Active voltage cooperative control method and system of photovoltaic energy storage integrated generator

Abstract

The present application belongs to the technical field of photovoltaic energy storage collaborative control, and provides an active voltage collaborative control method and system for a photovoltaic energy storage integrated generator. The active voltage collaborative control method for the photovoltaic energy storage integrated generator comprises analyzing and calculating photovoltaic power representing the power generation capacity of the photovoltaic power generation system, load power representing the load demand, residual capacity index representing the power reserve of the battery management system, and load stability index representing the voltage state of the power grid; the photovoltaic power and the residual capacity index are compared with the load power, and the load stability index is compared with a preset standard range; whether to issue a corresponding level of early warning signal is determined according to the comparison result; when the corresponding level of early warning signal is issued, the corresponding collaborative control strategy is executed until the photovoltaic power generation system, the battery management system and the power grid detection system are in a normal working state, which can realize comprehensive analysis and maintenance of the power grid, the photovoltaic system and the energy storage system.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photovoltaic energy storage collaborative control, and particularly relates to an active voltage collaborative control method and system for a photovoltaic energy storage integrated generator. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] In a conventional photovoltaic energy storage integrated generator, there are a photovoltaic power generation system, an energy storage battery and a power grid. The photovoltaic power generation system converts light energy to realize power generation, the energy storage battery stores electricity, and the power grid realizes power transmission and consumption. When calculating the residual capacity of the energy storage battery, a related sensor or detection system is usually used to monitor the residual capacity of the energy storage battery. However, in actual use, the service life of the energy storage battery and external factors will affect the energy storage effect of the energy storage battery. If the energy storage battery is used for a long time or in a poor environment, the data obtained by real-time monitoring will be greatly discounted, which will affect subsequent decision-making and regulation. The system designed at present cannot comprehensively evaluate and analyze the photovoltaic energy storage integrated generator, which will hinder the subsequent control adjustment operation to some extent. SUMMARY

[0004] To solve the above technical problems, the application provides an active voltage collaborative control method and system for a photovoltaic energy storage integrated generator, which can comprehensively analyze and maintain the power grid, the photovoltaic system and the energy storage system.

[0005] To achieve the above purpose, the application adopts the following technical solutions:

[0006] The first aspect of the application provides an active voltage collaborative control method for a photovoltaic energy storage integrated generator.

[0007] In one or more embodiments, an active voltage collaborative control method for a photovoltaic energy storage integrated generator is provided, which comprises:

[0008] Obtaining power generation data of a photovoltaic power generation system, battery data of a battery management system and power grid data of a power grid detection system;

[0009] According to the above data, a photovoltaic power generation power representing the power generation capacity of the photovoltaic power generation system, a load power representing the load demand, a residual capacity index representing the energy storage capacity of the battery management system and a load stability index representing the voltage state of the power grid are obtained;

[0010] The photovoltaic power and the residual capacity index are compared with the load power respectively, and the load stability index is compared with a preset standard range, and a corresponding level of early warning signal is determined according to the comparison result;

[0011] When the corresponding level of early warning signal is sent, the corresponding cooperative control strategy is executed until the photovoltaic power generation system, the battery management system and the grid detection system are in normal working state.

[0012] As an embodiment, if the photovoltaic power is greater than the load power, and the difference between the photovoltaic power and the load power exceeds a preset first loss threshold, it indicates that the photovoltaic power meets the load requirement, otherwise a first level of early warning signal is sent.

[0013] As an embodiment, the first level of early warning signal corresponds to a first level of control strategy, and the first level of control strategy includes any one or a combination of several of the following: increasing the standby photovoltaic generator set linkage start, and reducing the load demand.

[0014] As an embodiment, if the residual capacity index is greater than the load power, and the difference between the residual capacity index and the load power exceeds a preset second loss threshold, it indicates that the energy storage battery meets the energy supply requirement, otherwise a second level of early warning signal is sent.

[0015] As an embodiment, the second level of early warning signal corresponds to a second level of control strategy, and the second level of control strategy includes any one or a combination of several of the following: increasing the standby energy storage battery and adjusting the use of other energy sources.

[0016] As an embodiment, if the load stability index is within the standard range, it indicates that the grid load is currently in a stable state, otherwise a third level of early warning signal is sent.

[0017] As an embodiment, the third level of early warning signal corresponds to a third level of control strategy, and the third level of control strategy is to increase the reactive power regulation.

[0018] As an embodiment, the calculation process of the residual capacity index is as follows:

[0019] According to the health state parameter, a health state analysis calculation model is constructed to generate a health state evaluation value;

[0020] According to the residual capacity in the energy storage battery and the obtained rated capacity of the energy storage battery, a residual capacity percentage is calculated.

[0021] According to the multiplication of the residual capacity percentage and the corrected health state evaluation value, a residual capacity index is calculated.

