Intelligent regulation and control method and system for light storage charging and discharging station to participate in operation and maintenance of virtual power plant

Abstract

The invention relates to the technical field of battery management, in particular to an intelligent regulation and control method and system for light storage charge and discharge stations to participate in virtual power plant operation and maintenance. According to the method, batteries charged each time are divided into low-internal-resistance batteries and high-internal-resistance batteries, the two batteries are matched according to the difference between the voltage of the high-internal-resistance batteries and the voltage of the low-internal-resistance batteries after photovoltaic charging power adjustment, and matched batteries of the high-internal-resistance batteries are obtained; and according to the difference between the voltage of the high-internal-resistance battery and the voltage of the matched battery after photovoltaic charging power adjustment and the voltage of the high-internal-resistance battery, selecting a to-be-equalized battery, and carrying out electric quantity equalization on the to-be-equalized battery and the matched battery so as to obtain the actual discharging electric quantity of each time of charging and participate in regulation and control of operation and maintenance of the virtual power plant. According to the method, the to-be-equalized battery is selected, the illumination instability factor is considered in the selection process, the equalization efficiency is improved, the service life of the battery is prolonged, and the photovoltaic fluctuation is dynamically adapted.

Description

Technical Field

[0001] The present invention relates to the technical field of battery management, and particularly relates to an intelligent regulation method and system for a photovoltaic energy storage charging and discharging power station to participate in the operation and maintenance of a virtual power plant. Background Art

[0002] With its clean energy local consumption capacity and flexible regulation characteristics, the photovoltaic energy storage charging and discharging power station has become a key carrier in the construction of a new power system. As an important part of the virtual power plant, the photovoltaic energy storage charging and discharging power station participates in the intelligent regulation of the virtual power plant, coordinates and optimizes the operation of distributed energy and energy storage facilities, effectively balances the grid load, and improves the system stability and flexibility.

[0003] When the photovoltaic energy storage charging and discharging power station participates in the regulation of the virtual power plant, the unstable light intensity causes the charging power of the photovoltaic battery to fluctuate, and then due to the difference in battery manufacturing processes, the performance of different batteries is inconsistent, resulting in uneven battery power. The specific influence mechanism is as follows: when the light is sufficient, that is, the photovoltaic charging power is high, the charging requirements of different performance batteries can be met, and the influence of internal resistance difference on the charging amount is small; when the light is insufficient, the low internal resistance battery can absorb more electric energy due to less energy loss, while the high internal resistance battery, that is, the battery with poor performance, has a large energy loss. As a result, within the same charging time under the same light, the electric energy charged into the low internal resistance battery is much greater than that of the high internal resistance battery, exacerbating the uneven battery power. Through power balance, the total energy storage potential of the battery pack can be fully utilized, the accelerated aging phenomenon caused by inconsistent battery power can be reduced, and the battery life of the photovoltaic energy storage charging and discharging power station can be extended.

[0004] Existing balancing technologies usually detect the voltage difference between batteries and transfer the power of high-voltage batteries to low-voltage batteries to achieve power balance between batteries. However, the unstable light intensity will cause the corresponding relationship between the voltage and power of the battery to shift, resulting in the voltage difference between batteries not accurately reflecting the true power difference. During the power balance process, the high-voltage battery's power is insufficient to balance the low-voltage battery due to internal resistance consumption, and the balancing circuit continuously consumes energy but fails to achieve power transfer, resulting in low power balance efficiency of the batteries in the photovoltaic energy storage charging and discharging power station. Summary of the Invention

[0005] In order to solve the technical problem of low power balance efficiency of batteries caused by unstable light intensity, the purpose of the present invention is to provide an intelligent regulation method and system for a photovoltaic energy storage charging and discharging power station to participate in the operation and maintenance of a virtual power plant. The specific technical solutions adopted are as follows: In the first aspect, an embodiment of the present invention provides an intelligent regulation method for a photovoltaic energy storage charging and discharging power station to participate in the operation and maintenance of a virtual power plant. The method includes: Obtain the photovoltaic charging power of the battery in the photovoltaic energy storage charging and discharging power station during each charging and the voltage of the battery after each charging; The battery is divided into a low internal resistance battery and a high internal resistance battery based on the voltage of the battery after each charge; according to the difference between the voltage of the high internal resistance battery after each charge and the voltage of the low internal resistance battery after photovoltaic charging power adjustment, the low internal resistance battery and the high internal resistance battery for each charge are matched to obtain the matching battery of the high internal resistance battery; According to the difference between the voltage of the high internal resistance battery after each charge and the voltage of its matching battery after photovoltaic charging power adjustment, and the voltage of the high internal resistance battery, the battery to be balanced is selected from the high internal resistance batteries for each charge, and the power of the battery to be balanced and its matching battery is balanced; The battery after power balance is discharged, and according to the current change during the power discharge process of the battery, the actual discharge power of the photovoltaic energy storage charging and discharging power station after each charge is obtained and participates in the regulation of the virtual power plant operation and maintenance.

[0006] Further, the obtaining of the matching battery of the high internal resistance battery includes: Based on the photovoltaic charging power for each charge, the battery charge separation degree for each charge is obtained; The voltage of the low internal resistance battery after each charge is adjusted by using the battery charge separation degree to obtain a corrected voltage; the corrected voltages of the low internal resistance batteries after each charge and the voltages of the high internal resistance batteries are respectively arranged in sequence to obtain a low internal resistance voltage sequence and a high internal resistance voltage sequence; the target balanced voltage for each charge is obtained, the elements in the low internal resistance voltage sequence are greater than the target balanced voltage, and the elements in the high internal resistance voltage sequence are less than the target balanced voltage; Set the initial subscript to be measured as 0, and use the low internal resistance voltage sequence as the initial voltage sequence to be measured; determine whether the element corresponding to the subscript to be measured in the voltage sequence to be measured is less than the element corresponding to the subscript to be measured in the high internal resistance voltage sequence. If so, delete the element corresponding to the subscript to be measured in the voltage sequence to be measured to obtain a new voltage sequence to be measured; if not, determine the new subscript to be measured, and determine whether the element corresponding to the new subscript to be measured in the new voltage sequence to be measured is less than the element corresponding to the new subscript to be measured in the high internal resistance voltage sequence until the new subscript to be measured is greater than the subscript corresponding to the last element in the high internal resistance voltage sequence, then stop updating the voltage sequence to be measured, and use the updated voltage sequence to be measured as the balanced voltage sequence that meets the requirements; Determine the matching battery of each high internal resistance battery for each charge, and the subscript of the element corresponding to each high internal resistance battery in the high internal resistance voltage sequence is equal to the subscript of the corresponding element of the matching battery in the balanced voltage sequence that meets the requirements.

