This coordinate system can intuitively present the relationship between two key abnormal state parameters of the grid, providing a clear visual framework for subsequent division of different control intervals. Through this coordinate system, the staff can quickly locate the state area where the grid is currently located, facilitating the formulation of corresponding control strategies according to the characteristics of different areas, and improving the efficiency of grid state judgment and control decision - making. Then, the undervoltage duration - harmonic distortion rate two - dimensional coordinate system is divided into three gradient intervals according to the undervoltage duration and the harmonic distortion rate. Among them, the three gradient intervals include a reminder interval, a warning interval, and a danger interval. Furthermore, the two - dimensional coordinate system is divided into three gradient intervals, namely, the reminder interval, the warning interval, and the danger interval, based on the undervoltage duration and the harmonic distortion rate. This division method can hierarchically classify the abnormal states of the grid, and different intervals represent different degrees of grid problems. By clarifying the interval where the grid is located, the severity of the grid abnormality can be quickly judged, thus providing a clear guiding direction for subsequent adoption of different intensities and types of control measures, realizing the hierarchical management and differential control of grid abnormal conditions. Then, when in the reminder interval, obtain the first harmonic distortion rate interval value corresponding to the reminder interval, and obtain the corresponding first apparent power according to the first harmonic distortion rate interval value. Calculate the first power factor according to the first apparent power and the preset active power, and adjust the reference power factor based on the first power factor. The process of adjusting the reference power factor with the first power factor is regarded as the first strategy. This strategy, when the grid is in a relatively mild abnormal state, optimizes the power transmission characteristics of the grid by fine - tuning the power factor, reduces the impact of harmonics on the power factor, and improves the operating efficiency of the grid.Taking measures in a timely manner at this stage can prevent the further deterioration of grid abnormal conditions, play a role in early prevention and optimizing grid operation. When in the warning range, obtain the corresponding first reactive power according to the undervoltage duration, then obtain the corresponding second reactive power based on the harmonic distortion rate, and calculate the third reactive power according to the first reactive power and the second reactive power. This strategy optimizes the power transmission characteristics of the grid by fine-tuning the power factor when the grid is in a relatively mild abnormal state, reduces the impact of harmonics on the power factor, and improves the operating efficiency of the grid. Taking measures in a timely manner at this stage can prevent the further deterioration of grid abnormal conditions, play a role in early prevention and optimizing grid operation. Then when in the warning range, obtain the corresponding first reactive power according to the undervoltage duration, then obtain the corresponding second reactive power based on the harmonic distortion rate, and calculate the third reactive power according to the first reactive power and the second reactive power. Next, obtain the first active power corresponding to the warning range, calculate the second apparent power according to the first active power and the third reactive power, calculate the second power factor according to the second apparent power and the preset active power, adjust the reference power factor based on the second power factor, and take the process of adjusting the reference power factor by the second power factor as the second strategy. By precisely adjusting the power factor and reactive power output, it can effectively maintain the voltage stability of the grid, ensure the stable operation of the grid under relatively severe abnormal conditions, reduce the impact on user power supply. When in the dangerous range, issue a danger start command according to the dangerous range, perform off-grid protection control on the energy storage converter according to the danger start command, and take the process of performing off-grid protection control on the energy storage converter by the danger start command as the third strategy. And when in the dangerous range, issue a danger start command to perform off-grid protection control on the energy storage converter. This strategy is the last line of defense when the grid faces serious threats, can quickly cut off the connection between the energy storage converter and the grid, prevent further damage to the energy storage converter caused by grid faults, and at the same time avoid the possible negative impact of the energy storage converter on the grid under abnormal conditions, protecting the safety of the energy storage system and the grid. Finally, generate a gradient control strategy table according to the first strategy, the second strategy and the third strategy, and perform adaptive enhancement control on the grid according to the gradient control strategy table. In this way, generate a gradient control strategy table according to the control strategies in the above different ranges. This table provides a clear operation guide for the operation of the energy storage converter in different grid states. By performing adaptive enhancement control on the grid according to the strategy table, it can realize the automated and standardized management of the grid, ensure that the energy storage converter can quickly and accurately respond to grid abnormalities in various situations, take appropriate control measures, and effectively improve the stability and reliability of the grid.