[0022] As an embodiment, the calculation process of the load stability index is as follows:

[0023] The load utilization rate is calculated by using a ratio of an average load in a preset time period to a maximum load capacity in the preset time period;

[0024] The maximum load difference between adjacent time points in a preset time period is calculated, and a fluctuation difference between the maximum load difference between adjacent time points and the maximum load capacity in the preset time period is calculated.

[0025] After the load utilization rate and the fluctuation difference are weighted and summed, and after correction by using a set constant, a load stability index is obtained.

[0026] The second aspect of the present application provides an active voltage cooperative control system of a photovoltaic energy storage integrated generator.

[0027] In one or more embodiments, an active voltage cooperative control system of a photovoltaic energy storage integrated generator comprises:

[0028] A data acquisition module is configured to acquire power generation data of a photovoltaic power generation system, battery data of a battery management system, and grid data of a grid detection system.

[0029] An analysis and evaluation module is configured to obtain, according to the acquired data, a photovoltaic power generation power representing a power generation capacity of the photovoltaic power generation system, a load power representing a load demand, a residual capacity index representing an energy reserve of the battery management system, and a load stability index representing a grid voltage state.

[0030] A comparison and judgment module is configured to compare the photovoltaic power generation power and the residual capacity index with the load power, respectively, and compare the load stability index with a preset standard range, and determine whether to issue a corresponding level of early warning signal according to a comparison result.

[0031] A cooperative control module is configured to execute a corresponding cooperative control strategy when the corresponding level of early warning signal is issued, until the photovoltaic power generation system, the battery management system, and the grid detection system are all in a normal working state.

[0032] Compared with the prior art, the present application has the following advantages:

[0033] The present application monitors the photovoltaic power generation system, the battery management system, and the grid detection system, and uses the index quantities representing the running states of the corresponding systems obtained by the monitoring to actively determine whether to issue an early warning signal by comparison of the index quantities, and finally executes a corresponding cooperative control strategy according to the level of the early warning signal, so as to ensure that the entire system group and the corresponding generator can maintain normal and stable operation. BRIEF DESCRIPTION OF DRAWINGS

[0034] The accompanying drawings, which form a part of this specification, are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification. The embodiments of the application, together with its

[0035] Figure 1 is a flowchart of a method for active voltage collaborative control of a photovoltaic energy storage integrated generator according to an embodiment of the application;

[0036] Figure 2 is a schematic diagram of a system structure for active voltage collaborative control of a photovoltaic energy storage integrated generator according to an embodiment of the application;

[0037] Figure 3 is a schematic diagram of an electronic device according to an embodiment of the application. DETAILED DESCRIPTION

[0038] The application will be further described below in connection with the drawings and embodiments.

[0039] It should be noted that the following detailed description is merely exemplary and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0040] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0041] Terminology:

[0042] Photovoltaic energy storage, also known as a photovoltaic energy storage system, is a combination of solar photovoltaic power generation and energy storage technology, which stores the electrical energy generated by photovoltaic power generation to supply power when needed.

[0043] A photovoltaic energy storage system typically consists of two parts: a photovoltaic power generation system and an energy storage system. The photovoltaic power generation system converts light energy into electrical energy through a solar photovoltaic panel, and then converts direct current into alternating current through an inverter to supply power to electrical equipment.

[0044] The components of a photovoltaic power generation system include photovoltaic panels, brackets, cables, inverters, etc. The energy storage system is used to store the electrical energy generated by photovoltaic power generation to supply power during periods of solar energy unavailability or peak demand.

[0045] The energy storage system can select different technologies, including battery energy storage, heat storage energy storage, hydrogen energy storage, etc. Among them, the battery energy storage is the most commonly used photovoltaic energy storage technology at present, and the commonly used battery types include lithium ion battery, sodium-sulfur battery, lead-acid battery, etc.

[0046] The photovoltaic energy storage control refers to the intelligent control and optimized management process of the photovoltaic power generation system and the energy storage battery component, and specifically includes photovoltaic power generation power control: according to factors such as light intensity and environmental conditions, the working state of the photovoltaic power generation system is controlled to achieve the best power generation efficiency, and the output power of the photovoltaic power generation system is controlled by adjusting the working voltage and current of the photovoltaic module.

[0047] Figure 1 is a flowchart of an active voltage cooperative control method of a photovoltaic energy storage integrated generator in an embodiment of the present application, as Figure 1 The active voltage cooperative control method of the photovoltaic energy storage integrated generator in the embodiment can include:

[0048] S101, obtaining the power generation data of the photovoltaic power generation system, the battery data of the battery management system, and the grid data of the grid detection system;

[0049] S102, obtaining the photovoltaic power generation power representing the power generation capacity of the photovoltaic power generation system, the load power representing the load demand, the residual capacity index representing the energy reserve of the battery management system, and the load stability index representing the grid voltage state according to the above data;

[0050] S103, comparing the photovoltaic power generation power and the residual capacity index with the load power respectively, and comparing the load stability index with the preset standard range, and determining whether to issue a corresponding level of warning signal according to the comparison result;

[0051] S104, when the corresponding level of warning signal is issued, the corresponding cooperative control strategy is executed until the photovoltaic power generation system, the battery management system and the grid detection system are in normal working state.