[0007] Further, the obtaining of the battery charge separation degree for each charge includes: Select the full charge power from the photovoltaic charging powers of several charges before each charge, and the voltages of the batteries after the charges corresponding to the full charge power are all within the full charge voltage range; Normalize the sum of the differences between the full-charge power of each charge and the photovoltaic charging power respectively, to obtain the battery charge separation degree of each charge.

[0008] Further, the selection of the battery to be balanced from the high internal resistance batteries of each charge includes: Normalize the difference between the voltage of each high internal resistance battery after each charge and the target balance voltage, to obtain the balance reference deviation degree; According to the difference between the voltage of each high internal resistance battery after each charge and the corrected voltage of its matching battery, and the balance reference deviation degree, obtain the matching balance demand degree of the corresponding high internal resistance battery; select the high internal resistance battery corresponding to the matching balance demand degree less than the preset demand threshold from the high internal resistance batteries of each charge as the battery to be balanced.

[0009] Further, the target balance voltage is equal to the product of the sum of the battery charge separation degree and the constant 1 and the central value of the voltages of all batteries after each charge.

[0010] Further, the method for obtaining the actual discharge power includes: Obtain the discharge current of all batteries at each moment during the power release period, calculate the mean value of the discharge current at the same moment, perform curve fitting on the means corresponding to all moments during the power release period to obtain the discharge current function; integrate the discharge current function during the discharge period, and take the product of the integration result and the total number of batteries as the actual discharge power of the photovoltaic energy storage charging and discharging station after each charge.

[0011] Further, the power balance between the battery to be balanced and its matching battery includes: For each battery to be balanced, discharge the matching battery of the battery to be balanced, transfer the excess power to the battery to be balanced, respectively obtain the discharge voltage of the battery to be balanced and its matching battery at each moment during the power transfer process. When the difference in the discharge voltage of the battery to be balanced and its matching battery at the same moment is not within the balance requirement range, continue the power transfer until the difference in the discharge voltage is within the balance requirement range, and then stop the power transfer to complete the power balance of the battery after each charge.

[0012] Further, the division of the battery into low internal resistance batteries and high internal resistance batteries includes: For the battery after each charge, calculate the central value of the voltages of all batteries, and respectively take the batteries with voltages less than the central value as high internal resistance batteries, and the batteries with voltages greater than or equal to the central value as low internal resistance batteries.

[0013] Further, the battery charge separation degree and the corrected voltage are in a negative correlation relationship.

[0014] Furthermore, the number of low internal resistance batteries per charge is greater than the number of high resistance batteries.

[0015] Furthermore, the arrangement order of the elements in the low internal resistance voltage sequence is opposite to that in the high internal resistance voltage sequence.

[0016] In a second aspect, another embodiment of the present invention provides an intelligent regulation system for a photovoltaic energy storage charging and discharging station to participate in the operation and maintenance of a virtual power plant. The system includes: A data acquisition module, configured to obtain the photovoltaic charging power of the battery in the photovoltaic energy storage charging and discharging station during each charge and the voltage of the battery after each charge. A battery matching module, configured to divide the batteries into low internal resistance batteries and high internal resistance batteries based on the voltage of the battery after each charge; match the low internal resistance batteries and high internal resistance batteries for each charge according to the difference between the voltage of the high internal resistance battery after each charge and the voltage of the low internal resistance battery after photovoltaic charging power adjustment, and obtain the matching batteries for the high internal resistance batteries. A power balance module, configured to select the batteries to be balanced from the high internal resistance batteries for each charge according to the difference between the voltage of the high internal resistance battery after each charge and the voltage of its matching battery after photovoltaic charging power adjustment, and the voltage of the high internal resistance battery, and perform power balance between the batteries to be balanced and their matching batteries. A virtual power plant regulation module, configured to release the power of the batteries after power balance is completed, obtain the actual discharge power of the photovoltaic energy storage charging and discharging station after each charge according to the current change during the power release process of the batteries, and participate in the regulation of the operation and maintenance of the virtual power plant.

[0017] The present invention has the following beneficial effects: In the first aspect: The batteries for each charge are divided into high and low internal resistance batteries, and battery matching is performed during power balance of the two types of batteries. Considering that unstable light intensity and battery performance differences will cause power imbalance between batteries, the power of the low internal resistance batteries is insufficient to balance the power of the high internal resistance batteries due to internal resistance consumption during the power balance process. According to the difference between the voltage of the high internal resistance battery and the voltage of the low internal resistance battery after photovoltaic charging power adjustment, the two types of batteries are matched, and the matching batteries that can support the power balance of the high internal resistance batteries are selected to ensure the effectiveness of power balance; afterwards, through the two-dimensional evaluation of the difference between the voltage of the high internal resistance battery and the voltage of its matching battery, i.e., dynamic deviation detection, and the voltage of the high internal resistance battery, i.e., reference deviation calibration, the balance demand degree of the high internal resistance batteries can be accurately analyzed, and the batteries to be balanced with a higher balance demand degree are selected from the high internal resistance batteries for power balance, improving the balance efficiency and extending the battery life.

[0018] Second aspect: The photovoltaic charging power can measure the difference in battery power. The voltage of a low internal resistance battery after being adjusted by the photovoltaic charging power reflects its voltage after the energy consumption through the internal resistance of a high internal resistance battery. The matching battery of the high internal resistance battery determined based on this can be effectively matched according to the fluctuation of the light intensity. The difference between the voltage of the high internal resistance battery and the voltage of its matching battery after being adjusted by the photovoltaic charging power reflects the imbalance in energy distribution caused by the internal resistance difference, reflects the significant degree of dynamic deviation of the high internal resistance battery, and indicates the degree of demand for power balance, so that the selected battery to be balanced can dynamically adapt to the fluctuation of the light intensity.