[0116] The present application also provides a grid adaptability enhancement control system for a grid-forming energy storage converter, including:

[0117] The first acquisition module 1 is configured to acquire the voltage change characteristic information at the connection between the network-forming energy storage converter and the power grid, where the voltage change characteristic information includes the voltage amplitude change characteristic and the voltage harmonic change characteristic;

[0118] The second acquisition module 2 is configured to acquire multiple sampled-point voltage values within a preset time according to the voltage amplitude change characteristic, and acquire the effective voltage value according to the multiple sampled-point voltage values;

[0119] The first judgment module 3 is configured to judge whether the effective voltage value is less than a preset threshold;

[0120] If the effective voltage value is less than the preset threshold, it is determined that the power grid is in an undervoltage state, and the undervoltage duration of the undervoltage state is acquired;

[0121] The third acquisition module 4 is configured to acquire a voltage waveform diagram according to the voltage harmonic change characteristic, and acquire multiple harmonic component values according to the voltage waveform diagram;

[0122] The fourth acquisition module 5 is configured to acquire the effective value of the harmonic components according to the multiple harmonic component values, and acquire the harmonic distortion rate according to the effective value of the harmonic components and the multiple harmonic component values;

[0123] The first control module 6 is configured to perform gradient control on the energy storage converter according to the undervoltage duration and the harmonic distortion rate, and perform adaptive enhancement regulation on the power grid based on the gradient control.

[0124] In one embodiment, the second acquisition module includes:

[0125] The first acquisition unit is configured to acquire the voltage fluctuation diagram within a preset time according to the voltage amplitude change characteristic;

[0126] The second acquisition unit is configured to acquire multiple sampled-point voltage values according to the fluctuation diagram, and calculate the effective voltage value according to the multiple sampled-point voltage values, where the calculation formula is:

[0127]

[0128] where U(X) represents the effective voltage value, and u(t) i represents the voltage value at the i-th sampled point, and i represents the serial number of the sampled-point voltage value, where i = 1, 2, 3... N.

[0129] The present invention also provides a computer device, including a memory and a processor, where the memory stores a computer program, and the processor executes the steps of the method for adaptively enhancing the control of the network-forming energy storage converter power grid.

[0130] The present invention also provides a computer-readable storage medium, on which a computer program is stored, and the computer program, when executed by a processor, implements the steps of the above-described method for enhancing the grid adaptability control of a network-forming energy storage converter.

[0131] Those of ordinary skill in the art can understand that all or part of the processes in the above-described embodiment methods can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-described various methods. Among them, any reference to a memory, storage, database, or other medium provided in this application and used in the embodiments can include non-volatile and / or volatile memories. Non-volatile memories can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memories can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and Rambus dynamic RAM (RDRAM), etc.

[0132] It should be noted that in this article, the terms "including", "comprising", or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method including a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such a process, apparatus, article, or method. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, apparatus, article, or method including that element.

[0133] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural or equivalent process transformation made by using the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A control method for enhancing the grid adaptability of a grid-forming energy storage converter, characterized in that, Including: Obtain the voltage change characteristic information at the connection between the grid-forming energy storage converter and the power grid, where the voltage change characteristic information includes the voltage amplitude change characteristic and the voltage harmonic change characteristic; Obtain the voltage values of multiple sampling points within a preset time according to the voltage amplitude change characteristic, and obtain the effective voltage value according to the voltage values of multiple sampling points; Judge whether the effective voltage value is less than a preset threshold; If the effective voltage value is less than the preset threshold, it is determined that the power grid is in an undervoltage state, and the undervoltage duration of the undervoltage state is obtained; Obtain the voltage waveform diagram according to the voltage harmonic change characteristic, and obtain multiple harmonic component values according to the voltage waveform diagram; Obtain the effective value of the harmonic component according to the multiple harmonic component values, and obtain the harmonic distortion rate according to the effective value of the harmonic component and the multiple harmonic component values; Perform gradient control on the energy storage converter according to the undervoltage duration and the harmonic distortion rate, and perform adaptive enhancement regulation on the power grid based on the gradient control.