[0052] The embodiment monitors the photovoltaic power generation system, the battery management system and the grid detection system, and uses the index quantities representing the running states of the corresponding systems obtained by monitoring to actively determine whether to issue a warning signal, and finally executes the corresponding cooperative control strategy according to the level of the warning signal, so that the entire system group and the corresponding generator can maintain normal and stable operation.

[0053] In step S101, the photovoltaic power generation system includes a photovoltaic panel assembly, which includes a photovoltaic panel body, an inverter and a controller; the battery management system includes a storage battery assembly, which includes a plurality of storage batteries connected in series with each other; and the power grid detection system includes a power grid and a monitoring device matched with the power grid.

[0054] The power generation data in step S101 is photovoltaic power generation data, including current, voltage and power generated during photovoltaic power generation; for example, the data of current, voltage and power sensors are read from the interface of the photovoltaic cell assembly.

[0055] The battery data in step S101 includes the remaining capacity in the storage battery and a health state parameter for reflecting the health state of the storage battery. The health state parameter refers to some performance indicators of the storage battery, including cycle life, internal resistance, capacity attenuation rate and temperature difference; the remaining capacity can be directly obtained by the battery management system matched with the storage battery.

[0056] Among them, the cycle life, internal resistance and capacity attenuation rate are important performance indicators of the storage battery, which can be obtained in advance through experiments.

[0057] Cycle life: the cycle life refers to the number of charge and discharge cycles that the storage battery can withstand, and is the evaluation value of the cycle life. In order to obtain the evaluation value of the cycle life, the following steps can be taken:

[0058] Set the cycle test settings of the experiment, for example, specify the cycle depth, i.e. the range of power change of the storage battery during each charge and discharge process, the charge and discharge current and the temperature condition; perform continuous charge and discharge cycle experiments and record the capacity attenuation after each cycle;

[0059] For example, measure the capacity of the storage battery after each cycle, compare it with the initial capacity, and calculate the percentage of capacity attenuation; continue to perform cycle charging and discharging until the capacity of the storage battery attenuates to the preset cycle life limit, at which time the value of the cycle life can be evaluated.

[0060] Suppose the cycle life of a certain storage battery is defined as the cycle life when its capacity attenuates to 80% of the initial capacity, the cycle life can be recorded by continuous charge and discharge experiments. When the capacity attenuates to 80%, the corresponding cycle number is the evaluation value of the cycle life.

[0061] Internal resistance: the internal resistance is the internal resistance of the storage battery, which reflects the resistance of charge transfer in the battery, and is the evaluation value of the internal resistance; in order to obtain the evaluation value of the internal resistance, the following steps can be taken:

[0062] The AC impedance spectroscopy experiment is performed by applying AC voltage signals of different frequencies and amplitudes to the energy storage battery, measuring the response signals of the battery such as current and voltage; according to the measured response signals, the impedance values of the energy storage battery at different frequencies can be obtained; the impedance spectroscopy data are analyzed, especially in the low frequency part, through appropriate mathematical models and fitting algorithms, the equivalent circuit parameters of the energy storage battery can be obtained, including the evaluation value of the internal resistance;

[0063] In the AC impedance spectroscopy experiment, by applying a series of AC voltage signals of different frequencies to the energy storage battery, the response current and voltage are measured, and then according to the measured response data, using the equivalent circuit model and complex impedance analysis method, the internal resistance of the energy storage battery can be calculated from the impedance spectrum.

[0064] Capacity decay rate: the capacity decay of the energy storage battery refers to the decrease of the battery relative to the initial capacity during use, which is the percentage of capacity decay, and the steps for calculation are as follows:

[0065] Set the periodic capacity test, for example, perform charge and discharge test on the energy storage battery every certain period of time; in the periodic test, the capacity of the energy storage battery is measured and compared with the initial capacity to calculate the percentage of capacity decay, and the average of the percentages after a predetermined number of times is calculated, which represents the capacity decay rate;

[0066] In the periodic capacity test, the energy storage battery is cycled by charging to full and discharging to critical capacity, and the capacity after each charge is recorded. With the increase of use and charge and discharge times, the capacity gradually decays. By comparing the capacity test results with the initial capacity and calculating the average percentage of capacity decay each time, the capacity decay of the energy storage battery can be evaluated.

[0067] The temperature difference represents the difference between the outside and the inside of the energy storage battery, which is always positive. After detecting the temperature D1 of the environment where the energy storage battery is located by the corresponding temperature sensor, the temperature D2 detected by the temperature sensor configured in the energy storage battery is calculated to obtain the temperature difference: temperature difference = |D1-D2|.

[0068] The grid data includes grid current and grid voltage, which can be directly read from the grid monitoring device.