[0019] Through the power balance between the battery to be balanced and its matching battery in this solution, and considering the light fluctuation when screening the battery to be balanced and its matching battery, the power balance efficiency between batteries in the photovoltaic charging and discharging power station is effectively improved, and the influence of the light intensity fluctuation is reduced, making the actual discharged power more accurate, reducing the dispatching error of the virtual power plant, and enhancing the grid's ability to absorb the fluctuating power source caused by the light intensity fluctuation. Brief Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0021] Figure 1 It is a step flow chart of an intelligent control method for a photovoltaic energy storage charging and discharging power station participating in the operation and maintenance of a virtual power plant provided by an embodiment of the present invention; Figure 2 It is a flow chart of a method for obtaining a matching battery of a high internal resistance battery provided by an embodiment of the present invention; Figure 3 It is a system structure diagram of an intelligent control system for a photovoltaic energy storage charging and discharging power station participating in the operation and maintenance of a virtual power plant provided by an embodiment of the present invention; Figure 4 It is a schematic diagram of a computer device of an intelligent control device for a photovoltaic energy storage charging and discharging power station participating in the operation and maintenance of a virtual power plant provided by an embodiment of the present invention. Detailed Embodiments

[0022] To further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation manner, structure, features, and effects of an intelligent regulation method and system for a photovoltaic energy storage charging and discharging power station participating in the operation and maintenance of a virtual power plant. 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.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this invention belongs.

[0024] The following specifically describes the specific solution of an intelligent regulation method and system for a photovoltaic energy storage charging and discharging power station participating in the operation and maintenance of a virtual power plant provided by the present invention in conjunction with the accompanying drawings.

[0025] Embodiment 1: The present invention proposes an intelligent regulation method for a photovoltaic energy storage charging and discharging power station participating in the operation and maintenance of a virtual power plant. Please refer to Figure 1 , which shows the step flow chart of an intelligent regulation method for a photovoltaic energy storage charging and discharging power station participating in the operation and maintenance of a virtual power plant provided by an embodiment of the present invention. The method includes: Step S1: Obtain the photovoltaic charging power of the battery in the photovoltaic energy storage charging and discharging power station during each charging and the voltage of the battery after each charging.

[0026] Install a photovoltaic monitor on the DC side of the photovoltaic array in the photovoltaic energy storage charging and discharging power station, collect the voltage and current output by the busbar box at each moment during the charging cycle of each charging of the battery, take the product of the voltage and current at the same moment as the charging power, and take the average value of the charging powers at all moments as the photovoltaic charging power of each charging; at the same time, configure a voltage sensor and a current sensor for each battery respectively, connect the sensor probe to the battery terminal post, and use the voltage sensor to measure the terminal voltage of each battery at the last moment during the charging cycle as the voltage of the battery after each charging.

[0027] In an implementation manner of the embodiment of the present invention, the data acquisition frequency of the photovoltaic monitor is set to 5 Hz, the data acquisition frequencies of the voltage sensor and the current sensor are both set to 10 Hz, and the duration of the charging cycle is the time required for a normal battery with the same battery specification in the power station to be fully charged. The implementer can set it according to the specific situation.

[0028] It should be noted that since the batteries in the power station adopt a single charger centralized power supply mode, all batteries are connected in parallel and there is no group control, the photovoltaic charging power of all batteries is the same during the same charging; all batteries in the photovoltaic energy storage charging and discharging power station have the same specification.

[0029] Step S2: Based on the voltage of the battery after each charge, divide the batteries into low internal resistance batteries and high internal resistance batteries; according to the difference between the voltage of the high internal resistance battery and the voltage of the low internal resistance battery after photovoltaic charging power adjustment after each charge, match the low internal resistance battery and the high internal resistance battery for each charge to obtain the matching battery of the high internal resistance battery.

[0030] Due to differences in battery manufacturing processes, the performance of different batteries is inconsistent. Batteries with poor performance have a larger internal resistance than normal batteries. Since batteries with poor performance consume more energy during charging, the voltage of batteries with poor performance is smaller within the same charging time. Therefore, the batteries can be divided into low internal resistance batteries and high internal resistance batteries based on voltage.

[0031] When the photovoltaic charging power is high, i.e., when the light is sufficient, the charging requirements of batteries with different performances can be met, and the influence of internal resistance differences on the charging amount is small; when the photovoltaic charging power is low, i.e., when the light is insufficient, the low internal resistance battery can absorb more electric energy due to less energy loss, while the high internal resistance battery has a large energy loss, resulting in the fact that within the same light charging time, the amount of electricity charged into the low internal resistance battery is much greater than that of the high internal resistance battery, exacerbating the imbalance of the electricity between the batteries. Therefore, the photovoltaic charging power can measure the difference in electricity between the batteries.

[0032] To solve the problem of the imbalance of electricity between the batteries caused by the fluctuation of light intensity and the difference in battery performance, it is necessary to transfer the excess electricity of the low internal resistance battery to the high internal resistance battery to achieve electricity balance. It is known that the smaller the photovoltaic charging power, the greater the difference in electricity between the batteries, and the high internal resistance battery with poorer performance will consume more internal resistance energy during electricity balance. To ensure the effectiveness of electricity balance, the low internal resistance battery should ensure that it can still transfer electricity after the internal resistance energy consumption of the high internal resistance battery. The voltage of the low internal resistance battery after photovoltaic charging power adjustment reflects its voltage after the internal resistance energy consumption of the high internal resistance battery. If it is greater than the voltage of the high internal resistance battery, it indicates that electricity balance can still be achieved between the high and low internal resistance batteries considering the internal resistance energy consumption. Match the low internal resistance battery and the high internal resistance battery to ensure the effectiveness of electricity balance and improve the efficiency of electricity balance.