2. The grid adaptability enhancement control method of the grid-forming energy storage converter according to claim 1, wherein The step of obtaining the voltage values of multiple sampling points within a preset time according to the voltage amplitude change characteristic and obtaining the effective voltage value according to the voltage values of multiple sampling points includes: Obtain the voltage fluctuation diagram within a preset time according to the voltage amplitude change characteristic; Obtain the voltage values of multiple sampling points according to the fluctuation diagram, and calculate the effective voltage value according to the voltage values of multiple sampling points, where the calculation formula is: Among them, U(X) represents the effective voltage value, and u(t) i represents the voltage value at the i-th sampling point, and i represents the serial number of the voltage value at the sampling point, where i = 1, 2, 3... N.

3. The enhanced control method for the grid adaptability of the grid-forming energy storage converter according to claim 1, characterized in that, The step of obtaining the undervoltage duration of the undervoltage state includes: Obtain multiple first effective voltage values within a preset sampling period in the undervoltage state; Based on the time series, sequentially judge whether multiple first effective voltage values are less than a preset threshold interval until there is a first effective voltage value less than the preset threshold interval, and take the occurrence time of the first effective voltage value corresponding to the less-than-preset-threshold interval in the preset time series as the first start time; Sequentially judge whether the remaining multiple first effective voltage values are less than the preset threshold interval until there is a first effective voltage value greater than or equal to the preset threshold interval, and take the occurrence time of the first effective voltage value corresponding to the greater-than-or-equal-to-preset-threshold interval in the preset time series as the first end time; Calculate the undervoltage duration according to the first end time and the first start time.

4. The grid adaptability enhancement control method for the grid-forming energy storage converter according to claim 1, characterized in that, The step of obtaining the voltage waveform diagram according to the voltage harmonic change characteristic and obtaining multiple harmonic component values according to the voltage waveform diagram includes: Obtain multiple voltage harmonic electrical signals according to the voltage harmonic change characteristic; Based on Fourier transform, convert multiple voltage harmonic electrical signals into multiple voltage harmonic frequency domains, and obtain multiple harmonic amplitudes and multiple harmonic phases according to the multiple voltage harmonic frequency domains; Draw the voltage waveform diagram by arranging the multiple harmonic amplitudes and the multiple harmonic phases according to a preset voltage harmonic electrical signal acquisition period; Obtain the fundamental frequency according to the voltage waveform diagram; Obtain multiple harmonic frequencies according to the multiple harmonic amplitudes and the multiple harmonic phases, and obtain multiple harmonic component values according to the multiple harmonic frequencies and the fundamental frequency.

5. The grid adaptability enhancement control method for a grid-forming energy storage converter according to claim 1, wherein, The steps of obtaining the effective value of the harmonic component according to the multiple harmonic component values and obtaining the harmonic distortion rate according to the effective value of the harmonic component and the multiple harmonic component values include: Obtaining the effective value of the harmonic component according to the multiple harmonic component values, where the calculation formula is: Among them, V(X) represents the effective value of the harmonic component, and A(Z) h represents the value of the h-th harmonic component, where h represents the order of the harmonic component value, and h = 1, 2, 3... H; Obtaining the harmonic reference value; Obtaining the harmonic distortion rate according to the effective value of the harmonic component and the multiple harmonic component values, where the calculation formula is: Among them, THD represents the harmonic distortion rate, V(X) represents the effective value of the harmonic component, j(z) represents the harmonic reference value, and A(Z) o represents the value of the o-th harmonic component, where o represents the order of the harmonic component value, and o = 1, 2, 3... k.