[0069] It should be noted that for photovoltaic power generation data and power grid data, the current, voltage and power read by the corresponding device or sensor, the power is directly read, and then the product of the current and voltage can be calculated to obtain the predetermined power. Compare the predetermined power with the read power. If the difference exceeds the corresponding standard range, an alarm can be given. Specifically, the corresponding device or sensor can be matched with a warning device to alert the staff that the device or sensor has a reading error or damage problem, so as to facilitate subsequent replacement operation.

[0070] In step S102, the power generation capacity of the photovoltaic power generation system is represented by photovoltaic power generation power, and the load demand is represented by load power.

[0071] Power generation power and load power analysis: based on the collected power generation data and power grid data, real-time analysis of power and load is performed to evaluate the power generation capacity of the photovoltaic power generation system and the load condition of the power grid.

[0072] The calculation formulas of photovoltaic power generation power Pg and load power Fg are as follows:

[0073] Pg = Id * Ud (1)

[0074] In the formula, Id represents the current of the photovoltaic cell module, and Ud represents the voltage of the photovoltaic cell module.

[0075] Fg = Iw * Uw (2)

[0076] In the formula, Iw represents the grid current, and Uw represents the grid voltage.

[0077] Assuming that the current of the photovoltaic cell module is 10A, the voltage is 40V, the grid voltage is 220V, and the grid current is 4A, the photovoltaic power generation power and the load power demand can be calculated as follows:

[0078] Photovoltaic power generation power = 10A * 40V = 400W, load power demand = 220V * 4A = 880W. By comparing the size of photovoltaic power generation power and load power demand, it can be determined whether the power generation capacity of the photovoltaic power generation system meets the load demand. In the above example, the photovoltaic power generation power is 400W, and the load power demand is 880W. The power generation capacity is insufficient to meet the load demand.

[0079] The energy reserve of the energy storage battery module is represented by a residual capacity index. Specifically, the calculation process of the residual capacity index is as follows:

[0080] Step a1: according to the health state parameter, a health state analysis calculation model is constructed to generate a health state evaluation value;

[0081] Let the health state evaluation value be Has:

[0082] Has= b1*(a1*Xs+a2*Nz+a3*Rs)+b2*Wc(3)

[0083] In the formula, Xs, Nz, and Rs represent cycle life, internal resistance, and capacity attenuation rate, respectively, Wc represents temperature difference, and Wc > 0, a1, a2, and a3 are weight coefficients of cycle life, internal resistance, and capacity attenuation rate, respectively, (a1*Xs+a2*Nz+a3*Rs) represents a health assessment index, b1 and b2 are weight coefficients of the health assessment index and the temperature difference, respectively, and the value ranges of a1, a2, a3, b1, and b2 are all 0-1, and a1 > a2 > a3 > 0, b1 > b2 > 0.

[0084] It should be noted that the weight coefficient is the importance of each health state parameter, which is set according to the actual situation. The difference between the temperature of the energy storage battery during real-time charging and the ambient temperature will affect the health state of the energy storage battery. High temperature environment will accelerate the chemical reaction inside the battery, causing the battery capacity to decay faster, and also increasing the internal resistance of the battery, reducing the battery performance; therefore, considering the temperature difference can more accurately evaluate the health state of the energy storage battery; in each formula of the present application, the data used can be dimensionless processed before calculation to remove the units of each data, facilitating comprehensive calculation and processing.

[0085] Generally, the higher the cycle life, the lower the internal resistance, and the smaller the capacity attenuation, the higher the health state evaluation value of the energy storage battery; in the weighted calculation, the weight can be set according to the importance of each health state parameter, and the weight setting can be based on expert experience, historical data or reliability analysis; the weight setting needs to be adjusted according to the specific situation, so that the health assessment index can more accurately reflect the actual health status of the energy storage battery.

[0086] For example, assuming that the cycle life has a relatively important influence on the health state, the weight is set to 0.6; the internal resistance has a relatively minor influence on the health state, the weight is set to 0.3; the capacity attenuation also has a relatively minor influence on the health state, the weight is set to 0.1; the health assessment index = cycle life * 0.6 + internal resistance * 0.3 + capacity attenuation * 0.1; through such weighted calculation, the importance of different health state parameters can be considered comprehensively, and a more accurate health state evaluation value of the energy storage battery can be obtained; the weight setting should be adjusted according to the actual situation to ensure that the evaluation result can better reflect the state of the energy storage battery.

[0087] In addition, assuming that the internal temperature of a certain energy storage battery during charging is 40°C, and the external environment temperature is 25°C; according to the previously mentioned parameters such as cycle life, internal resistance and capacity decay, we can consider that the battery has a good health status at normal temperature; however, due to the large temperature difference, temperature difference = 40°C - 25°C = 15°C, which may cause the capacity decay of the battery to accelerate and the internal resistance to increase, such a temperature difference may indicate that the battery is working in a high temperature environment, which may have a negative impact on the life and performance of the battery; therefore, when calculating the health status evaluation value, temperature compensation can be considered to be introduced, by considering the temperature difference as a compensation coefficient according to the battery specifications and performance curve, and the influence of temperature on the performance of the battery, and the compensation coefficient is weighted and summed with the comprehensive value obtained by other health status parameters to obtain a more accurate health status evaluation value.