[0033] Step S3: According to the difference between the voltage of the high internal resistance battery after each charge and the voltage of its matching battery after photovoltaic charging power adjustment, and the voltage of the high internal resistance battery, select the battery to be balanced from the high internal resistance batteries for each charge, and perform electricity balance between the battery to be balanced and its matching battery.

[0034] The voltage of a low internal resistance battery after photovoltaic charging power adjustment reflects its voltage after energy consumption by the internal resistance of a high internal resistance battery. The difference between the voltage of the high internal resistance battery and the voltage of its matching battery after photovoltaic charging power adjustment reflects the energy distribution imbalance caused by the internal resistance difference. The greater the difference, the more significant the dynamic deviation of the high internal resistance battery, and the more urgent its demand for charge equalization. When performing charge equalization on the battery, there is an ideal equalization voltage, i.e., the equalization reference. If the difference between the voltage of the high internal resistance battery and the equalization target voltage is greater, it indicates that the deviation degree of the voltage of the high internal resistance battery from the equalization reference is more serious, and the equalization urgency is higher. Therefore, through the two-dimensional evaluation of dynamic deviation monitoring and reference deviation calibration, the equalization demand degree of the high internal resistance battery can be accurately analyzed. Select the battery to be equalized with a higher equalization demand degree from the high internal resistance batteries, perform charge equalization on the battery to be equalized and its matching battery, improve the equalization efficiency, extend the battery life, and dynamically adapt to the light intensity fluctuation.

[0035] It should be noted that there is a line with a control switch between all pairs of batteries in the photovoltaic energy storage charging and discharging power station. When the battery is charging photovoltaically, all control switches are closed; when the battery is performing charge equalization, the control switch of the line between each battery to be equalized and its matching battery is opened, and the other control switches are in the closed state; after the charge equalization is completed, all control switches are closed.

[0036] Step S4: Discharge the battery after the charge equalization is completed. According to the current change of the battery during the discharge process, obtain the actual discharge power of the photovoltaic energy storage charging and discharging power station after each charge, and participate in the regulation of the virtual power plant operation and maintenance.

[0037] The area of the curve of the current change with time during battery discharge and the coordinate axis represents the total charge released by the battery. The total charge that can be released after each light charging, that is, the actual discharge power, can be obtained according to the current change of the battery in the photovoltaic energy storage charging and discharging power station during the discharge process. The specific method for the actual discharge power to participate in the regulation of the virtual power plant operation and maintenance is as follows: First, pack the actual discharge power after each charge into a standardized data packet and upload it to the virtual power plant platform through the IEC 61850 protocol; Second, the platform calculates the dispatchable power window according to the reported power, and dynamically allocates the power usage in combination with the electricity price signal and the grid demand; Finally, after the virtual power grid platform issues an instruction, the photovoltaic energy storage charging and discharging power station dynamically adjusts through the local controller. Reduce the impact of light intensity fluctuation on the actual discharge power, reduce the dispatching error of the virtual power plant, and improve the grid's consumption capacity for the fluctuating power sources caused by light intensity fluctuation.

[0038] Preferably, in some possible implementation manners of the embodiments of the present invention, the battery classification method includes: for each battery after each charge, calculate the concentration value of the voltages of all batteries, and respectively regard the batteries with voltages less than the concentration value as high internal resistance batteries, and the batteries with voltages greater than or equal to the concentration value as low internal resistance batteries.

[0039] It should be noted that since a battery with a larger internal resistance consumes more energy during charging, resulting in a smaller voltage generated within the same charging time, the batteries with voltages less than the concentration value have a larger internal resistance, which are denoted as high internal resistance batteries. In the embodiments of the present invention, the concentration value is the average value, and the voltage concentration level is reflected by the average value of the voltages of all batteries after each charge; the average value, median, mode, etc. can all reflect the central tendency of a set of data, and in other embodiments, the average value can be replaced by the median or mode. The concentration values in other positions in this solution have the same representative meaning as the concentration value in this embodiment.

[0040] Preferably, in some possible implementation manners of the embodiments of the present invention, for the method of obtaining the matching batteries of high internal resistance batteries, please refer to Figure 2 , which shows a flowchart of a method for obtaining the matching batteries of high internal resistance batteries provided by an embodiment of the present invention. The method includes: Step S210: Based on the photovoltaic charging power of each charge, obtain the battery charge separation degree of each charge.

[0041] Preferably, in some possible implementation manners of the embodiments of the present invention, the method for obtaining the battery charge separation degree includes: select the full charge power from the photovoltaic charging powers of several charges before each charge, and the voltages of the batteries after the charge corresponding to the full charge power are all within the full charge voltage range; perform normalization processing on the sum of the differences between the full charge powers of each charge and the photovoltaic charging power respectively, to obtain the battery charge separation degree of each charge.

[0042] It should be noted that the full charge power refers to the photovoltaic charging power at which the battery in the power station can be fully charged. If the photovoltaic charging power of each charge is smaller, the difference between the full charge power and the photovoltaic charging power of each charge is larger, indicating that the illumination of this charge is less sufficient and more accurate, and the charge causes a greater difference in the battery charge, and the battery charge separation degree is larger. In the embodiments of the present invention, the Norm function is used for normalization processing, and other normalization methods such as function transformation can also be selected.

[0043] In an implementation manner of the embodiments of the present invention, the full charge voltage range is set to , where M represents the charging limit voltage of the battery, and 2% can be set according to specific circumstances. It should be noted that the charging limit voltage is the highest voltage threshold that the battery can reach during charging, and it is usually clearly marked in the battery specification sheet or label; when the battery is fully charged, the voltage of the battery may fluctuate due to environmental conditions and system operating status, etc. If the voltage of the battery fluctuates near the charging limit voltage, it can be considered that the battery is fully charged.

[0044] In other embodiments, the maximum value of the photovoltaic charging power in the n times of charging before each charging can also be used as the full-charge charging power, where n is set to 10.

[0045] Step S220: Adjust the voltage of the low internal resistance battery after each charging by using the battery charge separation degree to obtain a corrected voltage; arrange the corrected voltages of the low internal resistance battery and the voltages of the high internal resistance battery after each charging in sequence to obtain a low internal resistance voltage sequence and a high internal resistance voltage sequence; obtain the target equalization voltage for each charging, where the elements in the low internal resistance voltage sequence are greater than the target equalization voltage, and the elements in the high internal resistance voltage sequence are less than the target equalization voltage.