6. The grid adaptability enhancement control method for a grid-forming energy storage converter according to claim 1, characterized in that, The steps of performing gradient control on the energy storage converter according to the undervoltage duration and the harmonic distortion rate and performing adaptive enhancement control on the power grid based on the gradient control include: Obtaining the reference power factor of the grid-forming energy storage converter; Mapping the undervoltage duration and the harmonic distortion rate into a two-dimensional coordinate system to obtain an undervoltage duration-harmonic distortion rate two-dimensional coordinate system, where the undervoltage duration-harmonic distortion rate two-dimensional coordinate system includes an undervoltage duration interval with the undervoltage duration as the x-axis coordinate and a harmonic distortion rate interval with the harmonic distortion rate as the y-axis coordinate; Dividing the undervoltage duration-harmonic distortion rate two-dimensional coordinate system into three gradient intervals according to the undervoltage duration and the harmonic distortion rate, where the three gradient intervals include a reminder interval, a warning interval, and a danger interval; When in the reminder interval, obtaining the first harmonic distortion rate interval value corresponding to the reminder interval, obtaining the corresponding first apparent power according to the first harmonic distortion rate interval value, calculating the first power factor according to the first apparent power and the preset active power, adjusting the reference power factor based on the first power factor, and taking the process of adjusting the reference power factor with the first power factor as the first strategy; When in the warning interval, obtaining the corresponding first reactive power according to the undervoltage duration, then obtaining the corresponding second reactive power based on the harmonic distortion rate, and calculating the third reactive power according to the first reactive power and the second reactive power; Obtaining the first active power corresponding to the warning interval, calculating the second apparent power according to the first active power and the third reactive power, calculating the second power factor according to the second apparent power and the preset active power, adjusting the reference power factor based on the second power factor, and taking the process of adjusting the reference power factor with the second power factor as the second strategy; When in the danger interval, sending a danger start command according to the danger interval, performing off-grid protection control on the energy storage converter according to the danger start command, and taking the process of performing off-grid protection control on the energy storage converter with the danger start command as the third strategy; Generating a gradient control strategy table according to the first strategy, the second strategy, and the third strategy, and performing adaptive enhancement control on the power grid according to the gradient control strategy table.

7. A grid-connected energy storage converter grid adaptability enhancement control system, characterized in that, Including: A first acquisition module for acquiring the voltage change characteristic information at the connection between the grid-forming energy storage converter and the power grid, where the voltage change characteristic information includes the voltage amplitude change characteristic and the voltage harmonic change characteristic; A second acquisition module for obtaining multiple sampled voltage values within a preset time according to the voltage amplitude change characteristic and obtaining the effective voltage value according to the multiple sampled voltage values; The first judgment module is used to judge whether the effective value of the voltage is less than a preset threshold; If the effective value of the voltage is less than the preset threshold, it is determined that the power grid is in an undervoltage state, and the undervoltage duration of the undervoltage state is obtained; The third acquisition module is used to obtain a voltage waveform diagram according to the voltage harmonic change characteristics, and obtain a plurality of harmonic component values according to the voltage waveform diagram; The fourth acquisition module is used to obtain the effective value of the harmonic components according to the plurality of harmonic component values, and obtain the harmonic distortion rate according to the effective value of the harmonic components and the plurality of harmonic component values; The first control module is used to perform gradient control on the energy storage converter according to the undervoltage duration and the harmonic distortion rate, and perform adaptive enhancement control on the power grid based on the gradient control.

8. The grid-connected energy storage converter grid adaptability enhancement control system according to claim 7, characterized in that, The second acquisition module includes: The first acquisition unit is used to obtain the voltage fluctuation diagram within a preset time according to the voltage amplitude change characteristics; The second acquisition unit is used to obtain the voltage values of a plurality of sampling points according to the fluctuation diagram, and calculate the effective value of the voltage according to the voltage values of the plurality of sampling points. The calculation formula is: Among them, U(X) represents the effective voltage value, and u(t) i represents the voltage value at the i-th sampling point, where i represents the serial number of the voltage value at the sampling point, and i = 1, 2, 3... N.

9. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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