[0088] Step a2: Calculate the remaining capacity percentage according to the remaining capacity in the energy storage battery and the rated capacity of the energy storage battery obtained.

[0089] Let the remaining capacity percentage be Prc:

[0090] Prc = S1 / Er*100% (4)

[0091] In the formula, Sl represents the current remaining capacity, and Er represents the rated capacity;

[0092] For example: assuming that the rated capacity of the energy storage battery is 100 kWh, and the current capacity is 80 kWh, the remaining capacity percentage can be calculated as: remaining capacity percentage = 80 kWh / 100 kWh*100% = 80%.

[0093] Step a3: Calculate the remaining capacity index by multiplying the remaining capacity percentage and the corrected health status evaluation value.

[0094] According to the health status evaluation value Hsa and the remaining capacity percentage Prc, an energy storage and distribution calculation model is built to generate the remaining capacity index Ydc, and the formula is as follows:

[0095] Ydc = Prc*(Hsa*G) (5)

[0096] In the formula, G is a correction factor, the specific value of which can be adjusted and set by the user, or generated by an analysis function fitting, and the value of G ranges from 0 to 1; (Hsa*G) represents the correction coefficient, after the health status evaluation value Hsa is corrected by the correction factor G, the correction coefficient required is obtained, to complete the correction of the remaining capacity percentage Prc, to obtain the actual remaining capacity percentage value considering various factors, and to realize unit unification for subsequent comparison process.

[0097] The grid voltage state is represented by a load stability index I, which is calculated as follows:

[0098] Step b1: Calculate the load utilization rate by dividing the average load in the preset time period by the maximum load capacity in the preset time period.

[0099] The load utilization rate can be used to assess the response capability of the grid load to power demand, thereby representing the state of the grid. The load utilization rate Lu is calculated as follows:

[0100] Lu = ( * Fl max )*100 (6)

[0101] In the formula, Fl represents the average load in the preset time period T, and Fl represents the maximum load capacity. max

[0102] Suppose we have collected the load data of a certain grid for one day, with a time period T = 1, and calculated the load every hour. Based on these data, we accumulate the load of each hour in 24 hours, and then divide the sum by 24 to obtain the average load.

[0103] The maximum load capacity refers to the maximum load that the grid can withstand within a preset time period. To obtain the maximum load capacity, the following steps can be taken: collect load data: collect historical data about the grid load, which can be long-term or within a specific time period. These data can be obtained through grid monitoring devices, smart meters, etc.; analyze load data: analyze the collected load data to find the maximum value, which represents the time when the load reaches the highest peak; calculate the maximum load capacity: according to the found maximum value, i.e. the load value when the load reaches the highest peak, as an estimate of the maximum load capacity; generally, the maximum load capacity is expressed in power units, such as kilowatts or megawatts.

[0104] Suppose we have collected the load data of a certain grid for one day, and calculated the average load. By analyzing these data, we find that in a certain hour, the load value reaches the highest peak level, which represents the maximum load capacity of the grid in that hour. Assuming the highest peak value is 100 megawatts, then the maximum load capacity is 100 megawatts. It should be noted that the maximum load capacity is usually estimated and analyzed based on historical data, and may vary in different time periods. Therefore, when evaluating the load utilization rate, the value of the maximum load capacity should be based on representative load data, or updated and adjusted through long-term load monitoring.

[0105] ​Step b2: Calculate the maximum load difference between two adjacent moments within a preset time period, and calculate the fluctuation difference between the maximum load difference between two adjacent moments and the maximum load capacity within the preset time period.

[0106] Within a preset time period T, the maximum value Hf of the load difference between two adjacent moments is calculated. max And calculate the maximum value Hf of the load difference. max With maximum load capacity Fl max The fluctuation difference Cz is calculated as follows:

[0107] Cz=Hf max -Fl max (7)

[0108] In the formula, if Cz is a positive number, it means that the transient fluctuation of the load may cause the power grid to exceed its maximum load capacity for a short period of time, indicating that the load fluctuation is large. The larger the fluctuation difference Cz is, the worse the power grid stability is.

[0109] Step b3: After weighted summation of the load utilization rate and fluctuation difference, and correction by a set constant, the load stability index is obtained.

[0110] Based on the load utilization rate Lu and the fluctuation difference Cz, the load stability index I is generated, and the formula is as follows:

[0111] I=(f1*Lu+f2*Cz)*C(8)

[0112] In the formula, f1 and f2 are the preset proportional coefficients of load utilization rate Lu and fluctuation difference Cz, respectively. The values ​​of f1 and f2 are both in the range of 0 to 1, and f1 > f2 > 0. C is a constant correction coefficient, the specific value of which can be adjusted and set by the user or generated by the analysis function fitting, and the value of C is in the range of 0 to 1.