[0046] It should be noted that the greater the battery charge separation degree, the greater the difference in battery charge. The high internal resistance battery consumes more internal resistance energy during charge equalization, and the voltage of the low internal resistance battery is greater than the actual voltage used for charge equalization. Therefore, there is a negative correlation between the battery charge separation degree and the corrected voltage. The method for obtaining the corrected voltage is as follows: perform negative correlation and normalization processing on the battery charge separation degree, and use the processing result to weight the voltage of the low internal resistance battery after each charging to obtain the corrected voltage. In the embodiments of the present invention, the difference between the constant 1 and the battery charge separation degree is used to achieve negative correlation and normalization processing, and other methods such as taking the battery charge separation degree as the exponent of an exponential function with the natural constant as the base can also be used to achieve negative correlation and normalization processing.

[0047] The target equalization voltage is the ideal equalization voltage when the battery charge is equalized, that is, the equalization reference. The high internal resistance battery with a voltage less than the target equalization voltage has insufficient charge and requires charge equalization. The low internal resistance battery with a corrected voltage greater than the target equalization voltage can support the charge transfer to the high internal resistance battery. Matching these batteries can improve the equalization effectiveness. When the light is sufficient, the difference in battery charge, that is, the battery charge separation degree, is small. In order to reduce the ineffective energy transfer, the ideal equalization voltage should be closer to the voltage average value of all batteries; when the light is insufficient, the difference in battery charge, that is, the battery charge separation degree, is large. In order to compensate for the internal resistance energy loss of the high internal resistance battery, the ideal equalization voltage should be greater than the voltage average value of all batteries. In the embodiments of the present invention, the product of the sum value of the battery charge separation degree and the constant 1 and the voltage average value of all batteries after each charging is used as the target equalization voltage, that is, the equalization reference, which helps to improve the equalization effectiveness under low light conditions.

[0048] When equalizing the power of a low - internal - resistance battery with a large correction voltage and a high - internal - resistance battery with a large voltage, the power compensation required by the high - internal - resistance battery is small, but the low - internal - resistance battery will transfer a large amount of power to the high - internal - resistance battery, resulting in over - compensation of the power of the high - internal - resistance battery. To avoid local over - compensation of battery power, the arrangement order of elements in the low - internal - resistance voltage sequence is opposite to that in the high - internal - resistance voltage sequence, so that the equalizing current between the high - internal - resistance battery and its matching battery can overcome the high - internal - resistance loss and complete effective power transfer, avoid over - charging of the high - internal - resistance battery, and extend the battery life.

[0049] Step S230: Set the initial subscript to be measured as 0, and use the low - internal - resistance voltage sequence as the initial voltage sequence to be measured. Determine whether the element corresponding to the subscript to be measured in the voltage sequence to be measured is less than the element corresponding to the subscript to be measured in the high - internal - resistance voltage sequence. If so, delete the element corresponding to the subscript to be measured in the voltage sequence to be measured to obtain a new voltage sequence to be measured. If not, determine the new subscript to be measured, and determine whether the element corresponding to the new subscript to be measured in the new voltage sequence to be measured is less than the element corresponding to the new subscript to be measured in the high - internal - resistance voltage sequence until the new subscript to be measured is greater than the subscript corresponding to the last element in the high - internal - resistance voltage sequence, then stop updating the voltage sequence to be measured, and use the updated voltage sequence to be measured as the balanced voltage sequence that meets the requirements. Determine the matching battery for each high - internal - resistance battery during each charge. The subscript of the element corresponding to each high - internal - resistance battery in the high - internal - resistance voltage sequence is equal to the subscript of the element corresponding to the matching battery in the balanced voltage sequence that meets the requirements.

[0050] As an example, the high - internal - resistance voltage sequence , the low - internal - resistance voltage sequence , represents the voltage of the high - internal - resistance battery, represents the correction voltage of the low - internal - resistance battery. The initial voltage sequence to be measured C0 = D, and the initial subscript to be measured X0 = 0. If V3 at subscript 0 in sequence C0 is less than V1 at subscript 0 in sequence G, it indicates that the power of the low - internal - resistance battery corresponding to V3 after removing the internal - resistance energy consumption is not enough to support the power equalization of the high - internal - resistance battery corresponding to V1. Delete V3 to obtain a new voltage sequence to be measured ; Continue to determine whether V4 at subscript 0 in sequence C1 is less than V1 at subscript 0 in sequence G. If V4 is greater than or equal to V1, it indicates that the power of the low - internal - resistance battery corresponding to V4 after removing the internal - resistance energy consumption can support the power equalization of the high - internal - resistance battery corresponding to V1, and the two batteries are successfully matched. The new subscript to be measured X1 is equal to the sum of the previous subscript to be measured X0 and the constant 1, which is 1. If V5 at subscript 1 in sequence C1 is greater than or equal to V2 at subscript 1 in sequence G, it indicates that the batteries corresponding to V5 and V2 are successfully matched. The new subscript to be measured X2 is equal to the sum of the previous subscript to be measured X1 and the constant 1, which is 2. At this time, the subscript to be measured X2 is greater than the subscript 1 of the last element V2 in sequence C, indicating that all high - internal - resistance batteries have selected the low - internal - resistance batteries for power equalization. Then the sequence As a balanced voltage sequence is satisfied. Therefore, the matching battery for the high internal resistance battery corresponding to V1 is the low internal resistance battery corresponding to V4, and the matching battery for the high internal resistance battery corresponding to V2 is the low internal resistance battery corresponding to V5.

[0051] It should be noted that the subscript in the sequence starts from 0; the new subscript to be measured is equal to the sum of the subscript to be measured before update and the constant 1; since the power station is usually maintained regularly and batteries with poor performance are replaced, the number of low internal resistance batteries is much larger than that of high internal resistance batteries; there is a matching battery only for the high internal resistance battery with a voltage less than the target balanced voltage.

[0052] In other embodiments of the present invention, for the high internal resistance battery with a voltage less than the target balanced voltage and the low internal resistance battery with a corrected voltage greater than the target balanced voltage, the absolute value of the difference between the voltage of the high internal resistance battery and the target balanced voltage is used as the first difference, and the absolute value of the difference between the corrected voltage of the low internal resistance battery and the target balanced voltage is used as the second difference; the absolute value of the difference between the first difference of each high internal resistance battery and the second difference of all low internal resistance batteries is calculated, and the low internal resistance battery corresponding to the minimum absolute value of the difference is selected as the matching battery for each high internal resistance battery.

[0053] Preferably, in some possible implementation manners of the embodiments of the present invention, the method for obtaining the battery to be balanced includes: normalizing the difference between the voltage of each high internal resistance battery after each charge and the target balanced voltage to obtain the balanced reference deviation; obtaining the matching balanced demand degree of the corresponding high internal resistance battery according to the difference between the voltage of each high internal resistance battery and the corrected voltage of its matching battery after each charge, and the balanced reference deviation; selecting the high internal resistance battery corresponding to the matching balanced demand degree less than the preset demand threshold from the high internal resistance batteries charged each time as the battery to be balanced. Wherein, the difference refers to the absolute value of the difference.

[0054] It should be noted that if the difference between the voltage of the high internal resistance battery and the target balanced voltage is greater, the deviation of the voltage of the high internal resistance battery from the balanced reference is greater, and the balanced reference deviation is greater, the more it should be considered to balance the power of the high internal resistance battery. The greater the difference between the voltage of the high internal resistance battery and the corrected voltage of its matching battery, the more significant the dynamic deviation of the high internal resistance battery is, and the more urgent its demand for power balance is; the greater the deviation of the balanced reference, the higher the urgency of the high internal resistance battery for power balance. Therefore, the difference between the voltage of the high internal resistance battery and the corrected voltage of its matching battery and the balanced reference deviation are both positively correlated with the matching balance requirement. In an embodiment of the present invention, the product of the absolute value of the difference between the voltage of each high internal resistance battery and the corrected voltage after each charge and the balanced reference deviation is normalized to obtain the matching balance requirement. The battery to be balanced has a greater demand for power balance. In the embodiment of the present invention, the Norm function is used for normalization, and other normalization methods can also be selected, such as function conversion, maximum and minimum normalization, etc., which are not limited here. Only the batteries to be balanced are selected from the high internal resistance batteries whose voltage is less than the target balancing voltage.

[0055] In an implementation of the embodiment of the present invention, the preset demand threshold is an empirical value of 0.4.

[0056] Preferably, in some possible implementations of the embodiments of the present invention, the method for power balancing includes: for each battery to be balanced, discharging a matching battery of the battery to be balanced, transferring excess power to the battery to be balanced, respectively obtaining the discharge voltage of the battery to be balanced and its matching battery at each moment in the power transfer process, and when the discharge voltage difference between the battery to be balanced and its matching battery at the same moment is not within the balancing requirement range, continuing the power transfer until the discharge voltage difference is within the balancing requirement range, stopping the power transfer, and completing the power balancing of the battery after each charging.

[0057] It should be noted that the voltage of the battery at each moment during the battery balancing process is collected by the voltage sensor and recorded as the discharge voltage. When the discharge voltage difference between the battery to be balanced and its matching battery at the same moment is not within the balancing requirement range, it indicates that the two batteries have not completed battery balancing, otherwise it indicates that battery balancing is completed. The difference refers to the absolute value of the difference.

[0058] In one implementation of the embodiment of the present invention, the balance requirement range is set to , where B represents the target balancing voltage for each charge.

[0059] Preferably, in some possible implementation manners of the embodiments of the present invention, the method for obtaining the actual discharged power includes: obtaining the discharge current of each battery at each moment during the power release period, calculating the average value of the discharge currents at the same moment, performing curve fitting on the average values corresponding to all moments during the power release period to obtain a discharge current function; integrating the discharge current function during the discharge period, and taking the product of the integration result and the total number of batteries as the actual discharged power of the photovoltaic energy storage charging and discharging power station after each charge.

[0060] It should be noted that a current sensor is used to collect the current of the battery at each moment during the power release period, which is recorded as the discharge current. The battery discharge current changes non-linearly with time. The discharge current function is a current change model of the battery discharge process. The integration of the discharge current function during the discharge period reflects the power that a single battery can release. The actual discharged power represents the total power that all batteries in the power station can release after each photovoltaic charge. The specific fitting process is as follows: establish a two-dimensional coordinate system with time as the horizontal axis and current as the vertical axis, and select the least squares method to perform curve fitting on the coordinate points corresponding to the average values of the discharge currents of all batteries at the same moment during the power release period for each charge in the two-dimensional coordinate system.

[0061] In one implementation manner of the embodiments of the present invention, the end moment of the power release period is the moment when the battery that first reaches the cut-off voltage reaches the cut-off voltage. The cut-off voltage is the lowest voltage threshold that the battery can reach during discharge, and it is usually clearly marked in the battery specification or label.

[0062] So far, the present invention is completed.

[0063] Embodiment 2: The present invention provides an intelligent control system for a photovoltaic energy storage charging and discharging power station to participate in the operation and maintenance of a virtual power plant. Please refer to Figure 3 , which shows the system structure diagram of an intelligent control system for a photovoltaic energy storage charging and discharging power station to participate in the operation and maintenance of a virtual power plant provided by an embodiment of the present invention. The system includes: A data acquisition module 510, configured to obtain the photovoltaic charging power of the battery in the photovoltaic energy storage charging and discharging power station during each charge and the voltage of the battery after each charge; A battery matching module 520, configured to divide the batteries into low internal resistance batteries and high internal resistance batteries based on the voltage of the battery after each charge; according to the difference between the voltage of the high internal resistance battery and the voltage of the low internal resistance battery after photovoltaic charging power adjustment after each charge, match the low internal resistance battery and the high internal resistance battery for each charge to obtain the matching battery of the high internal resistance battery; The power balance module 530 is used to select the battery to be balanced from the high internal resistance batteries charged each time according to the difference between the voltage of the high internal resistance battery and the voltage of its matching battery after photovoltaic charging power adjustment each time after charging, and the voltage of the high internal resistance battery, and perform power balance between the battery to be balanced and its matching battery; The virtual power plant control module 540 is used to release the power of the battery after the power balance is completed, obtain the actual discharge power of the photovoltaic energy storage charging and discharging power station each time after charging according to the current change during the power release process of the battery, and participate in the control of the operation and maintenance of the virtual power plant.