[0113] Compared to traditional methods, this technical solution can comprehensively assess and analyze the power generation capacity and load demand of photovoltaic power generation systems, the energy reserves of energy storage battery modules, and the grid voltage status, demonstrating the following effects:

[0114] Improving energy efficiency: By analyzing the power generation capacity of the photovoltaic power generation system and the grid load in real time, it is possible to accurately assess whether the photovoltaic power generation system meets the load demand, thereby improving energy efficiency.

[0115] Improving the accuracy of health status assessment for energy storage batteries: By comprehensively considering health status parameters such as cycle life, internal resistance, capacity decay rate, and temperature difference, and through weighting and temperature compensation, the health status of energy storage batteries can be assessed more accurately, enabling accurate assessment of remaining capacity and facilitating subsequent coordinated control operations based on comparison results.

[0116] Enhancing the management and maintenance capabilities of energy storage batteries: By evaluating the remaining capacity indicators of energy storage batteries, the remaining capacity of the batteries can be understood in a timely manner, avoiding premature failure of the batteries, providing better battery management and maintenance capabilities;

[0117] Improving the evaluation capability of grid load stability: By analyzing the load utilization rate and load fluctuation difference of the grid, the load stability of the grid can be comprehensively evaluated to help determine whether the grid can withstand transient load fluctuations and improve the stability of the grid;

[0118] In summary, the technical solution can realize comprehensive evaluation and analysis of photovoltaic power generation systems and energy storage battery components, improve energy utilization efficiency, battery health management and maintenance capabilities, and grid stability evaluation capabilities.

[0119] In step S103, if the photovoltaic power generation power is greater than the load power, and the difference between the photovoltaic power generation power and the load power exceeds the preset first loss threshold, it indicates that the photovoltaic power generation meets the load requirement, otherwise a first warning signal is issued.

[0120] If the remaining capacity indicator is greater than the load power, and the difference between the remaining capacity indicator and the load power exceeds the preset second loss threshold, it indicates that the energy storage battery meets the energy supply demand, otherwise a second warning signal is issued.

[0121] If the load stability indicator is within the standard range value, it indicates that the grid load is currently in a stable state, otherwise a third warning signal is issued.

[0122] It should be noted that the first loss threshold, the second loss threshold and the standard range value can be obtained in various ways, including historical data analysis and experience setting methods.

[0123] Historical data analysis: The photovoltaic power generation power and the load power can be analyzed according to historical data to observe their relationship and change trend. Based on the analysis of historical data, the difference range or elasticity range of photovoltaic power generation power and load power under different conditions can be obtained, and the first loss threshold can be determined.

[0124] Experience setting: According to the experience and knowledge of experts in the field, combined with the characteristics and operation requirements of the system, appropriate first loss threshold, second loss threshold and standard range value can be set; for example, according to the experience of similar systems or industry standards, a reasonable range value is set to judge the stability of the power grid load; however, it should be noted that the threshold and standard range value may need to be adjusted and updated according to the actual system operation conditions and requirements, and the threshold and standard range value may also need to be adjusted according to real-time data and actual conditions as the system develops and changes; therefore, when determining the first loss threshold, the second loss threshold and the standard range value, it is recommended to consider historical data analysis, the experience and knowledge of experts in the field, and the actual operation requirements, and to conduct regular evaluation and calibration to ensure its accuracy and applicability.

[0125] In step S104, the first warning signal corresponds to a first control strategy, which includes any one or a combination of increasing the start of standby photovoltaic generator sets, reducing load demand.

[0126] The specific process of increasing the start of standby generator sets is as follows:

[0127] According to the degree and duration of power generation deficiency, the start of standby generator sets can be controlled to supplement the energy of power generation deficiency and meet the load demand, which may need to consider the start-up time and response speed of the generator set.

[0128] The specific process of reducing load demand is as follows:

[0129] In the case of power generation deficiency, the use of some loads is adjusted, such as reducing the power consumption of unnecessary equipment, to reduce the load demand and match the real-time power generation.

[0130] In step S104, the second warning signal corresponds to a second control strategy, which includes any one or a combination of the two schemes of increasing standby energy storage batteries and adjusting the use of other energy sources.

[0131] The specific process of increasing standby energy storage battery groups is as follows:

[0132] When a single energy storage battery cannot meet the energy supply, the connection and discharge of standby energy storage battery groups are controlled to output the energy of standby energy storage battery groups to the load to meet the energy demand; adjusting the use of other energy sources: if possible, the system can adjust the use of other energy sources, such as increasing the power supply of photovoltaic generator sets, to reduce the burden of energy storage batteries to meet the demand of load.

[0133] In step S104, the three-level early warning signal corresponds to a three-level control strategy, and the three-level control strategy is to increase the reactive power regulation.

[0134] The specific process of increasing the reactive power regulation is as follows:

[0135] When the grid voltage is unstable, the system can adjust the voltage by cooperatively controlling the reactive power output of the photovoltaic power generation system and the energy storage battery component, thereby maintaining the stable working state of the grid.