[0064] It should be noted that: the device provided in the above embodiment is only illustrated by the division of the above functional modules. In actual application, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the computer device is divided into different functional modules to complete all or part of the functions described above. In addition, the intelligent control system for a photovoltaic energy storage charging and discharging power station participating in the operation and maintenance of a virtual power plant provided in the above embodiment and the embodiment of the intelligent control method for a photovoltaic energy storage charging and discharging power station participating in the operation and maintenance of a virtual power plant belong to the same concept. The specific implementation process can be seen in the method embodiment and will not be repeated here.

[0065] Embodiment 3: The present invention also provides a schematic diagram of a computer device of an intelligent control device for a photovoltaic energy storage charging and discharging power station participating in the operation and maintenance of a virtual power plant. Please refer to Figure 4 This computer device includes a memory 601, a processor 602, and a computer program 603 stored in the memory 601 and running on the processor 602. Among them, when the processor 602 executes the computer program 603, the computer device can execute any one of the intelligent control methods for a photovoltaic energy storage charging and discharging power station participating in the operation and maintenance of a virtual power plant introduced above.

[0066] In addition, the embodiment of the present application also protects a device, which may include a memory and a processor. Among them, an executable program code is stored in the memory, and the processor is used to call and execute the executable program code to execute an intelligent control method for a photovoltaic energy storage charging and discharging power station participating in the operation and maintenance of a virtual power plant provided in the embodiment of the present application.

[0067] In this embodiment, the device can be divided into functional modules according to the above method example. For example, it can correspond to each functional module, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is illustrative, only a logical function division, and there may be other division methods in actual implementation.

[0068] In the case of dividing each module according to the corresponding functions, the device may further include a communication module, a signal analysis module, a complexity analysis module, a positioning module, etc. It should be noted that all relevant contents of each step involved in the above method embodiment can be cited in the function description of the corresponding functional module, and will not be elaborated here.

[0069] It should be understood that the device provided in this embodiment is used to execute the above intelligent regulation method for a photovoltaic energy storage charging and discharging power station to participate in the operation and maintenance of a virtual power plant, so the same effect as the above implementation method can be achieved.

[0070] In the case of adopting an integrated unit, the device may include a processing module and a storage module. Among them, when the device is applied to a device, the processing module can be used to control and manage the actions of the device. The storage module can be used to support the device to execute mutual program codes, etc.

[0071] Among them, the processing module can be a processor or a controller, which can implement or execute various exemplary logic blocks, modules and circuits included in combination with the disclosure content of the present application. The processor can also be a combination that realizes computing functions, such as including a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module can be a memory.

[0072] Embodiment 4: This embodiment also provides a computer-readable storage medium, in which computer program code is stored. When the computer program code runs on a computer, the computer is caused to execute the above relevant method steps to implement the intelligent regulation method for a photovoltaic energy storage charging and discharging power station to participate in the operation and maintenance of a virtual power plant provided in the above embodiment.

[0073] Embodiment 5: This embodiment also provides a computer program product. When the computer program product runs on a computer, the computer is caused to execute the above relevant steps to implement the intelligent regulation method for a photovoltaic energy storage charging and discharging power station to participate in the operation and maintenance of a virtual power plant provided in the above embodiment.

[0074] Among them, the device, computer-readable storage medium or computer program product provided in this embodiment are all used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be elaborated here.

[0075] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of devices or units can be in electrical, mechanical or other forms.

[0076] It should be noted that the above sequence of embodiments of the present invention is only for description and does not represent the superiority or inferiority of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0077] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and the differences between each embodiment and other embodiments are emphasized.

Claims

1. An intelligent regulation method for a photovoltaic energy storage charging and discharging power station to participate in the operation and maintenance of a virtual power plant, characterized in that The method includes: Obtaining the photovoltaic charging power of the battery in the photovoltaic energy storage charging and discharging station during each charging and the voltage of the battery after each charging; Based on the voltage of the battery after each charging, dividing the battery into a low internal resistance battery and a high internal resistance battery; according to the difference between the voltage of the high internal resistance battery after each charging and the voltage of the low internal resistance battery after adjustment by the photovoltaic charging power, matching the low internal resistance battery and the high internal resistance battery for each charging to obtain the matching battery of the high internal resistance battery; According to the difference between the voltage of the high internal resistance battery after each charging and the voltage of its matching battery after adjustment by the photovoltaic charging power, and the voltage of the high internal resistance battery, selecting the battery to be balanced from the high internal resistance batteries for each charging, and performing charge equalization between the battery to be balanced and its matching battery; Discharging the battery after charge equalization is completed, and according to the current change during the discharging process of the battery, obtaining the actual discharging power of the photovoltaic energy storage charging and discharging station after each charging, and participating in the regulation of the virtual power plant operation and maintenance.

2. The intelligent regulation method for a photovoltaic energy storage charging and discharging power station to participate in the operation and maintenance of a virtual power plant according to claim 1, characterized in that The obtaining of the matching battery of the high internal resistance battery includes: Based on the photovoltaic charging power for each charging, obtaining the battery charge separation degree for each charging; Adjusting the voltage of the low internal resistance battery after each charging by using the battery charge separation degree to obtain a corrected voltage; arranging the corrected voltages of the low internal resistance batteries after each charging and the voltages of the high internal resistance batteries in sequence to obtain a low internal resistance voltage sequence and a high internal resistance voltage sequence respectively; obtaining the target equalization voltage for each charging, where the elements in the low internal resistance voltage sequence are greater than the target equalization voltage, and the elements in the high internal resistance voltage sequence are less than the target equalization voltage; Setting the initial subscript to be measured as 0, and using the low internal resistance voltage sequence as the initial voltage sequence to be measured; judging whether the element corresponding to the subscript to be measured in the voltage sequence to be measured is less than the element corresponding to the subscript to be measured in the high internal resistance voltage sequence. If so, deleting the element corresponding to the subscript to be measured in the voltage sequence to be measured to obtain a new voltage sequence to be measured; if not, determining a new subscript to be measured, and judging whether the element corresponding to the new subscript to be measured in the new voltage sequence to be measured is less than the element corresponding to the new subscript to be measured in the high internal resistance voltage sequence, until the new subscript to be measured is greater than the subscript corresponding to the last element in the high internal resistance voltage sequence, then stopping updating the voltage sequence to be measured, and using the updated voltage sequence to be measured as the satisfied equalization voltage sequence; Determining the matching battery of each high internal resistance battery for each charging, where the subscript of the element corresponding to each high internal resistance battery in the high internal resistance voltage sequence is equal to the subscript of the corresponding element of the matching battery in the satisfied equalization voltage sequence.

3. The intelligent regulation method for the operation and maintenance of a virtual power plant participated by a photovoltaic energy storage charging and discharging power station according to claim 2, wherein, The obtaining of the battery charge separation degree for each charging includes: Selecting the full charge power from the photovoltaic charging powers of several previous chargings before each charging, and the voltages of the batteries after the corresponding chargings of the full charge power are all within the full charge voltage range; Normalizing the sum of the differences between each full charge power for each charging and the photovoltaic charging power respectively to obtain the battery charge separation degree for each charging.

4. The intelligent regulation method for the operation and maintenance of a virtual power plant participated by a photovoltaic energy storage charging and discharging power station according to claim 2, characterized in that, The selecting of the battery to be balanced from the high internal resistance batteries for each charging includes: Normalizing the difference between the voltage of each high internal resistance battery after each charging and the target equalization voltage to obtain the equalization reference deviation degree; Obtain the matching equalization demand degree of the corresponding high internal resistance battery according to the difference between the voltage of each high internal resistance battery after each charge and the corrected voltage of its matching battery, and the deviation degree of the equalization reference; select the high internal resistance battery corresponding to the matching equalization demand degree less than the preset demand threshold from the high internal resistance batteries charged each time as the battery to be equalized.

5. The intelligent regulation method for a photovoltaic energy storage charging and discharging power station to participate in the operation and maintenance of a virtual power plant according to claim 2, characterized in that, The target equalization voltage is equal to the product of the sum of the battery charge separation degree and the constant 1 and the central value of the voltages of all batteries after each charge.

6. The intelligent regulation method for the operation and maintenance of a virtual power plant participated by a photovoltaic energy storage charging and discharging power station according to claim 1, wherein, The method for obtaining the actual discharge power includes: Obtain the discharge current of all batteries at each moment during the power release period, calculate the average value of the discharge currents at the same moment, perform curve fitting on the average values corresponding to all moments during the power release period to obtain the discharge current function; integrate the discharge current function during the discharge period, and take the product of the integration result and the total number of batteries as the actual discharge power of the photovoltaic energy storage charging and discharging station after each charge.

7. An intelligent regulation method for a photovoltaic energy storage charging and discharging power station to participate in the operation and maintenance of a virtual power plant, characterized in that, The power equalization of the battery to be equalized and its matching battery includes: For each battery to be equalized, discharge the matching battery of the battery to be equalized, transfer the excess power to the battery to be equalized, respectively obtain the discharge voltages of the battery to be equalized and its matching battery at each moment during the power transfer process. When the difference in the discharge voltages of the battery to be equalized and its matching battery at the same moment is not within the equalization requirement range, continue the power transfer until the difference in the discharge voltages is within the equalization requirement range, and then stop the power transfer to complete the power equalization of the battery after each charge.

8. An intelligent regulation method for a photovoltaic energy storage charging and discharging power station to participate in the operation and maintenance of a virtual power plant, characterized in that, The division of the battery into low internal resistance batteries and high internal resistance batteries includes: For the battery after each charge, calculate the central value of the voltages of all batteries, and respectively take the batteries with voltages less than the central value as high internal resistance batteries, and the batteries with voltages greater than or equal to the central value as low internal resistance batteries.

9. The intelligent regulation method for the operation and maintenance of a virtual power plant participated by a photovoltaic energy storage charging and discharging power station according to claim 2, wherein, The battery charge separation degree and the corrected voltage are negatively correlated.

10. An intelligent regulation method for a photovoltaic energy storage charging and discharging power station to participate in the operation and maintenance of a virtual power plant, characterized in that, The number of low internal resistance batteries charged each time is greater than the number of high resistance batteries.

11. The intelligent regulation method for a virtual power plant operation and maintenance participated by a photovoltaic energy storage charging and discharging power station according to claim 2, wherein, The arrangement order of the elements in the low internal resistance voltage sequence is opposite to that in the high internal resistance voltage sequence.

12. An intelligent regulation system for a photovoltaic energy storage charging and discharging power station to participate in the operation and maintenance of a virtual power plant, characterized in that, The system includes: A data acquisition module for obtaining the photovoltaic charging power of the battery in the photovoltaic energy storage charging and discharging station during each charge and the voltage of the battery after each charge; A battery matching module for dividing the battery into low internal resistance batteries and high internal resistance batteries based on the voltage of the battery after each charge; matching the low internal resistance batteries and high internal resistance batteries charged each time according to the difference between the voltage of the high internal resistance battery and the voltage of the low internal resistance battery adjusted by the photovoltaic charging power, and obtaining the matching battery of the high internal resistance battery; A power equalization module for selecting the battery to be equalized from the high internal resistance batteries charged each time according to the difference between the voltage of the high internal resistance battery after each charge and the voltage of its matching battery adjusted by the photovoltaic charging power, and the voltage of the high internal resistance battery, and performing power equalization on the battery to be equalized and its matching battery; A virtual power plant control module is used to release the power of the battery after the power balance is completed. According to the current change of the battery during the power release process, the actual discharge power of the photovoltaic energy storage charging and discharging station after each charge is obtained, and it participates in the control of the operation and maintenance of the virtual power plant.

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