[0136] When the grid voltage is unstable, the system can adjust the voltage by cooperatively controlling the reactive power output of the photovoltaic power generation system and the energy storage battery component, thereby maintaining the stable working state of the grid.

[0137] The following is a simple example of operation:

[0138] Control the reactive power of the photovoltaic power generation system:

[0139] If the voltage is unstable, the voltage can be adjusted by controlling the reactive power output of the photovoltaic power generation system, increasing or decreasing the reactive power input of the photovoltaic power generation system, and the voltage can be adjusted; The specific operation mode can be realized by changing the power factor of the photovoltaic power generation system or using an inverter with reactive power regulation function; Control the reactive power of the energy storage battery:

[0140] If the voltage regulation demand cannot be met by adjusting the reactive power of the photovoltaic power generation system alone, the reactive power of the energy storage battery component can be adjusted to supplement the adjustment. The energy storage battery component can charge and discharge, and the reactive power injection or absorption can be adjusted by adjusting the charge and discharge power.

[0141] Figure 2 is a schematic diagram of an active voltage cooperative control system of a photovoltaic energy storage integrated generator in an embodiment of the present application. The embodiment corresponds to the active voltage cooperative control method of the photovoltaic energy storage integrated generator in Figure 1 , as shown in Figure 2 , the active voltage cooperative control system of the photovoltaic energy storage integrated generator in the embodiment can include:

[0142] The data acquisition module 201 is configured to acquire the power generation data of the photovoltaic power generation system, the battery data of the battery management system, and the grid data of the grid detection system.

[0143] The analysis and evaluation module 202 is configured to obtain the photovoltaic power generation power representing the power generation capacity of the photovoltaic power generation system, the load power representing the load demand, the residual capacity index representing the energy reserve of the battery management system, and the load stability index representing the grid voltage state according to the acquired data.

[0144] The comparison and judgment module 203 is used to compare the photovoltaic power generation and remaining capacity indicators with the load power, and to compare the load stability indicators with the preset standard range, and to determine whether to issue a warning signal of the corresponding level based on the comparison results.

[0145] The collaborative control module 204 is used to execute the corresponding collaborative control strategy when a warning signal of the corresponding level is issued, until the photovoltaic power generation system, battery management system and grid monitoring system are all in normal working condition.

[0146] It should be noted here that, Figure 2 The various modules in the active voltage coordinated control system of the photovoltaic energy storage integrated generator, and... Figure 1 The specific implementation process of each step in the active voltage coordinated control method of photovoltaic energy storage integrated generator is the same, and will not be repeated here.

[0147] Reference Figure 3 A schematic diagram of an electronic device is provided. It should be noted that... Figure 3 The electronic device 300 shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.

[0148] like Figure 3 As shown, the electronic device 300 includes a central processing unit (CPU) 301, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 302 or a program loaded from a storage section 308 into a random access memory (RAM) 303. The RAM 303 also stores various programs and data required for system operation. The CPU 301, ROM 302, and RAM 303 are interconnected via a bus 304. An input / output (I / O) interface 305 is also connected to the bus 304.

[0149] The following components are connected to I / O interface 305: an input section 306 including a keyboard, mouse, etc.; an output section 307 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; a storage section 308 including a hard disk, etc.; and a communication section 309 including a network interface card such as a local area network (LAN) card, modem, etc. The communication section 309 performs communication processing via a network such as the Internet. A drive 310 is also connected to I / O interface 305 as needed. Removable media 311, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., are installed on drive 310 as needed so that computer programs read from them can be installed into storage section 308 as needed.

[0150] When the central processing unit 301 in the electronic device of this embodiment executes the program, it achieves the following:Figure 1 The steps in the active voltage cooperative control method of the photovoltaic energy storage integrated generator shown.

[0151] In particular, according to embodiments of the present application, the processes described above with reference to the flowcharts can be implemented as a computer software program. For example, embodiments of the present application include a computer program product comprising a computer program carried on a computer readable medium, the computer program comprising instructions for performing the steps of the methods shown. In such embodiments, the computer program can be downloaded and installed from a network by the communication section 309, and / or installed from the removable medium 311. When the computer program is executed by the central processing unit 301, various functions defined in the apparatus of the present application are performed. Figure 1 The program code of the method shown. In such embodiments, the computer program can be downloaded and installed from a network by the communication section 309, and / or installed from the removable medium 311. When the computer program is executed by the central processing unit 301, various functions defined in the apparatus of the present application are performed.

[0152] wherein, Figure 1 The computer program instructions corresponding to the method shown can also be stored in a computer readable memory capable of directing a computer or other programmable data processing apparatus to work in a specific way, so that the instructions stored in the computer readable memory produce a product including instruction apparatus, which realizes the functions specified in the flow Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0153] Those of ordinary skill in the art can understand that all or part of the above-mentioned embodiment methods can be implemented by a computer program to instruct related hardware, and the program can be stored in a computer readable storage medium. When the program is executed, it can include the flow of each method embodiment as described above. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0154] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An active voltage coordinated control method for a photovoltaic energy storage integrated generator, characterized in that, include: Acquire power generation data from photovoltaic power generation systems, battery data from battery management systems, and power grid data from power grid monitoring systems; Based on the data obtained above, we obtain the photovoltaic power generation capacity of the photovoltaic power generation system, the load power of the load demand, the remaining capacity index of the battery management system's energy storage, and the load stability index of the grid voltage state. The photovoltaic power generation and remaining capacity indicators are compared with the load power, and the load stability indicators are compared with the preset standard range. Based on the comparison results, it is determined whether to issue an early warning signal of the corresponding level. When a warning signal of the corresponding level is issued, the corresponding coordinated control strategy is executed until the photovoltaic power generation system, battery management system and grid monitoring system are all in normal working condition. The calculation process for the remaining capacity index is as follows: Based on health status parameters, a health status analysis and calculation model is constructed to generate health status assessment values; The percentage of remaining capacity is calculated based on the remaining capacity in the energy storage battery and the obtained rated capacity of the energy storage battery. The remaining capacity index is calculated by multiplying the remaining capacity percentage by the revised health status assessment value. The calculation process for the load stability index is as follows: The load utilization rate is calculated by comparing the average load within a preset time period with the maximum load capacity within the preset time period. Within a preset time period, the maximum load difference between two adjacent moments is calculated, and the fluctuation difference between the maximum load difference between two adjacent moments and the maximum load capacity within the preset time period is calculated. After weighted summation of the load utilization rate and fluctuation difference, and then corrected using a set constant, the load stability index is obtained.

2. The active voltage coordinated control method for photovoltaic energy storage integrated generator as described in claim 1, characterized in that, If the photovoltaic power generation is greater than the load power, and the difference between the photovoltaic power generation and the load power exceeds the preset first loss threshold, it means that the photovoltaic power generation meets the load requirements; otherwise, a first-level warning signal is issued.

3. The active voltage coordinated control method for the photovoltaic energy storage integrated generator as described in claim 2, characterized in that, The first-level early warning signal corresponds to the first-level control strategy, which includes one or a combination of several of the following: increasing the linkage start-up of backup photovoltaic generator sets and reducing load demand.

4. The active voltage coordinated control method for photovoltaic energy storage integrated generator as described in claim 1, characterized in that, If the remaining capacity index is greater than the load power, and the difference between the remaining capacity index and the load power exceeds the preset second loss threshold, it indicates that the energy storage battery meets the energy supply requirements; otherwise, a second-level warning signal is issued.

5. The active voltage coordinated control method for photovoltaic energy storage integrated generator as described in claim 4, characterized in that, The secondary warning signal corresponds to the secondary control strategy, which includes any one or a combination of two options: increasing backup energy storage batteries and adjusting the use of other energy sources.

6. The active voltage coordinated control method for photovoltaic energy storage integrated generator as described in claim 1, characterized in that, If the load stability index is within the standard range, it indicates that the power grid load is currently in a stable state; otherwise, a level three warning signal will be issued.

7. The active voltage coordinated control method for the photovoltaic energy storage integrated generator as described in claim 6, characterized in that, The three-level early warning signal corresponds to a three-level control strategy, which is to increase reactive power regulation.

8. An active voltage coordination control system for a photovoltaic energy storage integrated generator, characterized in that, include: The data acquisition module is used to acquire power generation data from the photovoltaic power generation system, battery data from the battery management system, and power grid data from the power grid monitoring system. The analysis and evaluation module is used to obtain, based on the above data, the photovoltaic power generation capacity of the photovoltaic power generation system, the load power of the load demand, the remaining capacity index of the battery management system's energy storage, and the load stability index of the grid voltage state. The comparison and judgment module is used to compare the photovoltaic power generation and remaining capacity indicators with the load power, and to compare the load stability indicators with the preset standard range. Based on the comparison results, it determines whether to issue an early warning signal of the corresponding level. The collaborative control module is used to execute the corresponding collaborative control strategy when a warning signal of the corresponding level is issued, until the photovoltaic power generation system, battery management system and grid monitoring system are all in normal working condition; The calculation process for the remaining capacity index is as follows: Based on health status parameters, a health status analysis and calculation model is constructed to generate health status assessment values; The percentage of remaining capacity is calculated based on the remaining capacity in the energy storage battery and the obtained rated capacity of the energy storage battery. The remaining capacity index is calculated by multiplying the remaining capacity percentage by the revised health status assessment value. The calculation process for the load stability index is as follows: The load utilization rate is calculated by comparing the average load within a preset time period with the maximum load capacity within the preset time period. Within a preset time period, the maximum load difference between two adjacent moments is calculated, and the fluctuation difference between the maximum load difference between two adjacent moments and the maximum load capacity within the preset time period is calculated. After weighted summation of the load utilization rate and fluctuation difference, and then corrected using a set constant, the load stability index is obtained.

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